JPS6019051B2 - information recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an information recording apparatus, and more particularly to an optical information recording apparatus that records by exposing a photosensitive material using a laser beam, for example.

2. Description of the Related Art Conventionally, it has been known to use a laser beam to record a video signal on a disk coated with a photosensitive material such as a photoresist or a silver salt, on the same zero yen.

In such an optical video information recording device, the transmittance of the laser beam is changed by an optical modulator depending on the video signal to be recorded. This optical modulator blocks the laser beam when there is no video signal, but
At this time, it is not possible to completely block the light, and about 1% to 3% of the light leaks and passes through. If such leakage light is irradiated onto the disk for a long time, a disadvantage arises in that the photoreceptor coated on the disk is undesirably exposed to light. Therefore, the main object of the present invention is to provide an information recording device that does not cause the above-mentioned disadvantages.

In summary, this invention provides a mechanical shield in the optical path from the light source to the recording medium, and when no information signal is recorded, the shield completely blocks the light beam and prevents the recording medium from being undesirably damaged. This is an information recording device that is not exposed to light. The above objects and other objects and features of the invention will become more apparent from the following detailed description with reference to the drawings.

FIG. 1 is a functional block diagram of a video disc recording apparatus as an embodiment of the present invention.

In the configuration, the surface of the disk 1 includes a photoresist,
It is coated with a photosensitive material such as silver salt, and the rotating shaft of the motor 2 is connected to the center of the coated material, and the rotating shaft of the motor 2 is connected to the center of the coating. p. m. It is rotated by Although not shown, the motor 2 is rotated in synchronization with the NTSC composite video signal to be recorded (hereinafter simply referred to as "video signal") by a rotating servo mechanism (not shown). That is, the video signal is 30 frames per second, and the rotational speed of the disk 1 (motor 2) is 3 seconds. p. s. Therefore, images of frames are recorded on the disk 1 per revolution. Laser beam 2 from laser light source 3
3 undergoes optical modulation by an optical modulator 4 (using an electro-optic effect element or an acousto-optic effect element whose transmittance changes depending on an applied voltage) in accordance with the video signal to be recorded. The laser beam 23 that has been optically modulated by the optical modulator 4 is transmitted to the shutter section 2 which is a feature of the present invention.
2. The light is focused on the disc through a mirror 9 and a lens 10. Therefore, the photoreceptor material of the rotating disk is exposed by the spot of the laser beam 23, and the video signals are sequentially recorded on the disk 1. The video signal i is inputted from the input terminal VS and is given as an output k via the analog switch 11 to an optical modulator drive circuit 12 including, for example, an amplifier. The output voltage from this drive circuit 12 is given to the optical modulator 4. Now, with reference to FIG. 2, the shirt flap portion 22 will be explained in detail.

The shirt cover 5 is normally constrained to the left (FIG. 2) or upward (FIG. 1) by a spring 6 to block the laser beam 23 from the optical modulator 4. When the plunger 7 is energized by a signal from a plunger drive circuit 15, which will be described later, the shirt jacket 5 is attracted to the right (as shown by the broken line in FIG. 2) or downward (as shown in FIG. 1). Therefore, the laser beam 23 passes through the shutter portion 22 and is incident on the mirror 9. In this way, when the shirt sleeve 5 is attracted to the right or downward, the end of the shirt sleeve 5 comes into contact with the actuator of the microswitch 8, turning it on. Therefore, when the shirt cover 5 is opened, an on signal c is obtained from the microswitch 8. Returning to FIG. 1 again, the press signal a from the recording pushbutton switch 13, which is operated at an arbitrary timing to be consigned, is given as a set input to the flip-flop 14, and the output of this flip-flop 14 is sent to the plunger drive circuit 15. given to. As described above, the output b of the plunger drive circuit 15 energizes the plunger 7. Also,
The on signal c of the microswitch 8 is given as a set input to the flip-flop 16. The output of this flip-flop 16 is connected to the input terminal V as one input.
It is applied as the other input of the NAND gate 17, which receives the vertical synchronizing signal d applied from the NAND gate 17. The output e of this NAND gate 17 is given as a set input to a flip-flop 18. The output e of this flip-flop 18 is applied as the other input of a NAND gate 19, which receives a horizontal synchronizing signal f applied from the input terminal 1 as its one input. The output g of this NAND gate 19 is given as a set input to a flip-flop 21 and as a count input to a 525 ship counter 20. The count-up signal h generated by the 525 ship counter 201 is transmitted through the four flip-flops 14,
16, 18, and 21 as respective reset inputs. Furthermore, the output i from the flip-flop 21 is given as an opening/closing control signal for the analog switch 11. Note that the vertical synchronization signal d and the horizontal synchronization signal f are synchronized with the video signal i and are provided at the same timing as the synchronization portion of the video signal i.

