JP2005252334A - Optical transmission module and mobile information apparatus employing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of the impossibility of establishing a downsized and low profile foldable mobile information apparatus employing optical fibers as a high speed transmission means that is a powerful and leading means between the cases of the information apparatus because of a high optical loss caused in conventional optical fibers when they are folded. <P>SOLUTION: An optical transmission module is disclosed, wherein a plurality of mirrors 13a, 13b are arranged between a light emitting element 11 and a light receiving element 12, and the mirrors are optically coupled by an optical transmission line 14b turnably interconnecting at least the mirrors by using rotary joints 15a, 15b. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical transmission module mainly used for optical wiring and a portable information device having a folding mechanism on which the optical transmission module is mounted.

  In portable information devices, small size and thinness are very important requirements for easy carrying. In cellular phones, personal computers, and the like, a device configuration is commonly used in which a plurality of casings are folded to reduce the size to improve portability.

  In recent years, the progress of multifunctional and high-performance mobile devices has been remarkable. For example, in mobile phones, the installation of megapixel cameras, high-definition displays, large displays, and TV functions are rapidly advancing, and signal transmission within mobile devices is becoming increasingly faster and larger in capacity. It has become.

  A folding mobile phone generally has a configuration in which a main body portion on which a key operation portion and a control portion are mounted and a lid side portion on which a display and a camera are mounted are coupled by a folding hinge. Conventionally, signal transmission between the main body portion and the lid side portion has been performed by electrical signals using tens or more coaxial wires as a medium. However, although the signal transmission speed required for the device is increased, there is a limit in increasing the number of coaxial lines in terms of layout because the space of the hinge portion is limited. As a result, the signal speed that can be transmitted is limited. Further, electromagnetic interference occurs between the coaxial line of the hinge portion and the antenna, which has been a problem in terms of call quality and call reliability.

  In order to solve such a problem, it has been proposed that transmission between the main body portion and the lid side portion is performed using an optical wiring. For example, Patent Document 1 presents an example in which high-speed transmission is secured and electromagnetic interference countermeasures are used as an inter-chassis transmission means using an optical fiber.

Further, Patent Document 2 proposes a solution to the above problem by performing signal transmission between housings by an infrared signal from an infrared module. That is, the light emitting surface of the infrared module connected to one of the two housings faces the light receiving surface of the infrared module connected to the other housing, and is arranged coaxially with the rotation axis of the bending operation. Has been realized.
JP 2003-244295 A JP 2003-143272 A

  However, Patent Document 1 discloses an example in which an optical fiber is used, but if the optical fiber is made of glass, it is disconnected when bent. On the other hand, since a flexible plastic optical fiber is thick, if it is bent with a small bending radius at the hinge portion, it becomes impossible to confine light. That is, when the folded portion is closed or in the middle of folding, high-speed transmission cannot be performed, which causes a very great restriction on the use of the device. In order to prevent this, if bending is performed with a large bending radius with little optical loss, the thickness at the time of folding is increased, resulting in a problem in portability.

  In addition, recent movements for enhancing the functions of cameras in mobile phones have incorporated rotation operations at the folding section in addition to the mobile phone folding operations. However, in the case of using an optical fiber, not only is the rotation operation restricted, but further restrictions are added to the folding portion, which greatly impairs portability.

  Further, in Patent Document 2, since the separate light emitting module and the receiving module are used facing each other at the hinge portions of the two housings, it is necessary to align the optical axis and the rotational axis at the time of attachment. There were problems such as optical axis misalignment due to long-term use. Furthermore, when exchanging bidirectional signals, two pairs of light emitting / receiving modules must be installed on the rotating shaft, which not only saves space but also takes a lot of time for mounting. It was.

  Further, Patent Document 2 focuses on connecting the housings in the folding operation, and does not assume that the rotating operation is supported in addition to the folding operation. In other words, in order to operate the infrared module, it is necessary to supply power. When power is supplied from the casing, a power line is required, which restricts the rotational operation, and In the case of incorporating a battery, a battery arrangement space is required, a connection portion is increased, and the size and thickness of the battery are affected. This impairs portability.

