JPH08288909A - Optical signal transmitter - Google Patents

Abstract

PURPOSE: To save power consumption by driving a light emitting means only when the transmission of an optical signal is required in the transmitter converting a video signal and an audio signal into the optical signal and transmitting the optical signal through space. CONSTITUTION: With an AV pin plug plugged into input output common use terminals 5a, 5b, 5c, a reproduction signal of a VTR block 1 is outputted externally through the AV pin plug. In this case, a microcomputer 4 applies a power supply control signal to deenergize a drive voltage to an infrared ray transmission modulator 2 and a light emitting section 3. With no AV pin plug plugged in, the microcomputer 4 applies a power supply control signal to energize the drive voltage to the infrared ray transmission modulator 2 and the light emitting section 3. As a result, a reproduction signal from a VTR block 1 is converted into an FM signal at the infrared ray transmission modulator 2 and into an infrared ray signal by the light emitting section 3, from which the infrared ray signal is outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical signal transmission device for spatially transmitting an audio signal or a video signal by using an optical signal such as infrared rays.

[0002]

2. Description of the Related Art Conventionally, a video signal and an audio signal reproduced by a camera-integrated video tape recorder (hereinafter referred to as "camcorder") are received by a television receiver (hereinafter referred to as "TV").
As a means for transmitting the data to an audio / video (hereinafter, referred to as “AV”) cable, it is general to connect.

However, a camcorder and a TV are AV
The method of connecting with a cable has a problem that the operation is troublesome because it is necessary to attach / detach the AV cable each time the reproduced image and sound of the camcorder are viewed on the TV.

Therefore, as a means for solving such a problem, for example, as shown in FIG. 13, a camcorder and a TV are shown.
An infrared space transmission system has been proposed which wirelessly transmits an audio signal and a video signal using infrared rays.

In this system, the transmitting side frequency-multiplexes an FM-modulated carrier wave with a video signal and an FM-modulated carrier wave with an audio signal, and drives an LED by the frequency-multiplexed signal to transmit an infrared signal. Then, the receiving side performs the reverse process of the transmitting side to demodulate the video signal and the audio signal.

At this time, L in the transmitting side camcorder
It is considered that the drive voltage of the ED is configured to be always on when the power switch of the camcorder is on, or to be on only when the camcorder is set to the reproduction mode.

[0007]

However, if the drive voltage of the LED is always on when the power of the camcorder is on, the drive voltage is supplied to the LED even when infrared transmission is not performed. However, there is a problem that the power consumption increases and the battery drains faster.

Similarly, even if it is configured to be turned on only when the playback mode is set, the playback image is viewed when dubbing to another video tape recorder using the AV cable or on the LCD panel of the camcorder. In this case, there is a problem that the emission of infrared light is wasted.

The present invention has been made in view of the above problems, and makes it possible to save unnecessary power consumption by driving the light emitting means only when the transmission of the optical signal is necessary. An object is to provide an optical signal transmission device.

[0010]

In order to solve the above-mentioned problems, the present invention is an apparatus for spatially transmitting an optical signal such as an infrared signal, wherein an audio signal generating means and a carrier wave is modulated by an output of the audio signal generating means. Modulation means to
Light emitting means for converting the output of the modulating means into an optical signal and radiating it to the space, and an audio output terminal for outputting the output of the audio signal generating means to the outside, the audio signal generating means generating an audio signal, Further, when the audio signal is not output from the audio output terminal to the outside, the light emitting means is activated to spatially transmit the optical signal modulated by the audio signal.

Further, the present invention is, in an apparatus for spatially transmitting an optical signal such as an infrared signal, a video signal generating means, a modulating means for modulating a carrier wave by the output of the video signal generating means, and an output of the modulating means as an optical signal. And a display means for displaying the output of the video signal generating means, wherein the video signal generating means generates a video signal and the video signal is not displayed on the display means. The light emitting means is sometimes activated to spatially transmit the optical signal modulated by the video signal.

[0012]

According to the present invention, when the audio signal generating means generates an audio signal, and the audio signal is not output from the audio output terminal to the outside, the light emitting means is activated and the optical signal modulated by the audio signal is activated. To transmit in space.

