JP3752981B2 - Optical signal transmission device, optical data bus system, and signal processing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical signal transmission device, an optical data bus system, and a signal processing device. More specifically, the present invention relates to an optical signal transmission device that emits an incident optical signal in a branched state, and the optical signal transmission device. The present invention relates to an optical data bus system and a signal processing device used.
[0002]
[Prior art]
With the development of very large scale integrated circuits (VLSI), the circuit functions of circuit boards (daughter boards) used in data processing systems have increased significantly. As the circuit function increases, the number of signal connections to each circuit board increases, so a data bus board (motherboard) that connects each circuit board (daughter board) with a bus structure requires a large number of connection connectors and connection lines. A parallel architecture is adopted. Although parallel buses have been improved by increasing the number of connection lines and paralleling them, parallel bus operation speeds have been improved. However, the system processing speed has been increased in parallel due to signal delays due to inter-connection wiring capacitance and connection wiring resistance. It may be limited by the operating speed of the bus. In addition, the problem of electromagnetic interference (EMI) due to the high density of parallel bus connection wiring is also a major limitation to the improvement of the processing speed of the system.
[0003]
In order to solve such problems and to improve the operation speed of the parallel bus, it has been studied to use an in-system optical connection technique called optical interconnection. An overview of optical interconnection technology is described in Uchida, Circuit Implementation Conference 15C01, p.201-202 and H.Tomimuro et al, IEEE Tokyo Section Denshi Tokyo No.33 p.81-86 (1994). Similarly, various forms have been proposed depending on the configuration contents of the system.
[0004]
Of various types of optical interconnection technologies proposed in the past, Japanese Patent Application Laid-Open No. 2-41042 has devised an optical data transmission system using a light emitting / receiving device. In JP-A-2-41042, light emitting / receiving devices are arranged on both front and back surfaces of each circuit board, and light emitting / receiving devices on adjacent circuit boards incorporated in a system frame are spatially coupled with light, A serial optical data bus has been proposed for loop transmission between circuit boards. In this method, an optical signal sent from a certain circuit board is optically / electrically converted by an adjacent circuit board, and is further electrically / optically converted by the circuit board, and then the optical signal is sent to the adjacent circuit board. Each circuit board is sequentially arranged in series and transmitted between all circuit boards incorporated in the system frame while repeating photoelectric conversion and electrical / optical conversion on each circuit board. For this reason, the signal transmission speed depends on the optical / electrical conversion / electrical / optical conversion speed of the light-receiving / light-emitting device arranged on each circuit board, and at the same time, is restricted. In addition, data transmission between each circuit board uses optical coupling with free space by light receiving / light emitting devices arranged on each circuit board, so interference between adjacent optical data transmission paths (Crosstalk) occurs and data transmission failure is expected. It is also expected that a data transmission failure will occur due to scattering of the optical signal due to the environment in the system frame, such as dust.
[0005]
Japanese Patent Application Laid-Open No. 61-196210 devises a method of optically coupling circuit boards through an optical path composed of a diffraction grating and a reflecting element arranged on the plate surface. In this system, since light emitted from one point can be connected to only one fixed point, it is impossible to connect all circuit boards exhaustively like an electric bus.
[0006]
Also, several patents have been devised for data transmission between circuit boards using an optical connecting device having a branch element.
[0007]
Japanese Patent Application Laid-Open No. 58-42333 shows an example of data transmission between circuit boards using a plurality of half mirrors. However, when a plurality of half mirrors are used, the size of the apparatus increases, and each mirror needs to be optically aligned with the light emitting / receiving device. In addition, the transmitted light that has passed through the half mirror has almost half the light intensity with respect to the incident, so if you repeat branching and transmission multiple times, the light intensity becomes weak, and sufficient light intensity at the light receiving device is obtained. There is a problem that signal transmission becomes impossible.
[0008]
Japanese Patent Application Laid-Open No. 4-134415 has devised a system in which an optical signal is incident from a side surface of a lens array in which a plurality of lenses are formed and is emitted from each lens. In this method, the closer the lens is to the incident position of light, the larger the amount of emitted light, so there is a concern about variations in the intensity of the emitted signal due to the positional relationship between the incident position and the emitted position. In addition, since the rate at which light incident from the side faces escapes from the opposite side faces is high, the utilization efficiency of the incident light amount is low.
[0009]
Japanese Patent Application Laid-Open No. 63-1223 discloses an optical bus system using an optical fiber capable of transmitting a substantially uniform optical signal by increasing the branching ratio sequentially from the input end. A method of forming a coupler applicable to such a system is described in IEEE Photonics Technology Letters, vol. 8, No. 12, December (1996). The method for forming a coupler shown here branches by a V-groove formed in an optical fiber. It is considered possible to adjust the output light amount by adjusting the size of the V-groove, but the production is very difficult and the utilization efficiency of the incident light amount is low.
[0010]
A star coupler that equalizes the intensity of the branched optical signal is disclosed in Japanese Patent Laid-Open No. 9-184941. In general, this star coupler bundles and fixes one end of a plurality of optical fibers, a light guide path wide enough to cover the plurality of optical fibers is abutted on one end face, and a light reflecting means is provided on the other end face. I have.