  In order to solve the above problems, the present invention provides an optical transmission module that can rotate even with respect to a plurality of rotating shafts, and by using this, a portable information device that is very thin and can handle various operations such as rotation. The purpose is to provide.

  In order to achieve the above object, a first light transmission module of the present invention includes a light emitting element, a light receiving element, a plurality of mirrors arranged between the light emitting element and the light receiving element and deflecting light by approximately 90 °, An optical transmission module comprising an optical transmission path connecting between the light emitting element and the mirror, between the plurality of mirrors, and between the mirrors of the light receiving element, and is rotatable between the plurality of mirrors around the transmission direction. It is characterized by connecting to. With such a configuration, it is possible to rotate in a plurality of directions, and light transmission without optical loss can be performed even when bent and rotated.

  Furthermore, the second optical transmission module of the present invention is characterized in that the mirror and the optical transmission line are connected so as to be rotatable about the transmission direction. By adopting such a configuration, it is possible to connect to be rotatable about the transmission direction without taking up a large space.

  Furthermore, the third optical transmission module of the present invention is characterized in that the optical transmission path is an optical fiber. With such a configuration, the optical transmission path can be made flexible, the installation of the optical transmission module can be facilitated, and the influence of the optical transmission path due to rotation can be prevented.

  Furthermore, the fourth optical transmission module of the present invention is characterized in that the mirror is a condenser mirror. With such a configuration, the transmission light can be condensed, the positioning accuracy of the mirror and the optical transmission path at the connection portion can be relaxed, and the connection between the mirror and the optical transmission path can be facilitated.

  Furthermore, the fifth light transmission module of the present invention is a device in which a condensing lens is disposed between the mirror and the light transmission path. With such a configuration, the transmission light can be condensed, the positioning accuracy of the mirror and the optical transmission path at the connection portion can be relaxed, and the connection between the mirror and the optical transmission path can be facilitated.

  Furthermore, the sixth optical transmission module of the present invention is characterized in that a liquid having the same refractive index as that of the core of the optical fiber is filled between the mirror and the optical transmission path. By adopting such a configuration, reflection on the surface of the optical transmission line at the connection portion can be prevented, and light loss can be prevented. In addition, the lubrication effect of the liquid smoothes the rotation and improves the reliability of the optical transmission module.

  Further, the seventh light transmission module of the present invention is characterized in that the light emitting element is a surface light emitting type and the light receiving element is a surface light receiving type. This facilitates connection of the optical transmission line.

  Furthermore, the eighth optical transmission module of the present invention is characterized in that the light emitting element and the optical transmission path, the light receiving element and the optical transmission path, and the mirror and the optical transmission path are each connected and fixed with an optically transparent adhesive. It is what. By adopting such a configuration, it is possible to connect without requiring an optical connector, and it is possible to reduce the size of the optical transmission module.

  Furthermore, the ninth optical transmission module of the present invention is characterized in that the light emitting element is mounted on the first sub board and the light receiving element is mounted on the second sub board. With such a configuration, the board can be easily connected by mounting the sub board on the board.

  Furthermore, the 10th optical transmission module of this invention is characterized by the 1st sub board and the 2nd sub board being equipped with the electrical connector. With such a configuration, the electrical connection between the sub-board and the board can be simplified and mounted easily.

  Furthermore, the eleventh optical transmission module of the present invention is characterized in that the first sub board and the second sub board each include a light emitting element and a light receiving element. This enables bidirectional optical transmission between boards.

  A first portable information device according to the present invention includes an upper housing, a lower housing, and a portable information device having a hinge part having a folding opening / closing mechanism that connects the two housings. The second board arranged in the first housing and the first board arranged in the lower casing by using any one of the first and first to eleventh optical transmission modules of the present invention, and the hinge The opening / closing axis of the optical unit and the rotation axis of the optical transmission module are arranged to coincide with each other, and when the upper casing is folded into the lower casing, the rotation axis of the optical transmission module is rotated. It is a feature.

  With such a configuration, it is possible to provide a portable information device that is capable of optical transmission even when the upper and lower housings are opened, folded, and shifted, and has a very thin and high internal transmission speed. Can do.

