JP2001356236A - Signal processing circuit and optical bus device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a layout of an optical data bus and a plurality of circuit substrates and to provide the optical data bus suitable for the layout. SOLUTION: A plurality of circuit substrates 40 are erected vertically to a supporting substrate 20 and in parallel to each other. A plurality of circuit substrates 50 are respectively provided with a plurality of light emitting/ receiving elements 52 which are light incident/emitting bodies and electronic circuits 51 for processing optical signals which are made incident on or are emitted from the light emitting/receiving elements 52. The light emitting/ receiving elements 52 are arranged with prescribed intervals 54 and a plurality of circuit substrates 50 have the same constitution. Respective light incident/ emitting parts of an optical signal transmission device 10 are arranged with inclination of θ deg. to respective of a plurality of circuit substrates so as to correspond to respective light incident/emitting bodies of the circuit substrates 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal processing apparatus having an optical data bus for transmitting an optical signal between a plurality of circuit boards or devices, and an optical bus apparatus. It relates to a layout of a bus and a circuit board or a device.

[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 circuit functions increase, the number of signals connected to each circuit board increases. Therefore, a data bus board (motherboard) connecting each circuit board with a bus structure requires a parallel architecture requiring a large number of connectors and connection lines. Was adopted. The operation speed of the parallel bus has been improved by parallelizing the connection lines by multi-layering and miniaturization.
The processing speed of the system may be limited by the operation speed of the parallel bus due to the signal delay caused by the capacitance between connection lines and the connection line resistance. In addition, electromagnetic noise (EMI: Electromagnetic Inter
The occurrence of ference) is also a major constraint on the improvement of the processing speed of the system. In order to solve the above 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 Uchida, Circuit Packaging Academic Conference 15C01, pp.201-202, and H.Tomimu.
ro et al., IEEE Tokyo Section Denshi Tokyo, No.33,
As described in pp.81-86 (1994), various forms have been proposed depending on the configuration of the system.

[0003] Of the various types of optical interconnection technologies that have been proposed in the past, Japanese Patent Application Laid-Open No. 2-41042 discloses a light emitting / emitting device.
An optical data transmission method using a light receiving device has been devised. In Japanese Patent Application Laid-Open No. 2-41042, light-emitting / light-receiving devices are arranged on both front and back surfaces of each circuit board, and light is transmitted in a space between the light-emitting / light-receiving devices on adjacent circuit boards incorporated in a system frame. And a serial optical data bus for loop transmission between circuit boards. In this method, an optical signal transmitted from one circuit board is received by an adjacent circuit board and subjected to optical / electrical conversion. Again, the electrical signal is electro-optically converted and transmits the optical signal to the next adjacent circuit board. That is, the circuit boards are arranged in series, and signals are sequentially transmitted between the circuit boards incorporated in the system frame while repeating optical-to-electric conversion and electrical-to-optical conversion on each circuit board.

[0004] Therefore, the signal transmission speed depends on the light-to-electric conversion and electric-to-optical conversion speeds of the light receiving / light emitting devices arranged on each circuit board, and is restricted by them. In addition, since data transmission between the circuit boards uses optical coupling via a free space by light receiving / light emitting devices arranged on each circuit board, interference between adjacent optical data transmission paths ( It is expected that crosstalk will occur and data transmission failure will occur. In addition, it is expected that data transmission failure will occur due to scattering of an optical signal due to an environment in the system frame, for example, dust or heat. Japanese Patent Application Laid-Open No. S61-196210 discloses a method of optically coupling circuit boards through an optical path constituted by a diffraction grating and a reflection element arranged on a plate surface. In this method, light can be transmitted only between two points, and a plurality of circuit boards cannot be connected in various combinations like an electric bus. Also, several patents have been devised regarding data transmission between circuit boards using an optical connection device having a branching element. JP-A-58-42333 discloses 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 is increased, and optical alignment with a light emitting / receiving device is required for each mirror. Also,
The transmitted light that has passed through the half-mirror has almost half the light intensity compared to the incident light.Therefore, if the light is repeatedly branched and transmitted multiple times, the light intensity will be weak, and sufficient light intensity for light reception by the light receiving device will be obtained. There is a problem that signal transmission is effectively disabled. Japanese Patent Application Laid-Open No. H4-134415 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 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 becomes. Therefore, there is a concern that the intensity of the output signal varies depending on the positional relationship between the incident position and the output position. Further, since the ratio of light incident from the side surface to escape from the opposite side surface is high, the utilization efficiency of the incident light amount is low.