[0011]
When data transmission between circuit boards is performed using such a coupler, the number of fibers connected to the light emitting / receiving elements increases as the number of connection boards increases, which complicates the configuration and increases the size of the apparatus. Occurs.
[0012]
[Problems to be solved by the invention]
In view of the above circumstances, the present invention provides an optical signal transmission device that is easy to configure, an optical data bus system that uses a plurality of the optical signal transmission devices, and a signal that performs signal processing including transmission and reception of data including the optical data bus. An object is to provide a processing apparatus.
[0013]
[Means for Solving the Problems]
To achieve the above object, the present invention provides an optical signal formed by providing a plurality of steps at one end. For incident or exit or for entrance and exit A translucent medium having a plurality of incident / exit parts, and a reflecting means disposed at the other end of the translucent medium and reflecting an optical signal incident from the incident / exit parts in the direction of the plurality of incident / exit parts An optical signal transmission device comprising:
[0014]
That is, an incident / exit part is formed at one end of the translucent medium by providing a plurality of steps. The plurality of incident / exit portions are formed by providing a plurality of steps in a step shape at one end of the translucent medium. The other end of the translucent medium is provided with a reflecting means for reflecting the optical signal incident from the incident / exiting part toward the plural incident / exiting parts.
[0015]
Therefore, when an optical signal is incident from one of the multiple incident / exit portions, the optical signal passes through the translucent medium and reaches the reflecting means. The optical signal that has reached the reflecting means is reflected in the direction of a plurality of incident / exit portions.
[0016]
In the present invention, the side surface of the translucent medium reflects the optical signal other than the optical signal directly incident on the incident / exiting portion out of the optical signal reflected by the reflecting means so as to guide it to the incident / exiting portion.
[0017]
Of the optical signals reflected by the reflecting means, not only the optical signal directly incident on the incident / exiting part but also the optical signal other than the optical signal that is directly incident are reflected so as to be guided to the incident / exiting part. Can be high.
[0018]
Here, the step lengths of the plurality of steps formed at one end of the translucent medium may be equalized. Further, when the step length of each of the plurality of steps is L1, and the length from the other end of the translucent medium to the incident / exit portion located at the closest position to the other end is L2, the translucent medium A plurality of steps may be provided so as to satisfy L2 ≧ L1.
[0019]
Further, the entrance / exit section of the translucent medium reflects the incident optical signal in the direction of the reflecting means and reflects the optical signal reflected from the reflecting means and the side surface in the direction opposite to the incident direction. Also good. In such a case, the surface of the translucent medium serving as the incident / exit section is formed to be 45 ° with respect to the upper surface of the translucent medium. It is desirable to set the surface to be the incident / exit part to be a total reflection surface. Then, at least one of the plurality of incident / exit portions may reflect the optical signal in a direction different from the reflection direction of the other incident / exit portions.
[0020]
Further, the side surface of the translucent medium reflects an optical signal reflected by the reflecting means other than the optical signal directly incident on the incident / exiting part so as to be guided to the entire plurality of incident / exiting parts. May be.
[0021]
For example, when the diffusion angle of the light diffusing means is 2θ and the maximum prospective angle when the incident / exit portion that is closest to the diffusing means is viewed from the light diffusing means is 2θ ′, the translucent medium satisfies tanθ ≧ tan3θ ′. You may comprise so that a relationship may be satisfy | filled. Further, the translucent medium may be configured to satisfy the relation of θ ≦ φ when the diffusion angle of the light diffusing means is 2θ and the numerical aperture of the translucent medium is sinφ.
[0022]
In this way, since the optical signal reflected by the reflecting means is reflected so that the optical signal other than the optical signal directly incident on the incident / exiting part is guided to the entire plurality of incident / exiting parts, the light utilization efficiency is further improved. Can be improved.
[0023]
The reflection means may diffusely reflect an optical signal incident from the incident / exiting portion in the direction of the plural incident / exiting portions, or may reflect the optical signal specularly.
[0024]
In addition, since the translucent medium has the light incident / exit portions formed by providing a plurality of steps at one end, the circuit board can be provided upright on the translucent medium in parallel with each other. It is possible to arrange light receiving and emitting elements provided on the substrate as the light emitting / receiving means so as to face the light incident / exiting portion, thereby facilitating the configuration.
[0025]
Furthermore, it is possible to configure an optical data bus system that transmits data using an optical signal by using the optical signal transmission device of the present invention.
[0026]
At this time, an optical fiber may be connected to a part of the plurality of input / output portions for optical connection with an external device, and the connection portion may be configured as a connector. Or you may provide the connector for connection with an external apparatus in a part of entrance / exit part.