  Furthermore, the second portable information device of the present invention comprises an upper casing, a lower casing, and a coupling body, a hinge section that connects the upper and lower casings and has a folding opening / closing mechanism, and a coupling body that has a rotation mechanism. In the portable information device comprising: the first board of the present invention, the second board arranged inside the upper housing, the first board arranged inside the lower housing, and the coupling body. 11 is connected with one of the optical transmission modules, the open / close rotation axis of the hinge portion and the first rotation axis of the optical transmission module are aligned with each other, and the optical transmission is performed on the rotation axis of the coupling body. The second rotation axis of the module is arranged so as to coincide with each other, and when the upper casing is folded into the lower casing, the upper casing rotates with the first rotation axis arranged in the hinge portion. However, when rotating relative to the lower casing, Is characterized in that the rotating in the second rotation axis.

  With such a configuration, a portable information device that can transmit light even when the upper and lower housings are opened and closed and rotated, is extremely thin, can have various shapes, and has a high internal transmission speed. Can be provided.

  According to the optical transmission module of the present invention and the portable information device using the optical transmission module, the inter-board wiring having high speed, no electromagnetic interference and mounting on the board is realized. A thin portable information device that can rotate without restriction can be realized.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a configuration of an optical transmission module of the present invention. A light emitting element 11, a light receiving element 12, two mirrors 13a and 13b arranged between the light emitting element 11 and the light receiving element 12 and deflecting light by approximately 90 °, and between the light emitting element and the mirror and the plurality of mirrors Between the mirrors of the light receiving element and the optical transmission path 14b. The optical transmission path 14b is rotated about the two mirrors 13a and 13b by the rotary joints 15a and 15b about the axis XX. Connect as possible.

  That is, the optical signal emitted from the light emitting element 11 passes through the optical transmission path 14a and enters the mirror 13a. The optical signal deflected and reflected by approximately 90 ° by the mirror 13a travels to the optical transmission path 14b connected to the rotary joint 15a, enters the mirror 13b connected to the rotary joint 15b, is again deflected and reflected by approximately 90 °, and the optical transmission path. The light passes through 14 c and enters the light receiving element 12. In this way, the optical signal emitted from the light emitting element 11 can be transmitted to the light receiving element 12 connected rotatably.

  With such a configuration, it is only necessary to arrange a pair of mirrors and a single optical transmission path on the rotation axis, and little space is required for the rotating part. The light-emitting element 11 and the light-receiving element 12 are light transmission modules that can be arranged at convenient locations and are very compact and easy to mount.

  The light emitting element and the light receiving element are not particularly limited, but a surface light emitting element or a surface light receiving element is optimal. The surface emitting light emitting element and the surface light receiving light receiving element can ease the mounting cost because the alignment accuracy with the optical transmission path can be relaxed by about one digit, compared to the end face light emitting element and the end face light receiving element. In addition, a surface emitting laser (VCSEL), which is one of the surface emitting elements, is capable of low current drive and high speed drive, so that it can realize optical transmission of several Gbps to several tens of Gbps with low power consumption. is there.

  The optical transmission line is not particularly limited, but an optical fiber is suitable because it is rich in flexibility, has a good dimensional accuracy in the diameter direction, and has no axis misalignment during rotation. Commercially available quartz optical fibers and plastic optical fibers can be used.

  When considering mounting the optical transmission module of the present invention on a portable information device, a transmission distance of about 10 cm is sufficient. For example, for transmission with a commercially available aperture of 1 mm (core diameter of 0.98 mm) This plastic optical fiber is optimal because it is flexible, easy to handle, and easy to align the optical axis. As the mirror, a total reflection type using a prism, a reflection type in which a metal film is formed on a reflection surface, or the like can be used.

  Next, the rotary joint portion will be described with reference to FIG. FIG. 2 is an example of a rotary joint, and is not limited to this figure.

  FIG. 2A is a schematic cross-sectional view when the optical transmission line 22 b is connected to the prism 23 by the rotary joint 21. The optical transmission path 22b is held by a rotation holding body 24, and the rotation holding body 24 is rotatably held by a holder 26 bonded to the prism 23 via a bearing 25a. The rotation holder 24 is rotatably held by the holder 26b and the cover 27 via the bearing 25b while being restricted in the axial direction. With such a structure, the optical transmission line 22 b is held without being in contact with the prism 23.

