JPS6399676A - Remote receiver - Google Patents

Abstract

PURPOSE:To cause a numerous people to simultaneouly listen to desired sound in a limited space such as a same room, an office and to view a related video by providing a sound originator which has a first and a second light-receiving parts and which supplies a sound signal obtained by demodulating an output signal from the second light-receiving part to an electric acoustic converter. CONSTITUTION:If a signal from a sound signal source and a video signal source are supplied to a transmitter 7, it PCM-modulates and time divisionly multiplex the audio signals of plural channels, and generates laser beams modulated by the multiplexed signals from a light-emitting part 8. A video projector as a display device and a headphone device as the sound originator are provided in the same room as a stereo reproducing device and a television receiver 6. The light-receiving part 13 which receives light beams from the light-emitting part 8 in the transmitter 7 is provided on the top part of a fitting band 12 in the headphone device 11, and a circuit device 14 such as decoder circuit and an amplifier is provided along the rear surface of the fitting band 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a remote receiving device for remotely receiving audio signals and video signals.

When enjoying music etc., the audio source is
There are radio receivers, record players, television receivers, VTRs, etc. In this case, the television receiver, V
In TR, the audio that is played is incidental to the video.

Traditionally, using a common audio source (equipment),
For example, it was not possible for one person to listen to a record and another to watch television, or for each person to independently switch the type of audio.

In view of this, the present invention has a simple configuration and a common audio signal source and video @! Using a signal source, any number of people can arbitrarily select and reproduce the audio signal from the audio signal source and the audio signal from the video signal source, as well as the audio signal from the video signal source. The purpose of this project is to propose an apparatus that can simultaneously reproduce the video signal when selecting and reproducing the video signal.

An embodiment of the present invention will be described below with reference to FIG. As is well known, a stereo playback device is a device V'r consisting of a record player (1), an amplifier (2), a receiver (3), speakers (4a), (4b), etc.
An R (video tape recorder) (5) and a television receiver (6) connected thereto are added.

Signals from these audio signal sources and video signal sources are supplied to a transmitter (7). As will be described later, the transmitter (7) performs PCM modulation and time division multiplexing on the audio signals of multiple channels, frequency multiplexes a low-quality video signal on this multiplexed PCM signal, and uses this multiplexed signal to A modulated laser beam is generated from a light emitting section (8). The modulated video signal is formed from a television signal provided by a VTR (5) or received by an antenna (9).

The above-mentioned stereo playback device and television receiver (6)
A video projector (10) as a display device is installed in the same room as the video projector (10), and an image projected by the video projector (10) can be enlarged and displayed on a screen (not shown).

(11) represents the headphone device as a whole as a sounding device. Mounting band (12) for headphone device (11)
A light receiving section (13) for receiving light from the light emitting section (8) of the transmitting fi +71 is provided on the top of the transmitter FI+71, and circuit devices such as a decoder circuit and an amplifier are installed along the back side of this mounting band (12). (14) is provided.

Furthermore, there is a uni-throat storage section (1) that can be pressed against the left and right ears.
5L), (15R) and a selection means for extracting the PCM signal of the channel provided on the side of the case,
That is, the channel select switch (16L).

(16R) and volume adjustment knob (17L), (
1711), the headphone device (11) includes.

Although only one henodobon device (11) is shown in FIG. 1, a plurality of headphone devices (11) can be used by a plurality of people in the same room. Some people listen to the disc playback sound from the record player (11), others listen to the FM stereo broadcast from the receiver (3), and still others listen to the playback video from the V'r R+51 through the video projector (3). ]0), you can listen to the playback sound on the headphone device, and which audio to listen to is determined by each headphone device (3j!iIJ+!).
Channel select switch (16) installed in
L) and (16R). Also, in this example, the video projector (10) is connected to the transmitter (7).
A light receiving section (18) is provided to receive light from the
A mixer and video detector that converts the frequency of the output signal from the light receiving section (18).

A video amplifier and the like are housed within the video projector (10).

FIG. 2 shows the configuration of the transmitter (7). In FIG. 2, (20a) to (20h) indicate eight input terminals, each of which is supplied with an audio signal. For example, input terminals (20a) and (20b) are supplied with stereo signals reproduced from a record player (1), and input terminals (20c) and (20d) are supplied with a stereo signal from a receiver (
3) is supplied to the input terminal (2).
0e).

(2Of) 2 is supplied with the VTR (6) and (7) playback audio signals, and the input terminals (20g) and (2
0h) is supplied with two-channel audio signals (stereo signals, signals from two countries) extracted from audio multiplex broadcast radio waves. The television signal is transmitted through the antenna (
9), the audio signal is extracted from the output of a tuner (not shown) installed in the transmitter (7), and the video signal is sent to VHF 1m on the sky channel (channel 2 in the Tokyo area). The modulated video signal is frequency-multiplexed into a multiplexed PCM signal as described below.

