Hand held data processing apparatus having reduced power consumption

BACKGROUND OF THE INVENTION

1. THE iNVENTION field

The present invention relates to a data processing device which is equipped with a display device.

Second Description of the prior art

Among the microcomputers that are becoming compact and lighter, battery-powered portable computers have now become overwhelming. One in particular, known as a notebook computer, is lighter and smaller, yet offers the same capabilities as a desktop or laptop computer. The battery-powered notebook computer is convenient to use in a location where power supply facilities are rarely available, for example in a conference room or an auditorium.

The disadvantage of such a convenient use is that the battery life is short and limited. When used to record a business meeting or a lecture, the operating time of such a notebook computer with fully charged batteries is preferably 10 hours of continuous operation, more preferably 20 to 30 hours. If possible, more than 100 hours, a standard for handheld computers, would be very desirable.

So far, the operating time of a commercially available notebook computer is at best 2 to 3 hours. This leads to the depletion of the battery in the middle of a session or a lecture and leads to an interruption during the input work. As a result, it will be necessary to replace the batteries with new ones with considerable frequency.

Such a disadvantage of the notebook computer tends to balance portability despite its light weight and compactness. Known portable handheld computing devices, including handheld computers and electronic notebooks, are known to have much slower processing speeds than conventional microcomputers and, consequently, to use less power. You will be able to work with a common primary cell (s) for years, the life of which will therefore not be a concern. However, the notebook computer has a processing speed as fast as that of a desktop computer and consumes a considerable amount of electrical energy, namely 10 to 1000 times more than any portable pocket computing device. Even if a modern, high-quality rechargeable battery is used, the operating time will be a maximum of 2 to 3 hours. This is far from the desired duration required by the users. To compensate for the short battery life, numerous energy saving techniques have been developed and some are now being used in practice.

A very well known technique is described below.

This is called the "resume" function and is used extensively in a conventional notebook computer. It works in such a way that if there is no input for a given period of time, the data required to restart the computer and the corresponding information are stored in a non-volatile IC memory and then a CPU and display are systematically turned off. To restart, a power switch is closed and the data stored in the IC memory is immediately reloaded to indicate the previous data provided before the power was turned off. This technique is effective for extending the battery life and is suitable for practical use.

However, if no input is made for a certain period of time, for example 5 minutes, the entire system of the computer is switched off and the display data therefore disappear. As a result, the operator loses information and his input is interrupted. The power switch must be turned on each time to review the display data or to continue the input. This is a very annoying process for the operator. The resume technology is advantageous when saving battery power, but is very disadvantageous for the operability of the notebook computer.

In particular, as a means of saving energy, the foregoing technique includes a system that turns off all components, including processing circuitry and display circuitry.

The operator must therefore turn on the computer power switch quite often during intermittent data entry because not entering data for a given period triggers the automatic disconnection of the switch. Data entry in a notebook computer in particular is usually intermittent, and the foregoing disadvantage is therefore very much emphasized.

According to prior art document GB 2,134,676, a control system for a multiprocessor system having a plurality of processors is disclosed, which comprises a controlling processor and a controlled processor. The controlling processor is always on, but uses little power and works slowly. The controlled processor consumes more power and operates at high speed, but is usually disconnected from a power source. The controlling processor selects the controlled processor to be switched on, thereby allowing the battery to be protected in, for example, a portable computer.

Prior art document EP-A-0175935 discloses an arithmetic operation and display control integrated circuit connected to a power source and a liquid crystal (LCD) display device. The circuit includes an arithmetic operation circuit for performing a specific arithmetic operation, and the result of the arithmetic operation is displayed on the display. A step-up circuit receives and step-up the voltage of the power source, a driver circuit is fed from the step-up circuit to drive the LCD display, and a control circuit causes the display to stop driving when the arithmetic operation circuit performs the arithmetic operation.

SUMMARY OF THE INVENTION

According to the invention, a data processing device is disclosed which comprises:

a data entry unit for entering data;

a first processing unit for processing the data input via the data input unit;

a second processing unit, responsive to data processing by the first processing unit, for executing processing depending on the data processed by the first processing unit and for generating display data, and

a display unit for displaying an image corresponding to the display data, the display unit comprising a display driver unit responsive to the display data that generates a display drive signal corresponding to the display data, and a display unit responsive to the display drive signal that displays the image, the display device having a memory function such that it retains the image, even if the display driver signal is stopped from being supplied to them,

characterized by further comprehensive:

means which determines that the execution of the processing by the second processing unit has been completed and generates a processing completion signal which indicates that the execution of the processing by the second processing unit has been completed, and

means responsive to the processing completion signal and forcing the second processing unit into an inactive state by reducing power consumption in the second processing unit.

If no more data are entered, for example, the second processing unit or the display unit is deactivated or the clock rate is reduced in order to reduce the power consumption. In addition, the present invention allows the display of data to remain intact. When input data appears, the first processing unit activates the second processing unit in order to process the data. The operator can thus continue his work without knowing that the shutdown has been interrupted. As a result, a considerable amount of energy saving is guaranteed without affecting the operability, and the operating life of the batteries is therefore greatly increased.