  Here, an optical signal emitted from a light emitting element (not shown) enters the prism 23 through the optical transmission path 22a, is totally reflected by the inclined surface 28 of the prism, is deflected by 90 °, and is rotatably connected. The light enters the transmission path 22b and transmits an optical signal. The optical transmission line 22a is connected and fixed to the prism 23 together with the holder 26a.

  The optical transmission line 22b and the prism 23 are opposed to each other with a gap 29 therebetween. The gap 29 is preferably as small as possible in order to prevent light loss as long as the optical transmission path 22b and the prism 23 do not contact each other, preferably 500 microns or less, and more preferably 100 microns or less.

  Further, by filling a liquid having the same refractive index as that of the optical transmission path (core in the case of an optical fiber), reflection on the surface can be prevented, and light loss at the connection portion can be further prevented. Further, the rotational reliability can be increased by the lubricating action of the liquid.

  Such liquids include paraffinic oil, ester oil, fluorine oil, and silicon oil, and may be selected according to the refractive index of the optical transmission line used.

  For example, when using a plastic fiber having an acrylic resin as a core, the refractive index of the acrylic resin is about 1.49, so it is suitable to use an ester oil having a refractive index of 1.4 to 1.6. It is possible to adjust the refractive index with high accuracy by mixing ester oils having different groups. Moreover, since ester oil is excellent in lubrication characteristics, it can be expected to obtain high rotational reliability.

  The light emitting element and the optical transmission path, the light receiving element and the optical transmission path, and the mirror and the optical transmission path are connected and fixed with an optically transparent adhesive to the wavelength of the light used. As the adhesive, an ultraviolet curing type is optimal because it can be easily bonded in a short time. Further, the refractive index may be adjusted by fluorination (lower refractive index) and sulfurization (higher refractive index).

  FIG. 2B shows the structure of the rotary joint portion in which the condenser lens 211 is disposed between the optical transmission path and the prism. By disposing the condenser lens 211, light loss due to connection can be prevented, the tolerance of positional accuracy at the time of connection is increased, and mounting is facilitated. In this figure, the condensing lens is arranged on both the incident side and the exit side of the prism, but it can be used only on one side.

  FIG. 2C illustrates a cross-sectional structure of a rotary joint portion in which a concave condensing mirror 212 is disposed instead of a prism. In this case, similarly to the condensing lens, optical loss due to connection can be prevented, the tolerance of positional accuracy at the time of connection can be increased, and the number of parts can be reduced.

  In FIG. 1, a rotary joint is used at both ends of the optical transmission line 14b, but a rotary joint can be used only at one end of the optical transmission line.

  As a result of 10 Gbps signal transmission using a 10 cm long optical fiber and a rotary joint having the structure shown in FIG. 2 (a), sufficient transmission can be confirmed, and performance degradation even when rotated. Was not seen at all. Similar results were obtained when the gap between the rotary joints was filled with oil adjusted to have the same refractive index as the core of the optical fiber. Further, similar results could be obtained when the rotary joint having the structure shown in FIGS. 2B and 2C was used.

  The polarization angle of the mirror can be selected according to the design of the rotary joint part, and is preferably 90 ± 10 °. By setting the polarization angle within this range, it is possible to prevent the optical transmission path from interfering with the rotation axis, to facilitate connection within the allowable bending radius of the fiber, and to suppress bending loss. In addition, the size of the rotating part including the mirror can be reduced, which is effective for the miniaturization design of the portable terminal device.

(Embodiment 2)
FIG. 3 shows a configuration diagram of the second optical transmission module of the present invention.

  In this case, the optical transmission module is rotatable about two axes X and Y. Using rotation joints 35a, 35b, 35c, and 35d, mirrors 33a, 33b, and 33c deflecting approximately 90 ° are connected to both ends of optical fibers 34b and 34c to form an optical transmission path that can rotate in two axial directions. The light emitting element 31 is connected to the incident side of the mirror 33a via an optical fiber 34a, and the light receiving element 32 is connected to the exit surface of the mirror 33c on the outgoing side via an optical fiber 34d.

