JPS594913B2 - information recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention scans a recording material with a laser beam,
Regarding the method of recording images - In a recording method in which active radiation generated by a cathode ray tube, laser beam generator, electron beam generator, etc. is scanned over a recording material and information is recorded thereby. It is known to modulate the intensity of recording radiation according to the density signal of the original image, change the color of the recording material with the intensity-modulated radiation, and record the gray scale of the original image on the recording material.

However, in this recording method, the device that modulates the intensity of the radiation is complicated, and even if the recording material is irradiated with the modulated radiation, depending on the recording material, it may be difficult to accurately express the change in the intensity of the radiation as a change in the density of the discolored area. There is a problem in that the shading of the original image cannot be recorded correctly. For example, when recording an original image with a wide range of density gradations on photographic film using a laser beam, the original image is photoelectrically scanned and the shading of the image is converted into an electrical signal representing the strength of the voltage.
This electric signal changes the brightness of the laser beam,
Photographic film is scanned with a brightness-modulated laser beam, and then the exposed areas of the photographic film are processed to change color, thereby recording the shading of the original image on the photographic film. - Because of the high value, it is difficult to record the gradation of the original image over a wide range due to the difference in density in the discolored areas of the film, and the density range of the image recorded on photographic film is much wider than that of the original image. becomes narrower. Moreover, depending on the type of photographic film, there is a problem in that it is not possible to prepare films with various gamma values that can be recorded without impairing the contrast of the original image.

For example, recording materials such as bubble photographic film, dry silver film, electrostatic recording paper, and chalcogenide film only have a high gamma value, so it is difficult to record high-contrast original images. If such a recording material is used, the density of the recorded image will be completely different from that of the original image, and there is a drawback that the gradation of the original image cannot be sufficiently reproduced and recorded. The object of the present invention is to improve the gradation of the original image to be recorded on the recording material even when a recording material with an appropriate gamma value cannot be prepared, or even when a recording material with any gamma value is used. The purpose of this invention is to provide an information recording method that can approximately reproduce and record information. Specific examples of the present invention will be described below with reference to the drawings.

Figure 1 shows a recording device using a laser, where 1 is a laser generator that generates a laser beam 2 with a constant brightness, and 3 is a laser generator that changes the deflection angle of the laser beam 2 according to a frequency modulation signal input from a line 31. A laser beam diffraction grating, for example, made of an acousto-optic modulator. 5 is a light shielding plate having an opening 6 through which the laser beam passes.

The diffraction grating 3 and the light shielding plate 5 act as an optical shutter, and only the +1st-order laser beam that has been deflected at a predetermined angle by the diffraction grating 3 can pass through the aperture 6 of the light shielding plate. Therefore, by changing the deflection angle of the laser beam according to the frequency of the signal input to the diffraction grating 3, the laser beam can be passed through the aperture 6 of the light shielding plate or blocked by the light shielding plate. Note that the opening 6 is formed in an appropriate shape and size. 7 is a first deflector that directs the laser beam 8 that has passed through the light shielding plate 5 in the Y-axis direction (vertical direction); 9 is a first deflector that directs the laser beam 8 that has passed through the light shielding plate 5;
This is a second deflector directed in the axial direction (horizontal direction).

Each deflector is composed of a known device such as a rotating mirror, a rotating prism, or a crystal having an electro-optical effect such as KDP.
The laser beam 8 is deflected by a first deflector so as to main-scan the surface of the recording material 10 in the longitudinal direction, and is deflected by a second deflector so as to sub-scan the film surface in the width direction.

The recording material 10 is thus scanned by the laser beam from left to right, and when one line has been scanned, the next line is scanned at intervals in the longitudinal direction. As the recording material 10, a known silver salt photographic film, an electrophotographic photoreceptor, a bubble photographic film, a metal vapor deposited film, or the like can be used. The recording material 10 is fed in the direction of the arrow by a drive mechanism (not shown). The first polarizer 7 and the second polarizer 9 receive deflection signals from deflection drive circuits 11 and 12 through lines 13 and 14, respectively, and deflect the laser beams in respective directions. 15 indicates a signal conversion section;
A vertical synchronizing signal, a horizontal synchronizing signal,
and sampling signals are generated at regular intervals.

