JPH11190862A - Optical bus and signal processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control dispersion of light quantity of signal light made incident on a signal light incident end even if a positional relation between an incident position and an exit position of the signal light are relatively changed, by making a signal light emitting part control an emitting direction of the signal light made to exit from an end edge by a signal according to a position of signal light incident part. SOLUTION: Emitting angle control elements 26-28 receive a signal according to a position of, for example, a signal light incident part 17, on which a signal light is made incident, of three signal light incident parts 17-19. When this positional signal is inputted, for example, to an emitting angle control element 26, the emitting angle control element 26 controls an emitting direction of the signal light so that the signal light emitted from a signal light emitting part 23 is propagated toward a photo detector 32. Moreover, when a signal light is received from the signal light incident part 18 or 19, a positional signal according to the signal light incident parts 18, 19 is inputted to the emitting angle control elements 26-28, and the signal light reaching the signal light emitting parts 23-25 is controlled in the emitting angle by the emitting light control elements 26-28 so as to be propagated toward the photo detectors 32-34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an optical bus for transmitting an optical signal and a signal processing device using the optical bus.

[0002]

2. Description of the Related Art With the development of very large scale integrated circuits (VLSI), circuit functions of circuit boards (daughter boards) used in data processing systems have been greatly increased. As the number of signal connections to each circuit board increases as circuit functions increase, a data bus board (mother board) that connects each circuit board (daughter board) with a bus structure requires a large number of connectors and connection lines. Parallel architecture has been adopted. Although the parallel bus has been improved by increasing the number of connection lines and miniaturization, the operation speed of the parallel bus has been improved.However, due to the signal delay caused by the capacitance between the connection lines and the resistance of the connection lines, the processing speed of the system becomes parallel. It may be limited by the operating speed of the bus. In addition, electromagnetic noise (E
MI: Electromagnetic Interf
issue) is also a significant constraint on improving the processing speed of the system.

In order to solve such a problem and improve the operation speed of the parallel bus, use of an in-system optical connection technique called optical interconnection has been studied. For an overview of optical interconnection technology, see "Tadaji Uchida, 9th Circuit Packaging Academic Conference, 15C01, p.
p. 201 to 202 ”and“ H. Tomimiuro et
al. , "Packaging Technology
for Optical Interconnect
s ", IEEE Tokyo No. 33, pp. 81
-86, 1994], various forms are proposed depending on the configuration of the system.

[0004] Among various types of optical interconnection techniques proposed in the past, Japanese Patent Application Laid-Open No. 2-41042 discloses an optical data transmission system using a high-speed, high-sensitivity light emitting / receiving device applied to a data bus. An example is disclosed in which 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 the system frame are spatially optically coupled. A serial optical data bus for loop transmission between circuit boards has been proposed. In this method, signal light transmitted from one circuit board is transmitted to an adjacent circuit board by light / light.
Each of the circuit boards is sequentially arranged in series so that the electrical conversion is performed, the electrical / optical conversion is performed once again on the circuit board, and the signal light is transmitted to the next adjacent circuit board. Is transmitted between all circuit boards incorporated in the system frame while repeating electrical / optical conversion. For this reason, the signal transmission speed depends on the optical / electrical conversion speed and the 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, since data transmission between each circuit board is performed by optical coupling via a free space by a light receiving / light emitting device arranged on each circuit board, it is arranged on both front and back sides of an adjacent circuit board. Optical alignment of the light emitting / receiving device is required and all circuit boards need to be optically coupled. Furthermore, since the optical fibers are coupled via a free space, interference (crosstalk) between adjacent optical data transmission lines occurs, and poor data transmission is expected. In addition, it is expected that data transmission failure will occur due to scattering of signal light due to an environment in the system frame, for example, dust or the like. Further, since the circuit boards are arranged in series, if any one of the boards is removed, the connection is interrupted there, and an extra circuit board is required to compensate for the disconnection. That is, there is a problem that the circuit board cannot be freely inserted and removed, and the number of the fixed boards is fixed.

A technique for transmitting data between circuit boards using a two-dimensional array device is disclosed in Japanese Patent Application Laid-Open No. 61-196210.
No. 6,086,045. The technique disclosed herein comprises a plate facing a light source having two parallel surfaces,
This is a method in which circuit boards are optically coupled via an optical path constituted by a diffraction grating and a reflection element arranged on the plate surface. In this method, light emitted from one point can be connected only to a fixed point, and all circuit boards cannot be exhaustively connected like an electric bus. Also,
Since a complicated optical system is required and it is difficult to perform positioning, etc., interference (crosstalk) between adjacent optical data transmission paths occurs due to the displacement of the optical element, and poor data transmission is expected. Since connection information between circuit boards is determined by a diffraction grating and a reflective element arranged on the plate surface, there are various problems, such as the inability to freely insert and remove the circuit board and low expandability.