In a further aspect, the first processing unit can activate the second processing unit in accordance with the type of input data. If the input data is data that requires processing in the second processing unit, the first processing unit activates the second processing unit. After completion of a requested operation or processing, the second processing unit can automatically go into an inactive state or can be forced into the inactive state by the first processing unit. The power consumption is thus reduced to a considerable amount without impairing the functionality.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a block diagram of a data processing apparatus showing a first embodiment of the present invention; Fig. 2 is a timing diagram; Fig. 3 is an illustration showing the arrangement of a display unit; Fig. 4 is a sectional view explaining the principle of operation of the display unit; Fig. 5 is an illustration showing displayed images on the display unit; Fig. 6 is a flow chart; FIG. 7a is a block diagram showing an arrangement of components; Fig. 7b is a block diagram showing another arrangement; Fig. 7c is a block diagram showing another arrangement; Figure 7d is a flow chart; 8 illustrates the principle of operation of a reflection device when using different reflecting plates; Fig. 9 is a block diagram showing a second embodiment of the present invention; FIG. 10a is a block diagram associated with a first processing unit; Figure 10b is a block diagram associated with a second processing unit; Figures 11a and 11b are flow charts; Fig. 12 is a timing chart; 13 is a view explaining the illustration of a cursor. Fig. 14 is a view showing a sequence of translation procedures; Fig. 15 is a view explaining data insertion; FIG. 16 Fig. 12 is an illustration explaining a copy mode; Fig. 17 is a block diagram showing a modification of the second embodiment; Fig. 18 is a block diagram showing a third embodiment of the present invention; Fig. 19 is a flow chart; Fig. 20 is a block diagram showing a fourth embodiment of the present invention; Fig. 21 is a timing chart of the fourth embodiment; FIG. 22 Fig. 12 is a block diagram showing a fifth embodiment of the present invention; Fig. 23 is a timing chart of the fifth embodiment; Fig. 24 is a block diagram showing a data input unit, and Fig. 25 is a block diagram showing a combination of the first and second processing units.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

Version 1

Fig. 1 is a block diagram of a data processing apparatus showing a first embodiment of the present invention.

The data processing device comprises a data input unit 3, a first processing block 1, a second processing block 98 and a display block 99.

In operation, data input, which is led to the data input unit 3 of the data processing device by means of a key input with a keyboard or a communication interface, is transmitted to the first processing block 1, where a first processor 4 examines which key is pressed when the key input or what type of data can be entered from the outside, and the following procedure is determined in accordance with the information from a memory 5.

If no input is supplied to the input unit 3 for a whole given period of time, as shown in FIG. 2-a, and in addition the action of the second processor 7 has been completed, the supply of clock signals to the second processor 7 and a display unit 8 is carried out an interrupt controller 6 is stopped, and / or an energy-saving process is carried out systematically.

The energy saving process will now be described with reference to FIG. 2.

As shown in Fig. 2-a, data entry performed at t & sub1; is entered with an nth key on the keyboard, transferred from the data input unit 3 to the first processor 4.

When the first processor 4 examines the data entry and determines that further processing is required in the second processor 7, it provides a start instruction to the second processor 7 via the interrupt controller 6 and a start command line 80, which thus begins the data entry from the first Receive processor 4. The second processor 7 starts processing the data entry when t = t 3, as shown in FIG. 2-c, and sends an end signal to the first processor 4 on completion. Either the first processor 4 or the interruption controller 6 in turn delivers a stop instruction via the start command line 80 to the second processor 7. The second processor 7 consequently transmits finished processed Data from its RAM memory or register for temporary storage in the second memory and then stops processing when t = t 5, as in Fig. 2-c shown, or goes into a power saving mode where power consumption is sharply weakened. After t 5, where the activity of the second processor 7 ends, the data in the second memory 9 are retained because of its non-volatile properties or because of the action of a backup battery. If a display change is required, the second processor 7 sends a display change signal to the first processor 4. The first processor 4 then supplies a display start command to the display circuit 8 via a display start command line 81 to start the operation. When t = t4 as shown in Fig. 2-d, the command signal is sent to the display circuit 8, which in turn recovers the data of a previous display text from a video memory 82 or the second memory 9 and a new image corresponding to the display change signal and data from the second Processor 7 displays. When t = t 6, the display circuit 8 sends its own instruction or an end signal to the first processor 4 via the interrupt controller 6, and stops or decreases the clock generation upon receiving an instruction from the first processor 4 to enter a display power save mode. Thereafter, the power consumption of the display circuit 8 will drop sharply, as after t & sub6; shown in Fig. 2-d.

After t & sub6; The display circuit 8 remains completely or almost deactivated, but a display 2, which essentially consists of memory-preserving elements, for example ferroelectric liquid crystal elements, continues to hold the display image. The structure of the display 2 will now be described. The display 2, e.g. a simple matrix liquid crystal display includes a matrix of electrodes in which horizontal driver lines 13 and vertical driver lines 14 connected to a horizontal driver 11 and a vertical driver 12, respectively, intersect, as best shown in FIG. 3. 4 shows a pixel of the display 2 in action with an applied voltage.

In each pixel, a ferroelectric liquid crystal 17 is excited by the two horizontal and vertical lines 13, 14, which serve as electrodes and are formed on glass plates 15 and 16, respectively.

In particular, Fig. 4-a shows a state where light is transmitted through. When there is a signal, the ferroelectric liquid crystal 17 changes its crystalline orientation and acts as a polarizer in which a polarization angle is changed so that the light can flow through.

When a voltage is applied in the reverse direction, the ferroelectric liquid crystal 17 causes the polarization angle to rotate 90 degrees and prevents the passage of light with polarization effects as shown in Fig. 4-b. The ferroelectric liquid crystal 17 also has a memory preserving effect, which enables it to leave the crystalline orientation unchanged after the voltage supply is stopped, as shown in Fig. 4-c. As a result, the display remains intact without any operation of the display circuit 8 for a whole period tt6 to t14, which will be explained later. While after t & sub6; the energy saving mode is in action, only the data input unit 3 and the first processor 4 are in operation.

