JPH0533119U - Space optical transmission device - Google Patents

Abstract

(57) [Abstract] [Purpose] To facilitate the angle adjustment of the light receiving part of the spatial light transmission device. [Structure] The received light is condensed on a photodiode 107 by a light-receiving lens, converted into an optical-electrical signal, and demodulated. on the other hand,
Photodiodes 122a to 122d for condensing position detection are arranged around or in the vicinity of the photodiode 107, and the outputs of the photodiodes are amplified and then input to the level determination circuit.
When the angle of the light receiving portion is deviated with respect to the received light, a signal is obtained not by the photodiode 107 but by another photodiode, so that it is detected by the level determination circuit 124 and the received light position is displayed or the angle is adjusted according to the result. Information display (moving direction display, etc.) The user can adjust the angle of the light receiving unit by this display and can normally receive and demodulate light.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a spatial light transmission device, and more particularly to adjustment of a light receiving angle of a light receiving section.

[0002]

[Prior Art]

 FIG. 6 shows a general configuration of a conventional spatial light transmission device. In the figure, 101 is an information signal input terminal for audio signals and video signals, 102 is a modulation circuit for modulating the input signal, 103 is an LED drive circuit for driving a light emitting diode (LED) 104 by the modulation signal, 104 Is an LED for outputting information as light driven by the drive circuit, 105 is a light-transmitting lens for adjusting the spread of the light of the LED 105, and 106 is the light received and focused on the photodiode 107. For receiving light, 107 is a photodiode for converting light into an electric current, 108 is an amplifier circuit for amplifying the signal converted into an electric signal, 109 is a signal received from the amplifier circuit 108 to demodulate the original audio signal or image. A demodulation circuit that restores an information signal such as a signal, and 110 is an output terminal that outputs a demodulated signal.

In the above-described structure, the light receiving lens 106 efficiently collects the light appropriately diffused by the light transmitting lens 105 as described above, and the energy is concentrated and input to the photodiode 107. To use. Therefore, ideally, the light receiving lens 106 and the photodiode 107 are arranged as shown in the schematic diagram of FIG. That is, the received light 111 input to the light receiving lens 106 is collected and all the collected light 112 is made to strike the surface of the photodiode 107, whereby the light energy is collected most efficiently.

[0004]

[Problems to be solved by the device]

 However, in the case where the light receiving section is configured as described above, in order to collect the light in the photodiode 107, it is necessary to accurately match the angle of the light receiving lens 106 with the received light 111. Do not focus light at the photodiode position.

The present invention has been made to solve the above problems, and an object thereof is to obtain a spatial light transmission device in which the angle of the light receiving lens can be easily adjusted.

[0006]

[Means for Solving the Problems]

 The spatial light transmission device according to the present invention is provided with another light receiving element for detecting a light condensing position in the vicinity of or in the vicinity of a photodiode for receiving light, converting it into an electric signal, and then performing demodulation. The information display means for displaying the light receiving position or adjusting the angle using the output of the light receiving element is provided.

[0007]

[Action]

 The display means in the present invention displays information for adjusting the position where the received light is collected or the angle according to the output of the light receiving element for detecting the light collecting position, whereby the user can adjust the position of the light receiving part. Or to provide information for making angle adjustments.

[0008]

【Example】

 Example 1. FIG. 1 shows an embodiment of the structure of the light receiving portion of the spatial light transmission device according to the present invention. In the figure, 120 is a D / A conversion circuit, 121 is an output terminal for analog audio signals, 122a to 122d are photodiodes for detecting a focus position, and 123a to 123d are amplifiers for amplifying outputs of photodiodes 122a to 122D, respectively. An amplifier, 124 is a signal level determination circuit for the outputs of the amplifiers 122a to 122d and 108, and 125 is a display circuit for displaying the deviation of the focusing position, that is, the light receiving state.

Further, FIG. 2 is a view for schematically showing the mounting position of the photo diode in the embodiment of FIG. 1, and is a view of the apparatus from the side. Further, FIG. 3 is a conceptual diagram showing an embodiment of the display portion of the display circuit in the embodiment of FIGS.

In FIG. 1, the received light is for transmitting digital audio information, and is a transmission format based on the Electronic Industries Association of Japan (EIAJ) standard CP-340 “Digital Audio Interface”, that is, bi-phase. It is assumed that the light is pulse-modulated by the modulated information. Normally, when the received light is condensed at a regular position, the light collected by the lens 106 hits the photodiode 107, and the opto-electrically converted signal is amplified by the amplifier 108 and detected and demodulated by the demodulation circuit 109. The digital audio signal is converted into an analog signal by the D / A conversion circuit 120 and then output from the output terminal 121.