Another technique for transmitting data between circuit boards using a two-dimensional array device is disclosed in Japanese Patent Laid-Open No. 4-1344.
No. 15 discloses this. This publication discloses a lens array composed of a plurality of lenses having a negative curvature on a base made of a transparent substance having a higher refractive index than air, and a light source for emitting light emitted from a light source from a side surface of the lens array. A data transmission system provided with an optical system is disclosed. This publication also discloses a method of forming a region having a low refractive index or a hologram in the base, instead of a plurality of lenses having a negative curvature. In these systems, light incident from the side surface of the substrate is distributed to the upper surface of the substrate from a plurality of lenses having the above-described negative curvature, a region having a low refractive index instead of the lens, or a hologram, and emitted. It is configured to: Therefore, it is conceivable that the intensity of the emitted signal varies depending on the positional relationship between the incident position of the light and the plurality of lenses, the region having a low refractive index instead of the lens, and the emitting position on the substrate surface on which the hologram is formed. Also, it is considered that the ratio of light incident from the side surface of the base body to escape from the side surface opposite to the incident surface is high,
The efficiency of light used for signal propagation is low. Furthermore, since it is necessary to dispose a plurality of lenses having a negative curvature formed on the surface of the substrate and a region where the refractive index is low or an area where the hologram is used instead of the lens, the light input element of the circuit substrate is disposed. There are various problems that the degree of freedom is small and the expandability of the system is low.

[0007]

To solve these problems, it is conceivable to employ an optical bus that diffuses, propagates, and emits the incident signal light. However, if such an optical bus is simply manufactured, When signal light is incident from a certain incident position, the emission direction of the emitted signal light varies depending on the emission position of the signal light. In addition, when attention is paid to a certain one emission position, the emission direction of the signal light emitted from the emission position varies depending on the incident position of the signal light. Therefore, if the light receiving element is arranged opposite to the emission position to receive the signal light emitted from the emission position, the relative position between the incident position of the signal light and the emission position of the signal light causes the light from the emission position. The amount of emitted signal light received by the light receiving element varies. For this reason, it is necessary to detect light having a wide dynamic range. If a signal processing device is configured using such an optical bus, it is necessary to design a circuit that is suitable for the wide dynamic range. Suitable circuit design is difficult, and there is a problem that power consumption increases and costs increase.

In view of the above circumstances, the present invention reduces the variation in the amount of signal light incident on the signal light incident end of a light receiving element or the like even if the relative positional relationship between the incident position and the emission position of the signal light changes. It is an object of the present invention to provide an optical bus that can be suppressed, and a signal processing device that achieves low power consumption and cost reduction.

[0009]

An optical bus according to the present invention that achieves the above object has a plurality of signal light incident portions arranged along one edge for injecting signal light, and the plurality of signal light incident portions, which are arranged along one edge. Has a signal light emitting portion for emitting signal light along the other edge on the opposite side, and diffuses and propagates the signal light incident from the signal light incident portion and emits the signal light from the signal light emitting portion. A sheet-shaped optical bus, wherein the signal light emitting unit controls an emission direction of the signal light emitted from the other edge by a signal corresponding to a position of the signal light incidence unit on which the signal light is incident. It is characterized by having an angle control element.

The signal processing device of the present invention comprises: (1) a base; (2) a signal light emitting end for emitting signal light; and a circuit for generating a signal to be carried by the signal light emitted from the signal light emitting end. A plurality of circuit boards on which at least one of a signal light incident end for receiving signal light and a circuit for performing signal processing based on a signal carried by the signal light incident from the signal light incident end is mounted; A plurality of signal light incident portions, which are arranged along the edge of the signal light, and which carry the incidence of the signal light, and the signal light emitting portion, which carries out the emission of the signal light, along the other edge opposite to the edge. A sheet-shaped optical bus that diffuses and propagates the signal light incident from the signal light incident portion and emits the signal light from the signal light emitting portion, wherein the signal light emitting portion is located at the other end from the other edge. The emission direction of the outgoing optical signal is changed to the signal light incident (4) An optical bus having an emission angle control element controlled by a signal corresponding to the position of the optical bus. (4) The signal light emitting end or the signal light incident end mounted on the circuit board is connected to the optical bus. A plurality of base fixing portions fixed on the base are provided in a state of being optically coupled to the signal light input portion or the signal light output portion.

[0011]

Embodiments of the present invention will be described below. FIG. 1 is a plan view showing an optical bus according to an embodiment of the present invention. The optical bus 10 includes an optical transmission layer 11 for transmitting signal light, and an end face 12 of the optical transmission layer 11.
Is formed in an arc shape provided at the center of the other end edge 16 and centered on an emission angle control element 27 described later. The optical bus 10 includes three signal light incident portions 17, 18, and 19 that are arranged along one edge 15 of the optical transmission layer 11 and that receive the signal light. These signal light incident portions 17, 18, 19 are respectively provided with light diffusion layers 20, 20.
21 and 22. These light diffusion layers 20, 21,
Numeral 22 substantially completely diffuses the incident signal light. These light diffusion layers 20, 21, and 22 are adhered to the end face 12 of the light transmission layer 11.
The surfaces 20a, 21a, and 22a of 0, 21, and 22 opposite to the surface adhered to the end surface 12 are formed in an arc shape centered on an emission angle control element 27 described later. These signal light incident portions 17, 18, and 19 are respectively provided with surfaces 20a,
Signal light enters from the light transmission layers 21a and 22a, and is diffused toward the inside of the optical transmission layer 11.