The vertical synchronization signal is sent to the first deflection drive circuit 11 via line 18. 5. The first deflector receives the vertical synchronization signal. and outputs a deflection signal to deflect the laser beam 8 in the longitudinal direction of the recording material. The horizontal synchronization signal is sent to the second deflection drive circuit 12. When the second deflector receives the horizontal synchronization signal, it outputs a deflection signal and deflects the laser beam 8 in the width direction of the recording material. Further, these synchronization signals are sent to the recording information generating section 22 through lines 20 and 21. The recording information generating section 22 converts the gradation information of the original image to be recorded into an electrical signal. As the original image, one having information including at least two gradations other than the base density is used. An original image, such as a photograph, having gradations of light and shade is photoelectrically scanned by an imaging device such as a phototube television camera or a flying post scanner device, and a time-series electrical signal, or video, having a voltage corresponding to the density of the original image is generated. (image) is converted into a signal. This video signal is subdivided at regular intervals by a sampling signal generated at regular intervals from the synchronization signal generator 17, and divided into pixels. Furthermore, this sampling signal is applied to the set-side input terminal of the flip-flop circuit 24 to set the circuit 24. The output signal from the set side output terminal of flip-flop circuit 24 in the set state is sent to ramp waveform generator 26 and frequency modulator 30 through line 25. When the ramp waveform generating section 26 receives the set output signal of the flip-flop circuit, it is activated and generates a signal on the line 27.
Output a signal from. The ramp waveform generating section 26 includes a ramp signal generating circuit that generates a ramp waveform signal of triangular waveform pulses with a constant time constant, and a mixing circuit that compares and synthesizes the video signal sent from the line 23 and this ramp waveform signal. The combined signal is sent to the Schmidt circuit 28 via line 27. Based on this signal, the Schmitt circuit 28 performs a switching operation at a preset threshold value and outputs a signal from a line 29. This output signal is applied via line 29 to the reset side input terminal of flip-flop circuit 24 to reset the flip-flop circuit. Therefore, a pulse signal having a time width corresponding to the density of each pixel of the original image is obtained from the set output terminal of the flip-flop circuit 25, that is, the time width of the signal changes depending on the amplitude of the video signal. A pulse signal having a time width (pulse width) corresponding to the density of the original image is sent to a frequency modulation section 30, and this modulation section 30 modulates the pulse signal to a first frequency corresponding to the binary value (0, 1) of the pulse signal. It is modulated into two signals of a second frequency. The ratio of the duration (duration width) of the two signals of the first frequency and the second frequency changes in accordance with the image density, and when the signal of one frequency is input to the modulation section 30, the laser beam is The laser beam is deflected at an angle that is blocked by the light shielding plate, and when a signal of the other frequency is input to the modulation section 30, the laser beam is deflected at an angle that allows the laser beam to pass through the aperture 6 of the light shielding plate. The cut-off and transit times of the laser beam correspond to the duration of the first and second frequency signals input to the diffraction grating. Therefore, the laser beam 2 can pass through the aperture of the light shielding plate for a time corresponding to the time width of the pulse signal. The recording material 10 is subdivided at regular intervals in the width direction by a horizontal synchronizing signal, corresponding to equally divided areas of the original image, that is, images. Therefore, each equally divided area of the recording material has a different area exposed by a laser beam having a constant width (width in the longitudinal direction of the recording material) and a constant brightness according to the density of the corresponding pixel. be done. As a result, the shading of the original image is changed and recorded according to the size of the discolored portion consisting of minute dots or lines. Although this recorded image has the density of the original image converted into a difference in the size of the discolored portion, it appears to the human eye as an image with shading similar to the original image. The maximum size of the fine point or fine line varies depending on the diameter of the laser beam and the size of the divided area of the recording material. Further, the apparent contrast can be adjusted by changing the size of the discolored portion or the size of the divided area. Here, the recording device records the third
A case will be described in which an original image having the gradations shown in the figure is recorded on a photographic film. In FIG. 3, the original image 40 to be recorded has information whose density increases step by step from the left side to the right side. This original image 40 is photoelectrically scanned by a recorded information generating section 22 having a known reading device and converted into a video signal having a voltage corresponding to the density as shown in the waveform diagram of FIG. The original image 40 is scanned n times by horizontal scanning lines. The flip-flop circuit 24 is set by a sampling signal (waveform a in FIG. 5) generated at regular intervals from the synchronization signal generator 17, and outputs a set signal (waveform b in FIG. 5) with a voltage level of "1" from the set side output terminal. . This set signal is applied to the ramp signal generating circuit of the ramp waveform generator 26, and the ramp waveform circuit generates a ramp waveform signal (waveform d in FIG. 5). The ramp waveform generator synthesizes this ramp waveform signal and the video signal (waveform c in FIG. 5) sent from the recording information generator 22, outputs a signal with the waveform e in FIG. 5, and sends this output signal to the line 27. is sent to the Schmidt circuit 28 through The Schmitt circuit outputs a signal shown in the waveform of FIG. Reset 24. As a result, the set signal of the flip-flop circuit changes from voltage level "1" to "0". By resetting the flip-flop circuit 24, the ramp waveform signal of the ramp waveform generating circuit returns to its original potential (waveform d in FIG. 5). Through the above operations, the video signal is converted into a pulse signal (fifth pulse signal) with a time width corresponding to the video signal amplitude.
Figure b waveform). This pulse signal is modulated by a frequency modulation section 30 to a predetermined frequency according to the voltage level of the pulse signal, and the frequency modulated signal is applied to the laser diffraction grating 3. When the laser beam 2 passes through the diffraction grating 3, it is deflected according to the frequency input to the diffraction grating, and only the +1st order laser beam deflected at a predetermined angle can pass through the aperture 6 of the light shielding plate. Frequency modulation section 30
Of the pulse signals output from the flip-flop 24, the output signal representing, for example, "O" is modulated into a signal of a first frequency, and the output signal representing "1" is modulated into a signal of a second frequency. The signal at the first frequency has a duration corresponding to the time width of the output signal representing "o", and the signal at the second frequency has a duration corresponding to the time width of the output signal representing [1]. The first and second frequency signals are selectively sent to the diffraction grating 3. Since the time width of the pulse signal output from the flip-flop 24 changes in accordance with the image density, the ratio of the duration of the signal with the first frequency and the signal with the second frequency changes in accordance with the image density. It's going to change. The laser beam 2 is first applied to the diffraction grating 3.
When a signal with a frequency of
When a signal with a frequency of is input, it passes through the aperture of the light shielding plate.