An amplifier (21a) is connected to the input terminals (20a) to (20h).
) to (21h) and level adjusters (22a) to (2
2h) are connected respectively, and the 8 channels of audio signals passed through these are sent to the sampling multiplexer (2h).
3) is time-division multiplexed.

The output of the sampling multiplexer (23) is PCM modulated by the sampling hold circuit (24) and the A/D converter (25), and the parallel code from the A/D converter (25) is converted by the parallel-to-serial converter (26). The signal is converted into a serial code, and after unnecessary signal components are removed by a low-pass filter (27), it is supplied to a mixer (28). The mixer (28) is supplied with a modulated video signal, a frame synchronization pulse Fp, and a word synchronization pulse Wp, which are supplied to an input terminal (29) via a bypass filter (30).

FIG. 3 shows an example of PCM data generated from the mixer (28), in which each word F'W a s to W of the PCM signal of each channel is generated during one frame period defined by the frame synchronization pulse Fp. h1 are arranged sequentially.

One word, for example W c 1, is a word synchronization pulse (1 bit) and data bits (8 bits).

It has a total length of 10 bits including parity bits for error detection. Numerical values such as the length of one frame and the length of data bits are not limited to these, and can be selected from various values. Further, as shown in FIG. 4, the modulated video signal Sv is frequency-multiplexed so that it is located on the higher frequency side of the transmission data Sd.

A multiplexed signal of the transmission data Sd and modulated video signal Sv is supplied to a laser oscillation and drive circuit (31),
The output signal of the laser oscillation and drive circuit (31) is supplied to the semiconductor laser of the light emitting section (8), thereby generating modulated laser light from the light emitting section (8). In this case, a laser beam with a color close to a single spectrum is used, and a diffused laser beam is generated for safety and to prevent the light-receiving area from becoming narrow.

(32) indicates a reference oscillator, which generates a bit timing pulse of the focus period, and the bit timing pulse is divided by a counter (33) to generate a word timing pulse of 1ull word period, and then a word timing pulse of 1ull word period. The timing pulse is frequency-divided by a counter (34) to generate a frame timing pulse of a frame period. A word synchronization pulse Wp and a frame synchronization pulse Fp are generated from a synchronization signal generator (35) to which word timing pulses and frame timing pulses are supplied.

Further, the sampling multiplexer (23) is switched in word cycles by the parallel outputs of the counter (33). Further, the word timing pulse is supplied to the sampling hold circuit (24), and the bit timing pulse and word timing pulse are supplied to the A/D converter (24).
5) and a parallel-to-serial converter (26). Furthermore, the counter (33) is activated by the frame timing pulse.
is being reset.

The configuration of the headphone device W (11) will be described in detail with reference to FIGS. 5 and 6. The laser light is converted into an electrical signal by the light receiving section (13) and supplied to the low-pass filter (37) via the amplifier (36).

The light receiving section (13) includes a PIN photodiode and an avalanche photodiode (electron avalanche multiplication factor 100 to 20).
It is composed of a photodetecting element such as a light detecting element (which allows digital light to be received at 0) and a condensing means, some specific examples of which are shown in FIG. The configuration shown in FIG. 6A is a glass spherical lens (
A photodetecting element (54) is embedded at the focal point of the artificial diamond spherical lens (53'), and the configuration shown in FIG.
) is embedded. In addition, the configuration shown in FIG. 6C is such that a photodetector (54) is provided at the condensing position of the concave mirror (55) with a hemispherical curved surface, and a multilayer film interference filter that allows only a specific spectrum to pass through the light incident surface. A filter (dichroic filter) (56) is provided. A condensing means such as a spherical lens (53), (53') or a concave mirror (55) and a multilayer interference filter (5)
6), it is possible to efficiently extract only the transmitted light while distinguishing it from noise.

Furthermore, the low-pass filter (37) is for removing the modulated video signal 3v frequency-multiplexed into the multiplexed PCM signal Sd. This low pass filter (37)
The output of is supplied to the channel gate circuit (40) via the pulse amplifier (39).

This channel gate circuit (40) is controlled by select signals from channel selectors (4LL) and (41R), and controls PCM of 8 channels in one frame.
Among the signals, only the I) CM signals of two predetermined channels are extracted and supplied to the serial-parallel converter (42).

The multiplexed PCMrN signal from the pulse amplifier (39) is supplied to the synchronization separation circuit (43), thereby extracting the word synchronization pulse Wp and the frame synchronization pulse p. These synchronization pulses are fed to a pulse generator (44).