Japanese Patent Application Laid-Open No. 63-1223 discloses an optical bus system using an optical fiber capable of transmitting substantially uniform optical signals by sequentially increasing the branching ratio from the input end. A method of forming a coupler applicable to such a method is described in IEEE Photonics Technology Letters, Vol.
o.12, December (1996). The method of forming the coupler shown here is based on the V
Branching is performed by the groove. By adjusting the size of the V-groove, it is considered that the output light quantity can be adjusted. However, it is very difficult to make the output, and the utilization efficiency of the incident light quantity is low. Also, a star coupler for equalizing the intensity of a branched optical signal is disclosed in Japanese Patent Application Laid-Open No. 9-184941. This star coupler bundles and fixes one end of a plurality of optical fibers,
A light guide path large enough to cover the plurality of optical fibers is in contact with the end face, and the other end face is provided with a light diffuse reflection means. When data transmission between circuit boards is performed using such a coupler, if the number of connection boards increases, the number of fibers connected to the light-receiving / light-emitting elements increases, which complicates the configuration and increases the size of the device. Problems arise.

[0006]

SUMMARY OF THE INVENTION In view of the above facts, the present invention is suitable for an optical data bus shown in Japanese Patent Application No. 11-254057 filed earlier and a layout of a plurality of circuit boards or devices and its layout. To provide an optical data bus. In Japanese Patent Application No. 11-254057, an optical data bus is provided, in which the intensity of an emitted optical signal is substantially uniform, and a bus system with high optical signal utilization efficiency can be provided.

[0007]

According to a first aspect of the present invention, there is provided a first optical signal in which a plurality of input / output sections for inputting / outputting an optical signal are formed in a step-like manner. A transmission device and a second optical signal transmission device or a first optical signal transmission device in which a plurality of input / output portions for inputting / outputting an optical signal are formed in a stepped shape, and a plurality of connectors are provided. A support substrate, a circuit for processing the optical signal, and first input / output means for inputting / outputting the optical signal via the input / output unit opposite to the input / output unit of the first optical signal transmission device;
A second input / output unit that faces the input / output unit of the second optical signal transmission device and inputs / outputs the optical signal via the input / output unit or a connector to be connected to the connector; The distance between the first input / output unit and the second input / output unit or the connector is set substantially in common, and a plurality of circuit boards are installed upright with respect to the first optical signal transmission device. Wherein the plurality of circuit boards are arranged on the first optical signal transmission device so as to be substantially orthogonal to a line connecting the plurality of input / output sections of the first optical signal transmission device. A signal processing circuit characterized by the following.

According to the first aspect of the present invention, the design and manufacture of the base are facilitated, and the alignment when the circuit board and the base are combined is facilitated.

According to a fifth aspect of the present invention, there is provided an optical signal transmission device in which a plurality of input / output portions for inputting / outputting an optical signal are formed in a step shape, and a plurality of connectors supporting the optical signal transmission device and having a plurality of connectors. A support substrate provided, wherein the optical signal transmission device and the support substrate are provided such that a line connecting the plurality of input / output sections and a line connecting the plurality of connectors are substantially parallel to each other. An optical bus device is provided.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 is a schematic block diagram of a signal processing apparatus according to the present embodiment. In the present embodiment, an optical data bus 30 having a plurality of optical signal transmission devices 10 is fixed on a support substrate 20, which is a base. At this time, the lower surface of the optical data bus 30 is
It is fixed so as to be parallel to the upper surface of the zero.

