JPS61284128A - Signal transmission device - Google Patents

Abstract

PURPOSE:To obtain a signal transmitter with a small size and low cost making it possible to send the plural sets of information in parallel by using an electromechanical transducing element and a photodetector. CONSTITUTION:An electric signal is converted into an optical signal by using a DND element. In a DMD element, N<+> source, drain 8, 9 are provided on a P-channel Si 11, a base 7 and a polysilicon Si gate 5 are provided via an insulation film 4 and an Al reflection mirror 1 is supported by an Au plate 2 on a hinge 3. In giving a voltage VM to members 1, 2 and applying a drain signal D and a gate signal G, a potential difference between the members 1, 2 and the source 8 is changed to give the stress to the members 1, 2 and the electrode 8 and they are folded at the hinge. The DMD 100 is driven by using a signal inputted to a drive circuit 101 to project the reflected light to the photodetector 102 via a short focus lens 105 and the signal from the photodetector 102 is stored temporarily. Through the constitution above, a connector of small size and low cost sending plural sets of information in parallel is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a signal transmission device used in electronic equipment, communication lines, etc.

[Prior art]

Conventionally, this type of device 1, for example, a non-contact connector, uses a combination of a light emitting element and a light receiving element to transmit information using light as a medium. At this time, information is digitally encoded by directly energizing the light emitting element. However, when the number of information paths increases and the number of devices that need to be connected by connectors increases, increasing the number of light emitting elements increases the size and increases the cost even if an LED array or the like is used.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to provide a compact signal transmission device that eliminates the drawbacks of the conventional example described above and can connect a plurality of signal lines in parallel.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

First, a DMD, which is one of the electromechanical elements used in this example,
(Deformable Mirror l1svi
ce) will be explained.

Regarding DMD devices, IEE Iransact
ion on Electron Device V
ol, ED-30No, 5544 (1983
), and the optical system was also described in JP-A-59-1.
No. 7525.

Figure 2 (a) shows a cross-sectional view of the DMD. 1 is a mirror structure made of materials such as KL and Ag and plays a role in reflecting incident light. 2 is a substrate that supports the mirror structure 1 and is made of Au, etc. Consists of. Numerals 3 and 4 are 1.degree.2 support members, 3 is called a mirror contact, and is for receiving a diaphragm that performs an electromechanical operation, and 4 is an insulating material of polyoxide Si.

5 is a polysilicon gate, which shows the role of the gate of FET MO3) tensister, 6 is an air gap, o, e
=~How many tiles are empty? 7 is a floating field plate, and 7 is floating based on transistor ON/OFF information from the N+ floating source of 8.

Voltage is applied to the field blade. 9 indicates the N+ drain, which also serves as a configuration of a run sister (MO3 type FET). 10 is a gate oxide, and 11 is a P-type silicon substrate. FIG. 2(b) is a perspective view taken from direction A in FIG. 2(a), where 12 is an air gap, 13 is a part of the mirror that slides electromechanically, and 14 is a bottom part. 15
indicates a mirror part of the DMD surface, DMD is an IC or LS
It is manufactured using a process similar to I.

FIG. 2(C) shows an electrical equivalent diagram, 16 shows the voltage VM applied to the mirror and support member of 1.2, 17 shows the voltage VF applied to 8, 18 shows the transistor configuration, Turn on the D (drain) signal of 9 and the G (gate) signal of 5.

OFF J:S VF (7) Voltage is 8 + 7) ON, O
It will be FF. At this time, voltage V% is applied to 1.2.

The potential difference between 1.2 and 8 is increased or decreased by the ON and OFF signals. At this time, a force F according to the following equation is generated between 6.7 and 6.7 depending on the potential difference.

FφKV” (K: constant v: it position difference α: constant a F
: bending force) The mirror 1.2 is swung by the hinge portion 14. Figure 2 (a
) The left figure shows the case where there is a large voltage difference between 1.2 and 8, the mirror bends from the hinge, and due to this action, the incident light is reflected at an angle twice the deflection angle of the mirror. .

On the other hand, when the voltage difference is small, as shown in the right figure of Figure 2 (&), part of the mirror 1.2 is pulled by 7 and is not bent, so the incident light does not touch the mirror. It will be reflected. DMD element is electrically ON
, OFF is converted into ON/OFF of the rocking of the mirror, and further converted into the deflection angle of the light.

An electrical signal is converted into an optical signal using the DMD element described above.

FIG. 1 is a diagram showing the basic configuration of this embodiment.

In FIG. 1, 100 is a DMD element.

102 is a light receiving element, which is a phototransistor.

