JP2004101927A - Optical wiring board and optical bus system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical wiring board and an optical bus system in which light signals can be drawn in the incident side of the light signals and a small-size system with a high flexibility for the layout of optical parts can be obtained without increasing the light guide length. <P>SOLUTION: The optical wiring board 1 has optical parts composed of a sheet type light guide 3, a plurality of optical fibers 6 having the end faces 6a optically connected to the entrance face 3a as one end face of the light guide 3, a lenticular lens part 3b formed on the other end face of the light guide 3, and a light reflecting layer 3c formed on the back face of the lenticular lens part 3b, all disposed on a supporting substrate 2. The optical parts are sealed with a sealing member 7 made of a resin. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical wiring board and an optical bus system for transmitting data by light for the purpose of increasing the data speed between boards or chips, reducing electromagnetic noise, and the like.
[0002]
[Prior art]
Prior art document information related to the invention of this application includes the following.
[0003]
[Patent Document 1]
JP-A-10-282371
The optical wiring board disclosed in Patent Document 1 is provided on a sheet-shaped optical data bus, an optical signal incident portion provided on one end surface of the optical data bus for receiving an optical signal, and provided on the other end surface of the optical data bus. An optical signal emitting unit that emits an optical signal, and a diffusion unit provided at an edge of the optical signal incident unit. The diffusing means has a configuration in which a plurality of cylindrical surfaces are arranged, and is adapted to diffuse an incident optical signal over the entire edge of the optical signal emitting portion. Thereby, the transmission efficiency of the optical signal can be increased, and the variation in the amount of emitted light at the edge on the optical signal emitting portion side can be reduced.
[0005]
[Problems to be solved by the invention]
However, according to the conventional optical wiring board, the optical signal incident on the optical data bus is diffused and emitted from the other end face, so that the optical signal cannot be taken out on the optical signal incident side. In addition, there is a problem that a light guide path length sufficient to diffuse an optical signal over the entire surface of the optical data bus is required, and the optical data bus is enlarged.
[0006]
Accordingly, an object of the present invention is to provide an optical wiring board and an optical bus system which can take out an optical signal on the incident side of the optical signal, and which are small and have a high degree of freedom in layout of optical components without increasing the light guide path length. Is to do.
[0007]
[Means for Solving the Problems]
The present invention, in order to achieve the above object, a light guide path on which optical signals are incident from a plurality of optical fibers optically connected to one end,
A lens for diffusing the optical signal into the light guide path;
There is provided an optical wiring board having a reflecting portion provided at the other end of the light guide path to reflect the optical signal to an incident side.
According to such a configuration, the optical signal incident from one end of the light guide path is diffused by the lens in the process of being reflected by the reflecting portion provided at the other end and guided to the incident side, and thus is diffused to the incident side of the optical signal. Optical signal propagates.
[0008]
The present invention, in order to achieve the above object, a light guide path on which optical signals are incident from a plurality of optical fibers optically connected to one end,
A lens for diffusing the optical signal into the light guide path;
An optical wiring board having a reflecting portion provided at the other end of the light guide path and reflecting the optical signal to an incident side;
An optical bus system comprising: an input / output unit that converts an electrical signal into an optical signal or an optical signal into an electrical signal, and a plurality of conversion circuit units that are optically connected to the optical wiring board. provide.
According to such a configuration, the optical signal incident from one end of the light guide path is reflected by the reflecting portion provided at the other end, and is diffused by the lens in a process of being guided to the incident side. Can be arranged on the light incident side.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
1 and 2 show an optical bus system according to a first embodiment to which the optical wiring board of the present invention is applied. FIG. 1 (a) is a plan view, and FIG. 1 (b) is the same figure (a). 1A is a partially enlarged view, FIG. 1C is a sectional view taken along line BB of FIG. 1A, and FIG. 2 is a perspective view of a modularized optical wiring board. The optical bus system 10 includes a plurality of optical wiring boards 1 as shown in FIGS. 1 and 2, an electro-optical converter for converting an electric signal to an optical signal as shown in FIG. And a plurality of optical-to-electrical conversion circuit units 12 each having a photoelectric conversion unit that converts the light into an electric signal.
[0010]
The optical-electrical conversion circuit unit 12 includes a CPU, a memory, a photoelectric conversion element, an electro-optical conversion element, and the like, and is electrically connected to a circuit board of the optical bus system 10 described later.