The first processor 4 only carries out the conversion of the key input into the letter code or the like. In general, the key entry is made by a human operator and is carried out at most a few tens of times in a second. The speed of data entry by a human operator is 100 or more times slower than the processing speed of any microcomputer. The processing speed of the first processor 4 can therefore be as slow as that of a known handheld computer, and the power consumption is reduced to one hundredth or thousandth of a watt compared to that of a main CPU of a desktop computer. As shown in FIG. 2-b, the first processor 4 continues to operate while a power switch 20 of the data processing unit 1 is closed. However, it uses less energy and the device's power consumption will be low.

If the n + 1-th key input is made at tu, the first processor 4 examines at t & sub1; & sub2; the data of the input and, if necessary, delivers a start instruction via the interruption controller 6 or directly to the second processor 7 for activation. When the start instruction is received, the second processor starts using clock signals again, so that the data stored in the second memory 9, ie in the case of a previous stop as t = t 5, for example Memory data, register information or display data, read out and the CPU environment as t = t & sub5; can be fully restored. If t = t 13, the data in first processor 4 is transferred to second processor 7 for reprocessing. The second processor 7 is designed to operate at high speeds and its power consumption is as high as that of a desktop computer. If the second processor 7 is activated continuously, the life of the battery is shortened, as in a known notebook computer. However, the present invention provides a number of energy saving mode actions during operation, which will minimize energy consumption.

The energy saving mode is beneficial. For example, the length of time it takes to process word processing software data is typically less than 1 ms, while key input by a human operator takes at most a few 10 ms. Although the peak energy consumption during a period of t & sub1; & sub3; to t & sub1; & sub5; in the second processor 7, as in Fig. 2c is fairly high, the mean is no more than one tenth or one hundredth of the peak. Now it is clear that the energy saving mode allows a lower power consumption.

When t = t 14, the second processor 7 sends a desired part of the display data to the display 2. Before t14, the display 2 shows the one at t 6 due to the storage effects of the ferroelectric liquid crystal 17. changed text, while the display circuit 8 remains deactivated. The desired data entered at tu via the key input is entered at t 14. written for local replacement. The replacement of one or more lines of display text is accomplished by applying voltage to an appropriate number of the horizontal and vertical driver lines 13 and 14. This process takes a shorter processing time and therefore consumes less energy compared to replacing the entire display text.

The second processor 7 stops at t = t & sub1; & sub5; the operation and re-enters the power saving mode as shown in Fig. 2-c.

At the time when the operation of the second processor 7 before t & sub1; & sub5; has ended, or when a stop instruction is received by the first processor 4, the second processor 7 stores the last data in the second memory 9.

When t = t 14, the second processor 7 stops or reduces the operating speed and enters the power saving mode. If the input data is in short intervals, for example, at t21, t31, t41 and t 51, via a series of keystrokes or from a communication port, the processor 7 changes at T 23, t 33. and t 43 as shown in Fig. 2-c to the power save mode. If the first processor 4 determines that the interval between data entries is shorter than a predetermined time, it issues an energy-saving mode stop instruction to the second processor 7, which thus remains activated without a forced energy cut-off and no longer enters the energy-saving mode. The energy-saving mode is only called up again when the interval between two data entries is long enough.

If the first processor 4 determines that no data is being entered for a given period of time, it disconnects the power supply to main components, including the first processor 4, to enter a power supply hold mode. The backup data is backed up by the backup battery while the power supply is completely turned off.

Before the power is turned off, however, the first processor 4 sends a power supply stop indication instruction directly or through the second processor 7 to the display circuit 8 for displaying an "OFF" sign 21 shown in Fig. 5-b, and then goes into the power supply stop mode , The OFF sign 21 remains displayed due to the memory effect of the display 2 after the power supply is turned off, thus allowing the operator to distinguish the power supply hold mode from the power save mode.

In the power saving mode, the operation can be restarted by a key input action, and consequently the operator will not notice any interruption in the processing.

In the power supply hold mode, the OFF sign 21 is displayed, and the operator can then restart the operation with the previous data recovered from the second memory 9 by the second processor 7 when the power switch 20 is turned on. This procedure is similar to that in the conventional "resume" mode.

The foregoing operation will now be described in more detail with reference to a flow chart in FIG. 6. If the power switch 20 is turned on at step 101, the first processor 4 begins to operate at step 102. At step 103, the input data given by key input is transferred from the data input unit 3 to the first processor 4. At step 104, it is checked whether the duration of the non-input of data lasts for a predetermined time or not. If the non-data input period t is longer than the predetermined time, the flow goes to step 105, where the activity of the second processor 7 is checked. If the second processor 7 is active, the process goes back to step 103. If not, the whole device is turned off at step 106 and stops working at step 107 until it is new at step 101 where the power switch 20 is closed is started.

If the non-data input time t is larger but is only a few minutes, the flow goes from step 104 to step 108. If the processing frequency in the first and second processors 4 and 7 is low, the flow goes from step 108 to step 109 where the rear light is switched off to save energy.

If the non-data entry period t is not greater, the operation of the first processor 4 continues at step 110. It is also checked at step 110a whether or not the text data is displayed for a significant period of time. If too long, the data is refreshed at step 110b to prevent a frozen image on the screen. At step 110c, the processing frequency in the second processor 7 is checked, and if it is high, the second processor 7 is kept moving at step 110d. If the processing frequency is low, the process proceeds to step 111. If it is determined in step 111 that no further processing is required in the second processor 7, the process returns to step 103.