[0027]
In addition, a signal processing device is proposed that includes the optical signal transmission device of the present invention and a circuit board that is disposed opposite to the input / output unit and has input / output means for entering / exiting the optical signal. That is, when an optical signal carrying data is incident on the incident / exit section using the incident / exit means, the optical signal is branched as described above, and is emitted to the outside through the plurality of incident / exit sections. As the incident / exit means, a light emitting element and a light receiving element can be used, but both the light emitting element and the light receiving element may be provided for each of the incident / exit parts, or may be provided individually.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0029]
[First Embodiment]
FIG. 1A shows a schematic configuration diagram of an optical signal transmission device 10 according to the present embodiment. The optical signal transmission device 10 includes a rectangular parallelepiped translucent medium 1 in which a plurality of stepped steps 12 (three in this embodiment) are formed. A reflective light diffusion layer 2 is disposed on one end face of the translucent medium 1. The other end face (a plurality of end faces specified by the step 12) 13 of the translucent medium 1 functions as an incident / exit section.
[0030]
Next, with reference to FIG. 1B, a method of branching the input light of the optical signal transmission device 10 according to the present embodiment will be described.
[0031]
A description will be given of a case where the light is incident from the light incident / exit part 131 and is emitted from the light incident / exit parts 131, 132, 133 and 134 among the plurality of light incident / exit parts 13. The light (for example, collimated laser light) incident from the incident / exit section 131 travels straight in the translucent medium 1, reaches the reflective light diffusion layer 2, and goes up and down (the thickness direction of the translucent medium 1). And diffusely reflected in the left-right direction (width direction of the translucent medium 1). The diffused light that has been diffusely reflected propagates while being reflected by the side surface in the translucent medium 1, and is guided and emitted to the entire entrance / exit portions 131, 132, 133, and 134. Note that the diffusely reflected diffused light includes the diffused light reflected by the side surface of the translucent medium 1, so that only diffused light that is directly incident on the plurality of incident / exit portions (131, 132, 133, 134) is used. Absent.
[0032]
Here, in the present embodiment, the translucent medium 1 reflects an optical signal other than an optical signal whose side surface is directly incident on the plurality of incident / exiting portions (131, 132, 133, 134) to the entire incident / exiting portion. It is configured as follows.
[0033]
That is, when the diffused light diffusely reflected by the reflective light diffusing layer 2 spreads larger than the width of the translucent medium 1, the diffused light is totally reflected on the side surface of the translucent medium 1 at least once. The Therefore, the intensity of the emitted light guided to the incident / exit portions 131, 132, 133, and 134 is made uniform by appropriately selecting the spread angle of the diffused light diffusely reflected by the reflective light diffusion layer 2 in the left-right direction. It becomes possible.
[0034]
In particular, in the present embodiment, the optical signal transmission device 10 is placed on the end face where the reflective light diffusion layer 2 of the translucent medium 1 is disposed, as shown in FIGS. 11 (A) and 11 (B). When the maximum prospective angle to the position where the nearest end portion 13 (135) is formed is 2θ ′, and the spread angle (left-right direction) in the diffusion characteristic of the reflected light diffusion layer 2 is 2θ, tan θ ≧ 3 tan θ ′ It is configured to satisfy the relationship.
[0035]
Thus, by setting tan θ ≧ 3 tan θ ′, the diffused light signal diffused left and right by the reflective light diffusion layer 2 is totally reflected at the side of the translucent medium 1 at least once, and the translucent medium 1 To the other end face, that is, the face having the entrance / exit part. tanθ In the case of <3 tan θ ′, the emitted light intensity at the center is large, the emitted light intensity at the periphery is small, and the uniformity of the emitted light intensity is deteriorated. On the other hand, when tan θ = 3 tan θ ′, as shown in FIG. 11B, the diffused light signal (direct incident light) and the diffused light signal totally reflected on the left and right side surfaces (total reflected incident light) are superimposed. It becomes possible to improve the uniformity of the emitted light intensity.
[0036]
Further, when the divergence angle in the diffusion characteristic of the diffuse reflection part is 2θ and the numerical aperture of the translucent medium is sin φ, the relationship θ ≦ φ is satisfied, that is, the upper and lower surfaces of the translucent medium 1 for the diffused light signal. The angle of incidence on the light can be made larger than the critical angle, diffused light is not emitted to the outside, and all of the diffused light signal can be totally reflected on the upper and lower surfaces of the translucent medium 1 so that the optical signal can be used. Efficiency can be increased.
[0037]
As described above, according to the optical signal transmission device of the present embodiment, it is possible to improve the utilization efficiency of the incident optical signal and to evenly divide the light, and to make the output level uniform in the emission part. .
[0038]
In the embodiment described above, the optical signal transmission device 10 having four (five in FIG. 11) input / output units 13 has been described. However, the number of input / output units 13 is not limited to this, and a plurality of input / output units 13 are formed. It is possible.
[0039]
Further, at the time of input, the collimated laser light does not travel straight through the translucent medium 1 and reaches the reflective light diffusion layer 2 while being totally reflected inside, or the incident light is spread and transmitted. Even when reaching the reflection type light diffusion layer 2 while totally reflecting the inside of the optical medium 1, almost the same emitted light intensity can be obtained.
[0040]
Further, a clad layer (not shown) having a refractive index smaller than that of the translucent medium 1 is disposed on the upper and lower surfaces and the left and right side surfaces (side surfaces in the width direction and the front side) of the translucent medium 1. Is also possible. Thereby, the translucent medium 1 surrounded by the clad layer functions as a core part that forms the light guide path. The translucent medium 1 can be made of a plastic material such as polymethyl methacrylate, polycarbonate, amorphous polyolefin, inorganic glass, or the like, and the stepped step is formed by processing by grinding. Further, in the case of a plastic material, it can also be produced by a method such as injection molding.