[0011]
The optical wiring board 1 has a support substrate 2, a sheet-like light guide path 3 disposed on the support substrate 2, and a tip end 6 a optically connected to a light incident surface 3 a which is one end face of the light guide path 3. A plurality of (eg, eight) optical fibers 6, a lenticular lens portion 3b formed on the other end surface of the light guide path 3, a light reflecting layer 3c formed on the back surface of the lenticular lens portion 3b, and a rear end of the optical fiber 6 A positioning member 8 for positioning the rear end portion 6b by inserting the portion 6b into the positioning hole 8a, and the optical components of the light guide path 3 and the optical fiber 6 are sealed by a sealing member 7 made of resin. . 1A and 2, the sealing member 7 is illustrated as a transparent member.
[0012]
The support substrate 2 is made of a metal such as aluminum, a resin such as polymethyl methacrylate (PMMA), glass, ceramics, or the like, but the material is not particularly limited as long as it does not hinder the positioning and fixing of the optical components. Alternatively, a flexible substrate such as polyimide may be used.
[0013]
The light guide path 3 has, for example, a plate shape having a thickness of 0.5 mm, a width of 8 mm, and a length of 40 mm, and a plate-shaped core made of a translucent material, and upper and lower surfaces of the core excluding the light incident surface 3a. It is formed on both left and right sides, and comprises a clad having a lower refractive index than the core. The core is formed of, for example, a plastic material such as polymethyl methacrylate (PMMA), polycarbonate, amorphous polyolefin, or an inorganic glass, and the clad is formed of, for example, a fluorine-based polymer. The clad can be omitted when the sealing member 7 performs the function of the clad.
[0014]
The lenticular lens portion 3b is formed by arranging a plurality of convex (semicircular) lenses on the light signal incident side with respect to the width direction of the light guide path 3, and sputtering a metal material such as aluminum on the back surface. And the like, and the light reflection layer 3c formed by such a film formation method. The light reflecting layer 3c may be formed by any other method that does not lower the light transmitting property of the formation surface and does not affect the light guide path 3 by heat.
[0015]
The optical fiber 6 has, for example, an outer diameter of 0.5 mm, and includes a core having a circular cross section and a clad provided around the core, and the rear end 6 b is orthogonal to the long side of the support substrate 2. The support substrate 2 is slightly exposed from the long side of the support substrate 2 by being bent at the bending portion 6c. The cladding of the optical fiber 6 can be omitted when the sealing member 7 performs the function of the cladding.
[0016]
For the sealing member 7, a resin such as a silicone resin or an epoxy resin can be used. These resins can be cured by room temperature curing, heat curing, UV curing, or the like. The method for applying the resin for the sealing member 7 is not particularly limited as long as it is a method capable of applying a resin having a desired thickness, such as screen printing and spin coating, in addition to pouring, applying with a roller, and applying with a blade. Alternatively, a material such as a molten resin film that is melted by heat and cured by returning it to normal temperature may be used.
[0017]
3A to 3C show a light diffusion operation by the lenticular lens portion 3b and the light reflection layer 3c formed in the light guide path 3. FIG. As shown in FIG. 1A, an optical fiber 6 for receiving an optical signal has a core 6A and a clad 6B made of a material having a lower refractive index than the core 6A. The light is propagated in the front-back direction of the paper by being totally reflected at the boundary between the metal and the cladding 6B. 3A to 3C, the positions in the vertical direction correspond to each other in order to show the relationship between the shape of each part and the optical characteristics.
[0018]
FIG. 3B shows the light intensity at a position in the width direction of the optical fiber 6. The optical signal propagating through the optical fiber 6 has a Gaussian distribution as shown in the figure, and has a difference in light intensity between the center and the periphery.
[0019]
FIG. 3C shows an optical signal Li incident on the lenticular lens unit 3b and its reflected light Lr. The lenticular lens unit 3b has three lenses with respect to the width of the optical fiber 6 shown in FIG. And reflects the incident optical signal Li on the light reflecting layer 3c on the rear surface. Thereby, the reflected light Lr is diffused in a direction corresponding to the incident position of the lenticular lens unit 3b. The reflected light Lr is combined with the other reflected light Lr reflected by the light reflecting layer 3c, thereby eliminating the light intensity difference based on the Gaussian distribution shown in FIG. 3B. In FIG. 3C, a configuration in which three lenses are arranged in the width direction of the optical fiber 6 has been described, but six or nine lenses may be arranged.
