Foldable cellular phone set

This invention relates to an electronic device or foldable cellular phone set in which boards arranged in two casings bendably connected to each other through a connecting portion are electrically connected to each other by a wireless communication unit using infrared rays or the like. As the wireless communication unit, either an optical method using infrared rays or the like, or a radio wave method using a radio wave can be used.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electronic device, e.g., a foldable cellular phone set, having a bendable portion and, more particularly, to an electronic device in which the electrical connection of the bendable connecting portion is improved.

2. Description of the Prior Art

As shown inFIG. 1, a foldable cellular phone set60is comprised of one side portion62having a display screen61and the like, and the other side portion72having input buttons63and the like. The two side portions62and72are bendably connected at substantially their central position by a connecting portion80, so they can be opened/closed. As shown inFIG. 2, one side portion62of the foldable cellular phone set60is comprised of a first front casing64and first back lid66that can be divided in the front and back directions. The other side portion72is similarly formed of a second front casing74and second back lid76. The connecting portion80has a connecting member80aon the first front casing64side and a connecting member80bon the second front casing74side. The connecting members80aand80bare built in the connecting portion80together with other connecting members, so the connecting portion80is pivotal.

As shown inFIG. 3, one side portion62of the foldable cellular phone set has a first board52, to which a liquid crystal panel for the display screen61and a receiver for producing the voice of the other party are to be connected, such that the board52is stored between the first front casing64and first back lid66. The other side portion72has a second board54, to which contact components of the input buttons63for inputting telephone numbers and the like and a microphone are to be connected, such that the board54is stored between the second front casing74and second back lid76.

As shown inFIG. 3, the first and second boards52and54are electrically connected through a flexible FPC (Flexible Printed Circuit board)50. The FPC50is connected at its one end to the first board52through a connector56, and at its other end to the second board54through a connector58. The FPC50is twisted by one turn to form one helical loop at its substantial center in the longitudinal direction, and is connected to the first and second boards52and54. The first and second boards52and54are fixed to the first and second front casings64and74, respectively, and the first and second back lids66and76are attached to the first and second front casings64and74, respectively so the first and second boards52and54are stored. In this manner, since the FPC50is stored in the connecting portion80as it is twisted by one turn, one and the other side portions62and74respectively storing the first and second boards52and54can folded while maintaining electrical connection to each other.

In another prior art disclosed in Japanese Unexamined Patent Publication No. 11-308173, photocouplers are formed on those portions of two casings through which the casings are foldably connected to each other. The casings are electrically connected to each other through the photocouplers.

In the conventional foldable cellular phone set, the FPC connectors56and58are mounted on the respective boards. The two ends of the FPC50are fitted in the connectors56and58, so the first and second boards52and54are electrically connected to each other. Hence, the manufacturing line requires the operation of building the FPC50to the connectors56and58and the like, which is cumbersome. Since the ends of the FPC50are thin, when they are to be fitted in the connectors, the connector56may be damaged, or the FPC50may undesirably bend. Furthermore, if the FPC50and connector56and the like are not sufficiently fitted with each other, they cause defective electrical connection, resulting in a defective product.

The FPC50is twisted into a loop in the connecting portion80, and is usually in substantially tight contact with the inner surface of the connecting portion80. When water enters through the connecting portion80, capillarity occurs between the FPC50and the inner surface of the connecting portion80, and the water may flow deeply into the connecting portion80to wet the first board52and the like. This causes corrosion of the first board52and the like to lead to a trouble or the like. As the FPC50runs from the inside to the outside of the connecting portion80, the connecting portion80cannot be sealed completely.

As the functions of the cellular phone set increase, the amount of information transmitted between the first and second boards52and54increases. To transmit the information, it is required to increase the number of signal lines in the FPC50. The space in the connecting portion80through which the FPC50can run is limited. If the width of the FPC50is increased in an attempt to increase the number of signal lines, the FPC50cannot run through the connecting portion80. In addition, in recent years, demands for downsizing of the cellular phone set increase. To increase the width of the connecting portion80for the FPC50leads to an increase in size of the phone set main body, failing to downsizing. Information transmission using the FPC50is reaching its limit.

