Method of backlighting a display panel and an apparatus therefor

IS 2 162 199 T3

DESCRIPTION

Method of backlighting a display panel and an apparatus thereof.

The present invention relates to the background lighting of a display panel and is directed to using reflected sunlight to illuminate the background of a display panel of an ATM machine (MCA).

Many types of display panels are known to have visible display screens. Some display panels, such as liquid crystal display (LCD) panels, require backlighting to allow a person to look at the display panel's display screen to see the information that appears on the display screen. Commonly, the light source, such as an activated incandescent lamp, is located behind the LCD panel and, when activated, allows the person to see the information that appears on the LCD panel display screen.

When the LCD panel is used in an environment that has bright sunlight, it may be difficult to read the information that appears on the display screen as the light source behind the LCD panel may not be bright enough for contrast. With the brightness of sunlight. However, the use of a light source of increased intensity is not desirable as the level of heat generated by the source and its energy consumption will also increase. Generating excessive heat can lead to overheating.

GB-A-2 056 740 describes an LCD panel for a motor vehicle that uses incident sunlight to illuminate the panel in bright ambient conditions and an artificial light source in dark ambient conditions. The artificial light source is selectively turned on and off and an illumination selection plate with a diffuser reflector that selectively collects ambient light or, when close to the panel, reflects light from the artificial source, to illuminate the display.

GB-A-297 691 and EP-A-81603 describe ad displays which may be backlit by natural ambient light or by artificial light, depending on ambient conditions.

Document US-A-4 997 263 describes an LCD system for mounting on the helmet of aviation pilots to display navigation information or strategic flight information in the pilot's field of view. Therefore, the system uses an optical arrangement that is aligned so that ambient light in the direction of an observer is channeled behind the liquid crystal display to provide background lighting. An illuminator is provided to provide additional illumination for the liquid crystal display, as needed. A photodetector determines when the ambient light is inadequate for the required display brightness and by using the appropriate control circuit to turn the illuminator on or off, whichever is the case.

US-A-5 416 495 describes an electronic guide incorporating an LCD display unit that can be exposed to sunlight. The purpose of the described adjustment is to maintain the temperature of the display, despite ambient temperature and humidity variations, usually for normal ranges at least for temperature zones, and even if the display unit receives sunlight. direct. This is achieved by the use of a shade cover, and a concave exterior window that is mounted on the front of the display and reflects only the light from the bottom of the cover to the viewer.

It is the object of the present invention to provide a self-service terminal with a backlit display panel in a sunny environment to mitigate the difficulties previously experienced when reading on a display in such an environment.

The invention consists of a self-service terminal that allows the customer to carry out a transaction, comprising:

A card reader that receives the customer's customer identification card and reads the card data to verify the customer's identity; ^Y a display panel having a back and a front part to display the information that the customer sees while the customer carries out the transaction; characterized by a window means for directing sunlight behind the display panel, a reflector unit located in the vicinity of the rear of the display panel to receive and reflect sunlight; and a lens system positioned between the rear of the display panel and the reflector unit to focus reflected sunlight from the reflector unit towards the rear of the display panel to illuminate the background of the display panel and allow the customer to see the front part of the display panel while the customer carries out a transaction;

the reflector unit comprising a mirror surface that receives and reflects sunlight towards the lens system, the mirror surface being parabeolic.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of an automated teller machine (MCA) incorporating a display panel system constructed in accordance with the present invention;

Figure 2 is a block diagram representation of the MCA of Figure 1; and Figure 3 is a schematic illustration of a sectional view taken approximately along line 3-3 of Figure 1.

With reference to Figure 1, an automated teller machine (MCA) 10 comprises a user interface in the form of a front panel 12. The front panel 12 includes a card reader 14, a keyboard 16, a bill dispenser 18, a liquid crystal display (LCD) panel 20 with a display screen 21, and a receipt printer 22. Each card reader 14,

ES 2 cash dispenser 18 and receipt printer 22 have slots located in the front panel 12 of the MCA to allow the introduction of the user identification card 26 at the beginning of the transaction and delivery of the cash bills and a receipt to the customer 24 upon completion of the transaction, respectively.

When the customer 24 inserts the user identification card 26 into the card reader slot 14, the information contained on the card is read. The customer 24 is then prompted on the display screen 21 of the LCD panel 20 to enter the personal identification number (PIN) through the keypad 16. After the correct PIN is entered, menus are displayed on the display screen 21 to allow the customer 24 to carry out the desired transaction. Once the transaction is completed, the money can be dispensed through the money dispenser slot 18 and the receipt printer 22 prints a receipt of the transaction and delivers the receipt through the receipt printer slot 22 to the customer 24.

With reference to Figures 1 and 2, the MCA 10 further comprises a control unit 30 that communicates with the components of the front panel 12. The control unit 30 includes a processor unit 32, a memory unit 34 connected via a bus line 36 to processor unit 32 and a register unit 38. Processor 32 receives input signals on lines 42, 44 from card reader 14 and keyboard 16, respectively, and provides output signals 46, 48, 50 to money dispenser 18, LCD panel 20, and printer. of receipts 22, respectively, to control the amount of money dispensed by the money dispenser 18, the information displayed on the display screen 21 of the LCD panel 20, and the information printed by the receipt printer 22. Processor unit 32 may include a microcomputer, and memory unit 34 may be permanent RAM. Microcomputers and appropriate memories are already available on the market. Their structures and operation are well known and therefore will not be described.

As shown in Figures 1 and 3, a glare-free transparent window 60 surrounds the outer perimeter of LCD panel 20. A lens system 64 is located behind LCD panel 20 and a mirror surface 66 with parabolic shape is located. Locate behind the lens system 64.

A light source 68 such as an incandescent lamp is located between the lens system

199 T3 4 and mirror surface 66, as shown in Figure 3. When activated, light rays from light source 68 (represented by arrows 62 in Figure 3) are directed towards the lens system 64 that focus the light rays 62 and direct the focused light rays towards the rear of the LCD panel 20 to provide backlight to the LCD panel 20.

In accordance with the present invention, incoming sunlight (represented by arrows 72 in Figure 3) is transmitted through transparent window 60 without reflections surrounding LCD panel 20. Dimensions and position of mirror surface 66 behind LCD panel 20 are such that sunlight transmitted through window 60 (represented by arrows 74 in FIG. 3) is received by mirror surface 66 and reflected from there. Reflected rays from sunlight (represented by arrows 76 in Figure 3) are directed toward lens system 64 which focuses reflected rays 76 from sunlight and directs focused light rays 78 (represented by arrows at Figure 3) towards the rear of the LCD panel 20. It should be obvious that the focused light 78 directed towards the rear of the LCD panel 20 is a combination of light from light source 68 and light from incoming sunlight 72. The focused light from sunlight Incoming 72 complements the light originated by light source 68 to increase the intensity of the backlight from LCD panel 20 to allow the front of the display panel to be viewed with enhanced contrast.

A number of advantages result from using the incoming sunlight 72 to provide increased backlight intensity for the LCD panel 20. For example, an increased intensity light source 68 is not required in sunny ambient conditions as the Light rays originating from the incoming sunlight 72 are used as a supplement to the light rays originating from the light source 68. From here, the problems of increased energy consumption and heat generated during operation with the increased intensity of the light source 68 are eliminated.

Although the foregoing describes a system in which light source 68 is also used to provide backlight on LCD panel 20, it is possible that light rays from incoming sunlight 72 can provide sufficient backlight. on the LCD panel 20 so that activation of the light source 68 is not always necessary.