[0020]
According to the above-described first embodiment, the optical signal is incident on the lenticular lens portion 3b and is diffused by being reflected by the light reflecting layer 3c on the rear surface. Therefore, the optical signal is provided adjacent to the light incident surface 3a. An optical signal can also be incident on the optical fiber 6, thereby making it possible to construct an optical bus system having a degree of freedom in layout. Further, since the optical signal is reflected by the light reflection layer 3c, the optical path length of the light guide path 3 is twice as large as the actual size, and the size can be reduced as compared with the transmission type optical wiring board.
[0021]
In the first embodiment, the lenticular lens part 3b is formed integrally with the light guide path 3; however, the lenticular lens part 3b is formed separately from the light guide path 3 and joined. Is also good. In this case, it is preferable that the lenticular lens portion 3b and the light guide path 3 are formed of a translucent material having the same refractive index, and are further joined using an adhesive having the same refractive index.
[0022]
The joining of the light guide path 3 and the optical fiber 6 is performed by a method in which the optical fiber 6 is abutted against the light guide path 3 and fixed, or a method in which the optical fiber 6 and the light guide path 3 are bonded with an adhesive. Is also good. In this case, it is preferable to use an adhesive having a lower refractive index than that of the light guide path 3.
[0023]
The number of the optical fibers 6 may be 16 or 32 in addition to the eight shown in FIG.
[0024]
FIG. 4A partially shows the light guide path 3 of the optical wiring board according to the second embodiment of the present invention. Note that, in the following configuration (h), the same components as those of the first embodiment are denoted by the same reference numerals, and duplicate description will be omitted. The light guide path 3 has a lenticular lens portion 3d on the other end surface. The lenticular lens portion 3d is formed by arranging a plurality of concave lenses on the light signal incident side with respect to the width direction of the light guide path 3. Even with such a configuration, the same effects as in the first embodiment can be obtained.
[0025]
FIG. 4B partially shows the light guide path 3 of the optical wiring board according to the third embodiment of the present invention. The light guide path 3 is joined to a lenticular lens unit 4 formed separately on the light exit surface 3e. The lenticular lens unit 4 has a light incident surface 4a, a lenticular lens portion 4b located downstream of the light incident surface 4a, and a light reflecting layer 4c provided on the back surface of the lenticular lens portion 4b.
[0026]
The lenticular lens part 4b is formed by arranging a plurality of concave lenses on the light signal incident side with respect to the width direction of the light guide path 3. According to such a configuration, in addition to the preferable effects of the first embodiment, the light guide path 3 and the lenticular lens unit 4 can be manufactured and assembled in separate steps, so that the molding accuracy of each member is improved. I do.
[0027]
FIG. 4C partially shows the light guide path 3 of the optical wiring board according to the fourth embodiment of the present invention. The light guide path 3 has a lenticular lens portion 3f formed on the light incident surface and a planar light reflecting layer 5 formed on the light emitting surface 3e.
[0028]
The lenticular lens portion 3f is formed by arranging a plurality of convex lenses on the light signal incident side with respect to the width direction of the light guide path 3. The plurality of optical fibers 6 are abutted against the lenticular lens portion 3f, but may be bonded with an adhesive or the like. The light reflection layer 5 reflects the optical signal diffused by the lenticular lens unit 3f. According to such a configuration, it is possible to easily form the light reflection layer 5 in addition to the preferable effects of the first embodiment.
[0029]
FIG. 4D partially shows the light guide path 3 of the optical wiring board according to the fifth embodiment of the present invention. The light guide path 3 joins a lenticular lens unit 4 formed separately on the light incident surface 3a. The lenticular lens unit 4 has a light incident surface 4a in which a plurality of convex lenticular lenses are arranged, and a light emitting portion 4d located downstream of the light incident surface 4a. According to such a configuration, in addition to the preferable effects of the fourth embodiment, since the light guide path 3 and the lenticular lens unit 4 can be manufactured and assembled in separate steps, the molding accuracy of each member is improved. I do.
[0030]
FIG. 4E partially shows the light guide path 3 of the optical wiring board according to the sixth embodiment of the present invention. The light guide path 3 includes a lenticular lens portion 3g formed on the light incident surface and a planar light reflecting layer 5 formed on the light exit surface 3e.