Alternatively, it may be a solid-state image sensor (COD) or the like. 101 is DM
This is a driving circuit for the D element, and drives the DMD element 100 based on a signal input to the driving circuit 101. 103
is a buffer that temporarily stores the signal from the light receiving element 102. Reference numeral 105 denotes a short focus lens for causing the light irradiated from the DMD element lOO to the light receiving element 102 to be irradiated from the corresponding DMD element to the light receiving element 102, respectively.

FIG. 3 is a diagram showing the configuration of one embodiment.

In FIG. 3, 111 is a plug, 111 is a socket, and 104 is a light source for illuminating the DMD element 100, which is composed of a light bulb such as a halogen lamp, a light emitting diode (LED), or the like. Note that the light emitting source may be one, or a plurality of light sources may be provided.

Reference numeral 101' denotes a transmitting section consisting of a DMD element 100 and a drive circuit 101. 102' is the light receiving element 102 and the buffer 1
03.

When the signal input to the drive circuit 101 of the DMD element 100 is OFF (in the case of a "0" signal), the mirror part of the DMD element 100 is not curved, so the light from the light emitting source 104 is transmitted to the mirror part of the DMD element 100. The light is reflected by the light blocking section 105
', and the light does not reach the receiving section 102'.

Also, when the above input signal is ON (in the case of "l" signal),
A portion of the mirror of the DMD element 100 is curved, and the light from the light emitting source 104 reflected by the portion of the mirror passes through a short focal length lens 105 and reaches the receiving section 102'.

When the light receiving element 102 of the receiving section 102' detects light, it outputs an ON signal (a "1" signal) to the buffer 7103, and when it does not detect light, it outputs an OFF signal (a "0" signal). The signal is then temporarily docked by the buffer 103 and then output as an output signal.

Since DMD elements can be formed on a Si substrate at intervals of 50 hiro, a large number of electromechanical transducer elements can be arranged in a line. This allows a plurality of pieces of information to be transmitted in parallel by a plurality of DMD elements and a plurality of light receiving elements as shown in FIG.

In addition, in FIGS. 1 and 3, a short focus lens 105 is used to direct light from a light emitting source 104 to a corresponding DMD.
Although the configuration is such that the light is irradiated from the element to the light-receiving element, a short focus lens is placed between the light emitting source 104 and the DMD element lOO to create parallel light.
Light may be irradiated from the MD element to the light receiving element, or an optical fiber may be used for each instead of a short focal length lens.

In Figure 3, each element is housed in a housing and outputs its own signal line, but in Figure 4, each element is placed directly on a printed circuit board and is configured to allow communication between printed circuit boards. FIG.

In FIG. 4, 106 and 107 are printed circuit boards,
The printed circuit board is positioned using guide rails or the like. Input signal bin 109. Output signal bins 108 are each connected directly onto printed circuit boards 106 and 107.

The operations of the transmitter ioo' and the receiver 102' are the same as in the case of FIG. 3, but in the case of FIG. It is configured to irradiate a portion of the mirror of the DMD element 100 in the section 100'. In this case, the printed circuit board 106 is arranged so that light is irradiated from the corresponding DMD elements to the light receiving elements.
, 107 must be fixed.

Therefore, the input signal bin 109 and the output signal bin 108 may be connected by an optical fiber 112 as shown by the fifth UgJ.

The optical fiber 112 in FIG.
This corresponds to the optical fiber of the book, and in the case of Fig. 5, multiple pieces of information can be sent in parallel.

In the above, we have explained the case where the input/output signal is a digital signal, but the DMD element is configured to detect the amount of light because the deflection angle of the mirror changes depending on the analog signal and the amount of light irradiated to the light receiving element changes accordingly. In this case, the input/output signals may be analog signals.

Further, when light is detected by the light receiving element, an analog input signal can be output as a digital signal by providing a threshold value at a predetermined amount of light.

〔effect〕

As explained above, according to the present invention, since an electromechanical transducer and a light receiving element are used, it is possible to provide a compact and low-cost interlocking connector that can transmit a plurality of pieces of information in parallel.

[Brief explanation of drawings]

Figure 1 shows the basic configuration of this embodiment, Figure 2 shows the DM
FIG. 3 is a diagram showing the configuration of this embodiment. FIG. 4 is a diagram showing an example of application of this embodiment, and FIG. 5 is a diagram showing an example of application of this embodiment. 100 is a DMD element, and 101 is a drive circuit. 102 is a light receiving element, 103 is a buffer, 104 is a light emitting source, 105 is a short focus lens, and 1.05' is a light shielding plate.

Claims (1)

[Scope of Claims] An electromechanical transducer that reflects light from a light source, a control means that controls the electromechanical transducer based on an input signal, and a detection means that detects the light from the electromechanical transducer. . A signal transmission device, characterized in that the control means and the electromechanical conversion element convert an input signal into an optical signal, and the detection means outputs the optical signal as an electric signal.