[0041]
As the reflective light diffusing layer 2, for example, a beam shaping diffuser: LSD (manufactured by Physical Optics Corporation) is used to control the spread angle in the thickness direction and the spread angle in the width direction of the transmissive medium 1. I do. The transmissive LSD is formed by transferring a hologram surface that diffuses incident light to a predetermined diffusion angle on an epoxy layer disposed on a transparent substrate material such as polycarbonate. The reflective LSD is formed by transferring a hologram surface that diffuses incident light to a predetermined diffusion angle on an epoxy layer of a reflective substrate (for example, a transparent substrate on which Al is deposited) or directly on a transmissive LSD. A reflective surface such as is deposited and formed.
[0042]
[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the present embodiment, since there are the same components as those in the first embodiment described above, the same portions are denoted by the same reference numerals, description thereof will be omitted, and different portions will be described.
[0043]
FIG. 2A shows a schematic configuration of the optical signal transmission device 10 according to the present embodiment. In the second embodiment, the difference from the first embodiment is that the surface of the incident / exit portion 14 corresponding to the incident / exit portion 13 in the first embodiment is 45 ° with respect to the upper surface of the translucent medium 1. It is formed. Therefore, in the second embodiment, light can enter and exit in the vertical direction (upper surface direction) with respect to the translucent medium 1.
[0044]
Next, with reference to FIG. 2B, a method of branching the input light of the optical signal transmission device 10 according to the present embodiment will be described.
[0045]
Here, the case where it enters from the incident / exit part 141 and exits from the incident / exit parts 141, 142, 143, 144 among the plural incident / exit parts (total reflection surfaces) 14 is shown. Incident light (for example, collimated laser light) is totally reflected by the light incident / exiting portion 141, travels straight through the translucent medium 1, reaches the reflective light diffusion layer 2, and is diffusely reflected in the vertical and horizontal directions. .
[0046]
The diffused and diffused light propagates while being reflected by the side surface in the translucent medium 1, is guided to the entire entrance / exit portions 141, 142, 143, and 144, and the entrance / exit portions 141, 142, 143, At 144, the light is totally reflected again and emitted. The function of making the emitted light intensity uniform is the same as in the first embodiment.
[0047]
The incident / exit direction is not limited to the vertical direction (upper surface direction), and may be the vertical direction (lower surface direction) and the width direction (left / right direction). The incident / exit direction can be changed depending on the surface formation direction of the incident / exit portion. is there. For example, as shown in FIGS. 3A to 3D, various incident / exit directions can be combined.
[0048]
3 (A) and 3 (B) show the translucent medium 1 having the same form, and FIG. 3 (B) shows the translucent medium 1 shown in FIG. 3 (A). The direction of the light signal incident / exit is shown (incident from the incident / exit section 142). That is, the incident / exit portions 141 and 143 are formed at a 45 ° angle with respect to the upper surface of the translucent medium 1 so as to be incident in the lower surface direction and emitted in the upper surface direction. A surface is formed at 45 ° with respect to the lower surface of the translucent medium 1 so as to be incident in the direction and emitted from the lower surface.
[0049]
3 (C) and 3 (D) show the translucent medium 1 having the same form, and FIG. 3 (D) shows the translucent medium 1 shown in FIG. 3 (C). The direction of incoming and outgoing light signals is shown. That is, the entrance / exit section 141 is formed at a 45 ° angle with respect to the back side surface of the translucent medium 1 so as to be incident in the left direction and emitted in the right direction. The surface is formed at 45 ° with respect to the lower surface of the translucent medium 1 so as to be incident and emitted from the lower surface, and the incident / exit section 143 is light-transmitted so as to be incident in the lower surface and emitted from the upper surface. The surface is formed at 45 ° with respect to the upper surface of the transparent medium 1, and the incident / exit section 144 has a surface at 45 ° on the front side surface of the translucent medium 1 so as to be incident in the right direction and emitted in the left direction. Is formed.
[0050]
5 and 6, as shown in FIGS. 4A to 4D, in the second embodiment, the total length H1 of the translucent medium 1 is 45 mm, the width H2 is 4 mm, and the thickness H3. Is 1 mm, the distance H4 from the end face where the reflective light diffusing layer 2 is disposed to the nearest incident / exit portion 144 is 30 mm, the stepped step 12 has a length H5 of 5 mm, and the reflective light diffusing layer 2, LSD 0.2 × 40PC-8 in which Al is sputtered as a reflective layer on the opposite surface of the hologram forming surface (LSD substrate back surface) (the spread angle in the thickness direction of diffused light is 0.2 °, the width direction is When the divergence angle is 40 °, the uniformity of the output light efficiency and the output light intensity output from each input / output unit 13 is shown.