If further processing is required in the second processor 7, the process proceeds from step 111 to step 112a, where the activity of the second processor 7 is checked. If the second processor 7 is not in motion, a start instruction is sent to the second processor 7 in step 112b, which is then activated by the first processor 4 and the interrupt controller 6 in step 113. The second processor 7 then begins processing in step 114. If it is determined at step 115 that a change in the text of the display is needed, the process proceeds to step 116a, where a display change instruction is supplied to both the interrupt controller 6 and the first processor 4. Then, in step 116b, the interrupt controller 6 provides display excitation instruction to the display block 99. The display circuitry is activated at step 116c and the display change on the display 2, including the replacement of local data with desired data, is carried out at step 117. After the display change is checked at step 118, an end of display change signal is sent to the first processor 4 at step 117a. If the display change end signal is accepted at step 117b, the display 2 is turned off at step 119.

If no change in the display text is required, the process proceeds from step 115 to step 120, where the completion of the processing in the second processor 7 is checked. If so, a processing end signal is output at step 120a. As a result, at step 121, the second processor 7 stops operating upon receipt of a stop signal generated at step 120b, and the flow returns to step 103.

7-a and 7-b are block diagrams of a notebook computer according to the first embodiment of the present invention.

As shown in Fig. 7-a, a data entry block 97 includes a keyboard 201, a communication port 51 with RS232C, and a floppy drive controller 202. In addition, a hard disk unit 203 is provided separately. A first processing block 1 mainly consists of a first processor 4. A second processing block 98 contains a second processor 7, which is a CPU which is set up to stop or Applying a clock signal to go into and save the energy-saving mode and is connected to a bus line 210. In addition, a ROM 204 for starting, a second memory 9 made of DRAM and an auxiliary RAM 205, which is an SRAM for storing individual data for returning from the resume mode, are connected to the bus line 210. Both ends of the bus line 210 are connected to the first processor 4 or to a display block 99. The display block 99 has a graphics controller 206 and a liquid crystal controller driver 207, which are arranged in a display circuit. A video RAM 209 and a liquid crystal display 208 are also provided. In the arrangement, only corresponding components are activated for energy-saving operation, while the remaining components are switched off. Energy saving technology is illustrated in more detail in Table 1. In general, the input operation, for example for word processing, involves intermittent keyboard input. The power supply is consequently connected to every component except the communication I / O unit. While a clock signal is supplied to the first processing block 1, no clock signals are supplied to the second processing block 98 and the display block 99. Electricity is therefore only consumed in the first processing block 1. If necessary, block 98 and / or display block 99 are activated within a short period of time. If more frequent operations are needed, the second processing block 98 is kept activated to speed up processing speeds.

If the key input is absent for a given time, the second processing block 98 is turned off and at the same time its processing data is stored in an auxiliary memory to be retrieved in response to the following key input.

Fig. 7-b is similar to Fig. 7-a except that the first processor 4 with a lower clock frequency is used as a "monitor" for the entire system and the processing by the second processor 7 is carried out with a higher clock frequency. The first processor 4 is set up to carry out an event processing method by which the second processor 7 is activated for processing in accordance with data from the keyboard input. The second processor 7 stops operating for the purpose of saving energy when the processing operation is finished and remains deactivated until another key entry begins. The display block 99 starts to operate in response to a display signal from the second processor 7 and stops automatically after the display is completed. This procedure can be carried out with an ordinary operating system similar to any known operating system in order to ensure a high level of software compatibility. For example, MS-DOS is designed to run when using a full CPU. The energy saving effect will therefore hardly be expected during operation with conventional application programs. It is, therefore, a good idea that a specific operating system and corresponding word processing software installed in two CPUS are provided in addition to the conventional operating system. The word processing task can thus be performed using the specific software with the operating system of the present invention, and the power consumption is therefore reduced to less than a tenth or a hundredth. In addition, general sortware programs can work with the conventional operating system, although the energy saving effect will be reduced. It should be understood that about 80% of the work on a notebook computer is word processing and the foregoing setup can help save energy.

Fig. 7-c is a block diagram of another example according to the first embodiment, and Fig. 7-d is a flowchart showing a procedure using a conventional operating system such as MS-DOS. The second processor 7 is a CPU which is able to hold data of its register and internal RAM when no clock is present or is switched off. If a key entry is made at step 251, a keyboard code signal is transmitted from the keyboard 201 through the first processor 4 to a starter 221 which remains activated at step 252. At step 253, the starter 221 provides a clock signal to the main processor 222 which is switched off. Register 224 and internal RAM 223 are connected to an auxiliary power source and therefore begin to operate upon receipt of the clock signal. At step 254, the main processor 222 starts the program that has been ready for key input. The program is then processed in step 255, for example for word processing in accordance with data from the key input. At step 257, a display instruction to replace display text is issued if requested at step 256. At step 258, graphics controller 206 is activated. The data in video RAM 209 is therefore rewritten at step 259. After the liquid crystal controller driver 207 is activated at step 261, a desired change in the display text is made on the liquid crystal display 208 made of ferroelectric liquid crystal. Then, at step 262, the video RAM 209 is powered by the auxiliary power source, and at step 263, the display block 99 is turned off so as to enter the power saving mode. When processing in the second processor 7 is finished at step 270, the program stops and goes to a "keyboard input standby" state at step 271. At step 272, the data required to reactivate register 223 and internal RAM 234 is stored and the second memory 9 is powered by the auxiliary power source before a clock in the CPU is stopped. Then, at step 273, the second processor 7 stops operating and goes into the power saving mode. Since the starting device 221 remains activated, the second processor 7 remains ready for input from the keyboard at step 251 or from the communication port 5. As can be understood, only the starting device 221 is kept activated in the second processing block 98. The CPU shown in Fig. 7-c saves the registers when its clock is inactive and ensures an immediate return to operation when the clock is activated. Since a single CPU unit is usually activated, a conventional operating system can be used with equal success. In addition, existing software programs, including word processing programs, can be processed with less determination, and therefore private databases are allowed for optimal use. As a result, it is clear that this method is acceptable. In addition, the consumption of electric power will be greatly reduced by a technique of directly controlling the first processor 1 upon a display text change, which will be described later in a second embodiment of the present invention. As is known, resume mode allows most components to remain off if the data is not entered for a long time.

