JPS6238916B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plate-making apparatus, particularly to a color television image plate-making apparatus for producing printing plates for color television images.

As the content of television programs has expanded, there has been a need to record desired images from television images as photographs or prints, and to reproduce them in large quantities. Conventionally, when making large-scale reproductions of television images by printing, the television images are photographed using, for example, a steel camera, a color photograph is created, and the color photograph is run through a plate-making machine to create a printing plate. Mass copying of images is performed. However, the color temperature of television images projected on color cathode ray tubes is usually around 9000〓, and red (R),
Since it emits three types of phosphors, green (G) and blue (B), it looks good to the naked eye, but it does not match the sensitivity distribution of the photographic emulsion, so it is a television image projected on the CRT surface. A satisfactory color photograph cannot be obtained by simply converting the color temperature during color photography. Additionally, television images are composed of 525 scanning lines, regardless of screen size, and have the lowest resolution among commonly used images. Moreover, since the color photograph must be made into a color photograph and then plate-made again, the actual printed television image is considerably inferior in resolution, hue, gradation, etc.

Therefore, the present invention improves the resolution of television images,
An object of the present invention is to provide a plate-making device for printing television images without deteriorating hue, gradation, etc.

The present invention reads a video signal corresponding to one desired frame from a video tape recorder that records a television video signal, converts this signal into three primary color signals, and sends the three primary color signals to an electronic plate making device such as a color scanner. This relates to a television image plate-making device that produces color separation plates, etc. by supplying the images, and selects and extracts the necessary one frame image.
The image is then turned directly into a printing plate.

Therefore, the present invention eliminates the intermediate steps and directly makes a printing plate from a television image without degrading its original resolution, hue, or gradation, and it does not require the rotation of a plate-making scanner. It also controls and synchronizes signal readout.

Furthermore, the present invention is an interface circuit for directly transmitting a television signal to a plate-making scanner, in which either a field image or a frame image can be selected depending on the content of the plate-making image, and in the case of a field image, it is possible to select between a field image and a frame image by means of average value interpolation. It is characterized by creating another field image and correcting the deterioration in image quality seen in the conventional field image.

It is also possible to correctly select a specified frame from among images recorded on a videotape.
Furthermore, the scanning lines of the television image can be erased from the film exposed by the scanner.

The present invention will be explained with reference to the drawings. As shown in FIG. 1, an NTSC television signal 1 is supplied to a video tape recorder (VTR) 2. VTR2 is the first image to be used for printing.
This is a means for recording and reproducing television images and selecting a desired image from among the images. A 1-inch or 2-inch professional video tape recorder is used as the VTR 2. Further, this video tape recorder is preferably capable of slow playback and still playback in order to select frames as a manuscript for plate making. A frame number generator 3 and a read frame number indicator 4 are coupled to the video tape recorder 2.

A frame memory 5 and a 1/1 monitor television 6 are connected to the playback output of the video tape recorder 2. The frame memory 5 stores one frame of the television signal in synchronization with the synchronization signal generation circuit 10 in accordance with instructions from the storage instruction circuit.
The television synchronization signal generator 10 is necessary for correctly reproducing the VTR, and serves as a reference signal for correctly transferring and storing one selected frame to the frame memory 5.

One frame of television image is composed of two field images, and 525 television signals are divided into two and interlaced, so the reproduced signal from frame memory 5 cannot be supplied to the prepress scanner as is. Therefore, it is necessary to rearrange the order of the two-field interlaced signal into a one-frame signal and supply it to the prepress scanner. Further, the present invention is characterized in that even from one field image, another field image is created by means of average value interpolation.

Here, one frame of image will be explained. 1
Frame memories for storing frame images include analog magnetic disk memories and digital solid state memories. To simplify the explanation, we will use magnetic disk memory as an example. The magnetic disk memory stores video signals in a format as shown in FIG. One frame of television image is formed by 525 scanning lines and consists of odd and even fields. 1 to 20 and 2 for one frame image
It has a vertical blanking period of 63 to 283, and has a vertical synchronization signal therein, and also has a horizontal blanking period between each signal line, and has a horizontal synchronization signal therein. ing. Note that the odd field is defined by scanning lines 21 to 2 as shown in FIGS. 2 and 3.
63, and even fields are scan lines 283
~525. When reading a video signal from the frame memory shown in Figure 2, the third
Corresponding to the order of the scanning lines in the figure, the scanning line 283 of the even field, the scanning line 21 of the odd field,
The scanning line 284 of the even field, the even field, and the odd field must be read out alternately and sequentially. During this reading, the magnetic disk memory rotates at a constant speed, and a magnetic head (not shown) outputs video signals corresponding to the scanning lines in the order described above.

To read out the signals in the above order, the signals are read out as slow signals by the readout indicator in synchronization with the rotation of the scanner, and the opening/closing of the switch circuit 9 is controlled by the control signal from the gate signal generation circuit 13. It is carried out by. The output of this switch circuit 9 is stored in the 1H memory 25.

It is preferable that the playback speed of the frame memory 5 is slowed down in accordance with the rotation of the scanner 18, unlike when recording. The frame memory 5 is set in a reproduction mode during plate-making exposure, and the next switch circuit 9 arranges the order of the signals.

A gate signal generation circuit 13 that locks pulses synchronized with the rotation of the exposure cylinder from the plate-making scanner 18 in a synchronization circuit 17 and generates a signal to open the switch circuit 9, and a readout signal generator for obtaining reproduction signals from the frame memory 5. control. In the gate signal generation circuit 13, 283, 21,
A signal is generated to open and close the switch circuit 11 in the order of 284, . . . .

The signal that has passed through the switch circuit 9 is transferred to the 1H memory 25, and read out by the read signal from the storage/read indicator 15.

The television signal output from the 1H memory 25 is separated into three colors, R, G, and B, by the NTSC decoder 14 and supplied to the plate-making scanner 18. In the existing prepress scanner 18, R,
Y (yellow), M (magenta), C (cyan), and BK (black) signals are created from the G and B signals and supplied to the exposure section through an image quality correction circuit.

One of the features of the apparatus of the present invention is the use of existing prepress scanners. In existing scanners, the exposed film is wound into a cylinder as shown in Figure 4, and the film is exposed at a rate of 1400 films/cm or 200 films/cm.
It rotates at a speed such as cm and is exposed to light.

In a normal plate-making scanner, the document side and the exposure side rotate in synchronization, and it is possible to enlarge or reduce the original size as well as the original size.

The time required to read out one scanning line, for example 21, shown in FIG. 2 is assumed to be H seconds. 1H of one scanning line
The time R required to read the signal from the memory 25 is:
Assuming that the circumferential length of the cylinder of the scanner shown in FIG. 4 is L, and the circumferential length of the exposed film is Y, then L/Y=A/R (1). Here A=263H. That is, the fifth
284 from the frame memory as shown in Figure A.
The time interval of reading when reading in the order of 22, 285, . . . is A=263H. This is the second
In the magnetic disk memory shown in the figure, it rotates and reads out signals in the order of 283, 21, 284, 22..., so if the time to read one scanning line is H, then 283, 21, 284, 22...
This is because the interval at which each scanning line is read out in this order is 263H. Then, in order to store it in the 1H memory 12, as shown in FIG. 5A, 284, 22...
Since it takes 1H for each scanning line, the time R available for reading is in the range 0<R<A-H.

And from formula (1), R=Y/LA (seconds) becomes.

Next, a case will be described in which an image of one field is used to create another field image by mean value interpolation in the present invention.