  The light emitting element and the optical transmission path, the light receiving element and the optical transmission path, and the mirror and the optical transmission path are connected and fixed with an optically transparent adhesive at the wavelength of the light used, respectively, as in the first embodiment. It is.

  The optical signal emitted from the light emitting element 31 passes through the optical fiber 34a and enters the mirror 33a. The optical signal deflected and reflected by about 90 ° by the mirror 33a travels to the optical fiber 34b connected to the rotary joint 35a, enters the mirror 33b connected to the rotary joint 35b, is again reflected and reflected by about 90 °, and is connected to the rotary joint 35c. The optical signal that has passed through the optical fiber 34c, entered the mirror 33c connected to the rotary joint 35d, and deflected and reflected by approximately 90 ° by the mirror 33c enters the light receiving element 32 through the optical fiber 34d.

  In this way, the optical signal emitted from the light emitting element 31 can be transmitted to the light receiving element 32 through the optical transmission path connected so as to be biaxially rotatable.

  With such a configuration, the light emitting element 31 and the light receiving element 32 can be arranged at arbitrary positions, and the mirrors 33a, 33b, 33c and the optical fibers 34b, 34c need only be arranged on the rotation axes X, Y. This is a very compact optical transmission module that requires little space in the rotating part.

  Further, as in the first embodiment, the optical transmission module of the present invention is physically connected, so that there was no signal variation during rotation due to repeated rotation operations.

(Embodiment 3)
FIG. 4 is a diagram showing an embodiment of an optical transmission module when a light emitting / receiving element is mounted on a sub board.

  The optical module 41 shown in the first embodiment, the first sub board 43 on which the light emitting element 42 is mounted, and the second sub board 45 on which the light receiving element 44 is mounted. Each of the first and second sub-boards has electrical connectors 46 and 47 on the back surface.

  The light receiving element and the light emitting element are mounted on the sub-boards 43 and 45 by flip chip mounting or wire bonding, and are fixed to the optical fibers 48a and 48b, the light emitting element 42, and the light receiving element 43 with a transparent adhesive at the used wavelength. .

  For adhesion, after adjusting the light emitting / receiving element and the optical fiber to the optimum position, an ultraviolet curing adhesive was dropped and fixed by irradiating with ultraviolet rays for 2 minutes.

(Embodiment 4)
FIG. 5 is a diagram illustrating a form in which the optical transmission module 51 of FIG. 4 manufactured in the fourth embodiment is used to connect between two main boards 51 and 52. The light transmission module 51 is attached to the main boards 52 and 53 by electrical connectors 54 and 55 on the back surface, respectively.

  By adopting such a form, it is not necessary to provide optical wiring on the main boards 52 and 53, and therefore, the same material and process as those of the conventional printed circuit board may be used, and there are no restrictions on optical circuit wiring. . Only a light emitting element, an electric circuit attached to the light receiving element, and a power supply line need only be added. A circuit attached to the light emitting / receiving element, for example, a drive circuit or a signal amplifier circuit may be provided on either the sub board or the board. When performing high-speed transmission at Gbps or higher, it is desirable to use a sub-board material as a high frequency substrate such as FR4 or ceramic, and to provide a drive circuit, signal amplification, and processing circuit thereon from the viewpoint of shortening the wiring.

  Although the optical transmission module of this embodiment has an electrical connector, the sub board may be directly mounted on the main board without using the electrical connector. Use of an electrical connector is convenient because it can be freely attached and detached.

  In the present embodiment, the electrical connectors 54 and 55 are arranged on the back surface of the sub boards 56 and 57, but they may be provided on the same side as the light emitting element and the light receiving element. When it is provided on the back surface, it is desirable to establish electrical continuity with the electrical connector through vias penetrating the front and back surfaces.

  As a procedure for producing the optical transmission module of the present invention, it is desirable to mount the light receiving element, the light emitting element, and the electrical connector on the sub board, and finally fix the light transmission component, the light receiving element, and the light emitting element with a transparent adhesive. . According to such a procedure, since the solder reflow process is not performed, the optical transmission component only needs to have heat resistance that can withstand the use environment. Thereby, a commercially available plastic optical fiber can be used as the optical transmission line.