Since a ferroelectric liquid crystal material has a storage effect, permanent storage results known as temporally metastable phenomena will appear when the same text is displayed for a long time. To avoid such a phenomenon, a display change instruction is given to the first processor 4 and the power switch 20 when it is determined with a timer 22 that the display time in the power saving mode or in the power supply hold mode exceeds a predetermined time. Accordingly, the display circuit 8 activates the display 2 to change all or part of the display text, thereby eliminating the disadvantages of permanent storage.

If the persistence of such persistent memory effects does not allow for a change in the display text on the display 2, the crystalline orientation of the liquid crystal is realigned by heating the display 2 with a heater 24 which is triggered by a display reset switch 23 becomes. An arbitrary change in the display text on display 2 will then be possible.

The energy saving can be supported by stopping the clock in the second processor 7 during the energy saving mode. If more or full energy saving is desired, the power supply to the second processor 7 or the display circuit 8 is interrupted by the interrupt controller 6.

As can be understood, the power supply hold mode requires a minimum of power consumption to secure the second memory 9. As shown in FIG. 1, the taillight 25 is turned off when the power source is a battery, and a reflective element 27 is activated by a reflection circuit 26 for display in a reflection mode.

The reflective element 27 is composed of a ferroelectric liquid crystal film which provides a transmissive mode for transmitting light as shown in Fig. 8-a and an opaque mode for reflecting as shown in Fig. 8-b for alternative operation , Incoming light 32 is reflected on the reflection element 27 and returns as reflected light 33. At this time, polarization is also effected by the polarizers in the display 2 and the reflection element 27, whereby the number of components is reduced. In addition, a film-type electrochromic display device can be used to provide a transfer mode and a white diffusion screen mode in which it appears like a sheet of white paper.

The reflection element 27 can be of a fixed type, as shown in FIGS. 8-c and 8-d, which comprises a light-transmitting layer which consists of transmission regions with low refraction 28 and transmission regions with high refraction 29 and a reflective layer 31 with openings 30 that is.

As shown in Fig. 8-c, light emitted from the rear light 25 enters the high refraction transmission areas 29 where it is fully reflected at the interface between the high and low refraction transmission areas 29, 28 and through the openings 30 flows to a polarizer plate 35. The polarized light is then sent to a liquid crystal layer 17 to produce an optical display with outward light. During the reflection mode in battery operation, outside light passes through the liquid crystal layer 17 and is reflected by the reflective layer 31 formed by aluminum vapor deposition, and reflected light 33 flows again through the liquid crystal layer 17 to produce the optical display.

The reflection element 27 does not require an external driver circuit and thus contributes to the simple construction of an overall system. It is known that a combination of high and low refraction transmission areas is easy to manufacture by a molten salt immersion process that is commonly used to manufacture distributed refraction lenses.

Although such a transmission / reflection combination liquid crystal display is disadvantageous in the quality of a display image compared to a special transmission or reflection type liquid crystal display, the foregoing switching between transmission and reflection allows the display of an image as good as the special display both in transmission and even in reflection mode. This technique is therefore suitable for two-source supply applications, battery and AC power supply.

When the external power source is connected, the taillight 25 is illuminated when an instruction is received from the first processor 4, which also provides a transmission instruction to the reflection circuit 26, so that the reflection element 27 becomes transparent at the same time. As a result, transmission light can illuminate the display as shown in Fig. 8-a.

When the battery is connected, the first processor 4 supplies a reflection signal to the reflection circuit 26, and the reflection element 27 becomes opaque to cause reflection and scattering. As a result, the display is generated by reflected outside light, as shown in Fig. 8-b, while saving an amount of electrical energy required to operate the rear light 25.

Furthermore, the same results as shown in FIGS. 8-c and 8-d can be achieved with the use of a transmitting reflective plate 34 formed from a metal plate, eg aluminum, with a plurality of tapered round openings therein, as in FIG. 8-e and 8-f shown.

As stated above, the CPU in this embodiment provides intermittent operation in response to an intermittent keystroke and the device's average power consumption is reduced to a substantial amount.

In addition, the text remains on the display during operation so that the operator does not notice any sign of abnormality when the processing unit is deactivated. This means that a high degree of energy savings is guaranteed without impairing the functionality.

In particular, each key entry process takes a few tens of milliseconds, while the average CPU processing time in word processing is about a few tens to a hundred microseconds. As a result, the CPU is activated 1/100 to 1/1000 of the time of the key input operation, and therefore its power consumption is reduced in proportion. While the CPU's energy consumption is reduced to 1/1000, 1/10 to 1/20 of the total consumption remains intact, because the display unit consumes about 10 to 20%, namely 0.5 to 1 W, of the total power requirement. According to the invention, the display unit uses a memory effect display device, which is provided with ferroelectric liquid crystal, for example, and its power consumption and that of the CPU will therefore be minimized by intermittent operation.

