Anti-shock and water-resistant housing for portable electronic apparatus

0001This invention relates to portable electronic apparatus such as notebook computers, pen computers, mobile telephones, etc. More particularly, it relates to a housing for enclosing the inner structure of such an apparatus.

0002Conventionally, a housing for enclosing the inner structure of a portable electronic apparatus is shaped by plastic moulding using acrylonitrile butadiene styrene (ABS) or a composition of ABS and polycarbonate (PC).

0003Such a housing is so weak that it may be fractured and also result in the failure of the inner functional structure when dropped to the ground or exposed to shock. In addition, caps for a keyboard or for the input/output ports in a pen computer may be lost.

0004JP-A-4305418 discloses a housing for a portable electronic apparatus comprising a hard housing body, and a resilient layer formed on the hard housing body, in conformity therewith, the resilient layer being moulded of synthetic resin and having a plurality of protuberances positioned in correspondence with the position of operating switches mounted inside of said housing body.

0005It is an object of the present invention to provide an anti-shock and water-resistant housing for enclosing the internal structure of a portable electronic apparatus.

0006It is further another object of the present invention to provide a means for preventing the loss of the caps for covering the input/output ports of a pen computer.

0007According to the present invention there is provided a housing for enclosing the components of a portable electronic apparatus, the housing comprising: a hard housing body moulded of plastic material; a resilient layer formed on said hard housing body in conformity with the shape of the outer surface of said housing body, wherein said resilient layer is moulded of synthetic resin and has a plurality of protuberances positioned in correspondence with the position of a plurality of operating switches mounted inside of said housing body; wherein upper portions of said plurality of protuberances contacted by fingers are hemispherically shaped and opposing lower portions contacted with said operating switches are cylindrical in shape; an upper case assembly for mounting a display device, an internal part of the upper case assembly being made of plastic material and having a plurality of bosses to mount the components of the electronic apparatus, and an outer part thereof being made of rubber; a lower case assembly for mounting a battery to supply power to the electronic apparatus, an internal part of the lower case assembly being made of a plastic material and an outer part thereof being made of rubber; and a gasket formed between the upper case assembly and the lower case assembly for sealing up the space between the upper case assembly and the lower case assembly.

0008The housing body may be prepared by using acrylonitrile butadiene styrene (ABS) or a composition of ABS and polycarbonate (PC) while the resilient layer is prepared by using block copolymers. The block copolymer is preferably composed of polybutylene terephthalate (PBT) and long-chain polyether glycols. The block copolymer may be HYTREL™ resin manufactured by Dupont Company.

0009According to the present invention in a further aspect there is provided a housing for enclosing the components of a portable electronic apparatus, the housing comprising: an upper case assembly for mounting a display device, wherein the upper case assembly has a plurality of bosses to mount the components of the electronic apparatus; a lower case assembly for mounting a battery to supply power to the electronic apparatus; a gasket formed between the upper case assembly and the lower case assembly for sealing up the space between the upper case assembly and the lower case assembly; and a water-resistant door formed on a rear side of the housing for input/output ports of the portable electronic apparatus.

0010Preferably, the door comprises caps for covering the input/output ports, and flexible connection members for connecting the housing and the caps, wherein said connecting members have hook portions for hooking said housing at one end and ring-shaped portions for holding said caps at the other end, said hook portions being made of resilient material so that they may be held and recovered to hook said housing, said caps having resilient tube-like protuberances fitted into said ring-shaped portions.

0011The caps may be formed to have resilient tube-like protuberances fitted into the ring-shaped portions. The tube-like protuberances may be prepared to expand their middle portion to clutch the ring-shaped portions when stoppers with a diameter greater than the inner diameter of the tube-like protuberances are inserted into the openings of the tube-like protuberances.

0012The stoppers may be so formed as to have the shape of a reversed truncated cone with the height being about half the depth of the opening of the tube-like protuberances. The diameter of the upper end of the stopper is formed greater than the inner diameter of the tube-like protuberances and the diameter of the lower end.