  In FIG. 5, a light emitting element is mounted on the first sub board and a light receiving element is mounted on the second sub board. However, the light receiving element and the light emitting element are respectively mounted on the first sub board and the second sub board. If both are mounted and light-emitting elements having different wavelengths are selected and bidirectional communication is performed by wavelength multiplexing, bidirectional communication is possible even with a single optical transmission component. This is very effective for mounting on a device that allows only a limited space.

(Embodiment 5)
FIG. 6 is a schematic configuration diagram of the portable information device of the present invention. Among these, (a) is an external view. This is basically the same as a general folding cellular phone, and the lower housing 61 and the upper housing 62 are connected by a hinge portion 63 in the bending direction. A display unit 64 is disposed in the upper housing 61. A plurality of display units may be provided in the upper housing. A camera 65 can also be disposed on the back surface of the upper housing. A plurality of cameras may be provided in the upper housing. The upper casing can be freely bent with respect to the lower casing by the hinge part 63.

  On the other hand, (b) is a diagram showing the internal configuration of the portable information device of the present invention.

  Within the lower housing is a first main board 66 and a first sub board 68 connected to it via an electrical connector (not shown). Similarly, a second main board 67 and a second sub board 69 are provided on the upper housing side. A power source (not shown) is electrically connected to the first main board.

  The first sub board 68 and the second sub board 69 are optically connected by the optical transmission module 611 described in the first embodiment. This has been described above as the optical transmission module of the present invention.

  Here, (c) is an enlarged perspective view of the vicinity of the hinge portion. An optical fiber 613 having 90 ° deflection mirrors 612a and 612b coupled to both ends by a rotary joint is arranged in accordance with the rotation axis XX of the hinge portion.

  The mirror 612a is fixed inside the lower casing, and the mirror 612b is fixed inside the upper casing. Since the mirrors are connected by a flexible optical fiber, the tolerance for alignment with the rotation axis XX is large and mounting is easy. When the upper housing is folded onto the lower housing, the optical signal can be transmitted without optical loss because the upper housing is rotated by the rotary joint.

  In this embodiment, a power source (not shown) is arranged on the first main board in the lower housing and electric wiring is used for the upper board. However, since several wires are sufficient, the required space is also small. , The degree of freedom of arrangement is great and does not hinder downsizing and thinning. Further, another power source may be provided in the upper housing. In this case, the electrical wiring is also unnecessary.

  With such an arrangement, the internal transmission speed can be maintained regardless of the shape of the casing, and the operation can be performed without impairing the functions of the display unit and the camera. In particular, since the optical transmission module of the present invention does not cause an optical loss even by a bending operation, the portable information device of the present invention on which the optical transmission module is mounted has a feature that the thickness of the device when folded can be made very thin. Even if the antenna is laid out near the optical wiring, no problem is caused.

(Embodiment 6)
FIG. 7 is a schematic configuration diagram of a second portable information device of the present invention. Among these, (a) is an external view. This is basically the same as a general foldable mobile phone, and a lower casing 71 and an upper casing 72 are connected by a hinge 73 in a bending direction and a connecting body 74 in a rotating direction. A display unit 75 is disposed in the upper housing 72. A plurality of display units may be provided in the upper housing. A camera 76 can also be disposed on the upper housing 72 on the back surface of the upper housing. A plurality of cameras may be provided in the upper housing. The upper casing can be freely bent or rotated with respect to the lower casing by the hinge portion 73 and the connecting body 74.

  On the other hand, (b) is a diagram showing the internal configuration of the portable information device of the present invention.

  Within the lower housing is a first main board 77 and a first sub-board 78 connected to it via an electrical connector (not shown). Similarly, a second main board 79 and a second sub board 710 are provided on the upper housing side. Power supplies 711 and 712 are electrically connected to the first and second main boards.

  The first sub board 78 and the second sub board 710 are optically connected by the optical transmission module 713 described in the second embodiment. This has been described above as the optical transmission module of the present invention.