The optical bus 10 is connected to the edge 1 of the optical transmission layer 11.
And signal light emitting portions 23, 24, and 25 that are arranged along line 6 and emit signal light.
3, 24 and 25 are emission angle control elements 26 and 2 respectively.
7, 28 are provided. The emission angle control elements 26, 2
Numerals 7 and 28 control the emission direction of the signal light emitted from the edge 16. The emission angle control elements 26, 27, 2
The detailed operation of 8 will be described later.

The surface 20 of the light diffusion layers 20, 21, 22
a, 21a and 22a so as to face the light emitting elements 29 and 3
0, 31 are arranged, and the emission angle control elements 26, 2
Light receiving elements 32, 33, and 34 are arranged so as to face 7, 28. The light emitting elements 29, 30, and 31 are for emitting signal light to the signal light incidence sections 17, 18, and 19, respectively, and the light receiving elements 32, 33, and 34 are respectively emitted from the signal light emitting sections 23, 24, and 25. The received signal light is received. That is, the optical bus 10 diffuses the signal light emitted from the light emitting elements 29, 30, 31 by the light diffusion layers 20, 21, 22, respectively, and propagates the signal light inside the light transmission layer 11, and the light receiving elements 32, 33, At 34, light is received.

The optical transmission layer 11 of the optical bus 10 includes:
For example, the length 200 of the sides 13 and 14 and the side of the edge 16
mm, a thickness of 0.25 mm, and PMMA (polymethyl methacrylate) whose end face 12 is formed in an arc shape is used. As the light diffusion layers 20, 21, 22 adhered to the end face 12 of the light transmission layer 11, for example, an acrylic resin layer having a thickness of 10 μm mixed with a silica pigment is formed on a polyester film. The produced light diffusion film is used. As the light emitting element, for example, a laser diode having an oscillation wavelength of 680 nm and an output intensity of 3 mW is used. As the light receiving element, for example, a light receiving diameter of 0.5 mm including a condenser lens is used. Is used.

Hereinafter, while explaining the operation of the emission angle control elements 26, 27, and 28, how the signal light is emitted from the light emitting element and propagates inside the optical transmission layer 11 and is received by the light receiving element will be described. explain. Light receiving elements 32, 33, 34
In order to receive the signal light emitted from the light emitting elements 29, 30, and 31, the light emitting element 29 (here, the light emitting element 29) among the three light emitting elements 29, 30, and 31 is used.
) Only emits signal light.

When the signal light is emitted from the light emitting element 29,
This signal light enters the signal light incident portion 17 and is diffused by the light diffusion layer 20. Of the signal light 35 diffused by the light diffusion layer 20, the signal lights 35a, 35b, and 35c traveling toward the signal light emitting units 23, 24, and 25 propagate inside the light transmission layer 11. The light diffusion layers 20, 21, 22 have almost perfect diffusion characteristics as described above.
Since the surfaces 20a, 21a and 22a of 0, 21 and 22 have an arc shape centered on the emission angle control element 27, any of the signal lights diffused by the respective light diffusion layers 20, 21 and 22 is output from the signal light emitting section. The intensity of the signal light propagating toward 24 is the highest. Therefore, of the signal light 35 diffused by the light diffusion layer 20, the signal light 35 propagating toward the signal light
b has the largest strength. Thus, the signal light emitting unit 2
3, 24, 25, the signal light emitting portion 2 located in the middle
When the diffusion direction of the signal light diffused by the light diffusion layers 20, 21, 22 is adjusted so that the intensity of the signal light propagating toward the signal light 4 becomes maximum, the signal light exit portions 23, 24, and 25 are respectively adjusted. Variations in the intensity of the propagating signal light can be reduced.

The emission angle control elements 26, 27, 28
Is a signal light incident portion (here, the signal light incident portion 1) into which the signal light is incident among the three signal light incident portions 17, 18, and 19.
7) is input according to the position (hereinafter, referred to as a position signal). When the position signal is input to, for example, the output angle control element 26, the output angle control element 26
The signal light emitted from the signal light emitting section 23 is
The emission direction of the signal light emitted from the signal light emission unit 23 is controlled so that the signal light propagates toward. When a signal corresponding to the position of the signal light incidence unit 17 is input to each of the other emission angle control elements 27 and 28, the signal light emission units 24 and 2
5 are respectively output to the light receiving elements 33 and 3
The direction in which the signal light is emitted is controlled so that the signal light propagates toward. Specific structural examples of the emission angle control elements 26, 27, 28 will be described later with reference to FIGS.

Therefore, when the signal lights 35a, 35b, 35c reach the signal light emitting sections 23, 24, 25, respectively,
The emission directions of the signal lights 35a, 35b, and 35c are controlled by the emission angle control elements 26, 27, and 28, respectively, so that the signal lights 35 propagate toward the light receiving elements 32, 33, and 34.
d, 35e, 35f, and the respective light receiving elements 32, 33, 3
4 is received.