The pulse generator (44) is configured as an AFC circuit or the like, and generates a bit timing pulse that is synchronized with the received multiplexed PCM signal. From this bit timing pulse, counters (45) and (46) form word timing pulses and frame timing pulses for the reception system. A select signal is formed by supplying both timing pulses to channel selectors (41L) and (4111). A select signal at a predetermined timing for each frame is generated by a code signal generated according to the state of the channel select switches (16L) and (16R'').

For example, the transmitter input terminal (20a), (20
2-channel PCM signals corresponding to the audio signals supplied to the serial-to-parallel converter (42
).

PC for 2 channels from serial-parallel converter (42)
The M signal is supplied to D/A converters (47L) and (47R), and their analog outputs are supplied to sampling and hold circuits (48L) and (48R), respectively.

Series-parallel converter (42) and D/A converter (47L)
.

Bit timing pulses and word timing pulses are supplied to (47R), and word timing pulses are supplied to sampling hold circuits (48L) and (48R).

As described above, the PCM signals of two channels selected from among the eight channels are PCM demodulated. Although not shown, an error detection circuit using parity pits may be provided on the output side of the channel gate circuit (40). and a low pass filter (49L).

(49R) and sampling hold circuit (48L).

(48R) output is supplied, and a level adjuster (50R) is supplied.
L>, (50R) and amplifier (51L),
The signal passed through (51k) is the acoustic unit) (521,
'), added to (52R). Sound unit (
52L), (52R) are headphone devices (11
) unit storage compartment (15L).

(15R) and a level adjuster (5R).
0L'), (50R) are the volume adjustment knobs (1
7L).

(17R) is operated. sound unit) (52L).

(52R) may be of any type, such as an electromagnetic type or an electrostatic electromagnetic type.

Note that the modulated video signal Sv taken out by the light receiving section (18) of the video projector (10) is subjected to frequency conversion,
The signal is detected and amplified to produce a video signal, and this video signal is applied to a cathode ray tube of a video projector (10). Furthermore, the reproduction signal of each track by a multi-channel tape recorder may be supplied to the input terminals (20a) to (20h) of the transmitter (7). Furthermore, the transmitted light may be distributed to other rooms via optical fibers.

According to the present invention, an arbitrary number of people can select a desired channel from multiplexed multi-channel PCM audio signals and listen to it using a sounding device (headphone device), and a display device (video projector). This allows many people in a limited space, such as nine companies in the same room, to listen to the sound of their choice using their own sound production devices, as well as listen to the sound related to the audio signal of the selected channel. You can also watch videos.

Also, since the audio signal is converted to PCM, S
High quality sound with good /N can be reproduced, and the circuit device provided in the headphone device can be made small and lightweight. Furthermore, since light is used as the transmission medium,
Unlike when using radio waves, there is no unnecessary radiation to the outside, no interference with other radio waves, and no reception range limited by directivity, resulting in good reconstructed images and reproduction. It has the advantage of producing sound.

Furthermore, in the present invention, since the audio signal and the video signal are multiplexed and optically transmitted, there is no need to provide a transmitter for each transmission signal, and a single transmitter is sufficient. Furthermore, if there are multiple sets of display devices or sound production devices each equipped with a light receiving section on the receiving side, the number of devices that can be connected is limited by the output terminal of the display device or sound production device when connecting with a connection cord in the past. In the case of the present invention, there is no such restriction as long as the transmitting light is within the reachable range, and a remote receiving device can be obtained in which the installation position of the display device is not restricted as compared to a wired system.

Note that the number of channels to be multiplexed is of course not limited to eight channels, and the time axis of the PCM signal of each channel may be compressed to perform time division multiplexing.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a block diagram of an example of a transmitter, Figs. 3 and 4 are diagrams used to explain transmission signals, and Fig. 5 is a diagram of the invention. FIG. 1 is a block diagram of a henodophone device according to an embodiment of the present invention, and FIG. (7) is a transmitter, (8) is a light emitting unit, (10) is a video projector (display device), and (11) is a headphone device (
sound generating device), (13) is the light receiving section, (20a) to (2
0h) is the audio signal input terminal, (23) is the sampling multiplexer, (24), (48L)
, (48) 1) is a sampling hold circuit, (
25) is an A/Dfk converter, (40) is a channel gate circuit, and (41L). (41R) is the channel selector, (47L),
(47R) is a D/A converter.

Claims (1)

[Claims] Transmitting means comprising a light emitting element that multiplexes both output signals from an audio signal source and a video signal source and emits transmitted light modulated by the multiplexed signal; and transmitted light from the transmitting means. a display device that has a first light receiving section that receives the light and displays a video signal obtained by demodulating the output signal from the first light receiving section; and a second display device that receives the transmitted light from the transmitting means. A sounding device having a light receiving section and configured to supply an audio signal from the audio signal source or the video signal source obtained by demodulating the output signal from the second light receiving section to an electroacoustic transducer. A remote receiving device characterized by comprising: