JPS59119960A - Exposure device of hard copy - Google Patents

Abstract

PURPOSE:To attain a hard copy of picture of high quality from video signals by providing a data converting means which delivers electric signals after converting the electrical color signals into a data consisting of the combination of the light emitting time and the light emitting intensity, a light emitter for signal transmission, etc. CONSTITUTION:A conversion table 12 converts three kinds of electrical color signals 3a and 11a of a color picture into a data consisting of the combination of the light emitting time and the light emitting intensity and delivers the electric signals. A light emitter 16 for signal transmission emits the light with the time and intensity decided by the electric signal. A light emitter 21 for exposure is provided to a main scanning revolving body 17 and consists of three kinds of light emitters having different output wavelengths. A photodetector 22 for signal transmission receives the output light of the light emitter and converts it into the electric signal. This electric signal controls both light emitting time and the light emitting intensity of the light emitter 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exposure apparatus for making a high-quality hard copy of an image from a video signal from a television or the like.

K to make hard copies of TV images on paper, film, etc.
It is convenient to capture the image on the picture tube with a camera, but considering the image quality, it is necessary to use a light emitting diode or laser diode using three types of color signals such as R, G, and B obtained from the video signal. It is desirable to control the lighting, scan and expose the color photosensitive material with this output light, and then develop and fix it. Note that in the case of monochrome, a luminance signal is used.

In this case, the main problems are the control of the exposure amount per pixel and the scanning mechanism.

Regarding the scanning mechanism, it is possible to use a deflector to deflect the light in the main scanning direction and the sub-scanning direction, but
This is not practical due to the attenuation of light and the increased size and complexity of the device. Therefore, mechanical scanning is used, in which main scanning is performed by rotating an exposure light emitting device such as a light emitting diode or LED diode, and sub-scanning is performed by moving at least one of the exposure light emitting device and the photosensitive material in the direction of the rotation axis. It is considered promising. However, when the exposure light emitter rotates, the problem is how to transmit control signals without contact. In other words, the contact type using a sliding ring lacks reliability in terms of lifespan, contact noise, etc. Furthermore, electrical and magnetic wireless systems are susceptible to induced noise. Therefore, the above-mentioned problems can be solved by converting the control signal from an electrical signal to an optical signal, transmitting it by optical coupling, and then converting it back to an electrical signal.

On the other hand, to control the exposure amount per pixel, a method can be considered that first amplifies the color signal (luminance signal in monochrome) and modulates the emission intensity of the exposure light emitter, but the input/output characteristics of the light emitting element (iI Since the flow-emission intensity characteristics) have non-linearity, and the photosensitive materials also have non-linearity in the input/output characteristics (exposure-color density characteristics), in analog processing, the difference between the color signal and the color density of the photosensitive material is Correction is complicated and difficult, and it is not suitable for high-quality hard copies of images.

On the other hand, there is a digital processing method in which the color signal is sampled for each pixel and converted into a digital signal, and the exposure light emitter is made to emit light in a pulsed manner according to the digital signal value, and the emitted light intensity is set constant. For example, each pixel is emitted continuously for a time corresponding to the digital signal value (pulse width modulation:
PWP, 4), the light emission intensity and the light emission time per time are kept constant, and each pixel emits light the number of times corresponding to the digital signal value (pulse number modulation 2 PNM), and the light emission time is kept constant and the light emission time is fixed for each pixel. In the case of digital processing, it is possible to emit light with an intensity corresponding to the digital signal value (Pulse Amplitude Modulation: PAM), etc. In the case of digital processing, the non-linearity between the color signal and the color density of the photosensitive material must be corrected to linearize it. There is an advantage that correction can be made easily by using a conversion table made of coefficients. Furthermore, the resolution of television video signals, especially in the vertical direction, is rather low, so if interpolation such as forming a new pixel between pixels is desired, interpolation can be easily performed using digital processing. However, in the case of exposure control using digital processing, obtaining a high-quality image requires several hundred steps of gradation expression.
Even if an attempt is made to control the exposure amount using only the emission time as in NM or only the emission intensity as in PAM, the dynamic range of exposure cannot be wide and it is difficult to express rich gradations. In addition, the frequency band of the circuit system that drives the light emitting element becomes wide depending directly on the number of gradation steps itself, and there is no practical use in terms of circuit design, assembly/manufacturing, or cost.Especially in the case of PNM. Since the time width of one pixel is as short as about 4 μs even when considering a television image, although it is possible to control several hundred pulses within such a short time, it is not practical.