When the signal light enters from the signal light incident portions 18 to 19, the emission angle control element 2
Position signals corresponding to the positions of the signal light incident portions 18 and 19 are input to 6, 27 and 28, respectively.
The signal lights that have reached the respective light receiving elements 3, 24, and 25 are respectively output by the light emitting elements
The emission direction is controlled so as to propagate toward 2, 33, 34.

Hereinafter, as an example of the above-mentioned emission angle control element, an emission angle control for controlling the emission direction of the signal light emitted from the signal light emission portion by each of the electro-optic effect, the acousto-optic effect, and the thermo-optic effect. The element will be described. FIG. 2 is a diagram illustrating an example of an emission angle control element that controls the emission direction of signal light by an electro-optic effect.

The emission angle control element 40 controls the emission direction of the signal light from the signal light emission part of the optical bus by an electro-optic effect by an electric signal generated according to the position of the signal light incidence part where the signal light is incident. Is what you do. Specifically, it is as follows. The emission angle control element 40 includes two prisms 41 and 42 having different refractive indexes from each other. The prisms 41 and 42 have the same triangular shape. The prisms 41 and 42 are joined together. An electrode film 43 is formed on the surface of the joined prisms 41 and 42, and an electrode film 44 is formed on the back surface.

The emission angle control element 40 constructed as described above
When a position signal is input to the electrode film 43, an electric field E corresponding to the position of the signal light incident portion where the signal light enters is generated between the electrode films 43 and 44, and the electric field E is generated according to the magnitude of the electric field E. Thus, the refractive index of each of the prisms 41 and 42 changes (the change in the refractive index according to the magnitude of the electric field is called an electro-optic effect). Thus, each prism 41, 4
2 changes the refractive index of the output angle control element 40.
The emission direction of the signal light emitted from is controlled, and the emission angle control element 40 emits the signal light 46 whose angle with the signal light 45 incident on the emission angle control element 40 is θ. The angle θ can be represented by the following equation.

Θ = sin ⁻¹ {2 (ΔnL / D)} (1) where L: length of each prism D: thickness of each prism Δn; refractive index of prism 41 and refractive index of prism 42 For example, L = 50 mm, D = 0.25 mm of each prism
, The electric field E generated between the electrode films 43 and 44 =
Refractive index each n of each prism 41, 42 by E _1
1 , n ₂ , and this difference in refractive index Δn = (n ₁ −n
₂ ) becomes Δn = 3 × 10 ⁻¹⁴ , L = 50 mm, D = 0.25 mm, Δn = 3 × 10
Substituting ^-14 gives θ ≒ 7 degrees.

Since Δn changes according to the magnitude of the electric field E, the angle θ can be adjusted by changing the electric field E. Therefore, the three signal light incident portions 1
The magnitude of the electric field E is changed in accordance with which signal light incident portion among the signal light incident portions 7, 18, and 19 (see FIG. 1) to change the signal light incident on the emission angle control element. The light can be emitted toward the light receiving element.

When the refractive index of the prism is changed by the electro-optic effect, the time from the generation of the electric field E between the electrode films 43 and 44 to the change of the refractive index of the prism is 10 ^-12.
It is on the order of seconds, and the refractive index of the prism can be adjusted very quickly. As a material for the prism, for example, a ferroelectric material such as LiTaO ₃ , TnO, or PZT can be used.

FIG. 3 is a view showing another example of the emission angle control element for controlling the emission direction of the signal light by the electro-optic effect, which is different from FIG. The emission angle control element 50 is configured such that triangular electrode films 52 and 53 are formed on a front surface 51a and a back surface 51b of an optical waveguide 51 made of a ferroelectric material, respectively.

As described above, the emission angle control element may be constituted by employing an optical waveguide instead of the prism. FIG.
FIG. 3 is a diagram illustrating an example of an emission angle control element that controls an emission direction of signal light by an acousto-optic effect. The emission angle control element 60 controls the emission direction of the signal light from the signal light emission part of the optical bus by an acousto-optic effect by an elastic wave generated according to the position of the signal light incidence part where the signal light is incident. is there. Specifically, it is as follows.

The emission angle control element 60 has an optical waveguide 61, and a surface acoustic wave transducer 62 is provided on the surface of the optical waveguide 61. The surface acoustic wave transducer 62 is composed of a piezoelectric thin film 62 a having a comb-shaped electrode 62 b formed on the surface. The piezoelectric thin film 62 a is formed on the surface of the optical waveguide 61.

The emission angle control element 60 thus configured
When a position signal is input to, the position signal indicates
The voltage corresponding to the position of the signal light incident part where the signal light has entered is
The surface acoustic wave 6 is applied between the two comb-shaped electrodes 62b.
3 occurs. When the surface acoustic wave 63 propagates through the optical waveguide 61, the density of the optical waveguide 61 varies according to the frequency of the surface acoustic wave 63 in the traveling direction of the surface acoustic wave 63. Thereby, the optical waveguide 61
A change in the refractive index occurs in accordance with the density of the optical waveguide 61, and the portion of the optical waveguide 61 where the refractive index has changed serves as a diffraction grating (in this manner, the refractive index changes in accordance with the frequency of the elastic wave). Is called an acousto-optic effect). Therefore, the signal light 64 incident on the emission angle control element 60 is
When the light passes through the portion where the density is changed, the light is diffracted. The distribution of the diffracted light changes in accordance with the sparse and dense intervals formed in the optical waveguide 61, whereby the signal light 65 having an angle θ with the signal light 64 from the emission angle control element 60 is formed. Is emitted.