As a result, the total power consumption is reduced to 1/100 to 1/1000 when a key is entered, for example for word processing.

Version 2

Fig. 9 is a block diagram showing a second embodiment of the present invention.

In the second embodiment, the performance of the first processor 4 is improved, and the frequency of actuation of the second processor 7, the power requirement of which is relatively large, is reduced, so that the energy saving can be supported.

As shown in FIG. 9, the structure of the second embodiment differs from that of the first embodiment in that there is a signal line 97 for transmitting a display instruction signal from the first processing block 1 to the display block 99. In operation, the first processor 4 in the first processing block 1 supplies a display change signal to the display circuit 8 of the display block 99 for changing the display text on the display 2. As is known, after the first execution, the second processor 7 supplies such a display change signal to the display circuit 8.

Fig. 10-a is a block diagram showing the connection of the first processor 4 in more detail, in which the first memory 5 has a first font ROM 40 for storing dot patterns of the alphabet and Japanese characters or the like in a ROM, an image memory 41 and a general memory 42.

As shown in Fig. 11, the second memory 9 may include a second font ROM 43 serving as a font memory.

In operation, a number of simple display text change operations can be performed using the first processor 4. Character codes are generated in response to the key input, and font patterns corresponding to the character codes are read from the first 40 or second font memory 43 to be displayed on the display 2 after passing through the display circuit 8. The second memory 9 may also include a second general memory 44.

During the input of a series of data characters that does not require extensive processing, the first processor 4, whose power consumption is lower, is activated for the process of changing the display text. If extensive processing is required, the second processor 7 is used. The activation frequency of the second processor 7 is consequently minimized and energy savings will be ensured. In addition, as shown in Fig. 11 shown, the memory size of the first memory 5 can be reduced due to the recovery of font patterns from the second font ROM 43 of the second memory 9.

The operation according to the second embodiment will now be described in detail with reference to the flowcharts of Figs. 11-a and 11-b. Fig. 11-a is substantially similar to Fig. 6, which shows a flow chart in the first embodiment.

One difference is that the first processor 4 directly operates the display circuit 8 and a step 130 and a display flow diagram 131 are added. If, at step 130, the first processor 4 decides that desired data to be replaced in the display text is simple enough to be processed by the first processor 4, the startup goes to the display flow diagram 131. The display flow diagram 131 is briefly described. It begins at step 132 where the display block 99 is activated. At step 133, the display text is changed and the change is checked at step 133. After confirming the completion of the text change at step 134, the display block is turned off at step 135 and the flow returns to step 103 to wait for subsequent data entry. 11-b shows step 133 in detail. After activation of the display block 99 in step 132 by a start instruction of the first processor block 1, the unrestricted movement of a cursor is checked in step 140. If so, at step 141, data entry is performed throughout the cursor movement. If no, it is checked in step 142 whether or not the desired input area on the display 2 is occupied by existing data. This process can be carried out by reading the data in the image memory 41 with the first processor 4. If no, partial replacement of the text with desired data is performed at step 142. If so, the process proceeds to step 144, where the existing data in the input area of ​​the display block 99 is checked using the image memory 41 and it is examined whether or not it absolutely belongs to the desired data to be entered. If no, the overwriting of the desired data is carried out at step 143. If so, in step 145 the existing data is reloaded from the image memory 41 or read from the second font ROM 9 and combined with the desired data for the composition. At step 146, it is checked whether a black-and-white reversal mode is affected or not. If so, the data is displayed in reverse color at step 147. If no, the text change is made at step 148 with the composite data. Then, at step 134, completion of the text change is confirmed, and at step 135, the display block 99 is turned off.

For further explanation, Fig. 12 illustrates the processing of corresponding components when the key input is made. When the key input with "I" is performed at ti in FIG. 12-e, the first processor 4 converts the input data into a letter code "I", reads a font pattern of the letter code from the first font ROM 40 shown in FIG. 10 and activates the display circuitry to display the letter "I" on display 2. In the memory effect display with ferroelectric liquid crystal, partial replacement can be made in one character. The partial replacement can be done in two different ways. One to change point-by-point and the other to change one vertical or horizontal line of points at a time. The point-by-point change is carried out with less energy consumption but with a higher voltage, which results in higher costs. The line change must be made in the group of points, even if only one point is replaced, but at relatively low voltages. Both options in this version are now explained.

If the vertical and horizontal drivers 11, 12 shown in Fig. 3 accept higher voltages, it is possible to fill the dots forming the letter "I" one by one. The letter "I" can therefore be displayed by having font data of a corresponding character pattern supplied by the second processor 4. However, ICs that accept such a high voltage are expensive. In order to save costs, it is therefore desirable that the operating voltage be low. It should now be understood that, given the ability of modern semiconductors, each data processing device is preferably set up to provide the line-by-line text change function. It is also necessary that the first memory 5 of the first processor 4 carry at least the data of one line of text.

For Japanese characters, the data on a line of text is 640x24 points. Writing the letter "I" therefore involves replacing 24 of 640 dot lines.

In operation, the previous data of a target line is reloaded from the image memory 41 of the first memory 5, and also the pattern data of the letter "I" is read from the first font ROM 40. Then the two data are combined into composite data, which are then supplied to the display circuit 8 for rewriting a line of text on the display 2. At the same time, the same data is stored in the image memory 41. The entry of "I" is now finished.