The operation of the above configuration will be explained below with reference to FIG. FIG. 3 is a timing chart for explaining the operation of the embodiment shown in FIG.
This shows that.

In operation, since the above-mentioned recording has been completed in the initial state, the flip-flop 14 is
, 1, 6, 18, and 21 are all in the reset state.
In addition, the video signal j from the input terminal VS, the vertical synchronization signal d from the input terminal V, and the horizontal synchronization signal f from the input terminal 1 are as shown in FIGS. 3j, 3d, and 3f. , is always entered. Here, the pushbutton switch 13 is pressed to record regardless of the vertical synchronization signal d.

Therefore, the press signal a from the pushbutton switch 13 is applied to the flip-flop 14 as a single pulse, as shown in FIG. 3a. Therefore, the state of the output signal from the flip-flop 14 is inverted and becomes the TTL high level (hereinafter simply referred to as "H"), and in response to this "H" signal, the output signal from the plunger drive circuit 15 is transmitted to the output signal shown in FIG. 3b. As shown, plunger drive signal b is applied to plunger 7. Therefore, the plunger 7 is energized and the jacket 5 is attracted as described above, thereby opening the path of the laser beam 23. Almost simultaneously with the opening of this shirt cover 5, the microswitch 8 is closed, and accordingly, the microswitch 8 is closed.
From this, an on signal c is derived as shown in FIG. 3c.
The on-signal c of the microswitch 8 is applied to the set input of the flip-flop 16, and at this timing, the state of the flip-flop 16 is inverted, changing from the TTL low level (hereinafter referred to simply as "L") to "H" and NAND. is applied to gate 17. Here, it is assumed that approximately 10 seconds are required for the plunger 7 to be energized and the on-signal c to be obtained from the microswitch 8, as shown in FIG. 3b. Therefore, a gated vertical synchronization signal e is obtained from the NAND gate 17, as shown in FIG. Give to 9.

At the seventh moment, the gated horizontal synchronization signal g is obtained from the NAND gate 19 as shown in FIG. The state of the flip-flop 21 is reversed. Therefore, an output signal i (FIG. 3) of "rH" is obtained from this flip-flop 21, and the analog switch 11 is opened at this timing. Therefore, the video signal i is applied via this analog switch 11 to the optical modulator drive circuit 12 as a gated video signal k shown in FIG. 3k'. Accordingly, the optical modulator 4 optically modulates the laser beam 23 from the laser light source 3 by controlling its transmittance according to the output of the optical modulator drive circuit 12 (ie, the video signal k). The laser beam 23 optically modulated by the optical modulator 4 is input to the mirror 9 via the shutter section 22 opened as described above, and is focused by the lens 101 and reaches the disk 1.
Therefore, the photosensitive material on the disk 1 is exposed and the video signal k
is recorded. On the other hand, a 525-decimal counter 2 receives the gated horizontal signal g from the NAND gate 19.
0 derives a count-up signal h as shown in FIG. 3h in response to counting one frame's worth of horizontal synchronization signals (525 in Japan).

This count-up signal h is transmitted to the flip-flop 14,
16, 18, and 21 as reset inputs. Therefore, at this timing, the states of all of these flip-flops U4, 16, 18, and 21 are reversed and become the initial state, and "L" is derived as the output. Therefore,
At this timing, the NAND gates 17 and 19 are closed, and the analog switch 11 is also closed. Accordingly, the video signal k from the analog switch 11 is cut off at this timing and is no longer applied to the optical modulator drive circuit 12. Also, the flip-flop 14 is “L”.
'', the plunger drive signal b from the plunger drive circuit 15 is cut off at this timing (the timing at which one frame recording is completed), as shown in FIG. 3b, and the plunger 7 is accordingly deenergized.

