JP7715973B2 - Portable electronic devices - Google Patents

Description

The present invention relates to a portable electronic device that floats on the water surface even if dropped into water.

Among these types of portable electronic devices, there is known a portable communication device with a floating structure that provides buoyancy even if the electronic device is dropped into water by forming an air layer inside the electronic device's housing (see, for example, Patent Document 1).

Patent No. 3718497

However, in portable electronic devices such as those shown in Patent Document 1, the air layer is merely a space, and does not fully meet the demand for smaller and lighter portable electronic devices. In order to further reduce the size and weight of this type of portable electronic device, attention is focused on the operation key section of the electronic device. Conventionally, the display section and operation section have been constructed separately. However, when the operation keys are constructed solely from rubber keys to reduce the number of parts, the thickness of the rubber keys is made as thin as possible to reduce weight. However, there are structural limitations in order to ensure the necessary mechanical strength, making it difficult to achieve significant weight reductions.

The present invention aims to provide a portable electronic device that achieves both floating and cost reduction by reducing the amount of heavy rubber parts used and replacing them with resin, thereby reducing weight, and by having the resinized parts also function as light guide plates (display units) for the keys, thereby reducing the number of parts and cutting costs.

The present invention relates to a portable electronic device having a watertight housing,
a rubber operation key member having an operation portion facing an operation window of the housing and for pressing a switch element;
a liquid crystal panel adjacent to the operation unit and facing a display window of the housing;
a resin light guide plate for a backlight of the liquid crystal panel;
a control circuit board (hereinafter referred to as "board") that is fixed inside a housing and on which the liquid crystal panel, the light guide plate, and the switch element are mounted,
The operation key member has a key holding portion that movably holds a key acting portion that presses the switch element,
The light guide plate is extended to the position where the switch element is located and is shaped like a base on the substrate so as to support the key holding portion, the base shape having a top plate that holds the key holding portion and legs for holding the light guide plate on the substrate, and a cavity is formed between the inside of the base and the substrate.

In the above-mentioned portable electronic device, it is desirable that the key holding portion of the operation key member be formed shorter in the height direction of the operation key member than the key action portion.

In the portable electronic device, a cylindrical portion for inserting the key action portion is formed on the top plate of the base shape ,
It is desirable that the light guide plate guides light to the key action portion of the operation key member via the pedestal-shaped top plate and the cylindrical portion, thereby illuminating the operation portion.

According to the present invention, the light guide plate of the liquid crystal panel extends to the position where the switch element is located and has a hollow structure as a base, which effectively creates space for providing buoyancy without increasing the overall size. Furthermore, the thickness of the operation key members can be reduced, making them lighter for floating. This effect is particularly pronounced when the light guide plate is made of resin and the operation key members are made of rubber, which has a high specific gravity. Furthermore, by supporting the key holders of the operation key members with the extended portion of the light guide plate of the liquid crystal panel, the number of parts and assembly processes can be reduced, resulting in cost savings.

1 is a front view of a handheld radio according to an embodiment of the present invention; FIG. FIG. 2 is a perspective view showing a circuit board block on which various components to be built into the housing of the handheld radio are mounted. 4 is a perspective view of the state in which the operation key member is positioned on the light guide plate in FIG. 3; FIG. FIG. 1A is a perspective view of the operation key member as seen from the front side, and FIG. 1B is a perspective view of the operation key member as seen from the back side. FIG. 2 is a perspective view of a liquid crystal panel and a light guide plate built into the housing of the handheld radio, as viewed from the front side. FIG. 1A is an enlarged cross-sectional view of a key action portion of an operation key member, and FIG. 1B is an enlarged cross-sectional view of the key action portion when this embodiment is not adopted.

(Embodiment)
A handheld radio according to one embodiment of the portable electronic device of the present invention will now be described with reference to the drawings. FIGS. 1 and 2 show the external configuration of the handheld radio. In these figures, the handheld radio 1 has a watertight housing and is lightweight enough to float if dropped into water. The handheld radio 1 has an exterior housing 2 molded from resin or the like. The housing 2 comprises a front housing 21 and a rear housing 22, which are secured together with a sealing member. The front housing 21 is provided with a plurality of operation key windows 3, a display window 4 adjacent to the operation key windows 3, a speaker and microphone unit 5, and the like. In this specification, the direction in which the display window 4 is located relative to the operation key windows 3 on the front surface of the handheld radio 1 is referred to as the "upward direction."

Multiple operating elements 61 of the operating key member 6 face and are exposed in each of the operation key windows 3. A liquid crystal panel 7 faces the display window 4. The multiple operating elements 61 allow the user to select items on the screen displayed on the liquid crystal panel 7 and issue operating instructions such as scrolling the cursor. An antenna 13 is provided on the top surface of the housing 2, a power switch and a water submersion detection electrode 11 for the handheld radio 1 are provided on the side of the rear housing 22, and a battery pack storage cover 23 is provided on the back of the rear housing 22. The water submersion detection electrode 11 detects when the handheld radio 1 is submerged in water, activating an internal detection circuit to illuminate the liquid crystal panel 7 and other components.