Neither the first font ROM 40 nor the image memory 41 are needed when the second font ROM 43 capable of processing encoded data is used for the same function. This means that the same line of text can be expressed with around 40 2-byte characters and thus 40 x 2 = 80 bytes per line. The first memory 5 can therefore carry coded data of the entire screen.

During the processing of data input "I" in one of the two previous ways, the second processor 7 does not provide any processing as shown in Fig. 12-c.

Similarly, a series of key inputs are made by the first processor 4, "space" at t 2, "L" at t 3, "i" at t 4, "v" at t 5; and "e" at t 6. Although the processing speed of the first processor 4 is much slower than that of the second processor 7, the replacement of a line of text on the display can be performed at an acceptable speed with less energy consumption. As in Fig. 12 shown, t & sub7; is the keystroke of an instruction to process a large amount of data, such as a spell check in word processing, a translation from Japanese to English, a conversion of Japanese characters to Chinese characters or a calculation of table data.

If the first processor 4 determines that the second processor 7 is needed, the second processor 7 is switched off at t & sub1; & sub1; switched on. The starting of the second processor 7 is the same as that of the embodiment 1. As shown in Fig. 12-c, the second processor 7 returns after going at t & sub1; & sub1; has been activated, returns to the original state before the interruption and the processing of the text line data supplied by the first processor 4 begins. As processing continues, each character of the changed text is displayed on the display circuit 8 on the display 2, as at t 72. shown in Fig. 12-d.

This process is now explained in the form of data entry for translating Japanese to English. After entering the letter k at ti as shown in Fig. 12-f, it is displayed on the screen as shown in Fig. 12-h. Then the letter a is entered at t2 and the display shows "ka" as shown in Fig. 12-h.

Until then, the second processor 7 remains inactive, as shown in Fig. 12-c. If at t & sub7; a translation conversion key is pressed, the second processor 7 starts at t & sub1; & sub1; with processing. As a result, the Japanese string "kareha" is translated into "he is" in English. The resulting data is sent to the display circuit 8 to replace the display point by point.

Now the display shows "he is" as shown in Fig. 12-h. The dot-by-dot character replacement shown in Fig. 12-g requires less electrical energy than the text line replacement shown in Fig. 12-d.

To save energy while moving the cursor, the black / white reverse or negative mode is used, as shown in Figures 13-a and 13-b. However, this increases the power consumption when replacing lines. If a bar between the lines is used to display the cursor, as shown in Figs. 13-c and 13-d, the replacement of the entire line is not necessary and therefore energy saving will be expected. In addition, the processing speed is increased and the response will be accelerated during processing with the slow first processor 4. This advantage is also taken over when replacing points.

As shown in Fig. 14-a, the movement of the cursor is expressed by the bar. For the convenience of viewing, the bar can be illuminated at intervals by control with the first processor 4. When a key data entry is made, a corresponding character is displayed in the reverse color as shown in Fig. 14-b. This technique will also reduce energy consumption, at least while the cursor is moving.

14-a through 14-9 illustrate the display steps corresponding to t & sub1; to t 7. Fig. 14-h shows the conversion of the input text.

15-a to 15-f show the insertion of a word when replacing points. When using the second font ROM 43 in the arrangement shown in Fig. 10, it is necessary that the data of one line of text is stored in the image memory 41 because the first font ROM 40 does not carry all Chinese characters. When the cursor moves backward as shown in Figs. 15-c and 15-d, the letter n is recalled from the image memory 41. As a result, the data can be restored before insertion without using the second processor 7 or the second font ROM 43, as shown in Fig. 15-d.

Figures 16-a through 16-g show a copy of a sentence "He is a man". 16-a to 16-f can be carried out with the first processor 4. The step of Fig. 16-g includes an inserting process performed by the second processor 7.

According to the second embodiment, most of the work performed by the second processor 7 in the first embodiment is performed by the low power first processor 4. As a result, the average energy consumption will be much lower than that of the first version.

The optimum of a division of labor between the first and second processors 4 and 7 can vary depending on the special features of a program for, for example, word processing or spreadsheets. A portion of the first processor 4 in the operation of a software program can consequently be controlled by adjustment to the program in order to achieve an optimal balance between the energy consumption and the processing speed. Furthermore, a video memory 82 can be provided in the display block 99 and is connected to the first processor 4 via a connecting line 96. This allows the data to be stored in video memory 82 prior to replacement, and the image memory 41 shown in Fig. 10-a is consequently eliminated.

Version 3

Fig. 18 is a block diagram showing a third embodiment of the present invention. The difference between the third embodiment and the first and second embodiments will now be described. As in Fig. 1 the first embodiment has a display start instruction line 81, via which both a start instruction and a stop instruction are transmitted from the first processing block 1 to the display block 99, while identical instructions are transmitted by the start instruction line 80 from the same to the second processing block 98.

The third embodiment does not include a display start instruction line 81 to the display block 99 as shown in FIG. 18. In addition, the start instruction line 80 of the third embodiment allows only one start instruction but no stop instruction to be sent from the first processing block 1 to the second processing block 98.

The second processor 7 stops itself at the end of the processing and goes into the energy-saving mode. When the second processor 7 determines that the display change is needed, it provides a display start instruction via a data line 84 to the display block 99 which is then activated. After the display change on the display is completed, the display block 99 stops working and goes into the display power saving mode. This process is explained in detail with a flow chart in FIG. 19. The flow chart consists of a first processing step group 151, a second processing step group 152 and a third processing step group 153. First, the difference of this flow chart with respect to the sequence from start to stop of the second processing block 98 will be described.