[0051]
As shown in FIG. 5, the efficiency of the outgoing light at each incoming / outgoing part is approximately 18% regardless of which incoming / outgoing part is incident (incidents 1 to 4). Further, as shown in FIG. 6, the uniformity of the outgoing light intensity at each incident / outgoing part (((maximum efficiency−minimum efficiency) / (maximum efficiency + minimum efficiency)) × 100 [%]) is approximately 4%. And very good values are obtained.
[0052]
As the light source, an edge-emitting laser diode that emits light having a wavelength of 680 nm is used.
[0053]
8 to 10 show a distance 11 from the end face where the reflective light diffusion layer 2 is disposed to the nearest incident / exit portion 144 when the width of the translucent medium 1 is 4 mm and the thickness is 1 mm. The uniformity of the emitted light intensity in the ray tracing simulation when (L2) and the step length 12 (L1) are changed is shown. As can be understood from FIGS. 8 to 10, as L2 becomes shorter (L2 becomes 40 → 10) and as L1 becomes longer (L1 becomes 15 → 25), the uniformity tends to deteriorate. From the simulation results, it can be understood that the uniformity of the emitted light intensity can be achieved by 10% or less by setting L2 to L1 or more, more preferably about twice or more. In the first embodiment and the second embodiment, the length is determined and the shape is determined based on this result.
[0054]
[Third Embodiment]
Next, a third embodiment of the present invention will be described. Since the present embodiment is the same as the first and second embodiments described above, the same parts are denoted by the same reference numerals and the description thereof is omitted.
[0055]
FIG. 12A shows a schematic configuration of the optical signal transmission device 10 according to the present embodiment. The optical signal transmission device 10 includes a rectangular parallelepiped translucent medium 1 in which a plurality of stepped steps 12 (three in this embodiment) are formed. The plurality of end surfaces specified by the step 12 function as the incident / exit portions 131, 132, 133, and 134. A plurality of end surfaces facing the plurality of end surfaces of the translucent medium 1 are made of a material capable of specular reflection, such as Al (in the present embodiment, each of the incident / exit portions 131, 132, 133, 134). Four) light reflecting layers 4 are formed. Since the positions of the incident / exit portions 131, 132, 133, and 134 with respect to the optical signal transmission device 10 are different from each other, the angles of the respective light reflecting layers 4 are set so that the reflected optical signals are directed toward the entire incident / exit portions. ing.
[0056]
In FIG. 12B, each surface of the incident / exit portions 141, 142, 143, 144 corresponding to each of the incident / exit portions 131, 132, 133, 134 shown in FIG. The optical signal transmission apparatus 10 formed at 45 degrees with respect to the upper surface of FIG. In the optical signal transmission device 10 shown in FIG. 12A, light enters and exits in the horizontal direction (longitudinal direction) with respect to the translucent medium 1, but the optical signal transmission device shown in FIG. 10, light enters and exits the translucent medium 1 in the vertical direction (thickness direction).
[0057]
Next, a method for branching input light of the optical signal transmission device 10 according to the present embodiment will be described. FIG. 12A shows a case where, for example, the light is incident from the light incident / exit part 131 and is emitted from the light incident / exit parts 131, 132, 133, 134 among the plurality of light incident / exit parts 13. Light incident from the incident / exit section 131 (for example, light emitted from the laser diode) travels straight through the translucent medium 1 and reaches the light reflecting layer 4. Usually, laser light is emitted at an emission angle (thickness direction (θ1), width direction (θ2)). When the laser light reaches the light reflecting layer 4, it is reflected by the light reflecting layer at a spread angle of θ1 (thickness direction) and θ2 (width direction). (However, it is assumed that all incident light is reflected by the incident / exit section.)
[0058]
The reflected laser light is propagated while being reflected by the side surface in the translucent medium 1, guided to the entire entrance / exit portions 131, 132, 133, and 134 and emitted. Note that not only the light directly incident on the incident / exit portions 131, 132, 133, and 134 but also the light guided to the incident / exit portions includes light reflected by the side surface of the translucent medium 1.
[0059]
For this reason, when the light reflected by the light reflection layer 4 spreads larger than the width of the translucent medium 1, the laser beam is totally reflected at the side surface of the translucent medium 1 at least once. Accordingly, by appropriately selecting the spread angle (defined by the radiation angle of the laser diode) of the light reflected by the light reflection layer 4 in the left-right direction, the light is guided to the incident / exit portions 131, 132, 133, 134. It is possible to make the emitted light intensity uniform.
[0060]
As described above, in the present embodiment described above, the optical signal transmission device 10 including the four input / output units 131, 132, 133, and 134 has been described, but the number of the input / output units is not limited thereto.
[0061]
Furthermore, a clad layer (not shown) having a refractive index smaller than that of the translucent medium 1 may be disposed on the upper and lower surfaces of the translucent medium 1 and the lateral sides in the width direction. Thereby, the translucent medium 1 surrounded by the clad layer functions as a core part that forms the light guide path.
[0062]
According to the present embodiment, by using a material capable of specular reflection such as Al for the light reflecting layer 4, even if the laser light is spread, a part of the optical signal is transmitted to the translucent medium 1. Transmission to the outside can be prevented.