(Board block configuration)
3 to 5 show a board block on which various components to be housed in the housing 2 are mounted. The board block includes a liquid crystal panel 7, a light guide plate 8 for backlighting the liquid crystal panel 7, and a control circuit board 9 (hereinafter referred to as the board) on which the light guide plate 8 is mounted. In FIG. 4, the operation key member 6 appears to be placed on the light guide plate 8, but multiple operation units 61 are fitted from the inside so as to face the respective operation key windows 3 of the front housing 21. The operation key member 6 is made of rubber and is formed as a single unit.

The liquid crystal panel 7 is mounted on the light guide plate 8 with its periphery surrounded by the frame 82 of the light guide plate 8, and a metal panel frame 71 is provided around the frame 82 to act as a shield and secure the panel. The liquid crystal panel 7 is electrically connected to a socket provided on the substrate 9 via a flexible cable 72.

The light guide plate 8 has a planar backlight section 81 that illuminates the liquid crystal panel 7 from the backside, a frame 82 that surrounds the periphery of the liquid crystal panel 7, and an extension section 83 that extends to the position of the switch element 10 on the substrate 9. The frame 82 forms a space (cavity) on the backside of the backlight section 81, and this space eliminates interference with components mounted on the substrate 9. The light guide plate 8 is made of resin and is integrally formed from transparent resin. The extension section 83 is shaped like a base on the substrate 9 so that it can support the operation key member 6, and the inside of the base is a hollow structure 87.

In addition to the electronic device's control circuit, the board 9 is equipped with a number of switch elements 10 that are pressed by the operation key members 6, LEDs 12 as light-emitting elements that direct light into the light guide plate 8, and receiving terminals that come into contact with the submersion detection electrodes 11. The board 9 with the various components mounted thereon is fixed to the inside of the front housing 21. The LEDs 12 are positioned opposite the lower end surface of the frame 82 of the light guide plate 8, and emit light that enters the light guide plate 8. The light that enters the light guide plate 8 is guided to the backlight section 81 and extension section 83.

(Effects of the embodiment)
In the handheld radio 1 configured as described above, the light guide plate 8 of the liquid crystal panel 7 extends to the position where the switch element 10 is located, forming a hollow structure 87 in the shape of a base. This effectively creates space for providing buoyancy without increasing the overall size of the radio. Furthermore, because the key holder 63 of the operation key member 6 is supported on the base of the light guide plate 8, the thickness of the key holder 63 can be reduced, resulting in a lighter weight for floating. This effect is particularly noticeable when the light guide plate 8 is made of resin and the operation key member 6 is made of rubber, which has a high specific gravity.

In addition, the key holding portion 63 of the operation key member 6 is supported by the extension portion 83 integrally formed with the light guide plate 8, thereby reducing the number of parts and assembly processes, and contributing to cost reductions. Furthermore, the extended base-shaped portion of the light guide plate 8 functions to hold the operation key member 6 and act as a light guide plate for the operation key member 6, so the LEDs 12 of the liquid crystal panel 7 can be used to illuminate the operation portion 61 of the operation key member 6, and reducing their number contributes to cost reductions.

(Example configuration of operation key member)
The configuration of an embodiment of the operation key member 6 will be described. Figures 6(a) and 6(b) are views of the operation key member 6 as seen from the front and back sides, respectively. The operation key member 6 is integrally formed from a translucent rubber material, and has a plurality of operation portions 61 and a frame portion 65 on the front side, and a plurality of key action portions 62, a key holding portion 63, and a key bending portion 64 on the back side. The front side of the operation key member 6 is colored the same color as the housing 2, and the key display portion of the operation portion 61 can be illuminated. The frame portion 65 is watertightly fitted into a circumferential groove provided on the inner wall surface of the front housing 21.

The key action portion 62 of the operation key member 6 is provided in correspondence with the operation portion 61 and is a convex portion that presses the switch element 10. The key holding portion 63 abuts against the base of the extension portion 83 of the light guide plate 8 to support the operation key member 6 while movably holding the key action portion 62. The thickness (height) of the key holding portion 63 can be made thinner by the height of the base of the extension portion 83 compared to when it is supported on the substrate 9, contributing to weight reduction. The key bending portion 64 is thin-walled (thin) on the periphery of the key action portion 62 and bends to move the key action portion 62.