According to the present invention, the light emitting means is operated when the video signal generating means generates the video signal and the video signal is not displayed on the display means,
The optical signal modulated with the video signal is spatially transmitted.

[0014]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing the basic configuration of a camcorder to which the present invention is applied. As shown in this figure, a camcorder to which the present invention is applied includes a video tape recorder block (hereinafter referred to as a VTR block) 1 for recording / reproducing a video signal and an audio signal, and a carrier wave FM-modulated by an output signal of the VTR block 1. For transmitting the infrared rays, the light emitting unit 3 for generating the infrared rays driven by the output signal of the infrared transmission modulator 2, the detection output of the reproduction button provided on the camcorder, and the infrared transmission. 4 for supplying a power supply control signal a to the modulator 2 and the light emitting section 3 and a remote control signal (hereinafter referred to as "remote control signal") b to the infrared transmission modulator 2
And output terminals of the I / O terminals 5a, 5b, 5c and the VTR block 1 to the I / O terminals 5a, 5b, 5c, or switch line input signals from the I / O terminals 5a, 5b, 5c. An input / output switching circuit 6 for switching whether to send to the VTR block 1 via SW1 and a switch SW1 for switching a signal from a camera block of a camcorder and a line input signal to send to the VTR block 1 are provided.

In this figure, the input / output terminal 5 is also used.
a, 5b, 5c are AV pin jacks,
V means video, L means L channel audio, and R means R channel audio. Further, 3 attached to the signal line between the VTR block 1, the input / output switching circuit 6 and SW1 means that there are the above-mentioned V, L and R signal lines.

The camcorder shown in FIG. 1 operates as follows. First, in the recording mode of the camcorder, the AV signal from the camera block passes through SW1 and VTR block 1
Is input to. The VTR block 1 records the input AV signal.

Then, in the reproduction mode of the camcorder, the microcomputer 4 knows that the reproduction button has been pressed. The output destination of the AV signal reproduced from the VTR block 1 in the reproduction mode is input / output terminals 5a, 5b, 5
It differs depending on whether or not an input / output AV pin plug for inputting / outputting an AV signal is connected to c.

When the input / output combined AV pin plug is connected, the AV signal reproduced by the VTR block 1 is output from the combined input / output terminals 5a, 5b, 5c to the outside. At this time, the microcomputer 4 supplies the infrared transmission modulator 2 and the light emitting unit 3 with a power supply control signal for turning off the drive voltage.

On the other hand, when the input / output combined AV pin plug is not connected, the AV signal reproduced by the VTR block 1 is not output from the combined input / output terminals 5a, 5b, 5c to the outside, so that the microcomputer 4 transmits infrared rays. A power supply control signal for turning on the drive voltage is supplied to the modulator 2 and the light emitting unit 3. As a result, the AV signal reproduced by the VTR block 1 is transmitted to the modulator 2 for infrared transmission.
At the same time, it is converted into an FM signal, and at the light emitting section 3, it is converted into an infrared signal and spatially transmitted.

The switching of the operation in the reproduction mode, which has been outlined above, will be described later in detail with reference to FIGS.

FIG. 2 shows a modulator 2 for infrared transmission in FIG.
3 is a block diagram showing a configuration of a light emitting unit 3. FIG. The infrared transmission modulator 2 shown in this figure is roughly divided into a part for processing a video signal, a part for processing an L / R audio signal, and a part for processing a remote control signal.

The portion for processing the video signal is a clamp circuit 1 for clamping the video signal input from the terminal T1.
1, a low-pass filter 12 that cuts noise and high frequency components in the output signal of the clamp circuit 11, a pre-emphasis circuit 13 that applies pre-emphasis to the output signal of the low-pass filter 12, and a pre-emphasis circuit 1.
FM modulation circuit 14 for FM-modulating the carrier wave by the output of 3
And a high-pass filter 15 that passes a high frequency component in the output signal of the FM modulation circuit 14.