[0063]
[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. As shown in FIG. 13, the signal processing apparatus according to the present embodiment has a plurality of optical data buses 30 formed by using a plurality of optical signal transmission apparatuses 10 shown in the second embodiment (FIG. 2). The circuit boards 50 are optically connected to each other.
[0064]
That is, in the signal processing device according to the present embodiment, the optical data bus 30 in which a plurality of optical signal transmission devices 10 are mounted in parallel is fixed on the support substrate 20. The length of the stepped step 12 (see FIG. 2) of the optical signal transmission device 10 is determined by the mounting positions of the plurality of circuit boards 50. The distance between each of the plurality of circuit boards 50 is usually the same, but if there is a difference in the distance between the boards, the length 12 of the step is adjusted.
[0065]
A board connector 40 is fixed on the support board 20, and each circuit board 50 is attached to each board connector 40. Further, on the support substrate 20, a power line and electrical signal transmission electrical wiring 21 are provided, and the electrical wiring 21 is a circuit attached to the board connector 40 via the board connector 40. The electronic circuit 51 on the substrate 50 is electrically connected.
[0066]
Each circuit board 50 is provided with a plurality of light emitting / receiving elements 52. When the circuit board 50 is attached to the board connector 40, as shown in FIG. The input / output units 141 to 144 of the optical signal transmission device 10 constituting the optical data bus 30 are arranged to face each other. With this arrangement, each light emitting / receiving element 52 is optically coupled to the optical data bus 30, and an optical signal emitted from a certain light emitting / receiving element 52 is incident on the optical data bus 30 (input / output unit 14). The light is branched as described above, and is received by the other light emitting / receiving elements 52 via the respective incident / exit portions. For example, as indicated by the broken-line arrows in FIG. 18, the optical signal incident from the incident / exit section 141 is reflected by the incident / exit section 141 toward the longitudinal direction of the optical signal device 10 and is again reflected in the reflective layer 4 (FIG. (Not shown), branched at each of the incident / exit portions 141 to 144, reflected toward the light emitting / receiving element 52, and incident on the light emitting / receiving element 52. With this configuration, parallel optical signals composed of a plurality of bits can be transmitted and received, and independent simultaneous transmission and reception can be performed for each bit.
[0067]
[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described. As shown in FIG. 14, a plurality of signal processing apparatuses according to this embodiment are provided by an optical data bus 30 formed by using a plurality of optical signal transmission apparatuses 10 shown in the second embodiment (see FIG. 3). Circuit boards 50 are optically connected to each other.
[0068]
In the signal processing apparatus (FIG. 13) according to the fourth embodiment, the plurality of circuit boards 50 are connected to the support board 20 in the same direction, whereas the signal processing apparatus according to the present embodiment. In FIG. 14, the plurality of circuit boards 50 are different in that they are connected to the front and back surfaces of the support board 20.
[0069]
That is, as shown in FIG. 19, the incident / exit portions 141 and 143 of the optical signal transmission device 10 are formed at an incident / exit portion formed so as to form an angle of 45 ° with respect to the upper surface of the optical signal transmission device 10. The corresponding circuit board 50 is erected on the upper surface side of the optical signal transmission device 10, and the incident / exit portions 142 and 144 of the optical signal transmission device 10 form an angle of 45 ° with respect to the lower surface of the optical signal transmission device 10. The circuit board 50 corresponding to the incident / exiting portion thus formed is erected on the lower surface side of the optical signal transmission device 10.
[0070]
With this arrangement, each light emitting / receiving element 52 is optically coupled to the optical data bus 30, and an optical signal emitted from a certain light emitting / receiving element 52 is incident on the optical data bus 30 (input / output unit 14). The light is branched as described above, and is received by the other light emitting / receiving elements 52 via the respective incident / exit portions. For example, as indicated by the broken-line arrows in FIG. 19, the incident optical signal is reflected by the incident / exiting portion 141 toward the longitudinal direction of the optical signal transmission device 10 and then reflected again by the reflective layer 4 (not shown). After branching, the light is reflected and emitted toward the light-emitting / light-receiving elements 52 facing each other by the incident / exit parts 141 to 144.
[0071]
As described above, in the fourth embodiment and the fifth embodiment, a signal processing device having a plurality of circuit boards is configured using an optical data bus including the present optical signal transmission device. Signal transmission between the circuit boards is possible, and since a translucent material is used as a transmission medium, an optical bus system having high resistance to temperature changes and environmental changes such as dust can be obtained.
[0072]
[Sixth Embodiment]
In the first to fifth embodiments, the light emitting / receiving elements provided on the circuit board as the optical signal input / output means for transmitting / receiving the optical signal to / from the optical signal transmission device are shown. Here, an embodiment will be described in which the optical signal transmission device transmits and receives an optical signal to and from an external device other than a circuit board, such as an image scanner.
[0073]
FIG. 22 is a diagram illustrating a configuration of the signal processing device according to the present embodiment. On the support substrate 20, a plurality (four in this embodiment) of optical signal transmission devices 10 having input / output portions generated by forming a plurality of steps at one end in a step shape are juxtaposed.