Therefore, the shirt cover 5 is pulled by the spring 6 and returns to the open state, and the laser beam 23 is moved to the shirt cover 22.
The incidence on the disk 1 is cut off by this. in this way"
It takes about 5 seconds from when the count-up signal of the 525 ship counter 20 is obtained until the shirt cover 5 is opened and the microswitch 8 is opened, and this is shown in FIG. 3c. As mentioned above, according to this embodiment, the video signal is switched to the analog switch 11 after the switch 5 is opened.
, and after one frame has passed, the shirt cover 5 is closed. Therefore, only one frame worth of video signal is recorded on the disk 1, and the subsequent laser light source 3
The laser beam 23 from the disk 1 is not undesirably irradiated onto the disk 1. Therefore, there is no problem that the photosensitive material on the disc is undesirably exposed to light due to the leakage of the laser beam 23. In other words, the time during which the leaked laser light is irradiated onto the disk 1 is the time from when the cover plate 5 is opened until the first vertical synchronization signal is input (less than 1667 seconds) and one frame of the video signal. The total time from the last vertical synchronization signal to the closing of the jacket 5 (less than 5 seconds) can be kept to less than 21.67 seconds. In the above embodiment, the video signal, horizontal synchronization signal, and vertical synchronization signal are generated by the video signal and the main synchronization circuit, respectively, which are synchronized with the synchronization signal generated from the main synchronization circuit (not shown). Of course, this is a synchronization signal separated from the video signal using a synchronization separation circuit.

Further, in the embodiment, a disk is used as the recording medium, but it may be a tape-like or sheet-like medium coated with a photosensitive material.

Although the signal to be recorded is also an NTSC composite video signal, it may also be a video signal that has undergone modulation such as AM modulation, FM modulation, PM modulation, or the like. Further, although the flip-flop, NAND gate, counter, etc. are TTL, other logic elements may be used. Although a mechanical microswitch was used to detect the opening and closing of the shirt cover, an electronic or optical detection element may also be used, and its operating time may be longer than that of the embodiment (lows, 5ms). Of course, it can be made shorter. As described above, according to the present invention, a video signal for one frame is accurately recorded on the recording medium, and the recording medium is undesirably exposed to light due to leakage light from the optical modulator, which is the so-called "fogging". is kept to a minimum.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram showing one embodiment of the present invention. FIG. 2 is an enlarged illustrative view of essential parts showing an example of the shirt shirt portion of the present invention. FIG. 3 is a timing chart illustrating the operation of the embodiment shown in FIG. 1, and FIGS. 3a to 3k correspond to signals a to k' in FIG. 1. In the figure, 1 is a disk, 2 is a motor, 3 is a laser light source,
4 is an optical modulator, 5 is a shirt, 6 is a spring, 7 is a plunger, 8 is a microswitch, 9 is a mirror, 10 is a mirror, 11 is an analog switch, 12 is an optical modulator drive circuit,
13 is a push button switch, 14, 16, 18, 21 are flip-flops, 15 is a plunger drive circuit, 17, 1
9 is a NAND gate, 20 is a 525-decimal counter, and 22 is a shutter section. Figure 2 Figure 1 Figure 3

Claims (1)

[Scope of Claims] 1. An information recording device for recording a video signal including a horizontal synchronization signal, comprising: a recording medium whose surface is coated with a photosensitive material; a light beam irradiated onto the recording medium; and the light beam. means for optically modulating the light beam according to the video signal; a shutter member configured to be openable and closable and, when closed, blocks irradiation of the light beam onto the recording medium; a command means for issuing a command; a counting means for counting the number of horizontal synchronization signals;
Shutter opening control means for opening the shutter member in response to the operation of the commanding means and closing the shutter member in response to the counting means counting a predetermined number of the horizontal signals; Information recording device. 2. The counting means further includes a means provided in relation to the shutter member and detecting whether the shutter member is opened or closed, and the counting means responds to the opening detection output from the shutter member detecting means to The information recording device according to claim 1, which starts counting synchronization signals. 3. The information recording device according to claim 2, wherein the means for detecting opening or closing of the shutter member is a micro switch. 4. Opened in response to the opening of the shutter member to provide the video signal to the light modulation means, and closed in response to the shutter member to be closed to provide the video signal to the light modulation means. The information recording device according to any one of claims 1 to 3, further comprising an analog gate means for blocking. 5. The information recording apparatus according to claim 4, wherein the video signal includes a vertical synchronizing signal, and the analog gate means is opened in response to the first vertical synchronizing signal immediately after the shutter member is opened.