The parts for processing the audio signals are divided into pre-emphasis circuits 17 and 21 for applying pre-emphasis to the L / R audio signals inputted from the terminals T2 and T3, and outputs from the pre-emphasis circuits 17 and 21, respectively. FM modulator circuits 18 and 2 for FM-modulating a carrier wave
2 and band pass filters 19 and 23 that cut low-frequency components and high-frequency components in the output signals of the FM modulation circuits 18 and 22.
And an adder 20 that adds the outputs of the bandpass filters 19 and 23.

Then, the part for processing the remote control signal is
It is composed of a low-pass filter 24 that passes low-frequency components in the remote control signal input from the terminal T4.

The infrared transmission modulator 2 further includes:
An FM video signal output from the high pass filter 15 and an FM audio signal output from the adder 20;
The adder 16 for frequency-multiplexing the remote control signal output from the low-pass filter 24, the terminal T5 for outputting the output signal of the adder 16 to the light emitting unit 3, and the FM audio signal output from the adder 20 are externally supplied. And a terminal T6 for outputting to.

The light emitting section 3 is composed of three LED groups connected in series two by two, and a transistor for driving each LED group. This many LEDs
By increasing the light emission intensity, each set of L
The emission intensity can be adjusted by individually turning on / off the ED group.

FIG. 3 is a diagram showing frequency allocation of each signal described in FIG. The operation of the infrared transmission modulator 2 will be described below with reference to this figure and FIG.

The pedestal of the video signal input from the terminal T1 is clamped in the clamp circuit 11, the noise component and the like are cut in the low-pass filter 12, and the video signal is sent to the pre-emphasis circuit 13. Then, after receiving the emphasis here, in the FM modulation circuit 14, as shown in FIG.
z, FM so that the white peak is 13.5 MHz
Undergoes modulation processing. The FM video signal generated in this manner has a component higher than 6 MHz extracted by the high-pass filter 15 and sent to the adder 16.

Further, L / input from terminals T2 and T3
The R audio signal is the pre-emphasis circuit 17, 2
After being subjected to the pre-emphasis processing by 1, the FM modulating circuits 18 and 22 FM-modulate the carrier waves of 2.3 MHz and 2.8 MHz to form FM audio signals. And
In the bandpass filters 19 and 23, 2.3 MHz
The components around and around 2.8 MHz are extracted and added by the adder 2
After being frequency-multiplexed at 0, it is sent to the adder 16.

Further, the remote control signal of 40 kHz, for example, inputted from the terminal T4 is cut by the low pass filter 24 to eliminate noises in the high frequency range and sent to the adder 16.

6M output from the high-pass filter 15
The FM video signal of Hz to 20 MHz, the FM audio signal of about 2.3 MHz and 2.8 MHz output from the adder 20, and the remote control signal of 40 kHz, for example,
The frequency is multiplexed in the adder 16. Then, it is sent from the terminal T5 to the light emitting unit 3 and converted into an infrared signal and transmitted.

FIG. 4 is a block diagram showing the configuration of the light receiving section on the receiving side and the demodulator for infrared transmission. These basically perform the reverse processing of the light emitting unit on the transmission side and the modulator for infrared transmission.

The light receiving portion 8 is composed of a photodiode. The infrared transmission demodulator 9 includes a portion for processing a video signal corresponding to the transmission side infrared transmission modulator 2, a portion for processing an L / R audio signal, and a portion for processing a remote control signal. It is roughly divided into. Further, the infrared transmission demodulator 9 is provided with an amplifier 31 for amplifying the frequency-multiplexed signal input from the terminal T7.

The amplifier 31 is the part that processes the video signal.
6MHz or more FM from the frequency multiplexed signal amplified by
A high-pass filter 32 that separates the video signal, a limiter 36 that removes the amplitude fluctuation of the output signal of the high-pass filter 32, an FM demodulation circuit 40 that demodulates the video signal from the output of the limiter 36, and an output signal of the FM demodulation circuit 40. De-emphasis circuit 4 for de-emphasis
3 and a video buffer 46 for amplifying the output of the de-emphasis circuit 43.