[0074]
FIG. 21 shows the plate-like optical signal transmission device 10 used in FIG. The optical signal transmission device 10 has a plurality of stepwise optical signal input / output portions 141 to 144. The surfaces of the input / output portions 142 to 144 that transmit and receive optical signals from the input / output means of the circuit board 50 are formed at an angle of 45 ° with respect to the upper surface of the optical signal transmission device 10, and The surface of the incident / exit section 141 connected to the ends of the optical fibers 181 and 182 for transmission and reception is formed perpendicular to the upper surface of the optical signal transmission device 10.
[0075]
20 is a cross-sectional view showing the configuration of the optical signal device shown in FIG. Each of the plurality of circuit boards 50 is provided with a plurality of light emitting / receiving elements 52, and light input / output sections 142, 143, 144 out of a plurality of light input / output sections of the light emitting / receiving elements 52 and the optical signal transmission device 10. A plurality of circuit boards 50 are erected in parallel with each other on the optical signal transmission device so as to face each other.
[0076]
An input optical fiber 181 and an output optical fiber 182 are connected to the input / output unit 141 of the optical signal transmission device 10 in order to transmit and receive optical signals to and from an external device. The optical fibers 181 and 182 are connected to one of the connectors 184 fixed on the support substrate 20. The other end of the connector 184 is connected to an optical fiber that transmits and receives an optical signal from an external device.
[0077]
When an optical signal is transmitted from an external device via the optical fiber 181, the optical signal is incident on the optical signal transmission device 10 from the incident unit 141. When an optical signal is incident on the optical signal transmission device 10 from the other incident / exit units 142 to 144, the optical signal emitted from the incident / exit unit 141 is transmitted to the external device via the optical fiber 182. The incident and exit of the optical signal from the incident / exit sections 142 to 144 and the reflection / propagation of the optical signal in the optical signal transmission device 10 are the same as those in the first to fifth embodiments, and thus will not be described in detail. .
[0078]
In the present embodiment, an optical fiber is connected to a part of the incident / exit section of the optical signal transmission device 10 and is connected to an optical fiber that transmits / receives an optical signal of the external device via a connector. Optical coupling with the apparatus can be easily performed.
[0079]
At this time, the optical fiber of the external device may be detachable from the connector 184. Further, a connector may be directly provided on the optical signal transmission device 10 (that is, the input / output unit 141) to connect an optical fiber that connects the optical signal transmission device 10 and an external device (FIG. 23). In the present embodiment, the optical fiber is connected to the incident / exit section 141, but the present invention is not limited to this. The optical fiber may be connected to any single or a plurality of incident / exit portions.
[0080]
FIGS. 15 to 17 show the configuration of an optical data bus 30 using a plurality of optical signal transmission devices 10 shown in the first and second embodiments, respectively. That is, FIG. 15 shows a configuration in which a plurality of optical signal transmission devices (see FIG. 1) according to the first embodiment are stacked in the thickness direction, and FIG. 16 shows the light according to the second embodiment. The structure which piled up the signal transmission apparatus 10 (refer FIG. 2) in multiple width direction is shown. FIG. 17A shows a configuration in which a plurality of optical signal transmission devices 10 (see FIG. 2) according to the second embodiment are stacked in the thickness direction, and FIG. This is a modification of the configuration shown in FIG. 6 and shows a configuration in which the surface of the incident / exit section is formed at 45 ° with respect to the back side surface or the front side surface of the translucent medium 1. The configuration shown here is an example, and a configuration in which the optical signal transmission device 10 shown in FIG. 3 is combined is also possible.
[0081]
【The invention's effect】
As described above, the present invention provides a translucent medium having a plurality of input / output portions for entering and exiting an optical signal at one end, and an optical signal incident from the input / output portions in a plurality of input / output portion directions. By providing an optical signal transmission device having reflection means disposed at the other end of the translucent medium that reflects light, the configuration of the signal processing device becomes easy and the utilization efficiency of the optical signal can be increased. .
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an optical signal transmission device according to a first embodiment.
FIG. 2 is a schematic configuration diagram of an optical signal transmission device according to a second embodiment.
FIG. 3 is a schematic configuration diagram showing a modification of the optical signal transmission device according to the second embodiment.
FIG. 4 is a diagram showing an incident / exit state of an optical signal in an optical signal transmission device according to a second embodiment.
FIG. 5 is a diagram showing the emitted light efficiency in the second embodiment.
FIG. 6 is a diagram showing uniformity of emitted light intensity in the second embodiment.
FIG. 7 is a diagram showing L2 and L1.
FIG. 8 is a diagram showing the uniformity of emitted light intensity in a ray tracing simulation when L2 and L1 are changed.
FIG. 9 is another diagram showing the uniformity of the emitted light intensity in the ray tracing simulation when L2 and L1 are changed.
FIG. 10 is still another diagram showing the uniformity of the emitted light intensity in the ray tracing simulation when L2 and L1 are changed.
FIG. 11 is a conceptual explanatory diagram of a configuration that enables uniformity of emitted light intensity.
FIG. 12 is a schematic configuration diagram of an optical signal transmission device according to a third embodiment.
FIG. 13 is a perspective view showing a signal processing device using an optical data bus.
FIG. 14 is a perspective view showing another example of a signal processing device using an optical data bus.
FIG. 15 is a diagram showing a configuration example of an optical data bus using a plurality of optical signal transmission devices according to the first embodiment of the present invention.
FIG. 16 is a diagram showing a configuration example of an optical data bus using a plurality of optical signal transmission devices according to the second embodiment of the present invention.
FIG. 17 is a diagram showing another configuration example of an optical data bus using a plurality of optical signal transmission devices according to the second embodiment of the present invention.
FIG. 18 is a diagram showing a positional relationship between a light emitting / receiving element on a circuit board and an incident / exit portion of an optical signal transmission device in a fourth embodiment of the present invention.
FIG. 19 is a diagram showing a positional relationship between light emitting / receiving elements on a circuit board and an input / output part of an optical signal transmission device according to a fifth embodiment of the present invention.
FIG. 20 is a diagram illustrating a configuration example of a signal processing device that connects an optical signal transmission device according to a sixth embodiment of the present invention and an external device through an optical fiber.
FIG. 21 is a diagram showing an optical signal transmission device according to a sixth embodiment of the present invention.
FIG. 22 is a diagram showing a positional relationship between a light emitting / receiving element on a circuit board and an incident / exit portion of an optical signal transmission device in a sixth embodiment of the present invention.
FIG. 23 is an enlarged view showing a modification of the sixth embodiment of the present invention when a direct connector is provided in the optical signal transmission device.
[Explanation of symbols]
1 Translucent medium
2 Reflective light diffusion layer
10 Optical signal transmission device
13, 14 Input / output part
20 Support substrate
30 Optical data bus
40 connectors
50 circuit board
51 Electronic circuit
52 Light emitting / receiving element

Claims (15)

A translucent medium formed by providing a plurality of steps at one end, and having a plurality of incident and exit portions for entering or emitting an optical signal or entering and emitting;
Reflecting means disposed at the other end of the translucent medium and reflecting an optical signal incident from the incident / exiting portion toward the plurality of incident / exiting portions;
An optical signal transmission device comprising:   The optical signal transmission device according to claim 1, wherein the reflection unit diffusely reflects an optical signal incident from the incident / exiting unit toward the plurality of incident / exiting units.   2. The optical signal transmission device according to claim 1, wherein the reflection unit specularly reflects an optical signal incident from the incident / exiting unit in the direction of the plurality of incident / exiting units.   The side surface of the translucent medium reflects an optical signal other than an optical signal directly incident on the incident / exit portion of the optical signal reflected by the reflecting means so as to guide the incident / exit portion. The optical signal transmission device according to any one of claims 1 to 3.   The side surface of the translucent medium reflects an optical signal other than the optical signal directly incident on the incident / exiting portion among the optical signals reflected by the reflecting means so as to guide the entire incident / exiting portion. The optical signal transmission device according to claim 1, wherein the optical signal transmission device is an optical signal transmission device.   The optical signal according to any one of claims 1 to 5, wherein the plurality of incident / exit portions are formed by providing a plurality of steps in a step shape at one end of the translucent medium. Transmission device.   The translucent medium is plate-shaped, and a plurality of incident / exit portions are provided at one end of the translucent medium and reflective means are provided at the other end of the translucent medium. The optical signal transmission device according to claim 1. Each of the end surfaces of the plurality of incident / exit portions is inclined with respect to any one of the upper surface of the translucent medium, the lower surface facing the upper surface, the rear side surface in the width direction, and the front side surface in the width direction. The optical signal transmission device according to claim 1, wherein the optical signal transmission device is a reflecting surface that is formed. Each of the end surfaces of the said incident / exit part is an optical signal transmission apparatus as described in any one of Claims 1 thru | or 7 which is a reflective surface formed at 45 degrees with respect to the upper surface of the said translucent medium. 8. The light according to claim 1, wherein each of the end faces of the incident / exiting portion is a reflecting surface formed at 45 ° with respect to a lower surface facing the upper surface of the translucent medium. Signal transmission device. Each of the end surfaces of the said incident / exit part is a reflective surface formed at 45 degrees with respect to either the upper surface of the said translucent medium, or the lower surface which opposes this upper surface. The optical signal transmission device according to one item. The optical signal transmission device according to any one of claims 1 to 11, a support substrate on which the optical signal transmission device is provided, and a circuit substrate having optical signal input / output means are connected to each other. A mounting structure in which the means is arranged to face the light incident / exit part formed at one end of the translucent medium;
An optical data bus system comprising: One end of the optical fiber is optically coupled to a part of the plurality of incident / exit portions formed at one end of the translucent medium, and a connector for optical connection with an external device is provided at the other end of the optical fiber. 13. The optical data bus system according to claim 12, wherein the optical data bus system is provided. A connector for optical connection with an external device is provided at a part of the plurality of incident / exit portions formed at one end of the translucent medium, and optical coupling with an optical fiber connected to the external device is performed. The optical data bus system according to claim 12. The optical signal transmission device according to any one of claims 1 to 11,
A circuit board having input / output means for entering / exiting an optical signal arranged so as to face the input / output part;
A signal processing apparatus comprising:

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