[0031]
The lenticular lens portion 3g is formed by arranging a plurality of concave lenses on the light signal incident side with respect to the width direction of the light guide path 3. Even with such a configuration, the light reflection layer 5 can be easily formed in addition to the favorable effects of the first embodiment.
[0032]
FIG. 4F partially shows a light guide path 3 of an optical wiring board according to a seventh embodiment of the present invention. The light guide path 3 joins a lenticular lens unit 4 formed separately on the light incident surface 3a. The lenticular lens unit 4 has a light incident surface 4a in which a plurality of concave lenticular lenses are arranged, and a light emitting portion 4d located at a stage subsequent to the light incident surface 4a. According to such a configuration, in addition to the preferable effects of the fourth embodiment, since the light guide path 3 and the lenticular lens unit 4 can be manufactured and assembled in separate steps, the molding accuracy of each member is improved. I do.
[0033]
FIG. 4G partially shows the light guide path 3 of the optical wiring board according to the eighth embodiment of the present invention. The light guide path 3 has a lenticular lens portion 3g on the light incident surface having the configuration described in the first embodiment. According to such a configuration, in addition to the favorable effects of the first embodiment, the diffusivity of the optical signal in the light guide path 3 is further improved, so that the light guide path 3 can be further downsized.
[0034]
FIG. 4H partially shows the light guide path 3 of the optical wiring board according to the ninth embodiment of the present invention. The light guide path 3 has the transmission type diffusion material layer 9 on the light incident surface 3a having the configuration described in the first embodiment.
[0035]
The transmission type diffusion material layer 9 is formed by forming an epoxy layer on the light incident surface 3a and curing it with ultraviolet light to form a concavo-convex pattern for light diffusion, or by directly forming the concavo-convex pattern on the light incident surface 3a by injection molding. The formed one can be used. The diffusion plate may be of a type in which particles having different refractive indexes are dispersed inside and the inside becomes a diffusion portion. With such a configuration, as in the eighth embodiment, the diffusivity of the optical signal in the light guide path 3 is further improved, so that the light guide path 3 can be further downsized.
[0036]
FIG. 5 shows a schematic configuration of an optical bus system 10 according to the tenth embodiment of the present invention. In FIG. 1, the optical-to-electrical conversion circuit section 12 is shown transparently except for a part. The optical bus system 10 includes: an optical wiring board module 11 in which a plurality of optical wiring boards 1 are stacked to form a module; a plurality of optical / electrical conversion circuit units 12 optically connected to the optical wiring board module 11; And a circuit board 13 that is electrically connected to the optical-to-electrical conversion circuit section 12.
[0037]
The optical / electrical conversion circuit unit 12 includes a substrate 121, a circuit component 122 mounted on the substrate 121 and including the CPU and the memory, an optical signal input / output unit 123 connected to the optical wiring board module 11, 13 and an electric signal input / output unit 124 connected to the electric signal input / output unit 13.
[0038]
The optical signal input / output unit 123 includes a pair of a photoelectric conversion element (for reception) and an electro-optical conversion element (for transmission). When an optical signal is input from the optical wiring board module 11, the optical fiber 6 for reception is used. Then, the optical signal emitted from the other optical / electrical conversion circuit unit 12 by the photoelectric conversion element is incident and converted into an electric signal. When an optical signal is emitted to the optical wiring board module 11, the electrical signal to be transmitted is converted into an optical signal by the electro-optical conversion element and emitted to the optical fiber 6 for transmission. A plurality of pairs of the photoelectric conversion element and the photoelectric conversion element described above are provided corresponding to the optical wiring board module 11.
[0039]
The electric signal input / output unit 124 supplies power to the optical / electrical conversion circuit unit 12 and inputs a control signal output from the control unit (not shown) to the circuit component 122. It is also possible to adopt a configuration in which input and output of control signals and the like are performed by the above-described optical signal input / output unit.
[0040]
Next, an operation example of the optical bus system 10 will be described.