The laser beam 8 that has passed through the light shielding plate is deflected by deflectors 7 and 9 to two-dimensionally expose and scan the recording material. The synchronization signal generated from the synchronization signal generating section 18 and the sampling signal are synchronized. The laser beam scans the areas equally divided in the width direction of the recording surface of the photographic film 10 in accordance with the horizontal synchronizing signal, and the laser beam is scanned in accordance with the time width of the pulse signal of the flip-flop circuit 25 for each of the equally divided areas. Expose to different irradiation areas. In other words, each of the equally divided areas of the photographic film 10 has a different exposed area corresponding to the density of the pixels of the original image, and as a result, the shading of the original image is changed to minute points or This means that the size of the fine line was changed and recorded. In FIG. 5g, black areas indicate exposed areas and white areas indicate unexposed areas. FIG. 9 shows a photographic film on which the original picture 40 of FIG. 3 was recorded by the above-mentioned apparatus.
This film is made of negative film, with black areas indicating exposed areas. When recording a positive image, an inversion film may be used, or the polarity of the pulse signal output from the flip-flop circuit 24 may be inverted, and the inverted pulse signal may be sent to the frequency modulator. Regarding the divided areas of the recording material corresponding to the lowest density of the original image,
It does not matter if it is exposed (to the minimum point) or not.
Here, the relationship between the synchronization signal and the sampling signal will be mentioned. The frequency Fs of the sampling signal and the frequency Fx of the horizontal synchronization signal are set as Fs-Nfx. When n is a positive integer (horizontal sampling number), if an original image with a constant density is recorded on a recording material using this relationship, the recorded image will be as shown in Figure 6, and each of the images on the recording material will be Since the phases of the sampling signals in the scanning lines, that is, the phases of the fine lines recorded in each scanning line are the same, certain blank areas occur in the vertical direction, making it difficult to see the recorded image.