Unlike the flowchart of the first embodiment shown in FIG. 6, there is no control flow from the second processing step group 152 of the second processing block 98 to the first processing step group 151. That is, the first processor 4 issues a start instruction to the second processor at step 112 7, which is then activated. This step corresponds to that of the first execution. However, the second processor 7 is automatically deactivated in step 121, compared to the shutdown by an instruction from the first processor 4 in the first embodiment. At step 103, the second processor 7 is brought into a data input standby mode.

The difference is further described in terms of the sequence from start to stop of the display block 99.

In the first embodiment, after completion of the display data processing, a display start instruction is given to the display block 99 by the second processor 7. According to the third embodiment, the start instruction at step 115a in FIG. 19 is supplied from the second processing block 98 to the display block 99. At step 116, display block 99 is activated, and at step 117, the display change is made. After the display change has been checked in step 118, the display block stops itself in step 119.

As can be seen, the third embodiment, the function of which is similar to the first embodiment, provides the self-controlled shutdown of both the second processing block 98 and the display block 99.

In addition, the second processing block 98 gives a start instruction to the display block 99. The task of the first processing block is consequently reduced, which increases the overall processing speed and facilitates the arrangement itself.

Version 4

Fig. 20 is a block diagram showing a fourth embodiment of the present invention, which discloses a power saving using an input / output port for external communications. A data processing device of the fourth embodiment comprises an input / output unit 50 arranged in its data input block 97. The input / output unit 50 contains a communication port 51 and an external interface 52. In operation, the unit 50 performs operations as shown in a time chart in Fig. 21, which is similar to the time chart shown in Fig. 12 of key data input. When a series of inputs at ti to t74 is introduced from the communication port, as shown in Fig. 21-a, the input / output unit 50 supplies corresponding signals to the first processing block 1. The first processor 4 sends input data to the at ti Display circuit 8, as in Fig. 21-d shown becomes active to display a data string as shown in Fig. 21-e. If at t & sub7; one input is extensive, the second processor 7 is switched off at t & sub1; & sub1; activated as shown in Fig. 21-c.

The second processor 7 provides at t 72 a start instruction to the display circuit 8, which is then activated to replace data on the display 2. If the input via the communication port is not extensive, it is processed in the first processor 4 or in the input / output unit 50, while the second processor 7 remains inactive. As a result, energy saving will be ensured during the input and output process.

Version 5

22 is a block diagram showing a fifth embodiment of the present invention in which a solar battery 60 is added as an auxiliary power source. The first processor 4 operates at low speeds and therefore uses a small amount of energy. The device can thus be powered by the solar battery 60. However, while the function is approximately the same as that of the first embodiment, the solar battery stops supplying power when the amount of incident light is significantly reduced. When the supply is stopped, it is switched to the source 61. If there is no key input for a period of time and no power is supplied from the solar battery 60, the power source hold mode is entered as shown in Fig. 23-b. The first processor 4 stores the processing data in the first memory 5 and then stops working. Electricity consumption will therefore be reduced. If at t ?? the solar battery 60 again provides power or further key input data is supplied from the data input unit 3, the first processor 4 begins at t 72. to work to perform an equal job.

An example of the starting procedure of the first processor 4 will now be described. As shown in FIG. 24, a key input device 62 of the data input unit 3 supplies a voltage from the battery 64 to a holding circuit 63. When a key is pressed, the hold circuit 63 connects the power source to the first processor 4 to supply it. At the same time, the key input device 62 transmits key input data to the first processor 4, and processing will begin.

Each key of the key input device 62 can have a plurality of switches; one for power supply and one for data entry.

As a result, since the solar battery is connected, the power consumption will be minimized and the operating time of the device will last much longer.

The solar battery 60, which becomes inactive when no light is incident, can be mounted on the same level as the display 2, so that neither text nor keyboard are displayed when the solar battery 60 is made inactive.

In practice, no particular problem will arise from this. In the case of word processing in the dark, for example during the projection of slide images in a lecture, a key input process triggers the hold circuit 3 in order to activate the first processor 4.

Since the data processing device of the fifth embodiment provides more energy saving, it can be realized in the form of a notebook microcomputer which is not characterized by a battery change for years. In addition, the first and second processors in each of the first to fifth embodiments can be combined in a single unit, as shown in FIG. 25.

From simulated calculations that we performed, it was found that the average power consumption during a word processor was reduced from 5 watts of a reference value to a few hundredths of a watt when the present invention was added. This means that a conventional secondary cell lasts for hundreds of hours and a primary cell, for example a high-performance lithium cell, lasts for more than 1000 hours. In other words, a notebook computer is provided which, like a pocket calculator, can be used for 5 years a day without changing the battery for a year. Attempts are being made to operate at higher speed and with a display with more pixels at the same time, and also the cumbersome charging of rechargeable batteries must be avoided. The present invention is intended to free notebook computers from confusing cables and time-consuming chargers.

The advantages of high speed and high resolution attributed to ferroelectric liquid crystal materials are well known.

In particular, the present invention pays more attention to the energy saving effects of the ferroelectric liquid crystal that have received less attention.

No such attempt has been made to solve the problem. The energy saving effects will certainly contribute to the low power requirements of portable data processing devices, such as notebook computers.

Although the embodiments of the present invention use a ferroelectric liquid crystal display device to take advantage of memory effects, other smectic liquid crystal or electrochromic material memory devices will be used with equal success. The liquid crystal display is not limited to a matrix drive as described and can be driven by a TFT drive system.