[0041]
When one CPU in the optical-electrical conversion circuit section 12 outputs a clock signal as an electric signal, for example, the clock signal is converted into an optical signal by an electro-optical conversion element in the optical signal input / output section 123, and the optical wiring board Input to the corresponding one optical fiber 6 of the module 11. The optical signal input to the optical fiber 6 enters the light guide path 3 from the light incident surface 3a, further enters the lenticular lens portion 3b, is diffused by being reflected by the light reflecting layer 3c, and returns to the light incident surface 3a. Are output to another optical fiber 6 and input to the optical signal input / output unit 123 of the other optical / electrical conversion circuit unit 12. The optical signal input to the other optical / electrical conversion circuit unit 12 is converted into an electric signal by a photoelectric conversion element in the optical / electrical conversion circuit unit 12. When inputting data corresponding to a predetermined condition (for example, ID collation), the CPU of the optical-electrical conversion circuit unit 12 stores the data in a memory.
[0042]
According to the tenth embodiment, since the optical wiring board module 11 composed of a light reflection type optical wiring board is used, the optical bus is excellent in light diffusivity, while ensuring an effective light guide path length. The structure can be reduced in size, and the degree of freedom in layout can be improved. Also, since the plurality of optical fibers 6 are optically connected via the light guide path 3, multipoint-to-multipoint communication can be performed.
[0043]
【The invention's effect】
As described above, according to the present invention, the optical signal is diffused by the lens provided in the light guide path, and is reflected by the reflection section toward the light incident side. It is possible to increase the degree of freedom in layout of optical components without increasing the light guide path length.
[Brief description of the drawings]
FIGS. 1A and 1B show an optical bus system to which an optical wiring board according to a first embodiment of the present invention is applied, wherein FIG. 1A is a plan view, FIG. 1B is a partially enlarged view of A of FIG. () Is a sectional view taken along line BB of (a).
FIG. 2 is a perspective view of a modularized optical wiring board according to the first embodiment of the present invention.
FIGS. 3A to 3C are diagrams for explaining a light diffusion operation by a lenticular lens portion and a light reflection layer formed in a light guide path according to the first embodiment.
FIGS. 4A to 4H are schematic configuration diagrams illustrating light guide units according to second to ninth embodiments.
FIG. 5 is a perspective view of an optical bus system according to a tenth embodiment of the present invention.
[Explanation of symbols]
1, optical wiring substrate 2, support substrate 3b, lenticular lens portion 3d, lenticular lens portion 3f, lenticular lens portion 3g, lenticular lens portion 3a, light incident surface 3c, light reflecting layer 3e, light emitting surface 3, light guide path 4, Lenticular lens unit 4a, light incident surface 4b, lenticular lens part 4c, light reflection layer 4d, light emitting part 6, optical fiber 6A, core 6B, clad 6a, front end part 6b, rear end part 6c, curved part 7, sealing Member 8, positioning member 8a, positioning hole 9, transmission type diffusion material layer 10, optical bus system 11, optical wiring board module 12, optical / electrical conversion circuit section 13, circuit board 121, board 122, circuit component 123, light Signal input / output unit 124, electric signal input / output unit

Claims (10)

A light guide path on which an optical signal is incident from a plurality of optical fibers optically connected to one end,
A lens for diffusing the optical signal into the light guide path;
An optical wiring board, comprising: a reflecting portion provided at the other end of the light guide path to reflect the optical signal to an incident side. The optical wiring board according to claim 1, wherein the lens is formed integrally with the light guide path. The optical wiring board according to claim 1, wherein the lens is formed separately from the light guide path. The optical wiring board according to claim 1, wherein the lens is provided at the one end. The optical wiring board according to claim 1, wherein the lens is provided at the other end opposite to the one end. The optical wiring board according to claim 1, wherein the lens is a lenticular lens configured by arranging a plurality of lenses in a width direction of the light guide path. 7. The optical wiring board according to claim 6, wherein the plurality of lenses include one of a convex lens and a concave lens. The optical wiring board according to claim 1, wherein the lens diffuses the reflected light of the optical signal reflected by the reflection section into the light guide path. A light guide path on which an optical signal is incident from a plurality of optical fibers optically connected to one end,
A lens for diffusing the optical signal into the light guide path;
An optical wiring board having a reflecting portion provided at the other end of the light guide path and reflecting the optical signal to an incident side;
An optical bus system, comprising: an input / output unit for converting an electric signal to an optical signal or an optical signal to an electric signal; and an optical bus system including a plurality of conversion circuit units optically connected to the optical wiring board. 10. The optical bus system according to claim 9, wherein the plurality of conversion circuit units are optically connected by an optical wiring board module in which a plurality of the optical wiring boards are stacked and modularized.

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