  (C) is an enlarged perspective view of the vicinity of the hinge portion. An optical fiber 715a to which 90 ° deflection mirrors 714a and 714b are connected at both ends according to the rotation axis XX of the coupling body 74 is arranged, and both ends according to the folding axis YY of the hinge portion. An optical fiber 715b to which 90 ° deflection mirrors 714b and 714c coupled to each other by a rotary joint are connected is disposed.

  The mirror 714a is fixed inside the lower casing, the mirror 714b is fixed inside the coupling body, and the mirror 714c is fixed inside the upper casing. Since the mirrors are connected by a flexible optical fiber, the tolerance for alignment with the rotating shaft is large and mounting is easy. Moreover, since it is physically connected, the optical axis does not shift by rotation.

  When the upper housing is folded onto the lower housing, the upper housing rotates around the folding rotation axis Y-Y, and rotates at both ends of the optical fiber 715b with rotary joints. When rotating on the side casing, the upper casing rotates about the rotation axis XX and rotates at both ends of the optical fiber 715a by rotating joints. Therefore, the light emitting element on the first sub board 78 The optical signal emitted from 716 passes through the optical fiber 715a, is reflected by the 90 ° deflection mirror 714a, passes through the optical fiber 715b, is reflected by the 90 ° deflection mirror 714b, passes through the optical fiber 715c, and is reflected by the 90 ° deflection mirror 714c, The light enters the light receiving element 717 on the second sub board 710 through the optical fiber 715d. With such a structure, the optical signal can be transmitted without increasing the optical loss by the folding operation and the rotating operation.

  In this way, the hinge part and the coupling body need only have an optical transmission line composed of an optical fiber and a mirror, no light emitting and receiving elements need be arranged, and no electrical wiring is required. The degree of freedom can be large and small, and portable information devices can be made smaller and thinner.

  Even when the power supply is arranged only on the first main board in the lower casing, the power supply to the second main board in the upper casing may be several wires, so the required space is small. , The degree of freedom of arrangement is great and does not hinder downsizing and thinning.

  With such an arrangement, the internal transmission speed is maintained even when the casing is bent and rotated in any shape, and the operation is performed without impairing the functions of the display unit and the camera. In particular, the optical transmission module of the present invention only has to place an optical fiber and a mirror at the hinge portion, and the portable information device of the present invention equipped with the optical transmission module has a feature that the thickness of the device when folded can be made very thin. In addition, since the upper and lower housings are connected by optical wiring, high-speed transmission is possible, which is advantageous for the multi-function and high performance of the display unit / camera unit. Similarly to the fifth embodiment, no electromagnetic noise is generated from the wiring, or transmission is not affected by the electromagnetic noise, so that no problem is caused even if the antenna is laid out near the wiring.

  As described above, in the portable information device of the present invention, it is sufficient that a thin optical wiring is passed through the hinge portion, and the electrical connector that is bulky with the coaxial wiring is not necessary, so that the mechanical restrictions are small, and the hinge portion It has the advantage of being able to introduce a hinge mechanism that is advantageous for miniaturization and has a high degree of freedom. Needless to say, high-speed transmission between housings is possible and the EMC resistance is extremely high. As a result, the antenna sensitivity can be increased, and the antenna can be downsized or the number of electrical shield parts can be reduced.

  As described above, the optical transmission module of the present invention is most suitable for use as a connection between housings of a folded mobile phone, but it has a high degree of freedom in applications where optical wiring is introduced at an arbitrary position in the board. It is suitable.

  The optical transmission line module and the portable information device using the same according to the present invention realize high-speed transmission between housings inside the device and flexible bending and rotation between the housings. It is particularly suitable for portable information devices such as mobile phones and notebook computers that require both multifunctionality and thinning.

Configuration diagram of optical transmission module of the present invention in Embodiment 1 The figure which shows the cross-section of the rotation joint part of the optical transmission module of this invention in Embodiment 1. Configuration diagram of optical transmission module of the present invention in Embodiment 2 The figure which shows the structure of the optical transmission module of this invention in Embodiment 3. FIG. The figure showing the connection condition of the optical transmission module of this invention and main board in Embodiment 4 Configuration diagram of portable information device of the present invention in Embodiment 5 Configuration schematic diagram of portable information device of the present invention in Embodiment 6

Explanation of symbols

11, 31, 42, 716 Light emitting element 12, 32, 44, 717 Light receiving element 13a, 13b, 33a, 33b, 33c Mirror 14a, 14b, 14c, 22a, 22b Optical transmission line 15a, 15b, 21, 35a, 35b, 35c, 35d Rotating joint 23 Prism 24 Rotating holder 25a, 25b Bearing 26a, 26b Holder 27 Cover 28 Prism slope 29 Gap 211 Condensing lens 212 Condensing mirror 34a, 34b, 34c, 34d, 48a, 48b, 613, 715a , 715b, 715c Optical fiber 41, 51, 611, 713 Optical transmission module 43, 45, 56, 57, 68, 69, 78, 710 Subboard 46, 47, 54, 55 Electrical connector 52, 53, 66, 67, 77 79 Main board 61 71 the lower housing 62 and 72 upper housing 63, 73 hinge portions 64,75 the display unit 65 and 76 the camera 611 receiving element 612a, 612b, 714a, 714b, 714c 90 ° polarizing mirror 74 connecting bodies 711 and 712 supply

Claims (13)

A light emitting element;
A light receiving element;
A plurality of mirrors arranged between the light emitting element and the light receiving element and deflecting light by approximately 90 °;
An optical transmission module comprising an optical transmission path connecting the light emitting element and the mirror, the plurality of mirrors and the mirror of the light receiving element;
An optical transmission module, wherein the plurality of mirrors are connected so as to be rotatable about a transmission direction. The optical transmission module according to claim 1, wherein the mirror and the optical transmission path are rotatably connected around a transmission direction as an axis. The optical transmission module according to claim 1, wherein the optical transmission path is an optical fiber. The optical transmission module according to claim 1, wherein the mirror is a condensing mirror. The optical transmission module according to claim 1, wherein a condensing lens is disposed between the mirror and the optical transmission path. The optical transmission module according to claim 1, wherein a liquid having the same refractive index as that of an optical fiber core is filled between the mirror and the optical transmission path. The light transmission module according to claim 1, wherein the light emitting element is a surface light emitting type and the light receiving element is a surface light receiving type. 8. The optical transmission module according to claim 7, wherein the light emitting element and the optical transmission path, the light receiving element and the optical transmission path, and the mirror and the optical transmission path are each connected and fixed with an optically transparent adhesive. 9. The optical transmission module according to claim 1, wherein the light emitting element is mounted on a first sub board, and the light receiving element is mounted on a second sub board. The optical transmission module according to claim 9, wherein the first sub board and the second sub board include electrical connectors. The optical transmission module according to claim 1, wherein each of the first sub board and the second sub board includes a light emitting element and a light receiving element. In the portable information device provided with a hinge part having a folding opening and closing mechanism while connecting the upper casing and the lower casing to both casings,
The second board arranged inside the upper housing and the first board arranged inside the lower housing are connected by the optical transmission module according to any one of claims 1 to 11, An opening / closing axis of the hinge part and a rotation axis of the optical transmission module are arranged to coincide with each other, and when the upper casing is folded to the lower casing, the rotation axis of the optical transmission module is rotated. A portable information device characterized by In a portable information device comprising an upper casing, a lower casing, and a connecting body, including a hinge portion having a folding opening / closing mechanism, and a connecting body having a rotation mechanism,
The optical transmission module according to any one of claims 1 to 11, wherein the second board disposed inside the upper housing, the first board disposed inside the lower housing, and the coupling body. Connected, the opening / closing axis of the hinge portion and the first rotation axis of the optical transmission module are aligned and the rotation axis of the coupling body is aligned with the second rotation axis of the optical transmission module And when the upper casing is folded into the lower casing, the upper casing rotates around the first rotation axis of the optical transmission module disposed in the hinge portion. When rotating with respect to a housing | casing, it rotates in the 2nd rotating shaft of the said optical transmission module arrange | positioned at the said coupling body, The portable information device characterized by the above-mentioned.

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