The support board 20 has a circuit board connector 40 for mounting the circuit board 50, and the plurality of circuit boards 40 are perpendicular to the support board 20 by the circuit board connector 40. Are erected in parallel with each other. The plurality of circuit boards 50 are optically connected by the optical data bus 30.

Each of the plurality of circuit boards 50 has a plurality of light-emitting / light-receiving elements 52 and light-emitting / light-receiving elements 5 as input / output bodies.
An electronic circuit 51 is provided for processing the optical signals input and output from 2. The light-emitting / light-receiving elements 52 are arranged at predetermined intervals 54, and the plurality of circuit boards 50 are
And the interval between the circuit board connectors 40 is the same.

The support board 20 has an electric wiring 21 for power supply and electric signal transmission. The plurality of electric wirings 21 are provided on the circuit board 50 mounted on the circuit board connector 40 via the circuit board connector 40. It is electrically connected to the electronic circuit 51.

FIG. 2A shows an example of the optical signal transmission device 10 constituting the optical data bus 30. Optical signal transmission device 1
0 has the translucent medium 1. In the translucent medium 1, a plurality of incident / emission sections 13 into which an optical signal is incident are formed in a stepped shape having a step 12. On the side 25 opposite to the side on which the step-like step 12 is formed, the reflection layer 2 as the first reflection surface is disposed. The end face 23 of the incident / exit portion 13 is formed at an angle of 45 ° with respect to the upper surface of the translucent medium 1 so that the optical signal enters and exits perpendicular to the upper surface of the translucent medium 1.

As the reflection layer 2, a metal mirror surface of Al or the like may be used, or a reflection type diffusion layer may be used. The reflection type diffusion layer is, for example, a beam shaping diffuser: LSD (Physic
al Optics Corporation) to control the spread angle in the thickness direction and the spread angle in the width direction of the diffused light signal with respect to the translucent medium 1 so that the intensity of the emitted light is made uniform over the entire emission portion. Accuracy can be improved. The reflective diffusion layer
A reflective surface such as Al is deposited on a transmission type LSD formed by transferring a hologram surface that diffuses incident light at a predetermined diffusion angle to an epoxy layer arranged on a transparent substrate material such as polycarbonate, and formed. Is done. In addition, a reflective substrate (for example, Al
A hologram surface for diffusing incident light at a predetermined diffusion angle may be transferred and formed on an epoxy layer of a transparent substrate on which is deposited a film.

When a metal mirror surface of Al or the like is used for the reflection layer 2, the optical signal transmission device 10 has a reflection type diffusion layer so that an optical signal is transmitted to the entire area of the input / output section 13 of the optical signal transmission device 10. It is formed longer than the optical signal transmission device 10 having the used reflection layer 2.

FIG. 2B shows the input and output directions of the optical signal in the optical signal transmission device 10 shown in FIG. 2A. Here, of the plurality of input / output units 131, 132, 133, and 134, the light enters from the input / output unit 131, and the input / output units 131, 1
The case where light is emitted from 32, 133, and 134 will be described.

The optical signal is incident on the entrance / exit portion 131 from the top to the bottom along the thickness direction of the translucent medium 1. The incident optical signal is totally reflected at the end face of the input / output unit 131,
The light travels substantially straight in the translucent medium 1 in the longitudinal direction, and reaches the reflective layer 2. The optical signal arriving at the reflective layer 2 is reflected by the reflective layer 2 and propagates through the translucent medium 1 by reflection.
It is led to all areas 132, 133, and 134. The optical signal is totally reflected by the end faces of the input / output units 131, 132, 133, and 134, and emitted from the input / output units 131, 132, 133, and 134 from bottom to top along the thickness direction of the translucent medium 1. Is done.