In the emission angle control element 60, the comb-shaped electrode 6
By changing the voltage applied to 2b, the frequency of the elastic wave generated by the surface acoustic wave transducer 62 changes. This adjusts the interval of the density sparseness generated in the optical waveguide 61, and adjusts the angle θ between the signal light 64 and the signal light 65. In the emission angle control element 60, the time from when the voltage is applied to the comb-shaped electrode 62 b to when the density of the optical waveguide 61 is changed, the surface acoustic wave 63 generated from the surface acoustic wave transducer 62 passes through the optical waveguide 61. It is determined by the running time and is on the order of 10 ^-9 seconds or more.
Also, the diffraction efficiency of the diffracted light obtained by passing through the portion of the optical waveguide 61 where the density is sparse and dense depends on the frequency of the surface acoustic wave 63 and the RF input to the comb-shaped electrode 62b.
It depends on the power and is about 80-90%.

FIG. 5 is a diagram showing an example of an emission angle control element for controlling the emission direction of signal light by the thermo-optic effect.
The emission angle control element 70 controls the emission direction of the signal light from the signal light emission part of the optical bus by a thermo-optic effect due to a temperature change according to the position of the signal light incidence part where the signal light is incident. Specifically, it is as follows.

The output angle control element 70 is provided with an optical waveguide 71
And a Ti thin film 72 formed thereon. When a signal corresponding to the position of the signal light incident portion where the signal light is incident is input to the emission angle control element 70 thus configured, a voltage is applied from the power supply 73 to the Ti thin film 72, and the Ti thin film 72 Generates heat, which changes the temperature of the optical waveguide 71 and generates a temperature gradient. The temperature gradient causes a change in the refractive index according to the temperature gradient inside the optical waveguide 71 (this change in the refractive index according to the temperature change is called a thermo-optic effect). Therefore, when the signal light 74 incident on the emission angle control element 70 passes through the portion of the optical waveguide 71 where the temperature gradient occurs, the traveling direction of the signal light 74 is controlled according to the temperature gradient, and the emission angle control is performed. Element 7
From 0, the signal light 75 whose angle with the signal light 74 is θ
Is emitted.

In the emission angle control element 70, the Ti thin film 7
By changing the voltage applied to 2, the temperature gradient generated inside the optical waveguide 71 changes. Thus, the angle θ between the signal light 74 and the signal light 75 is adjusted. In this emission angle control element 70, the time from when a voltage is applied to the Ti thin film 72 to when a temperature gradient is generated inside the optical waveguide 71 is on the order of 10 ^-3 seconds, and the electrical engineering shown in FIGS. The response is slightly slower than the emission angle control element by the effect or the acousto-optic effect.

The operation of the optical bus 10 shown in FIG.
The operation will be described in comparison with the operation of an optical bus (comparative example) in which the signal light emitting unit does not have the emission angle control element. FIG. 6 is a plan view showing an optical bus in which the signal light emitting unit has no emission angle control element. 6, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and only the differences from FIG. 1 will be described.

The difference between the optical bus 110 shown in FIG. 6 and the optical bus 10 shown in FIG. 1 is that the optical bus 110 signal light emitting units 111, 112 and 113 shown in FIG. Only points. Here, the optical bus 110 shown in FIG.
Considering the case where the signal light is incident from the signal light incident portion 17 of FIG. 1, the signal light 114 propagating toward the signal light emitting portion 111 of the signal light incident on the signal light incident portion 17 and diffused is a light receiving element. The signal light 114 is efficiently received by the light receiving element 32 because the signal light 114 propagates from the front toward the signal light emitting unit 111 with respect to the signal light emitting unit 1.
Since the signal light 115 propagating toward the signal light 12 propagates obliquely to the light receiving element 33 toward the signal light emitting unit 112, even if the signal light 115 is emitted from the signal light emitting unit 112, As compared with 114, the efficiency of receiving light by the light receiving element is lower. That is, the amount of signal light received by each light receiving element varies depending on the position of the signal light emitting unit.

Focusing on one signal light emitting portion, the traveling direction of the signal light emitted from the signal light emitting portion differs depending on the position of the signal light incident portion. Therefore, the amount of signal light received by the light receiving element varies depending on the position of the signal light incident portion. In other words, depending on the relative positional relationship between the position of the signal light entrance and the position of the signal light exit,
The amount of signal light received by each light receiving element varies.

On the other hand, in the optical bus 10 shown in FIG. 1, the signal light emitted from the signal light emitting portion is transmitted from the front to the light receiving device regardless of the signal light incident portion. The optical bus 11 shown in FIG.
Compared with 0, the variation in the light amount of the signal light received by the light receiving element is suppressed. FIG. 7 is a perspective view showing an optical bus according to the second embodiment of the present invention.