2n-1 Also, if we use the relationship Fs-(?)Fxn: a positive integer (horizontal sampling number), the recorded image from the same original image as above will be as shown in Figure 7, and the image recorded in adjacent scanning lines will be The recorded information becomes easier to see because the phase of the fine lines differs by -Fs time.

Figure 8 shows a recorded image obtained by recording multiple horizontal scanning lines by changing the phase of fine lines for each scanning line; this also makes the recorded image easier to see. be able to.

In the embodiment described above, the original image is converted into an analog signal in the signal conversion section 15, but this may be converted into a digital signal. That is, FIG. 2A shows a digital signal conversion section, in which a synchronization signal generation section 117 receives a clock signal at regular intervals from a line 116 and outputs a vertical synchronization signal and a horizontal synchronization signal to lines 118, 119, 120, 12.
1 through the first and second deflection sections and the recording signal generation section 12.
Send to 2. ．． Further, the synchronizing signal generating section 117 sends sampling signals to the set input terminal of the flip-flop circuit 124 and the A/D converter 126, respectively. Furthermore, the synchronizing signal generating section 117 generates pulses with a higher frequency than the frequency of the sampling signal at regular intervals, and transmits these pulses to the counting section 117.
Send to input terminal 00. Counting section 100 counts these pulses and sends the counted value to comparator circuit 128. Counting part 10
0 is set by the sampling signal input to the input terminal. The video signal sent from the recording signal generator 122 through the line 123 is sent to the A/D converter 126, where it is converted into a digital signal having a width corresponding to the amplitude of the video signal. When the sampling signal enters the counting section 100, the counting section is set, so that the counting section 100 counts each pulse sent from the synchronizing signal generating section 117 and sends the counted value to the comparator circuit 128. This sampling signal also sets flip-flop circuit 124 and operates A/D converter 126. A digital signal enters the comparator circuit 128 due to the operation of the A-D converter;
Comparison circuit 128 compares the code of this digital signal with the count value of the count signal sent from the counting section, and outputs a match signal to line 129 when the two match. This match signal is sent to flip-flop circuit 124 to reset it and also to counter 100 to reset it.
By the above operation, the video signal is converted into a pulse signal having a time width corresponding to the amplitude of the video signal, and this pulse signal is frequency-modulated by the frequency modulation section 130 in the same manner as described above. The following operations are similar to those described above. FIG. 2B shows yet another embodiment in which a video signal is stored once and read out as required.

The video signal is stored in a storage section 101 having an A-D converter, and is read out by a sampling signal from a synchronization signal generation section 117. According to this method, the grayscale information output from the computer can be processed off-line.

In the present invention, as a recording medium for recording information using a laser beam, a silver salt photographic material, a bubble photographic material,
Various materials such as heat-sensitive recording materials, discharge recording materials, and electrostatic recording materials can be used. FIG. 10 shows an embodiment in which the device of the present invention is applied to a rotary camera.