In this embodiment, the optical signal transmission device 10 having the four input / output units 131, 132, 133, and 134 has been described, but the number of input / output units is not limited to this. Further, a cladding layer (not shown) having a smaller refractive index than that of the translucent medium 1 can be disposed on the upper and lower surfaces or the side surfaces in the longitudinal direction of the translucent medium 1. The translucent medium 1 surrounded by the cladding layer functions as a core forming a light guide path.

As the translucent medium 1, a plastic material such as polymethyl methacrylate, polycarbonate, amorphous polyolefin, or inorganic glass can be used. Further, the step-like steps of the translucent medium 1 may be formed by grinding, or when the translucent medium 1 is made of a plastic material, it may be formed by a method such as injection molding. Good.

The plurality of circuit boards 50 are connected to the optical data bus 30.
Are optically connected to each other. That is, the light emitting / light receiving elements 52 on each circuit board 50 are connected by the optical data bus 30. Therefore, the optical signal emitted from the light emitting / receiving element 52 is first made incident on the optical data bus 30 and emitted to the other light emitting / receiving element 52.

That is, the optical signal incident on the input / output unit 131 is generated by the electronic circuit 51 on the circuit board 50 and emitted from the light emitting / receiving element 52. Also, the input / output unit 13
Optical signals emitted from 1, 132, 133 and 134 are as follows:
The light is received by the light emitting / receiving element 52 on the circuit board 50 and analyzed by the electronic circuit 51 on the electric signal circuit board 50.

In the present embodiment, since the optical data bus 30 is composed of a plurality of optical signal transmission devices 10, transmission and reception of parallel optical signals composed of a plurality of bits and independent simultaneous transmission and reception of each bit are possible. .

FIG. 9 shows that the present inventors filed Japanese Patent Application No. 11-2.
FIG. 5 is a diagram illustrating an arrangement of an optical data bus 30 and a circuit board 50 using a plurality of optical signal transmission devices 10 disclosed in Japanese Patent No. 54057. The sides 25 having the reflective layer 2 of each optical signal device 10 are arranged in a line, and the input / output section 13 is arranged so as to correspond to each of the input / output bodies 52 of the circuit board 50. Therefore, the end surface 56 of each circuit board 50 is not located on the same plane, and the side 23 of the light emitting / receiving portion in the width direction of the optical signal transmission device 10.
(See FIG. 2).

On the other hand, in the present embodiment, as shown in FIG. 3, the input / output sections 13 of the optical signal transmission device 10 correspond to the input / output bodies 52 of the circuit board 50, respectively. The plurality of circuit boards 50 are arranged to be inclined by θ °. Thus, by arranging the optical signal transmission device 10, it becomes possible to arrange the plurality of circuit boards 50 so that the end faces 56 are located on the same plane.
The circuit board 50 can be arranged in a bookshelf type as shown in FIG.

As shown in FIG. 9, a plurality of circuit boards 5
If there is a shift 29 in the end surface 56 of the zero, it is necessary to consider the shape of the optical data bus 30 when designing the support board 20 and the connector 40 for the circuit board. Design and fabrication becomes difficult. Also, when the support substrate 20 and the circuit board 50 are combined, the relative position is not horizontal or vertical, so that alignment is difficult. On the other hand, the arrangement as shown in FIG. 3 facilitates the design and manufacture of the support board 20 and the circuit board connector 40, and the alignment when the support board 20 and the circuit board 50 are combined. Becomes easier.

FIG. 5 shows an example of this embodiment. FIG.
Then, the maximum length of the translucent medium 1 in the longitudinal direction, that is, the side 1
5 is 60 mm, the maximum length in the width direction, that is, the side 25 is 4 mm, the thickness is 1 mm, the distance 11 from the end face where the reflective layer 2 is arranged to the nearest input / output section is 30 mm, and the length of the step-like step is 12
FIG. 2 shows an example using an optical signal transmission device 10 in which the width 23 of each input / output section is 1 mm (see FIG. 2). Here, each of the spaces 27 between the plurality of circuit boards 50 is 10.05 mm, and (1)
It is determined by the formula. Each circuit board 50 has the same design and emits light at the same position on the circuit board 50.
The light receiving element 52 is attached.