The optical bus 80 is provided with the light diffusion layer 2 shown in FIG.
0, 21, 22 and emission angle control elements 26, 27, 28
A light transmission layer having the same structure as that of the light transmission layer 11 provided between the cladding layers 81 and a light absorption layer 82 (a layer indicated by oblique lines in FIG. 7) are alternately laminated. It is. Here, as the emission angle control elements 26, 27, and 28, the emission angle control elements having the same structure as the emission angle control element based on the electro-optic effect shown in FIG. 2 are used.

When a plurality of optical transmission layers are provided, signal light composed of bits corresponding to each optical transmission layer can be transmitted and received as parallel signals. Also, this optical bus 80
Since it has the clad layer 81 and the light absorption layer 82,
Crosstalk of signal light between adjacent optical transmission layers is suppressed. FIG. 8 is a schematic configuration diagram illustrating a signal processing device according to an embodiment of the present invention.

An optical bus 80 shown in FIG. 7 is provided on a motherboard 91 (an example of a base according to the present invention) constituting the signal processing device 90. The signal processing device 90 includes three circuit boards 100, 101, and 102. Each of the circuit boards 100, 101, and 102 includes
In each case, a light emitting element unit 9 including four light emitting elements
A light receiving element unit 95 having four or four light receiving elements and an electronic circuit 96 are mounted. This circuit board 10
Each of the electronic circuits 96 mounted on the light emitting elements 0, 101, and 102 generates a signal to be carried by the signal light emitted from the light emitting element of the light emitting element unit 94, and transmits the signal via the signal line 97. A circuit for outputting to the light emitting element of the light emitting element unit 94;
And a circuit that performs signal processing based on the signal carried by the signal light received by the light receiving element. Also, the circuit board 10
Each of the electronic circuits 96 mounted on the optical buses 0, 101, and 102 has three signal light incident portions 17, 18, and 19 provided in the optical bus 80 (the signal light incident portions 18 and 19 each have one location). (Only shown), a position signal is generated in accordance with the position of the signal light incident portion on which the signal light is incident, and the position signal is transmitted via the signal line 92 and the light receiving element unit 95 to the signal light emitting portion of the optical bus 80. 23, 24, 25
(Only one signal light emitting section 24, 25 is shown.) The emission angle control elements 26,
Circuits 27 and 28 (not shown in FIG. 8; see FIG. 7) are provided. Each circuit board 10
The light emitting elements and the light receiving elements mounted on the circuit boards 100, 101, and 102 are light-emitting elements 0, 101, and 102, respectively, by a board fixing section 93 (an example of a base fixing section according to the present invention) provided on the motherboard 91. The signal light entrances 17, 18, 19 and the signal light exits 23, 2 of the bus 80
4, 25 and optically coupled to the circuit board 10
Electronic circuits 96 mounted on the optical buses 0, 101, and 102 are fixed on the motherboard 91 in a state of being electrically connected to the emission angle control elements of the signal light emitting units 23, 24, and 25 of the optical bus 80, respectively. ing.

On the motherboard 91, when the signal light is received by the light receiving elements of the light receiving element units 95 mounted on the three circuit boards 100, 101, 102, respectively, of the three light emitting element units 94 A control circuit (not shown) for controlling an electronic circuit 96 mounted on each of the circuit boards 100, 101 and 102 so that signal light is emitted from any one of the light emitting element units 94 is mounted. 100, 101, 102 are motherboard 9
By being fixed to 1, the control circuit on the motherboard 91 is electrically connected to the electronic circuit 96 of each of the circuit boards 100, 101, 102.

Each of the signal light incident portions 17 and 1 of the optical bus 80
Optical connection between the light emitting elements 8 and 19 and the light emitting elements of each light emitting element unit 94;
4, 25 and optical connection between the light receiving elements of each light receiving element unit 95, and each signal light emitting section 23, 2 of the optical bus 80.
Output angle control elements of the circuit boards 10 and
The electrical connections of the electronic circuits 96, 0, 101, and 102 are made as follows.

First, the signal light incident portions 17 of the optical bus 80,
A method for optically connecting the light emitting elements 18 and 19 to the light emitting elements of each light emitting element unit 94 will be described. Since this optical connection is similarly performed for each of the signal light incident portions 17, 18, and 19, the optical connection between the signal light incident portion 17 of the optical bus 80 and the light emitting element of the light emitting element unit 94 is representatively performed. An example will be described.

9 and 10 are views showing the vicinity of the signal light incident portion 17 of the optical bus 80 and the light emitting element unit 94. FIG. 9 is a view before optical connection, and FIG.
FIG. 3 is a diagram after optical connection. In order to connect the signal light incident portion 17 to each light emitting element 94a (see FIG. 9) included in the light emitting element unit 94, the light diffusion layer 20 (see FIG. 1) included in the signal light incident portion 17 and the light emission are connected. What is necessary is just to make the element 94a and the element 94a approach each other. This completes the optical connection as shown in FIG.