Now, when the angle of the device including the light receiving lens 106 is shifted with respect to the received light, for example, when the light condensed by the lens is shifted downward from the photodiode 107 as shown in FIG. The received light is focused on. At this time, the received light is photoelectrically converted by the photodiode 122C, amplified by the amplifier 123C, and the output thereof is supplied to the level determination circuit 124. The level determination circuit 124 detects the signal level input from each amplifier, identifies the photodiode into which light is incident, and gives the result to the display circuit 125. Here, it can be seen from the output of the amplifier 123C that the received light is incident on the photodiode 122C, and the result is sent to the display circuit 125.

FIG. 3 shows an embodiment of the display unit, the display of which is composed of five LED display elements. When the photodiode 122C is exposed to the received light, the shaded LED in FIG. 3 emits light to inform the user that the lens surface needs to be moved slightly upward. On the contrary, when the condensed light is shifted upward from the photodiode 107, the lens surface is displayed to move downward, and the correct light reception is performed when the central LED in FIG. 3 is turned on. I try to show that.

FIG. 4 is a conceptual diagram showing the arrangement of the photodiodes at this time as seen from the front of the lens 106. The photodiodes are arranged in a line in the y-axis direction. In such an embodiment, the angle adjustment of the light receiving portion including the lens 106 can be performed by the following procedure. A: First, the lens surface is moved in the x-axis direction, and the X-axis direction is fixed at a position where one of the LEDs shown in FIG. 3 lights up. B: Next, the lens surface is moved in the y-axis direction, and the y-axis direction is also fixed at the position where the central LED of the display section in FIG. 3 lights up.

Example 2. FIG. 5 is a conceptual diagram showing another embodiment of the arrangement of photodiodes, in which photodiodes for detecting a light receiving position are circumferentially arranged around a photodiode 107 for receiving a signal. In this case, the angle adjustment can be performed more easily without performing the angle adjustment according to the above-described procedure for each of the x-axis and the y-axis as in the example of FIG. Further, as an example of the display method in this case, a display indicating the movement direction as shown in FIG. 3 and not only the y-axis direction but also the movement in the x-, y-axis and oblique directions can be considered.

In the above description, the angle adjustment is performed while receiving the light modulated by the information signal, but the purpose is to adjust the angle of the light receiving portion with respect to the received light. Therefore, unmodulated light may be received. In this case, the photodiode for detecting the focusing position and its amplifier can be used because of their slow response speed, which has the advantage of cost reduction.

[0016]

[Effect of the device]

 As described above, according to the present invention, a light-receiving element for detecting the light-condensing position is separately provided, and the output of this light-receiving element is used to display for the light-receiving position or angle adjustment. Since it is configured, there is an effect that it becomes easy to adjust the angle of the light receiving portion.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a light receiving unit of a spatial light transmission device according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a form of a light receiving unit of a spatial light transmission device according to an embodiment of the present invention.

FIG. 3 is a conceptual diagram showing a display unit of a spatial light transmission device according to an embodiment of the present invention.

FIG. 4 is a conceptual diagram showing an arrangement of light receiving elements of a spatial light transmission device according to an embodiment of the present invention.

FIG. 5 is a conceptual view showing an arrangement of light receiving elements according to another embodiment of the present invention.

FIG. 6 is a configuration diagram of a light transmitting unit and a light receiving unit of a conventional spatial light transmission device.

FIG. 7 is a schematic diagram showing a light collecting state of a light receiving portion of a conventional spatial light transmission device.

[Explanation of symbols]

 106 light receiving lens 107 photodiodes 122a to 122d light collecting position detecting photodiode 124 level determination circuit 125 light receiving position information display section

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location H04N 5/30 Z 8838-5C 7/22 8943-5C (72) Creator Sadanobu Ishida Kyoto Prefecture Nagaokakyo No. 1 Ichibaba Institute, Electronic Product Development Laboratory, Mitsubishi Electric Corporation

Claims (2)

[Scope of utility model registration request] 1. A spatial light transmission device for transmitting an information signal from a light transmitting section to a light receiving section by using light, wherein the light receiving section condenses the light into one or a plurality of light receiving elements by a lens. In a plurality of second light receiving elements arranged so as to surround the light receiving element, and means for displaying information for adjusting the light condensing position or the angle of the light receiving portion by a signal obtained from the second light receiving element. A spatial optical transmission device comprising: 2. A spatial optical transmission device for transmitting an information signal from a light transmitting section to a light receiving section using light, wherein the light receiving section condenses the light onto one or a plurality of light receiving elements by a lens. In, a plurality of second light receiving elements arranged on a straight line including the light receiving element and information for adjusting the light condensing position or the angle of the light receiving portion are displayed by a signal obtained from the second light receiving element. And a means for spatial light transmission.