According to the invention disclosed in Japanese Unexamined Patent Publication No. 11-308173, the casings are electrically connected to each other through the photocouplers respectively provided to the two casings. The two photocouplers abut against each other when the respective casings are opened completely. During opening/closing operation, communication between the two photocouplers is disconnected.

SUMMARY OF THE INVENTION

The present invention has been made to solve the above inconveniences of the prior art, and has as its object to provide an electronic device or foldable cellular phone formed by foldably connecting two casings, which can be assembled easily, perform communication reliably, cope with a large communication amount, and always make electrical connection regardless of the folded state of the casings, so downsizing and cost reduction can be realized.

In order to achieve the above object, according to the present invention, there is provided an electronic device or foldable cellular phone set, in which boards arranged in two casings foldably connected to each other through a connecting portion are electrically connected to each other by a wireless communication means using infrared rays or the like. More specifically, transmission/reception modules for infrared communication (IrDA) are arranged in the connecting portion coaxially with the rotation axis of the connecting portion, such that they oppose each other. Even when the connecting portion of the foldable cellular phone set is bent, the transmission/reception surfaces of the transmission/reception modules can always oppose each other, and communication between them is not disconnected by folding operation.

As the wireless communication means, ultraviolet rays, visible light, and a radio wave with a weak output can be used in addition to the infrared rays. When the transmitting/receiving portions use light, their transmitting/receiving surfaces must oppose each other. When the transmitting/receiving portions use a radio wave, their transmitting/receiving surfaces need not oppose each other, and transmission/reception antennas may be appropriately arranged on the two casings respectively. When the pivot angle of the connecting portion is not large, the boards may be connected by using optical fibers.

The transmission/reception modules can be arranged at that portion of the connecting portion having the conventional structure where the FPC used to run. When the FPC is used, it is twisted and arranged, so a substantially cylindrical space is formed in advance. When the transmission/reception modules are arranged at the portion where the FPC used to run, a connecting method which uses infrared modules and the like can be easily applied to the structure of the conventional foldable cellular phone set in which the transmission/reception modules are connected by using the FPC, without largely changing the shape of the basic constituent components such as casings.

As is apparent from the above aspects, with the electronic device or foldable cellular phone set that can be obtained by the present invention, the cumbersome operation of connecting the FPC can be omitted, so the assembly cost can be reduced. In particular, as the IrDA modules can be mounted on the boards by an automatic mounter or the like, they do not need manual assembly unlike in the case using the FPC, so the assembly cost can be reduced largely.

Damage to the FPC connector which occurs when connecting the FPC to the FPC connector can be prevented. Also, disconnection in the FPC, which is due to the bending of the FPC, can be prevented.

Water can be prevented from entering the foldable cellular phone set through the connecting portion. Even if water should enter the phone set, it does not come in contact with any board.

Even if the amount of information exchanged between the connected boards increases, this increase in the amount of information can be easily coped with without adding or enlarging the interconnections structurally, unlike in the case of connection using wires.

The above and many other objects, features and advantages of the present invention will become manifest to those skilled in the art upon making reference to the following detailed description and accompanying drawings in which preferred embodiments incorporating the principle of the present invention are shown by way of illustrative examples.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Several preferred embodiments of the present invention will be described with reference to the accompanying drawings by way of a foldable cellular phone set.

FIG. 4shows a foldable cellular phone set2of the present invention entirely. Similarly to the conventional foldable cellular phone set60, the foldable cellular phone set2is comprised of one side portion12having a display screen10and the like, and the other side portion22having input buttons20and the like. As shown inFIGS. 5 and 6, one and the other side portions12and22are foldably connected to each other at substantially their center by a connecting portion8.FIG. 5shows an open state, andFIG. 6shows a folded state.

As shown inFIG. 7, one side portion12is formed of a first front casing14and first back lid16to be respectively fitted in its front and back sides, and a first board4to be inserted between the first front casing14and the first back lid16. A connecting member8ato serve as part of the connecting portion8is formed on the first front casing14on the connecting portion8side.