The parts for processing the audio signals are each 2.3 from the frequency multiplexed signal amplified by the amplifier 31.
Bandpass filters 33 and 34 for extracting FM audio signals near MHz and 2.8 MHz, limiters 37 and 38 for removing amplitude fluctuations of output signals of the bandpass filters 33 and 34, and L from outputs of the limiters 37 and 38.
FM demodulation circuits 41 and 4 for demodulating the / R audio signal
2, and de-emphasis circuits 44 and 45 that de-emphasis the output signals of the FM demodulation circuits 41 and 42.
And buffer amplifiers 47 and 48 for amplifying the outputs of the de-emphasis circuits 44 and 45.

The part for processing the remote control signal is
From the frequency multiplexed signal amplified by the amplifier 31, for example, 4
It is composed of a low-pass filter 35 for taking out a remote control signal of 0 kHz and a limiter 39 for removing the amplitude fluctuation of the output signal of the low-pass filter 35.

The infrared transmission demodulator 9 is not directly related to the gist of the present invention, and its operation is clear from the above description, and therefore detailed description thereof is omitted here.

FIG. 5 is a block diagram showing a structure of a portion for switching the operation in the reproduction mode in the camcorder shown in FIG. Here, parts corresponding to those in FIG. 1 are assigned the same numbers.

The feature of the apparatus shown in this figure is that the camcorder is in the reproduction mode and the input / output terminals 5a, 5b, 5 are used.
The drive voltage is supplied to the infrared transmission optical modulator 2 and the light emitting section 3 only when the input / output AV pin plug is connected to c. The switches SW3 to SW5 in the input / output switching circuit 6 are switched so that the reproduction signal of the VTR block 1 is supplied to the input / output terminals 5a, 5b, 5c through the amplifiers 51 to 53 in the reproduction mode. Input / output terminals 5a and 5 for line input
The input signals from b and 5c are switched so as to be supplied to the VTR block 1.

In order to detect whether or not the input / output combined AV pin plug is connected to the combined input / output terminal 5a, 5b, 5c, a switch SW2 is provided which is switched according to the insertion / removal of the combined input / output AV pin plug. S
A signal B indicating the state of W2 is input to the microcomputer 4. Also, the signal C indicating the state of the play button is input to the microcomputer 4. Further, the power source voltage Vcc supplied to the infrared transmission modulator 2 and the light emitting unit 3 is turned on / off.
A power supply control circuit 54 for turning off is provided, and its on / off control is controlled by the output of the microcomputer 4.

Now, three examples of means for detecting whether or not the input / output combined AV pin plugs are connected to the input / output combined terminals 5a, 5b, 5c will be described with reference to FIGS.

In the first mechanical detection means shown in FIG. 6, the input / output terminal has a signal input / output contact TA,
A voltage detection contact TB that is pulled up by a resistor (not shown) and a contact TC that is connected to the ground are provided. An insulator such as a non-conductive resin is fixed to the contact TC on the surface facing the contact TA.

This detecting means operates as follows. First, as shown in FIG. 6A, when the AV pin plug for both input and output is not inserted, the contact TB is pulled up by the resistance and therefore has a predetermined positive potential. On the other hand, when the input / output combined AV pin plug is inserted as shown in FIG. 6B, the tip of the combined input / output AV pin plug pushes down the contact TC, so that the contact TB contacts the contact TC and its potential is zero. fall into. Therefore, by detecting the potential of the contact TB, the input / output terminal A
It can be identified whether the V pin plug is connected or not.

In the second mechanical detection means shown in FIG. 7, the input / output terminal has a signal input / output contact TA connected to the ground by a high resistance of 10 kΩ, and 10
A voltage detection contact TB that is pulled up with a high resistance of kΩ is provided.

This detecting means operates as follows. First, as shown in FIG. 7A, when the input / output AV pin plug is not inserted, the contact TA and the contact TB are in contact with each other. Therefore, as is clear from the circuit diagram of FIG.
The potential of the contact TB is Vcc / 2. On the other hand, FIG.
When the input / output AV pin plug is inserted as shown in (b), the tip of the input / output AV pin plug pushes up the contact TA, so that the potential of the contact TB rises to Vcc. Therefore, by detecting the potential of the contact TB, it is possible to identify whether or not the input / output combined AV pin plug is connected to the input / output combined terminal.