[0029]

(Equation 1)

In the equation (1), p is the distance 27 between the circuit boards (see FIG. 3), w is the width 23 of the input / output part, d
Indicates the length 12 of the step-like step.

Further, the optical signal transmission device 10 is
The angle θ between the optical signal transmission device 10 and the circuit board 50 when the optical signal transmission device 10 is mounted on the device is determined by equation (2). By attaching the optical signal transmission device 10 to the support substrate 20 at this angle θ, the circuit board 50 can be configured as a bookshelf type.

[0032]

(Equation 2)

[Second Embodiment] A second embodiment shown in FIG. 6 is an optical signal transmission device 10 according to the first embodiment.
3 (FIG. 3), and shows an example in which the shape of the optical signal transmission device 10 is modified.

That is, as shown in FIG. 6A, the angle θ at which the optical signal transmission device 10 is attached to the support substrate 20 is considered when designing the optical signal transmission device 10, and
A side 25 formed by intersecting the upper surface of the optical signal transmission device and the reflection layer 2 as the first reflection surface is opposed to the supporting substrate 20.
Is arranged on the support substrate 20 so as to be parallel to the side 72 of the above.

By forming the optical signal transmission device 10 in such a shape, the alignment becomes easy when the optical signal transmission device 10 is combined with the support substrate 20. Further, it does not significantly affect the uniformity of the transmission of the optical signal and the efficiency of using the optical signal.

Further, as shown in FIG. 6B, the entrance / exit surface of the entrance / exit portion 13 of the translucent medium 1 and the optical signal transmission device 1
0 may be arranged on the support substrate 20 so that the side 23 in the width direction formed by intersecting the upper surfaces of the 0 is parallel to the side 73 of the support substrate 20 facing the side 23.

[Third Embodiment] FIG. 7A shows a portion (a reflection layer 2) of a longitudinal side surface of an optical signal transmission device 10 having the arrangement shown in the first embodiment. Short side 2 with
5), a reflecting surface 4 which is a second reflecting surface.
An example is provided. The reflection surface 4 is formed as a flat surface, and the optical signal transmission device 10 is arranged on the support substrate 20 so as to be parallel to a side 71 of the support substrate 20 facing the reflection surface 4.

If the incident light from the entrance / exit portion 13 can be reflected directly or by the reflection surface 4 and guided to the end surface on which the reflection layer 2 as the first reflection surface of the optical signal transmission device 10 is arranged, Even if the signal transmission device 10 is formed in such a shape, the transmission uniformity of the optical signal and the utilization efficiency of the optical signal are not significantly affected. Further, similarly to the second embodiment, when the optical signal transmission device 10 is assembled to the support substrate 20, the alignment becomes easy.

Further, as shown in FIG. 7B, this embodiment is combined with the second embodiment, and the upper surface of the optical signal transmission device 10 and the input / output surface of the input / output unit 13 intersect. At least one of the side 23 formed in the width direction and the side 25 formed by intersecting the upper surface with the reflective layer 2 is parallel to the sides 71 and 72 of the support substrate 20 facing each side. And the optical signal transmission device 10 may be disposed on the support substrate 20. The reflection surface 4 uses total reflection conditions determined by the refractive index of the translucent medium 1 or reflection using a mirror surface such as Al.

[Fourth Embodiment] FIG. 8A shows an example in which the long side surface of the optical signal transmission device 10 is formed as a gentle arc-shaped reflecting surface 5.

By designing the optical signal transmission device 10 in such a shape, as shown in FIG. 8B, in the third embodiment, the condition of total reflection on the reflection surface 4 is not satisfied. The propagating light can be guided to the end face of the optical signal transmission device 10 where the reflection layer 2 is arranged, and the utilization efficiency of the optical signal can be increased.