In FIG. 10, the document original 200 is
The light beam is placed on an endless belt 202 stretched across the substrate, and is transported integrally with the endless belt 202 through the exposure position at a constant speed by driving the drive roller 201. The document 200 is exposed to a flying spot scanning cathode ray tube 203 at the exposure position.
The spot light is exposed and scanned from end to end through the lens system 204. The spot light reflected from the document surface is guided by an optical fiber bundle 205 and then guided to a photomultiplier tube 206. The cathode ray tube 203 has a deflection drive section 209 that receives a synchronization signal from a synchronization signal generation section 208, and a deflection coil 207 is driven by the deflection signal generated from the deflection drive section 209. Deflection coil 2
07 causes the electron beam to be deflected in a predetermined direction.
The light beam reflected from the document surface enters the photomultiplier tube 206, where it is photoelectrically converted to obtain an image signal containing grayscale information. This image signal is divided into fixed time intervals by a sampling signal sent from the synchronization signal generation section 208 in a signal conversion section 210 similar to the signal conversion section 15 described above, and is divided into fixed time intervals corresponding to the amplitude of the image signal. The signal converter 210 outputs a frequency modulated signal, and the modulated signal is transmitted to the diffraction grating 21 similar to the diffraction grating 3 described above.
Sent to 2. As a result, the laser beam passes through the slit opening of the light shielding plate 213 according to the time width of the pulse signal.
The laser beam passing through the light shielding plate 213 is transmitted to the deflection drive circuit 21
The beam is deflected by a deflection device 215 driven by the deflection signal No. 4 and projected onto a predetermined position on a roll-shaped micro film 216. The deflection drive section 214 is a synchronization signal generation section 208
It is actuated by a synchronization signal sent from the device and generates a deflection signal. The microfilm drive reel 217 is driven and controlled by a drive signal from a film drive control circuit 218 which is activated by a synchronization signal. On the other hand, the drive roller 201 of the endless belt 202 is driven in synchronization with refilm feeding by a drive signal from a belt drive control circuit 219 which is activated by a synchronization signal. The microfilm 216 is fed at a speed corresponding to the reduction ratio of the subject 200. As a result, the image density of the document is changed to the size of fine lines or minute dots and recorded on the microfilm. Note that in the above embodiment, the document reading section and the recording section can be separated and used as a facsimile device by connecting them through an electrical transmission line.

FIG. 11 shows an embodiment in which the present invention is applied to a COM device (computer desktop microfilmer). Conventionally, information recorded on microfilm using a COM device is code information such as letters, symbols, numbers, etc., and it has been difficult to record images with gradations such as photographs. According to the present invention, photographic information and the like can be recorded on microfilm along with computer output information using a COM device. In FIG. 11, the electronic computer 300
The output information is stored on the magnetic tape 301.

Information stored on the magnetic tape 301 is read by a reader (not shown) and sent to the control unit 302. When performing online with a computer, the output information is sent directly to the control unit. The control unit 302 controls the character generation unit 303 based on the read information.
A character selection signal is sent to the character selection signal, and a brightness information signal of the selected character is received from there. Furthermore, the control unit 302
A camera control signal such as a film feed command is sent to the camera unit 304 through a line 306, and a deflection signal is sent to a laser deflection device 307 through a line 306. A laser beam generated from a laser generator 308 disposed in the camera section 304 passes through a modulation device 309 and heads toward a light shielding plate 310 .