In the electrical detecting means shown in FIG. 8, the signal input / output contact TA of the input / output combined terminal is pulled up with a high resistance of 10 kΩ. Further, an integrator circuit including a resistor R and a capacitor C and a comparator for comparing the output voltage of the integrator circuit and the reference voltage V are connected. The contact TA has a resistance of 75Ω and is used for both input and output.
The V pin plug is inserted and removed.

This detecting means operates as follows. First, when the AV pin plug for both input and output is not inserted,
Since the contact TA is pulled up with high resistance, its potential is Vcc. On the other hand, when the AV pin plug for both input and output is inserted as shown in FIG. 8, the potential is lowered because it is terminated by the resistance of 75Ω. Therefore, by comparing the potential of the contact TA with the reference potential V of the comparator, it is possible to identify whether the input / output terminal is connected to the input / output AV pin plug. The integrating circuit composed of the resistor R and the capacitor C is for integrating the video signal on the terminal TA so as not to affect the detection of the potential.

The switch SW2 shown in FIG. 5 has been specifically described above. Next, the operation of the apparatus shown in FIG. 5 will be described. FIG. 9 is a flowchart showing the processing of the microcomputer 4 in FIG.

First, in step S1, it is determined whether or not a power switch (not shown) of the camcorder is turned on. And if it is not on, step S
6, the power supply voltage Vcc is prevented from being supplied to the infrared transmission modulator 2 and the light emitting unit 3 (these are referred to as "IR block" in the following description of FIG. 9). That is, FIG.
The microcomputer 4 of 1 supplies a high level voltage to the base of the transistor in the power supply control circuit 54 to turn off the transistor. Then, after executing step S6, the post-processing is ended.

On the other hand, when the power switch of the camcorder is turned on, the process proceeds to step S2, where it is determined whether the AV pin plug for both input and output is inserted. When it is determined that the AV pin plug for both input and output is not inserted, the process proceeds to step S3, and it is determined whether the camcorder is in the reproduction state. If it is in the reproducing state, the process proceeds to step S4, and the power supply voltage Vcc is supplied to the IR block. That is, the microcomputer 4 of FIG. 5 supplies a low level voltage to the base of the transistor in the power supply control circuit 54 to turn on the transistor. Then, after executing step S4, the process is repeated from step S1.

If the AV pin plug for both input and output is inserted in step S2 or it is not in the reproduction state in step S3, the process proceeds to step S5 so that the power supply voltage Vcc is not supplied to the IR block. Then, after executing step S5, the process is repeated from step S1. The order of the process of step S2 and the process of S3 may be reversed.

Here, the flowchart explained above,
The relationship with the logic level of each input signal to the microcomputer 4 will be supplemented. In FIG. 5, the on / off detection signal A of the power switch of the camcorder is high when it is on and low when it is off. Also, the switch SW2 is
Since it closes when the AV pin plug for both input and output is inserted,
The detection signal B becomes low when the input / output AV pin plug is inserted, and becomes high when it is not inserted. Further, the on / off detection signal C of the reproduction button is high when it is on and low when it is off.

At this time, in the microcomputer 4, only when the power switch of the camcorder is ON, the input / output AV pin plug is not inserted, and only in the reproduction mode, that is, A, B, and C are all at the high level. Only at that time, a low level voltage is generated and supplied to the base of the transistor in the power supply control circuit 54. That is, the microcomputer 4 is equivalent to supplying the NAND outputs of the input signals A, B, and C to the power supply control circuit 54. Therefore, it is possible to configure this processing by a hard logic instead of the microcomputer 4.

FIG. 10 is a block diagram showing the essential parts of another embodiment of a camcorder to which the present invention is applied. Here, FIG.
The same numbers are given to the portions corresponding to. A feature of this embodiment is that it comprises an LCD device, whose on / off switch
The off signal is used to control the light emitting unit 3. Further, in this embodiment, the input signal of the light emitting section 3 is controlled to be turned on / off,
The infrared transmission modulator 2 is not on / off controlled. Further, in this embodiment, the user can set whether to control ON / OFF of the input signal to the light emitting unit 3 by the menu.