As shown in FIG. 6, the signal of one field is sent from the switch circuit 9 to the distribution circuit 19, and the A delay circuit 20 is delayed by A seconds in the distribution circuit 19.
2A delay circuit 22 that delays by 2A seconds.
The signals are divided into those sent to the OR circuit 21 via the . The signal sent directly to the OR circuit 21 and
The signals delayed by 2A seconds by the 2A delay circuit 22 and sent to the OR circuit 21 are summed by the OR circuit 21, divided by 2 and averaged by the averaging circuit 23,
The signal delayed by A seconds by the A delay circuit 20 is summed by the OR circuit 24, sent to the 1H memory 25, and further sent to the NTSC decoder 14.

The relationship between these signals will be explained with reference to FIG. 5B. FIG. 5B shows the signal read out from the frame memory 5. The figure shows the signal delayed by A seconds. The figure shows a signal delayed by 2A seconds in the same way. The figure shows a signal obtained by averaging the signal read from the frame memory and the signal delayed by 2A seconds. The figure shows a combination of a signal delayed by A seconds and an averaged signal.
This is a 1H memory storage signal, and the figure shows a readout signal of the signal.

To explain again with reference to FIG. 6, the signal shown in FIG. 5B is distributed by the distribution circuit 19, and the signal shown in FIG.
The signal that has passed becomes the signal shown in FIG. This signal and the signal passed through the A delay circuit 20 are combined in the OR circuit 24 to form a signal, which is stored in the 1H memory 25, and the read signal is read out from the 1H memory 25 to the NTSC decoder 14.

In this way, by the average value interpolation method, a signal that approximates the image signal of one frame can be obtained from the image signal of one field, and a smooth image can be obtained.

Further, a method for selecting a desired one-frame image for printing from the images recorded on the VTR 2 shown in FIG. 1 will be further explained. It is extremely difficult to select a frame desired for printing from among images recorded on a videotape and to instruct a plate maker to print it. For example, a videotape is played on a VTR and displayed on a monitor, the videotape is stopped at the desired screen, and this screen is photographed with a Polaroid camera. At this time, the counter on the VTR is read and recorded, and these are then given to the plate maker. The plate maker plays a videotape on a VTR, pauses the screen at a specified counter number, and selects a frame image from the nearby frames that most closely matches the photo taken with a Polaroid camera. is conventionally done. This method cannot accurately select the designated frame image. Therefore, in the present invention, as shown in FIG. 1, a frame number generator 3 is provided to generate a frame number and record it on a video tape, and a read frame number indicator 4 is provided to read out the frame number to be printed. The frame number indicator 4 instructs the frame memory 5 to send the designated frame image from among the images of the video tape played on the VTR 2.

In this case, the frame number generator 3 is
A time code signal generator containing hours, minutes, seconds, and frames is used, such as SMPTE time code signal generator, VITC (Vertical Interval Time Code)
There is a signal generator. The former is placed in the audio track of the videotape, and the latter is placed during vertical blanking of the video signal on the videotape. Then, when recording the VTR image, the time code is also recorded, and during playback, the frame to be printed is determined by still playback, and the frame number of that frame is instructed to the plate maker, and the instructed frame number is set in hours, minutes, and seconds. , is set in the frame number indicator 4 in the form of a frame. When the video tape is played back by the VTR 2, the time code is read by the frame number reader 4' as shown in FIG. 7, and the signal is sent to the frame number indicator 4. The frame number indicator 4 detects the difference between the frame number signal sent from the frame number reader 4' and the frame number signal instructed in advance, and outputs a pulse at the moment the difference becomes zero. The pulse causes the memory instruction circuit 7 to operate, and a predetermined frame is memorized from the VTR 2 to the frame memory 5. As shown in FIG. 8, the output from the frame number indicator 4 may be a step signal in addition to a pulse, and the rising edge of a pulse or a step signal can be treated as a storage instruction signal.