As shown inFIG. 7, the other side portion22is formed of a second front casing24and second back lid26to be respectively fitted in its front and back sides, and a board6to be inserted between the second front casing24and the second back lid26. A connecting member8bto serve as part of the connecting portion8is formed on the second front casing24on the connecting portion8side.

As shown inFIG. 8, the connecting portion8is substantially cylindrical as a whole, and has stoppers17at its two ends for pivotally stopping the respective connecting members of one and the other side portions12and22. A cylindrical space is formed in the center of the connecting portion8.

A liquid crystal panel for the display and a receiver for producing the voice of the other party are mounted on the first board4. The contact components of the buttons for inputting telephone numbers and the like, a microphone, and the like are mounted on the board6.FIG. 9shows a state wherein the first and second boards4and6are respectively fixed to the first and second front casings14and24.

As shown inFIGS. 9 to 11, infrared modules5and7are attached to the first and second boards4and6on the connecting portion8sides. InFIG. 10, a line denoted by a reference character X shows a rotation axis of the connecting portion8. The infrared module5having an infrared-ray-receiving/emitting element (not shown) in it converts a signal from the first board4into infrared rays and emits an infrared signal. Upon reception of an infrared signal, the infrared module5converts it into an electrical signal and sends it to the first board4. The infrared module7has the same arrangement as that of the infrared module5. The infrared modules5and7oppose each other with their light-receiving/emitting surfaces, as shown inFIG. 13, and are attached to the first and second boards4and6, respectively, such that their two center axes coincide with the rotation axis X of the connecting portion8, as shown inFIG. 12, when the first and second boards4and6are respectively fixed to the first and second front casings14and24.

In this manner, in the foldable cellular phone set2of the present invention, since the center axes of the infrared modules5and7are arranged coaxially with the rotation axis X of the connecting portion8, the positional relationship between the infrared modules5and7relative to each other does not change at all whether in the open state or the folded state, as shown inFIGS. 5and6, and the infrared modules5and7are constantly held to oppose each other.

Therefore, no matter how the connecting portion8of the foldable cellular phone set2is bent (rotated) during communication using the infrared modules5and7, communication can be maintained. The foldable cellular phone set2can operate not only in the open state but also in any state.

Other than the above embodiment, the infrared modules5and7may come into tight contact with the inner surface of the connecting portion8, or the gap between the first or second board4or6extending from one or the other side portion12or22, respectively, and one or the other side portion12or22may be waterproofed. This can prevent water or the like from entering one and the other side portions12and22through the connecting portion8. At this time, the transmitting/receiving surfaces of the infrared modules5and7may expose from the foldable cellular phone set2or may be inside the connecting portion8.

The infrared modules5and7need not be formed in the connecting portion8, but may be formed at appropriate portions of the main bodies of the first boards4and6arranged in one and the other side portions12and22, respectively, and may be connected to each other through optical fibers9and11, as shown inFIG. 14. In this case, one end of the optical fiber9is attached to the light-receiving/emitting surface of the infrared module5. The other end of the optical fiber9runs into the connecting portion8and is arranged coaxially with the rotation axis of the connecting portion8. One end of the optical fiber11is attached to the light-receiving/emitting surface of the infrared module7. The other end of the optical fiber11runs into the connecting portion8and is arranged coaxially with the rotation center of the connecting portion8, so it opposes the end face of the optical fiber9.

With this arrangement, infrared communication is performed through the optical fibers9and11. The other end face of the optical fiber9and that of the optical fiber11constantly oppose each other regardless of whether the foldable cellular phone set2is folded or not. Hence, communication is not disconnected.

Furthermore, according to the present invention, one and the other side portions12and22may be connected to each other by a radio wave method, in place of the infrared modules5and7. In this case, the first and second boards4and6have a wireless transmitting/receiving function (not shown) with a predetermined frequency and output. As shown inFIG. 15, antennas13and15are formed in the connecting portion8or at those positions of one and the other side portions12and22where a radio wave can be transmitted or received. Hence, one and the other side portions12and22can transmit and receive signals to and from each other through the antennas13and15regardless of whether the foldable cellular phone set2is folded. Also, since the antennas can be formed even when the connecting portion8is sealed, entering of water or the like can be prevented reliably.