(Example configuration of light guide plate)
An example configuration of the light guide plate 8 will be described. FIG. 7 is a front view of the liquid crystal panel 7 and the light guide plate 8. As described above, the light guide plate 8 includes a backlight unit 81, a frame 82 surrounding the periphery of the liquid crystal panel 7, and an extending extension 83. The extending extension 83 is shaped like a base, with a hollow structure 87 formed therein, and includes a top plate 84 supporting the key holding portion 63 and legs 85 for holding the light guide plate 8 to the substrate 9. The top plate 84 is formed with a cylindrical portion 86 through which the multiple key action portions 62 of the operation key member 6 are inserted. The light guide plate 8 also includes multiple locking claws 88 extending downward from the frame 82. As shown in FIG. 3 and other figures, the light guide plate 8 is fixed by engaging the locking claws 88 with notches 91 and slits 92 formed in the substrate 9.

With the above configuration, the light guide plate 8 guides light to the key action portion 62 of the operation key member 6 via the pedestal-shaped top plate 84 and cylindrical portion 86, illuminating the operation portion 61. This eliminates the need for a separate LED to illuminate the operation portion 61 of the operation key member 6. Furthermore, the light guide plate 8 integrates a resin part for illuminating the keys with the light guide plate of the LCD panel 7, and by raising the keys with the integrated resin part (the pedestal-shaped extension portion 83 of the light guide plate 8), an air layer can be formed to provide buoyancy.

(Configuration of handheld radio example)
8 is a longitudinal cross-sectional view of the handheld radio 1. Within the housing 2, the extension 83 of the light guide plate 8 is shaped like a base relative to the substrate 9 so as to raise and support the operation key member 6, and the inside of the base is hollowed out to reduce weight by forming a hollow structure 87. This hollow structure 87 is provided in an area close to the front side of the handheld radio 1, and a pack storage section 24 for storing a heavy battery pack is provided near the lower rear side.

As configured above, even if the handheld radio 1 falls into water, it will float on the water's surface with its front side facing up and the display window 4 facing upward. Therefore, when the submersion detection electrode 11 detects that the handheld radio 1 has fallen into water, the liquid crystal panel 7 and other components will emit light, making it easy to see the handheld radio 1 above the water's surface.

(Comparison of action and effect)
Next, the differences in effects depending on whether or not the configuration according to this embodiment is adopted will be explained. Fig. 9(a) shows the key action portion of the operation key member 6 according to this embodiment, and Fig. 9(b) shows the key action portion when this embodiment is not adopted. In Fig. 9(a), the key holding portion 63 of the operation key member 6 is formed shorter than the key action portion 62 in the height direction of the operation key member 6 due to the presence of the pedestal-shaped portion of the light guide plate 8.

On the other hand, as shown in Figure 9(b), in a configuration in which the light guide plate 8 does not have a pedestal-shaped portion, the key holding portion 63 is supported on the substrate 9, and therefore the operation key member 6 has a certain thickness in the height direction. In this way, according to this embodiment, the operation key member 6 is raised, and the overall thickness of the operation key member 6 can be reduced, resulting in a lighter weight.

The present invention is not limited to the configuration of the above embodiment, and various modifications are possible without departing from the spirit of the invention.

1 Handheld radio 10 Switch element 11 Submersion detection electrode 12 LED
13 Antenna 2 Housing 21 Front housing 22 Rear housing 23 Battery pack storage lid 24 Pack storage section 3 Operation key window 4 Display window 5 Speaker and microphone section 6 Operation key member 61 Operation section 62 Key action section 63 Key holding section 64 Key bending section 65 Frame section 7 Liquid crystal panel 71 Metal panel frame 72 Flexible cable 8 Light guide plate 81 Backlight section 82 Frame body 83 Extension section 84 Top plate 85 Leg section 86 Cylindrical section 87 Hollow structure 88 Locking claw 9 Control circuit board 91 Notch 92 Slit

Claims (3)

In a portable electronic device having a watertight housing,
a rubber operation key member having an operation portion facing an operation window of the housing and for pressing a switch element;
a liquid crystal panel adjacent to the operation unit and facing a display window of the housing;
a resin light guide plate for a backlight of the liquid crystal panel;
a control circuit board (hereinafter referred to as "board") that is fixed inside a housing and on which the liquid crystal panel, the light guide plate, and the switch element are mounted,
The operation key member has a key holding portion that movably holds a key acting portion that presses the switch element,
a light guide plate extending to a position where the switch element is located and having a pedestal shape relative to the substrate so as to support the key holding portion, the pedestal shape having a top plate that holds the key holding portion and legs for holding the light guide plate on the substrate, and a cavity formed between the inside of the pedestal and the substrate. The portable electronic device described in claim 1, characterized in that the key holding portion of the operation key member is formed shorter in the height direction of the operation key member than the key action portion. The base-shaped top plate is formed with a cylindrical portion for inserting the key action portion therethrough,
3. The portable electronic device according to claim 1, wherein the light guide plate guides light to the key action portion of the operation key member through the pedestal-shaped top plate and the cylindrical portion to illuminate the operation portion.