Therefore, we came up with the idea that if we controlled the exposure amount using both the emission time and emission intensity as parameters, the dynamic range of exposure would be expanded, and at the same time, the frequency band of the drive system would be narrowed.

The above explanation is about color hard copies, but the same thing can be said about monochrome hard copies.

SUMMARY OF THE INVENTION An object of the present invention is to provide an exposure apparatus suitable for making a hard copy of a high-quality image from a video signal from a television or the like. The exposure apparatus of the present invention that achieves this object has the following configuration based on the above-mentioned considerations. That is, it is determined by a data conversion means that converts the three types of electrical color signals of a color image into data consisting of a combination of light emission time and light emission intensity and outputs the electric signal, and the output data of this data conversion means. A signal transmission light emitter that emits light depending on time and intensity, a rotating body that rotates for main scanning, and three types of exposure light emitters with different output wavelengths provided on this rotating body,
The output light of the signal transmitting light emitter provided on the rotating body is received through the shaft of the rotating body and converted into an electric signal, and this electric signal is used to determine the light emission time and the light emission intensity of the exposure light emitter. a light receiver for signal transmission to control, a photosensitive material mounting means for mounting a color photosensitive material close to the periphery of the rotating body, and at least one of the color photosensitive material and the rotating body in the axial direction of the rotating body. This is a hard copy exposure apparatus equipped with a moving sub-scanning means. Hereinafter, the present invention will be explained with reference to the drawings.

FIG. 1 shows an exposure apparatus according to an embodiment of the present invention. The device of this embodiment uses NTSC signals obtained from a television tuner, VCR, video camera or video disc.
Hard copies from television signals obtained from microcomputers or R, G, B televisions, and digital color signals obtained from digital image memories such as high-speed digital disks or frame memories. The NTSC signal is input to the first input terminal 1, the R2O, B signal is input to the second input terminal 2, and the digital color signal is input to the third input terminal 3. Man-powered.

Since it is necessary to create three types of color signals R, G, and B for the NTSC signal, the NTSC/B signal is
, G, B color signals 5a by the G, R conversion circuit 5.
shall be. This converted R, G, B color signal 5a is the second
Like the R, G, and B color signals 2a from input terminal 2, they are television signals, so they are normally processed to the 1/γ power, so any RoG, B color signals 5a, 2a are γ-corrected. The R, G, and B color signals 7a after the OR correction, in which the 1/r power is removed through the circuit 6 and the 1oll conversion circuit 7, are inverted by the color invert circuit 8 as necessary, and then sent to the sampling hold circuit 9 and A/D conversion. Each pixel (quantized and converted into a digital color signal 10a) is passed through the color signal generator 10 and subjected to subsequent digital processing.

11 is an interpolation circuit. As mentioned above, the resolution of television video signals in the horizontal direction (main scanning direction) and vertical direction (sub-scanning direction) is low, and the pixel density is low, and as it is, the image will be coarse. It is necessary to additionally form at least one pixel between each adjacent pixel. Specifically, the number of horizontal scanning lines is increased, and for example, two signals adjacent in the vertical direction on each color signal side are averaged to create a new signal for one horizontal scanning. However, since television and video use an interlaced scanning method, interpolation is performed after converting to progressive scanning. In addition, resolution in the horizontal direction (main scanning direction) can be improved by increasing the sampling frequency, or, similar to vertical interpolation, by sequentially taking the average of two horizontally adjacent signals on each color signal side and combining this with both signals. It can be improved by inserting it in between.

Digital color signal 11 interpolated as necessary as described above
a is input to the conversion table 12 in the same way as the digital color signal 3a from the third input terminal 3. These digital color signals 11a and 3a represent the brightness when each pixel is divided into three primary colors, and this brightness corresponds to the density of each color of each pixel of the color photosensitive material in a bird copy.

The color density of a photosensitive material depends on the amount of exposure, and the amount of exposure is given by the product of the light emission time and the light emission intensity.

Therefore, the conversion table 12 associates the value of the digital color signal with data that is a combination of light emission time and light emission intensity. However, as mentioned in Mi1, there is a nonlinear characteristic between the coloring density of the photosensitive material and the exposure amount, and furthermore, the photosensitive material has a spectral sensitivity characteristic, and the human output characteristic of the light emitter for exposure is also nonlinear. In addition, in the present invention, the exposure control signal is first converted into an optical signal, transmitted, and then received and converted into an electric signal again, so two non-linear circuits are present during the transmission. Then, the conversion table 12 is created. In other words, the conversion table 12 has tables for each color of R, G, and B, and each table performs corrections to remove the various nonlinearities described above when converting the corresponding digital color signal into a combination of light emission time and light emission intensity. It is alms.

In addition, as an example of matching the luminescence time and luminescence intensity,
Figure 2 (a) shows a constant amplitude l/f pulse per pixel layer, Figure 2 (b) shows multiple pulses with different amplitudes per pixel layer, and Figure 2 (c) shows a single pixel pulse. A single pulse with varying layer amplitude is conceivable. Figure 2(b),
When the amplitude changes in the -II element as shown in (C), adjusting the front and rear amplitudes will smoothly connect horizontally adjacent pixels to prevent moiré, and conversely increase the front and rear amplitudes. By setting the table, it is possible to enhance the outline, and by setting the table, it is possible to perform exposure for each pixel in a pattern suitable for the nature of the image.

When creating a table, in addition to setting the exposure amount steps constant, set the step intervals by making the steps in the low exposure amount area dense and the steps in the high exposure amount area coarse, or vice versa. By changing K, the gradation expression can be made even richer.

The output data of the conversion table 12 is, for example, 16 bits per pixel as shown in FIG. 7A, with the upper 4 bits specifying the light emission intensity a, the next 6 bits specifying the rising light emission time, and the lower 6 bits specifying the rising light emission time. Specify the downward light emission time C. Also,
The conversion table 12 in this example shows the conversion data for each color of R, G, and B: R-+G→B-SR-+G-+B→R...
・Output cyclically, that is, serially for one horizontal scan. The strength data 12a of the upper 4 bits is D
The data is input to the /A converter 13 and converted into an analog quantity pixel by pixel, but at this time, the lower 12 bits of time data 12
b is input to the D/A converter 13 via the pulse modulator 14. In addition, in the example shown in FIG. 7B, one pixel is arbitrarily divided into n equal parts for each pixel, and the top four parts of the data in the conversion table are divided into n equal parts.
Sequentially read n data of emission intensity a bit by bit D/
This is a method of performing A conversion and producing a converted output with controlled amplitude and time. Through these, conversion outputs 13a in various forms shown in FIGS. 2(a) to 2(e) are obtained. Note that circuits such as a buffer memory necessary for the above digital processing are not essential to the invention and will therefore be omitted.

The converted output 13a whose amplitude and time are controlled is input to the driver 15 of the signal transmission light emitter 16, where it is converted into an optical signal 16a.

This optical signal 16a is received by a photosensor 18 provided with a shaft portion of a rotating body 17, converted into an electrical signal 18a, and inputted to a driver 20 of an exposure light emitter 21 via an amplifier 19. As a result, the light emitter 21 for exposure is converted to the conversion table 1.
2, and the photosensitive material 22 is exposed to light.

Next, a specific example of the scanning mechanism will be explained with reference to FIGS. 3 and 4. The rotating body 17 is coupled to a rotating shaft 23a of a motor 23,
It is rotatably supported by a pair link 25a of a bearing holder 25 integrated with the motor bracket 24. A signal transmission light emitter 16 is fixed to the center of the bearing holder 25, and a prism reflector 26 is fixed to the shaft of the rotating body 17 as a light transmitting means, and the reflected light of this prism reflector 26 is fixed to the center of the bearing holder 25. The sensor 18 receives the light. 27 is a printed circuit board;
It is fixed to the rotating body 17, and the amplifier 19 and driver 2 are connected here.
There is o. There are three types of light emitters for exposure with different output wavelengths: 21 a, 2 l b, 21 c are 12
They are equally spaced at 0° intervals, and a condenser lens 28 is installed in front of each lens. In addition, each light emitter 21 for exposure
The output wavelengths of a, 2 l b, 21 c are R, G
.

It is not limited to the three types of B, but color photosensitive materials 2
20 types may be determined depending on the characteristics.

Further, the output wavelength may be set using a filter.