Further, this embodiment is combined with the second embodiment, and as shown in FIG. 8C, the upper surface of the optical signal transmission device 10 and the input / output surface of the input / output unit 13 intersect. At least one of the formed side 23 in the width direction and the side 25 formed by intersecting the upper surface with the reflective layer 2 is parallel to the sides 71 and 72 of the instruction substrate 20 facing each side. The optical signal transmission device 10 may be formed and disposed on the support substrate 20.

[0043]

According to the optical data bus having a plurality of optical signal transmission devices and the plurality of circuit boards, or the device layout and the optical data bus suitable for the layout according to the present invention, the arrangement of the support substrate and the circuit board is achieved. Can be made into a bookshelf type layout. The layout in which the arrangement of the support board and the circuit board is a bookshelf type facilitates the design and manufacture of the support board, and also facilitates the alignment when the support board and the circuit board are combined.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of a signal processing device of the present invention.

FIG. 2 is a schematic configuration diagram of an optical signal transmission device according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a layout of an optical signal transmission device according to the present invention.

FIG. 4 is a schematic diagram showing an example of a bookshelf type layout.

FIG. 5 is a diagram showing a layout of an optical signal transmission device according to an example of the first embodiment.

FIG. 6 is a diagram illustrating a shape and a layout of an optical signal transmission device according to a second embodiment.

FIG. 7 is a diagram illustrating a shape and a layout of an optical signal transmission device according to a third embodiment.

FIG. 8 is a diagram illustrating a shape and a layout of an optical signal transmission device according to a fourth embodiment.

FIG. 9 is a diagram showing a conventional layout of an optical signal transmission device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 translucent medium 2 reflective layer 3 reflective diffusion layer 4 reflective surface 5 arc-shaped reflective surface 10 optical signal transmission device 13 input / output unit 20 support substrate 30 optical data bus 40 connector 50 circuit board

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04B 10/12

Claims (5)

[Claims] 1. A first optical signal transmission device in which a plurality of input / output sections for receiving and emitting optical signals are formed in a step-like manner, and a plurality of input / output sections for receiving and emitting optical signals are formed in a step-like manner. A second optical signal transmitting device or a supporting substrate supporting the first optical signal transmitting device and provided with a plurality of connectors; a circuit for processing the optical signal; and the first optical signal transmitting device A first input / output unit that faces the input / output unit and receives the optical signal through the input / output unit; and a unit that faces the input / output unit of the second optical signal transmission device via the input / output unit. A connector connected to the second input / output unit or the connector for inputting / outputting the optical signal, and the distance between the first input / output unit and the second input / output unit or the connected connector is The first optical signal transmission device is set to be substantially common to the first optical signal transmission device. A plurality of circuit boards mounted on the first optical signal transmission device, wherein the plurality of circuit substrates are disposed on the first optical signal transmission device with respect to a line connecting a plurality of input / output sections of the first optical signal transmission device. A signal processing circuit characterized by being juxtaposed and juxtaposed. 2. The optical signal transmission device according to claim 1, wherein the optical signal transmitting device reflects an optical signal incident from one input / output unit over an entire area of the input / output unit, and an optical signal incident from the input / output unit. A second reflection surface that reflects toward the first reflection surface, and a side formed by a second reflection surface of the input / output unit and an upper surface of the optical signal transmission device intersecting with each other; 2. The substrate according to claim 1, wherein at least one of sides formed by intersecting the upper surface and the first reflection surface is arranged on the base so as to be parallel to a side of the base opposed to the side. A signal processing circuit as described. 3. The signal processing circuit according to claim 2, wherein the second reflection surface is formed as a plane, and is formed as a plane in which one side of the base opposed to the second reflection surface is parallel. . 4. The signal processing circuit according to claim 2, wherein said second reflection surface is formed in an arc shape. 5. An optical signal transmitting device in which a plurality of input / output portions for receiving and outputting optical signals are formed in a stepped manner, and a support substrate supporting the optical signal transmitting device and provided with a plurality of connectors. The optical signal transmission device and the support substrate are provided such that a line connecting the plurality of input / output units and a line connecting the plurality of connectors are substantially parallel to each other. Optical bus device.