0013Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: <ul id="ul0001" list-style="none" compact="compact"><li>Figure 1 is a cross-section of the upper cover of a housing body for enclosing the internal structure of a portable computer, showing a resilient layer coated on the upper cover according to an embodiment of the present invention;</li><li>Figure 2 is a perspective view for illustrating the upper surface of the housing of a portable computer in which the present invention is preferably embodied;</li><li>Figure 3 is a perspective view for illustrating the lower surface of the housing shown in Figure 2;</li><li>Figure 4 is an exploded perspective view for illustrating the assemblage of the upper cover of the housing according to an embodiment of the present invention;</li><li>Figure 5 is an exploded perspective view for illustrating the assemblage of the lower cover of the housing shown in Figure 4;</li><li>Figure 6 is a block diagram for illustrating the system board of a computer fitted into the housing according to the present invention;</li><li>Figure 7 is a perspective view of a portable computer for illustrating the caps for covering the input/output ports of a portable computer according to an embodiment of the present invention;</li><li>Figure 8 is a perspective view for illustrating in detail the cap of the input/output ports made in accordance with an embodiment of the present invention;</li><li>Figure 9 is a cross-section of a cap attached to an output port of a portable computer in accordance with an embodiment of the present invention;</li><li>Figure 10 is a perspective view for illustrating a connecting member for connecting a cap and a housing according to the present invention;</li><li>Figure 11 is a cross-sectional view for illustrating the attaching action of the connecting member shown in Figure 10;</li><li>Figure 12 is a perspective view for illustrating the connecting member attached to a housing of a portable computer;</li><li>Figure 13 is a perspective view for illustrating the outer surface of a handphone in which the present invention is preferably embodied; and</li><li>Figure 14 is a cross-section of the handphone shown in Figure 13 for illustrating a preferred embodiment of the present invention.</li></ul>

0014As shown in Figure 1 according to an embodiment of the present invention, an anti-shock and water-resistant housing for enclosing the internal structure of a portable electronic apparatus comprises a housing body whose outer surface is coated with a resilient layer 11 made of rubber-like material. The housing body comprises an upper cover 12 and a lower cover (not shown in Figure 1), which are connected with a main gasket 13 interposed between them.

0015Attached to the main gasket 13 is a gasket support 131 to secure the relative position of the upper cover and lower cover so that the two covers are separated when the housing is shocked. The upper and lower covers of the housing body are moulded of plastic material whose mechanical strength is hard when shaped and finished. The outer surface of the housing body is coated with a resilient layer 11 in conformity with its shape. The resilient layer 11 is moulded of a synthetic resin which gives resilient rubber-like characteristics when shaped and finished.

0016The plastic material used in preparing the upper and lower covers is acrylonitrile butadiene styrene (ABS) or a composition of ABS and polycarbonate (PC), and the synthetic resin used to form the resilient layer 11 is a block copolyer which is preferably HYTREL™ resin of the Dupont Company composed of polybutylene terephthalate (PBT) and long-chain polyether glycols. A conventional moulding process is used to fabricate the housing. In one embodiment of the present invention, the resilient layer is preferably formed to have a thickness of 1.2 to 2.0 mm.

0017The upper and lower covers 21 and 22 are assembled together with the main gasket 13 as schematically shown in Figures 2 and 3. Referring to Figure 3, the lower cover 22 has a pair of cylindrical supporting means formed integrally with it to hold a computer steady. Referring to Figure 4, there are described the steps for mounting the parts in housing.

0018At first, a tray gasket 310 is placed on a flange formed around the internal space of the upper cover 21 for receiving LCD panel 324 so as to absorb shocks that may occur between the upper cover 21 and the part placed on the upper cover. On the tray gasket 310 is mounted a lower support frame 316 with a pair of pads 312 and 314 attached to the left and right bordering surfaces of the lower support frame 316.

0019The LCD panel 324 is mounted on the lower support frame 316. A tape 320 is attached to a left bordering portion of the upper surface of the lower support frame 316 and a communication cable 318 complying with the FCC (Federal Communications Commissions) standard. A gasket 322 is placed on the lower support frame 316 on which the LCD panel 324 is mounted with a cable 326 attached to the left side of it.