The rotating body 17 is given rotation for main scanning by the motor 23, and is linearly moved together with the motor 23 by the feed screw 29 to perform sub-scanning. That is, the feed screw 29 is
A female screw member 3 is rotationally driven by 0 and screwed into the female screw member 3.
1 is fixed to a motor bracket 24 and a bearing holder 25 integrated therewith. Note that 32 is a bearing, but the sub-scanning guide of the rotating body 17 is not shown.

The power source for the amplifier 19 and driver 20 of the rotating body 17 may be a battery, but in this embodiment, a rotary transformer 33 is used.
is used to supply electricity. In addition, 33a is a ferrite core divided into two parts, 33b is a single layer coil, and 33a is a ferrite core that is divided into two parts.
3C is a secondary coil, but the rectifier circuit on the secondary coil side is not shown.

34 is a rotary encoder, encoder disk 3
4a is fixed to the motor shaft 23a, and its output 34b is given to a timing control circuit 35 in order to synchronize the rotation speed of the rotating body 17 with each electric circuit.

36 is a platen, and the color photosensitive material 22 is transferred to the rotating body 1.
7 and close to each other along one-third of the outer circumference. However, it is held by vacuum suction. In this example, the platen 36 is fixed, but the platen 36 may be moved in the sub-scanning direction.

In the hard copy exposure device described above, conversion table 1
2 to R, G, and B color conversion data from R→G-+B-+
The data is output serially as R-+G→B→R..., and from the D/A converter 13 to the driver 2 of the exposure light emitter.
The circuit up to 0 is shared by each color to simplify the device. Therefore, the three types of light emitters will also emit light in response to control signals of other colors, but at that time there is no problem since they do not face the photosensitive material 22. Of course, separate circuits may be used for each color. Further, for driving the sub-scanning, the motor 30 may be a stepping motor to intermittently feed one horizontal scan at a time, or a normal motor may be used to continuously feed. However, when sub-scanning is continuous feeding, three exposure light emitters 21 a, 2 l b,
21 (so that ! takes the same scanning trajectory for each main scan,
The light emitters for exposure are not placed on the same circumference but are staggered from each other in the sub-scanning direction.

Regarding the color photosensitive material 22, since it is difficult for ordinary light emitting diodes to effectively emit blue light, three kinds of light emitting diodes emitting green light, red light, and infrared light are used, for example, with an output wavelength of 550. 650
．． It is also conceivable to use a material with a diameter of 750 mμ and design the sensitive layer portions that are sensitive to these lights to be colored yellow, magenta, and cyan, respectively. That is, exposure is by spectral sensitization, and an example of the structure of the light-sensitive material layer of such a color light-sensitive material is shown in FIG. In the figure, 22a is a polyethylene paste, 22b is a cyan coloring layer, 22c is an intermediate layer,
22d is a magenta coloring layer, 22e is a yellow coloring layer, 2
2f is a protective layer.

Specific numerical examples of the scanning mechanism are as follows.

Scanning area: A6 size (150 x 100 square) Scanning line density = 10 lines / spot diameter: 100 μm Main scanning rotation speed 73000 rpm Horizontal scanning frequency: 50 Hz / color image frequency @: 225' KHz Internal light time: 20 seconds FIG. 6 shows an example of a No. 1 docobee apparatus equipped with the exposure apparatus of the present invention. In the figure, 37 is a high-frequency oscillator for timing, 38 is a guide rail, 39 is a wire-type feeding mechanism for sub-scanning, 40 is a vacuum pump, 41 is a vacuum-type platen on which a heat-developable color photosensitive material is mounted, and 42
4 is a feed roller to the developing section; 43 is a thermal developing section;
4 is a far-infrared heater, 45 is a rubber heater, and other reference numbers indicate the same members as in other figures.

Here, a case will be described in which the conversion table 12 outputs conversion data for each color of R, G, and B in four parallels. In this case, D/A converter 13, pulse modulator 1
4. Three sets of the driver 15, the signal transmission light emitter 16, and the photosensor 18 are used. If each signal transmission light emitter 16 has the same wavelength, the signal transmission light emitter 16 and the odometer 18
Although the optical transmission between the two is spatially separated, if the wavelengths are different from each other, the same optical transmission path can be shared as wavelength multiplexing, and the light is separated by a filter or the like on the photosensor 18 side. Furthermore,
The amplifier 19 and driver 20 after the photosensor 18 are connected to 3
By using three types of exposure light emitters 21a, 21
b.