The laser beam is deflected by a modulation signal sent from the control unit 302 to the modulation device 309 through a line 311, and passes through the light shielding plate 310 intermittently. The laser beam passing through the light shielding plate 310 is deflected by the deflection device 307 and projected onto a predetermined position on the microfilm 312. Since the detailed configuration of the COM device is already known, the details will be omitted. Next, a case where an image such as a photograph related to the output information of the computer 300 is recorded on the microfilm 312 will be described. Subject 31 with gradation such as a photograph
5 is exposed and scanned by a spot light from a flying spot scanning cathode ray tube 316 via an optical system 317. A deflection coil 318 of the cathode ray tube 316 deflects the electron beam according to a deflection signal from a deflection 1 drive section 319 that receives a synchronization signal from the control section 302 . The subject 315 is the subject supply device 3
Delivered at 20. The light beam reflected from the surface of the object 315 enters the photomultiplier tube 321, where it is photoelectrically converted. The time-series image signal generated by the multiplier tube 321 is sent to a signal converter 322, where it is divided into predetermined time intervals based on the sampling signal sent from the single controller 302. Reference numeral 323 denotes an image correction device, which performs shading correction, gamma correction, etc.

Therefore, in the signal conversion section, the object image is converted into a pulse signal or a coded digital signal having a time width corresponding to the density of the object image. Note that when the image is converted into a digital signal in the signal conversion section 322, the digital signal may be sent to the control section 302, where the digital signal is converted into a pulse signal having a time width corresponding to the code. good. The pulse signal is then frequency modulated and sent from the control unit 302 through a line 311 to a modulation device 309.
sent to. The following operations are performed in the same manner as described above. As a result, the microfilm 312 can record information such as letters and numbers from the computer 300 as well as shading information such as photographs. As described above, the present invention is capable of producing an original image having gradations based on its apparent gradation even when using any recording material, such as a recording material with various gamma values or a recording material that cannot record gradation. It can be reproduced and recorded, and the contrast of the recorded image, or negative,
Positive switching adjustment can be easily performed.

Further, a signal consisting of two frequencies in which the duration ratio of the first frequency and the second frequency changes in accordance with the image density is outputted, the light modulation element is driven by the signal, and the signal is input to the light modulation element. A laser beam of constant intensity is deflected at different angles according to the signal Q frequency, and among the laser beams output from the optical modulation element, a laser beam deflected corresponding to a signal of one of the two frequencies is used. By selecting an intermittent laser beam, an intermittent laser beam is obtained, and the recording medium is scanned at a constant speed by the intermittent laser beam, so that the density of an image can be recorded at a high speed depending on the length of the fine line.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a recording device showing one embodiment of the present invention;
FIG. 2A is a partial configuration diagram showing another embodiment, FIG. 2B is a partial configuration diagram showing still another embodiment, FIG. 3 is a front view of information to be recorded, and FIG. 4 is a video signal 5 is a diagram showing the signal waveform of each output line in FIG. 1, FIG. 6 is a diagram explaining the image recording method, FIG. 7 is a diagram showing another example of the recording method, FIG. 8 is a diagram showing still another example, FIG. 9 is a front view of a recording material on which an image is recorded, FIG. 10 is a schematic diagram of a rotary camera to which the present invention is applied, and FIG. 11 is a diagram to which the present invention is applied. FIG. 2 is a schematic diagram of a COM device. 1... Laser generator, 3... Laser light diffraction grating, 5... Light shielding plate, 8, 9...
Deflector, 10... Recording material, 17...
Synchronization signal generation section, 22... Recording information generation section, 2
4...Woripflop circuit, 26...
Ramp waveform generator, 28...Schmitt circuit,
30... Frequency modulation section.

Claims (1)

[Claims] 1 Output a signal consisting of two frequencies in which the ratio of the duration of the first frequency and the second frequency changes in accordance with the image density, drive a light modulation element with the signal, and input it to the light modulation element. A laser beam of constant intensity is deflected at different angles depending on the frequency of the signal, and among the laser beams output from the optical modulation element, a laser beam that is deflected corresponding to a signal of one of the two frequencies is used. By selecting an intermittent laser beam and scanning the recording medium at a constant speed with the intermittent laser beam,
changing the ratio of the length in the scanning direction of the area to which the laser beam is applied to the length in the scanning direction of each subdivision area of the recording medium subdivided in the scanning direction, depending on the image density;
An information recording method characterized in that an image is recorded by varying the length of fine lines of constant density in the scanning direction.