0020On the LCD panel 324 is placed a gasket 328 on which is mounted a digitizer 330 for processing the input signals of a pen computer. An upper support plate 332 is mounted on the digitizer 330 with six pieces 334 of shock absorbing materials interposed between them. The upper supporting plate 332 is made of a magnesium alloy with a good mechanical strength to prevent the distortion of the LCD panel 324. Meanwhile, although not shown in Figure 4, the main circuit board of a computer system is mounted on the upper supporting plate 332, having a structure as shown in Figure 6.

0021Referring to Figure 5, there is described the procedure for mounting the internal parts of a portable computer in the inside of the lower cover 22. The lower cover 22 has a space formed in the rear part thereof for receiving a battery 350 whose rear end surface is associated with battery pin 352 and gasket 356 by means of screws 354.

0022A pair of brackets 358 are connected to the gasket 356 against which a plate 362 having an infrared emitter with holding means 360 is attached together with a gasket 364. The interred emitter of plate 362 is for communicating with external mechanism, and the gasket 364 is for absorbing shocks occurring between the plate 362 and lens 370. The lens 370 and gasket 368 are mounted against the gasket 364 by means of bolt 366. The gasket 368 is for preventing the lens 370 from being damaged by the bolt 366.

0023Figure 6 illustrates schematically the structure of the main circuit board of a computer. Its operating principles are described in brief. A central processing unit (CPU) 410 is connected with a random access memory (RAM) 412 and a system controller 414 via local bus.

0024The CPU is a microprocessor chip such as a 486DX or 486DX2 for example. The RAM 412 is used as the main memory of the system and has a capacity of, eg, 4MB, 8MB or 16MB. The capacity of the RAM 412 may be expanded by using JEDEC memory, for example. The system controller 414 is also connected with the system bus to interface the CPU 410 and local buses, while working as a DRAM controller and power manager.

0025An internal logic controller 416 is connected by local buses with a keyboard controller 418, a ROM 420, a buffer 422 and the system bus to control the parallel port, interrupt and direct memory access (DMA) and includes a timer and real time clock (RTC) to provide the system with standard time.

0026The keyboard controller 418 generates scan codes of the keyboard interrupted and transferred to the CPU 410 via local buses, the buffer 422, the system bus and the system controller 414. The ROM 420 stores a basic input output system (BIOS) program, various interrupt service routines and power on self test (POST) program executed on booting of the system.

0027The buffer 422 interfaces the system bus with the local buses connecting the internal logic controller 416, keyboard controller 418 and ROM 420. PCMCIA (Personal Computer Memory Card International Association) controller 434 has at least one socket 436 designed to be connected with a memory card even during power-on state of the system.

0028A video controller 438 connected to the system bus is also connected with a display 442 and a video RAM 440 to generate colour signal, synchronizing signal, clock signal and colour level signals from video data produced by the CPU 410. The video data is temporarily stored in the video RAM 440. The above generated signals are inputted to the display 442. A buffer 424 interfaces the system bus and local buses connecting a hard disk 426, a flash ROM 428, an external input/output controller 430 and a program logic device 432.

0029The hard disk 426 includes a hard disk controller and the flash ROM 428 stores the operating system and utility programs. The external input/output controller 430 includes a logic circuit for interfacing the hard disk through addressing and controls serial ports such as the floppy disk drive and printer port. The program logic device 432 is a programmable logic array including the bus control logic circuit of the buffers 422 and 424 connected with the system bus.