First, the configuration of FIG. 10 will be described. As shown in this figure, in this embodiment, an LCD device 10 for displaying the reproduction output of the VTR block 1 and an OSD insertion circuit 59 for performing OSD (on-screen display) display on the LCD device 10 are provided. ing.

The LCD device 10 includes an LCD panel 57 and an LC.
It is composed of a D driver 58. Although not shown, a switch for controlling ON / OFF of the LCD device 10 is provided, and the ON / OFF information D
Is input to the microcomputer 4.

Further, in this embodiment, a control circuit 5 for controlling on / off of an input signal to the light emitting section 3 is provided between the microcomputer 4 and the base of the transistor 55.
6 is provided. The control circuit 56 is turned on when a high level signal is supplied from the microcomputer 4, and sets the base of the transistor 55 to almost zero potential. As a result, the output signal of the infrared transmission modulator 2 is not supplied to the light emitting unit 3. On the other hand, when a low level signal is supplied from the microcomputer 4, the signal is turned off, so that the output signal of the infrared transmission modulator 2 changes to the transistor 5
The light is input from the base 5 to the light emitting unit 3.

Next, the operation of the apparatus shown in FIG. 10 will be described. FIG. 11 is a flowchart showing the processing of the microcomputer 4 in FIG.

First, in step S11, it is determined whether or not a power switch (not shown) of the camcorder is turned on. If it is not turned on, the process proceeds to step S17 so that the output signal of the infrared transmission modulator 2 is not input to the light emitting unit 3 (this will be referred to as "power off IR block" in the following description of FIG. 11). To do it). That is, the microcomputer 4 of FIG. 5 supplies a high level voltage to the control circuit 56 to turn on this transistor. Then, after executing step S17, the post-processing is ended.

On the other hand, when the power switch of the camcorder is turned on, the process proceeds to step S12, in which the LCD device 10 is automatically turned on when the switch is turned on.
Determine if powering off the R block is set in the menu. If it is determined that the LCD device 1 is set, the process proceeds to step S13 and the LCD device 1
Determine if 0 is on. Then, the LCD device 10
If is on, the process proceeds to step S16, and the IR block is powered off. Then, after executing step S16, the process is repeated from step S11.

If it is not set in the menu to automatically power off the IR block when the switch of the LCD device 10 is on in step S12, or if the LCD device 10 is not on in step S13, The process proceeds to S14. Then, it is determined here whether the camcorder is in the reproduction state. If it is in the reproduction state, the process proceeds to step S15, and the output signal of the infrared transmission modulator 2 is input to the light emitting unit 3. That is, FIG.
The microcomputer 4 of 6 supplies a low level voltage to the control circuit 56 to turn off this transistor. Then, after executing step S15, the process is repeated from step S11.

If it is determined in step S14 that the camcorder is not in the reproducing state, the process proceeds to step S16 to power off the IR block. Then, after executing step S16, the process is repeated from step S11.

In this case, the ON / OFF detection signal A of the power switch of the camcorder, the ON / OFF detection signal C of the reproduction button, the switch detection signal D of the LCD device 10, and the switch of the LCD device 10 are turned on. Setting signal E for whether to power off the IR block automatically when
Is high when it is on and low when it is off, it is equivalent to the microcomputer 4 giving the control circuit 56 the result of the logical operation shown in FIG.

Two embodiments have been described above for controlling the power on / off of the IR block. Figure 2 is this 2
The process when the processes of the two embodiments are combined is shown. The details of this processing are apparent from FIGS. 9 and 11, and thus the description thereof is omitted. Further, the configuration of the device in this case is the device of FIG. 10 with the addition of the switch SW2 in the device of FIG.

The present invention is not limited to the above-mentioned embodiments, but various modifications can be made within the scope of the present invention, and these modifications are not excluded from the scope of the present invention. For example, although the above-described embodiment has applied the present invention to a camcorder, the present invention applies a device for spatially transmitting a video signal generated by a video disc player, a television receiver, a television camera, or a CD player. It can also be applied to a device that spatially transmits an audio signal generated by the.