Next, each signal light emitting section 23 of the optical bus 80,
A description will be given of a method of optically connecting the light-receiving elements 24 and 25 and each of the light-receiving elements, and a method of electrically connecting the emission angle control elements included in each of the signal light emitting units 23, 24 and 25 and the electronic circuit 96. This optical connection is made by each of the signal light emitting units 23, 24, 25.
And the electrical connection is also performed similarly for each of the emission angle control elements 26, 27 and 28 (see FIG. 7) provided in each of the signal light emitting units 23, 24 and 25. , On behalf of bus 80
Optical connection between the signal light emitting section 23 of the light emitting element and the light receiving element of the light receiving element unit 95 mounted on the circuit board 100, and the emission angle control element 26 of the signal light emitting section 23 and the circuit board 100. An example will be described in which electrical connection with the mounted electronic circuit 96 is performed.

11 and 12 are views showing the vicinity of the signal light emitting section 23 of the optical bus 80 and the light receiving element unit. FIG. 11 is a view before optically and electrically connected.
FIG. 12 is a diagram after optical and electrical connections have been made.
As shown in FIG. 11, the emission angle control element 26 (here,
As the emission angle control element 26, an emission angle control element having the same structure as the emission angle control element based on the electro-optic effect shown in FIG. 2) is used for the electrode film 26 for generating an electric field.
1,262 (corresponding to the electrode films 43,44 shown in FIG. 2)
A terminal 263 for inputting a position signal via the signal line 92 (see FIG. 8) is provided. The light receiving element unit 95 is provided with a hole (not shown) into which the tip of the terminal 263 is inserted. As shown in FIG. 12, when the tip of the terminal 263 is inserted into this hole, an electronic circuit is formed. 96 (see FIG. 8) and the emission angle control element 26 are electrically connected.
a and the signal light emitting unit 23 are optically connected.

Thus, the circuit boards 100 and 10
The signal processing device 90 is configured by fixing the optical buses 1 and 102 and the optical bus 80 on the motherboard 91 so as to be optically and electrically connected to each other. In the signal processing device 90, when the light receiving element of each light receiving element unit 95 receives the signal light emitted from the light emitting element of each light emitting element unit 94, of the three light emitting element units 94,
The signal light is emitted only from the light emitting elements included in any one of the light emitting element units 94. Specifically, the control circuit on the motherboard 91 includes three circuit boards 100, 1
The electronic circuit 96 mounted on each circuit board is controlled such that only the electronic circuit 96 mounted on one of the circuit boards 01 and 102 generates a signal to be carried by the signal light emitted from the light emitting element. I do. The signal generated by the electronic circuit 96 under the control is converted into signal light by the light emitting element of the light emitting element unit 94 via the signal line 97, and the signal light is incident on the signal light incident portion. The signal light is diffused toward the inside of the light transmission layer 11 by the light diffusion layer of the signal light incident portion. Further, each of the circuit boards 100, 101, 102
The electronic circuit 96 mounted on each of them generates a position signal corresponding to the position of the signal light incident portion where the signal light is incident, and the position signal is transmitted via the signal line 92 to each of the emission angle control elements 2.
6, 27 and 28 (see FIG. 7). As a result, an electric field corresponding to the position of the signal light incident portion where the signal light is incident is generated in each of the emission angle control elements 26, 27 and 28, and the signal emitted from the signal light emitting portion is generated. The emission direction of the signal light emitted from the signal light emission unit is controlled so that the light propagates toward the light receiving element.

Therefore, signal light is emitted from each signal light emitting portion toward the light receiving element, and the signal light enters each light receiving element and is converted into an electric signal, which is input to the electronic circuit 96 of each circuit board. Then, signal processing is performed. Since the signal processing device 90 includes the optical bus 80, variations in the amount of signal light received by each light receiving element are suppressed. Therefore, it is easy to design the electronic circuit 96 mounted on the circuit boards 100, 101, and 102, and the power consumption and cost of the signal processing device can be reduced.

In this signal processing device 90, the light emitting element unit and the light receiving element unit are mounted on the same circuit board, but the light emitting element unit and the light receiving element unit may be mounted on different circuit boards. Good.

[0050]

As described above, according to the optical bus of the present invention, even if the relative positional relationship between the incident position and the outgoing position of the signal light changes, the signal from which the signal of the light receiving element or the like is incident can be obtained. Variations in the amount of signal light incident on the light incident body can be suppressed. Further, according to the signal processing device of the present invention, low power consumption and cost reduction can be achieved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an optical bus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of an emission angle control element that controls an emission direction of signal light by an electro-optic effect.

FIG. 3 is a diagram illustrating an example of an emission angle control element that controls an emission direction of signal light by an electro-optic effect, which is different from FIG. 2;

FIG. 4 is a diagram illustrating an example of an emission angle control element that controls an emission direction of signal light by an acousto-optic effect.

FIG. 5 is a diagram illustrating an example of an emission angle control element that controls an emission direction of signal light by a thermo-optic effect.

FIG. 6 is a plan view showing an optical bus in which a signal light emitting unit does not have an emission angle control element.