0030The following table illustrates shock tests performed on a pen computer. <tables id="tabl0001" num="0001"><table frame="all"><tgroup cols="4" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="39.37mm" /><colspec colnum="2" colname="col2" colwidth="39.37mm" /><colspec colnum="3" colname="col3" colwidth="39.37mm" /><colspec colnum="4" colname="col4" colwidth="39.37mm" /><thead valign="top"><row rowsep="1"><entry namest="col1" nameend="col4" align="center">SHOCK TEST</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">Height</entry><entry namest="col2" nameend="col2" align="center">Contact Material</entry><entry namest="col3" nameend="col3" align="center">Number of Repetition</entry><entry namest="col4" nameend="col4" align="center">Structure</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">1.2 M (4 feet)</entry><entry namest="col2" nameend="col2" align="center">Concrete</entry><entry namest="col3" nameend="col3" align="center">5</entry><entry namest="col4" nameend="col4" align="right">No HDD</entry></row><row><entry namest="col1" nameend="col1" align="left">0.9 M (3 feet)</entry><entry namest="col2" nameend="col2" align="center">Concrete</entry><entry namest="col3" nameend="col3" align="center">5</entry><entry namest="col4" nameend="col4" align="right">1.3'' HDD</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">0.6 M (2 feet)</entry><entry namest="col2" nameend="col2" align="center">Concrete</entry><entry namest="col3" nameend="col3" align="center">5</entry><entry namest="col4" nameend="col4" align="right">1.8'' HDD</entry></row></tbody></tgroup></table></tables>

0031In the above table, the height represents the distance through which a pen computer is dropped, the contract material represents the ground material with which the pen computer collides, the number repetition represents the number of times the pen computer is dropped, and the structure represents whether the pen computer contains a hard disk.

0032Conventionally, a vibration test involves subjecting a pen computer to a vibrating motion made at the maximum resonance frequency for 15 minutes. The pen computer was subjected to forces corresponding to half gravity (0.5 G's) during operation and to forces corresponding to gravity (1.0 G's) during its inoperative state. The pen computer passed the above tests, showing good mechanical properties.

0033It is not practical to attach the caps for the input/output ports by hinges because the inventive housing body of a pen computer is coated with a rubber-like resilient layer.

0034Furthermore, since the keyboard is not frequently used in a portable pen computer, it is necessary to provide means for preventing the cap of the keyboard from being lost. According to the present invention, the housing of a pen computer is provided with means for preventing the caps of the input/output and keyboard ports from being lost.

0035Referring to Figures 7 to 12, the means for preventing the caps of the input/output and keyboard ports from being lost is composed of caps 3, 4 and flexible connecting members 2, 5 for connecting the housing body and the caps. The connecting members 2, 5 have hook portions for hooking the housing body at one end, as shown in Figure 8. At the other end, ring-shaped portions are formed to hold the caps.

0036Referring to Figures 10 and 11, the hook portions 22 of the connecting members 2 are made of resilient material so that they may be folded and recovered to hook the housing body when inserted into slits of the housing. In addition, the caps 3, 4 have resilient tube-like protuberances 31, 41 fitted into the ring-shaped portions.

0037Referring to Figures 8 and 9, the tube-like protuberances 31, 41 may have a middle portion which may expand to clutch the ring-shaped portions when stoppers 6 with a diameter greater than the inner diameter of the tube-like protuberances are inserted into the openings of the tube-like protuberances.

0038The stoppers 6 are so formed as to have the shape of a reversed truncated cone with the height being about half the depth of the opening of the tube-like protuberances 31, 41. The diameter of the upper end of the stopper is greater than the inner diameter of the tube-like protuberances and the diameter of the lower end. Preferably, the upper ends of the stoppers 6 have a knob.

0039According to an embodiment of the present invention, the tube-like protuberances 31, 41 are made of rubber, the connecting members 2, 5 of polyester resin and the stoppers 6 of plastic material. Of course, the materials are not limited to those described above . Preferably, double flanges are provided around the portions of the computer housing 1 connecting to the input/output caps 3,4, as shown in Figure 7. Thus the caps of the keyboard and input/output ports 3, 4 are fixedly attached to the housing, thereby being securely kept from being lost.

0040Referring to Figure 13 and 14, the present invention may alternatively be embodied other equipment, for example in a mobile telephone. In a mobile telephone, the housing body comprises upper and lower covers 54, 53 and a resilient layer 52 coated thereon. The resilient layer 52 has a plurality of protuberances positioned in correspondence with the positions of a plurality of the operating switches mounted on the internal plate 55 within the housing body. The protuberances are formed so as to work the operating switches when pressed by fingers. Indication numbers are preferably indicated on the positioning surfaces corresponding to the positions of the operating switches 56, thus eliminating the necessity of providing additional buttons for operating the switches.