, 21c and their condensing lenses 28 can be put together in one place, and each beam can be projected to the same point.

In this case, the time required for hard copying is significantly reduced.

We have explained the color hard copy above, but if a monochrome hard copy is sufficient, a luminance signal will be used instead of the three color signals, and the conversion table and exposure light emitter will each be one type. A monochrome exposure device was realized.

As explained above, the present invention has the following advantages.

(1) By driving an exposure light emitting device such as a light emitting diode or a laser diode with amplitude modulation and pulse modulation, the exposure dynamic range can be widened and many subtle gradations can be expressed.

(2) Although the gradation expression is rich, the frequency band of the signal transmission system does not widen, making circuit design and manufacturing easier.

(3) Since the light emitting pattern in one pixel can also be controlled using a conversion table, it is possible to easily prevent moire and enhance contours.

(4) Since pixels can be easily interpolated, it is possible to express thin images.

(By preparing several types of conversion tables,
Various tone corrections and r corrections can be freely achieved.

(6) Since scanning exposure is performed using a rotating body, the mechanism is simple.

(7) Since optical signals are used for signal transmission between the rotating part and the fixed part, highly reliable contactless transmission can be obtained.

[Brief explanation of the drawing]

The figures relate to the present invention; FIG. 1 is a block diagram of one embodiment, FIGS. 2(a), (b), and (c) are waveform diagrams showing light emission patterns in one pixel, and FIG. 3 is a scanning mechanism. 1st page of the part,
FIG. 4 is a front view of the rotating body, FIG. 5 is an explanatory diagram showing an example of a color photosensitive material, FIG. 6 is a perspective view of the entire hard copy device, and FIGS. 7A and 7B are each the light in one pixel. FIG. 3 is an explanatory diagram showing a data format of a conversion table. In the drawing, 1 is an NTSC signal input terminal, 2 is an R, G, B signal input terminal, 3 is a digital color signal input terminal, 10 is an A/D converter, 11 is an interpolation circuit, 12 is a conversion table, 13 is a D /A converter, 14 is a pulse modulator, 15 is a driver, 16 is a light emitter for signal transmission, 17 is a rotating body, 18 is a photosensor, 19 is an amplifier, 20 is a driver, 21 a, 2 l b , 21 c is a light emitter for exposure, 22 is a color photosensitive material, 23 is a main scanning motor, 26 is a prism reflector, 28 is a condensing lens, 29 is a feed screw, 30 is a sub-scanning motor, 31 is a female screw member , 33 is a rotary transformer, 34 is a rotary encoder, 35 is a timing control circuit, and 36 is a platen. Patent applicant: Fuji Photo Film Co., Ltd. Representative Patent Attorney Shibu Mitsuishi (and 1 other person) Figure 2 (22 Figure 3 728 Procedural amendment dated March 74, 1980, Director General of the Patent Office, Display of Case 1 1982) Patent Application No. 226555 2 Name of the invention Hard copy exposure device 107 9-15 Akasaka-chome, Minato-ku, Tokyo, same location [-Detailed description of the invention] column of the specification subject to the 6th amendment. Contents of the 7th amendment (1) Line 16 of page 10 of the specification and Same Kuji 17
to 18th line, respectively, and correct "-per pixel" to "within 11 pixels". (2) Page 10 of the specification, lines 18-19 ζ The phrase "like...one pulse" written here is corrected to "like." (3) In the 20th line of the 11th page of the specification, t is corrected to ``1 horizontal scan'' to 4 for every 1-1 horizontal scan.

Claims (1)

[Claims] data conversion means for converting three types of electrical color signals of a color image into data consisting of a combination of emission time and emission intensity and outputting the electric signal; A signal transmission light emitter that emits light, a rotating body that rotates for main scanning, three types of exposure light emitters with different output wavelengths provided on this rotating body, and the signal transmission light emitter provided on the rotating body. a signal transmission light receiver that receives the output light through the shaft of the rotating body, converts it into an electrical signal, and controls the light emission time and light emission intensity of the exposure light emitter using the electrical signal; and the rotating body A hard copy apparatus comprising: a photosensitive material mounting means for mounting a color photosensitive material along the periphery of the hard copy; and a sub-scanning means for moving the color photosensitive material and at least one of the rotating body in the axial direction of the rotating body. Exposure equipment.