FIG. 7 is a perspective view illustrating an optical bus according to a second embodiment of the present invention.

FIG. 8 is a schematic configuration diagram illustrating a signal processing device according to an embodiment of the present invention.

FIG. 9 is a diagram showing a portion near the signal light incident portion of the optical bus and the light emitting element unit before optical connection.

FIG. 10 is a diagram showing a portion near the signal light incidence portion of the optical bus and the light emitting element unit after optical connection.

FIG. 11 shows an optical bus 8 before being optically and electrically connected.
FIG. 4 is a diagram showing a portion near a signal light emitting portion of No. 0 and a light receiving element unit.

FIG. 12 shows an optical bus 8 after being optically and electrically connected.
FIG. 4 is a diagram showing a portion near a signal light emitting portion of No. 0 and a light receiving element unit.

[Explanation of symbols]

10, 80, 110 Optical bus 11 Optical transmission layer 12 End surface 13, 14 Side surface 15, 16 Edge 17, 18, 19 Signal light incident portion 20, 21, 22 Light diffusion layer 20a, 21a, 22a Surface 23, 24, 25 , 111, 112, 113 signal light emitting sections 26, 27, 28, 40, 50, 60, 70 emission angle control elements 29, 30, 31 light emitting elements 32, 33, 34 light receiving elements 35 35a, 35b, 35c, 35d, 35e, 35
f, 45, 46, 64, 65, 74, 75, 114, 1
Reference Signs List 15 signal light 41, 42 prism 43, 44, 52, 53 electrode film 51a surface 51b back surface 61, 71 optical waveguide 62 surface acoustic wave transducer 63 surface acoustic wave 72 Ti thin film 73 power supply 90 signal processing device 91 motherboard 92, 97 signal line 93 Board fixing part 94 Light emitting element unit 94a Light emitting element 95 Light receiving element unit 95a Light receiving element 96 Electronic circuit 100, 101, 102 Circuit board

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H04B 10/10 10/22 (72) Inventor Shinobu Koseki 430 Nakai-cho, Ashigagami-gun, Kanagawa Prefecture Green Tech Nakai Inside Fuji Xerox Co., Ltd. (72) Inventor Sakai Kazuhiro 430 Nakaicho, Nakai-cho, Ashigara-gun, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Kenichi Kobayashi 430 Sakai Nakai-cho, Ashigaruga-gun, Kanagawa Green Tech Nakai Inside Fuji Xerox Co., Ltd. (72) Masao Funada, Inventor Masao Funada, Kanagawa Prefecture 430 Imachi Sakai Green Tech Nakai Fuji Xerox Co., Ltd. (72) Inventor Keishi Fujimaga 430 Sakai Nakaicho Sakaigami-gun, Kanagawa Prefecture Green Tech Nakai Fuji Xerox Co., Ltd.

Claims (5)

[Claims] 1. A plurality of signal light incident portions arranged along one edge for receiving signal light and emitting signal light along the other edge opposite to the edge. A signal light emitting portion that carries, and spreads and propagates the signal light incident from the signal light incident portion and emits the signal light from the signal light emitting portion, wherein the signal light emitting portion is An optical bus, comprising: an emission angle control element that controls an emission direction of the signal light emitted from the other edge by a signal corresponding to a position of a signal light incident part where the signal light is incident. 2. The deflection angle control element controls an emission direction of signal light from the signal light emission unit by an electro-optic effect by an electric signal generated according to a position of the signal light incidence unit on which the signal light is incident. The optical bus according to claim 1, wherein the optical bus is an optical bus. 3. The deflection angle control element controls an emission direction of the signal light from the signal light emission portion by an acousto-optic effect by an elastic wave generated according to a position of the signal light incidence portion where the signal light is incident. 2. The method according to claim 1, wherein
The mentioned optical bus. 4. The device according to claim 1, wherein the deflection angle control element controls an emission direction of the signal light from the signal light emission portion by a thermo-optic effect due to a temperature change according to a position of the signal light incidence portion where the signal light is incident. The optical bus according to claim 1, wherein: 5. A base, a signal light emitting end for emitting signal light, a circuit for generating a signal to be carried by the signal light emitted from the signal light emitting end, a signal light incident end for receiving signal light, and the signal A plurality of circuit boards on which at least one of a signal processing circuit based on a signal carried by the signal light incident from the light incident end is mounted; and a plurality of circuit boards arranged along one edge. A plurality of signal light incident portions that carry, along the other edge opposite to the edge, a signal light emitting portion that is responsible for emitting signal light, the signal light incident from the signal light incident portion A sheet-shaped optical bus which diffuses and propagates and emits from the signal light emitting portion, wherein the signal light emitting portion determines an emission direction of an optical signal emitted from the other edge, and a signal into which signal light is incident. An emission angle control element controlled by a signal corresponding to the position of the light incident part An optical bus and a signal light emitting end or a signal light incident end mounted on the circuit board are optically coupled to the signal light incident portion or the signal light emitting portion of the optical bus, respectively. A plurality of base fixing portions for fixing the base on the base in a state in which the base is fixed.