Next, the exposure spot of the scanner 18 in FIG. 1 will be explained. In existing scanners, when exposing, the shape of the light source on the frame usually has many dots as shown on the left in FIG. 9, and it also seems to have a rectangular shape. By the way, just as if you look closely at the cathode ray tube surface of a television receiver, you can see 525 scanning lines one by one.If you enlarge the film exposed by the scanner 18, you can see 525 scanning lines in one image. You can see a book. However, it is undesirable for the scanning lines to be visible on a plate-making film, so in order to erase these scanning lines in the present invention, the shape of the light source on the film during exposure is made, for example, a rectangle as shown on the right in FIG. 9. Scan lines can be erased. The width of a is preferably 1.5 to 3.5 times the scanning line interval as a sufficient value to cancel out the scanning lines. Also, the width of b should be set to a value that sufficiently maintains the resolution of the television signal (approximately 5MHZ).

In the case of a scan density of 500 lines/inch, if there is a one-to-one correspondence between the 525 scanning lines of the television image and the exposure scanning lines of the plate-making scanner, the plate-making dimension is 27
(vertical) x 36 (horizontal) mm.

At this time, the shape of the exposure light source on the film is, for example, a≈150 μm and b≈55 μm.

In addition, if the scan density can be changed and it is set to 100 lines/inch, the plate making dimensions will be 133 (vertical) x 178 (horizontal) mm, and the size of the spot of the exposure light source will be the shape on the film, for example a = 700-750
μm, b=250 to 300 μm.

In this way, scanning lines can be erased without reducing resolution.

The present invention has the above-described configuration, and sends the television image as an electric signal to the plate-making scanner.
Because it exposes the film directly, there is no deterioration in resolution, gradation, or hue compared to the conventional method in which the television image on a cathode ray tube is taken as a color photograph using a camera, and then the color photograph is made into a plate. In addition, it is possible to control and synchronize signal readout according to the rotation of the prepress scanner, and it is also possible to obtain a smooth image close to that of one frame from an image of one field. It is also possible to precisely select frames that have been captured, and also to erase the scan lines of the television image and expose them to film.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of an embodiment of the present invention, Fig. 2 is an explanatory diagram of a magnetic disk memory, Fig. 3 is an explanatory diagram of a television scanning line, and Fig. 4 is an explanatory diagram of the film arrangement of a scanner cylinder. 5 is an explanatory diagram of the relationship of signals read from the frame memory, FIG. 6 is an explanatory diagram of the case where a frame image is created from an image of one field, and FIG. 7 is an explanatory diagram of the frame number instruction. Figure 8 is an explanatory diagram of the signal from the frame number indicator in Figure 7;
The figure is an explanatory diagram of the shape of a light source on a film to be exposed. 1...NTSC TV signal, 2...VTR, 3...
Frame number generator, 4... Read frame number indicator, 5... Frame memory, 9... Switch circuit, 14... NTSC decoder, 18...
Plate scanner, 19...Distribution circuit, 20...A
Delay circuit, 21...OR circuit, 22...2A delay circuit, 23...Averaging circuit, 24...OR circuit, 25...1H memory.

Claims (1)

[Claims] 1. A frame video signal storage device for storing one frame of color television video signal, a means for reading signals from the frame video signal storage device and storing them in a memory, and a means for reading signals from the frame video signal storage device and storing them in a memory, and a means for storing signals in the memory in synchronization with the scanning speed of a scanner. The scanner comprises a means for reading and color-separating the color-separated signals and inputting them to the scanner, and a scanner for producing Y, M, C, and BK separations from the color-separated signals, and a means for receiving signals from the frame video signal storage device. A method for reading and storing a video signal in the memory in the order of scanning lines constituting a frame image, and an image of the scanning lines constituting one of the even-numbered or odd-numbered field images. It is possible to carry out either of the following methods: reading only the signal, and interpolating the video signal of the scanning line of the other field image based on the signals of the adjacent scanning lines of the one field image, and storing it in the memory. , and a light source on the film exposed by the scanner has a vertically elongated shape such as a rectangle.