[0066]

As described above in detail, according to the present invention, since the light emitting means is driven only when the spatial transmission of the optical signal is necessary, it is possible to save unnecessary power consumption. . Therefore, if the present invention is applied to a battery-driven device, the battery usage time can be extended.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a camcorder to which the present invention is applied.

FIG. 2 is a block diagram showing a configuration of an infrared transmission modulator 2 and a light emitting section 3 in FIG.

FIG. 3 is a diagram showing frequency allocation of each signal described in FIG.

FIG. 4 is a block diagram showing a configuration of a light receiving unit on a receiving side and a demodulator for infrared transmission.

5 is a block diagram showing a configuration of a portion for switching operations in a reproduction mode in the camcorder shown in FIG.

FIG. 6 is a diagram showing an example in which the switch SW2 of FIG. 5 is realized by mechanical means.

FIG. 7 is a diagram showing another example in which the switch SW2 of FIG. 5 is realized by mechanical means.

FIG. 8 is a diagram showing an example in which the switch SW2 of FIG. 5 is realized by electrical means.

9 is a flowchart showing the processing of the microcomputer in FIG.

FIG. 10 is a block diagram showing a main part of another embodiment of a camcorder to which the present invention is applied.

11 is a flowchart showing the processing of the microcomputer in FIG.

FIG. 12 is a flowchart showing a process in which the processes of FIGS. 9 and 11 are combined.

FIG. 13 is a diagram showing an example of a configuration of an infrared space transmission system.

[Explanation of symbols]

1 ... VTR block, 2 ... Infrared transmission modulator, 3 ... Light emitting part, 4 ... Microcomputer, 5a, 5b, 5c ...
Input / output terminals, 6 ... I / O switching circuit, 10 ... LCD device

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[Procedure amendment]

[Submission date] June 6, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

The video signal input from the terminal T1 is
The sync chip is clamped in the clamp circuit 11, noise components and the like are cut in the low-pass filter 12, and the pre-emphasis circuit 13 is sent. Then, after undergoing emphasis here, the FM modulation circuit 14
In FIG. 3, as shown in FIG.
The FM modulation process is performed so that the MHz and white peak become 13.5 MHz. FM generated in this way
The video signal is 6MHz in the high pass filter 15.
The higher component is taken and sent to the adder 16.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction content]

The part that processes the remote control signal has a low-pass filter 35 for extracting a remote-control control signal of, for example, 40 kHz from the frequency-multiplexed signal amplified by the amplifier 31, and a waveform of the output signal of the low-pass filter 35.
It is composed of a limiter 39 for shaping .

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction content]

The feature of the apparatus shown in this figure is that the camcorder is in the reproduction mode and the input / output terminals 5a, 5b,
The drive voltage is supplied to the infrared transmission optical modulator 2 and the light emitting unit 3 only when the input / output AV pin plug is not connected to 5c. The switches SW3 to SW5 in the input / output switching circuit 6 are switched so that the reproduction signal of the VTR block 1 is supplied to the input / output terminals 5a, 5b, 5c through the amplifiers 51 to 53 in the reproduction mode. Input / output terminal 5a for line input,
The input signals from 5b and 5c are switched so as to be supplied to the VTR block 1.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display part H04N 7/22

Claims (2)

[Claims] 1. An audio signal generating means, a modulating means for modulating a carrier wave by an output of the audio signal generating means, a light emitting means for converting an output of the modulating means into an optical signal and radiating it to a space, and the audio signal. An audio output terminal for outputting the output of the generating means to the outside; and the light emitting device when the audio signal generating means generates an audio signal and the audio signal is not output from the audio output terminal to the outside. An optical signal transmission device characterized by operating means. 2. A video signal generating means, a modulating means for modulating a carrier wave by the output of the video signal generating means, a light emitting means for converting the output of the modulating means into an optical signal and radiating it into space, and the video signal. Display means for displaying the output of the generating means, wherein the video signal generating means generates a video signal, and the light emitting means is activated when the video signal is not being displayed on the display means. Optical signal transmission device.