JPH0117567B2 - - Google Patents

Description

[Detailed Description of the Invention] Conventionally, when creating printing plates, color-separated films from originals are pasted onto one transparent film for each color, and color-separated films from several types of originals are pasted onto a single transparent film. It is well known that a transparent film for each color is pasted in accordance with a predetermined layout and used as an original film. In this case, it is necessary to check whether the images on the pasted color separation film match each color. For example, in the case of four colors (yellow, red, eye, and black), one way to check is to use one of these as the standard, and then print the other one on top of it.
Check the registration by superimposing the original film of the plate,
A method is known in which the remaining plates are similarly stacked on top of the reference plate to confirm their register.

In such a case, there is a drawback that it is difficult to confirm whether or not the registration is correct because the reference original film and the other original films are both positive or negative.

For example, in the case of four colors of yellow, red, eye, and black, a method to remove such defects is to create a film with the opposite image from one of the original films, and then print that film. There is a method of superimposing another original film as a reference master film and checking the registration in the same manner as described above. In this case, it is easy to check the registration because the reference master film and the other original film are in a positive negative state, but since an extra film is required to make the master version, New inconveniences arise in terms of cost and time.

The present invention aims to eliminate the drawbacks and inconveniences seen in the conventional methods and to provide a new device that can instantly confirm whether or not the registration of each color of the original film is correct. It is something to do.

That is, according to the apparatus of the present invention, it is possible to confirm whether or not the registration between each color is correct by using a television camera and superimposing images on a color monitor television.

According to the present invention, it is extremely easy to check the register, and it is also possible to achieve great results in checking for overlaps with flat mesh and for checking for duplicates of letters, etc.

Further, according to the present invention, the relative positional relationship of a plurality of television cameras can be checked with high accuracy, and the plate inspection accuracy of the film plate inspection apparatus is further improved.

The present invention will be explained in more detail below with reference to the drawings.

FIG. 1 is a schematic explanatory diagram of the film inspection device of the present invention, and shows Y (ki), M (red), C (eye), BL (black).
An example of typical color printing using four colors is shown.

In FIG. 1, original films 2 corresponding to Y, M, C, and BL are placed on an original film holding plate 1.
3, 4, and 5 are placed. In this case, these original films need to be placed at predetermined positions on the holding plate 1, but this can be done by using a punch system or by preparing a reference line on the holding plate 1 and aligning it with this. Any appropriate method may be selected and used, and there are no particular limitations on what method to use. The original film placed on the original film holding plate 1 may curl and is not necessarily flat, and the original film may shift position during operation. It goes without saying that efforts should be made to prevent this.

Any appropriate means can be adopted to prevent curling or positional displacement. For example, as shown in FIG. 2 illustrating an example of the original film holding plate 1, a pachyume hole 6 is drilled in the original film holding plate 1, and after the original film is placed, a vacuum pump (not shown) is connected through this vacuum hole 6. Exhaust may also be provided. In this case, the shape of the vacuum hole 6,
The position and the like are not particularly limited, and any position may be used as long as the original film can be held well.

Another method may be to place the original film on an original film holding plate and then cover it with a transparent sheet-like material such as a transparent film or transparent glass. However, in cases where it is necessary to increase the magnification of photography using a television camera (described later), it is necessary to increase the magnification to a very high level (for example, approximately 60
80 times), the vacuum method is preferred as the original film holding method.

The method of placing the original films on the original film holding plate is not limited to the method of arranging them horizontally in a line as shown in Fig. 1, but may be arranged in any way, such as in a row. Since there are no restrictions, the method that is easiest to use can be selected as needed, and adjustments can be made in advance to avoid image shifts due to differences in the positions of television cameras, which will be described later.

In the apparatus of the present invention, the original film holding plate 1
It is equipped with television cameras 7, 8, 9, and 10 for photographing the original film placed thereon.

These TV cameras are set at predetermined positions and the electrical signals from each TV camera are combined to display the image on the monitor TV, so the relative positions between each TV camera are If the position is changed, it is also necessary to change the position where the original film is placed accordingly. Or conversely, if the position where the original film is placed is changed, it goes without saying that the position of the television camera is also changed accordingly.

According to the apparatus of the present invention, it can be easily confirmed whether the adjustment of the relative positional relationship of images by each television camera is correct.

Images of the original film 2, 3, 4, 5 are taken by these television cameras 7, 8, 9, 10, and zoom lenses 7', 8', 9 attached to the television cameras 7, 8, 9, 10 ', 10' allows it to be enlarged to a desired size.

Or prepare lenses with different magnifications,
It is also possible to enlarge the image to a desired size by switching to a lens with a desired magnification.

The light containing image information from the original film, which has been enlarged to a desired size and passed through zoom lenses 7', 8', 9' and 10', is sent to television cameras 7, 8, 9 and 10.
It is converted into an electrical signal by a photoelectric conversion element provided inside. The photoelectric conversion element may be a well-known device such as a vidicon, and the television camera itself may be a conventionally known device. The image signals Y, M, C, and BL converted into electrical signals are input to the electrical signal processing device 11. After the white and black levels are adjusted through an adjuster 12 that adjusts the white and black levels, the electric signal processing device 11 enters the matrix 13, where each signal of Y, M, C, and BL is processed. Processes such as width amplification, synchronization, and conversion from Y, M, C, and BL signals to the three primary colors of television, R (red), G (green), and B (blue), are performed.

The signals thus converted into R, G, and B are input to the monitor television 14, and the images of the original film of each color are compositely displayed in color on the screen of the monitor television.

In this way, it is possible to instantly check whether or not there is a misregistration from the image on the monitor television screen in which the four-color original film images are displayed in a composite manner. That is, if the color of a certain plate is misaligned, the color of that plate will be displayed on the monitor television, making it extremely easy to check whether the registration is correct or not.

As can be understood from the above explanation, in the apparatus of the present invention, if the original film of each color is pasted in the correct register and the original film is set in the correct position on the holding plate, each color will be shifted in the composite image. It needs to be displayed without That is, the relative positional relationship of the images taken by the television camera needs to be adjusted accordingly.

For example, whether or not the relative positional relationship of images taken by each television camera is correct can be confirmed as follows. That is, the test pattern films 2'3', 4', and 5', which are correctly registered, are placed in the fourth
As shown in the figure, the original film holding plate 1 is set in the correct position by using register pins 30 or the like. You can photograph this with each TV camera and display the composite image on a monitor TV to check whether the relative positional relationship of each TV camera is adjusted correctly by checking whether the test pattern image is shifted. can. FIG. 4 shows an example of a registration mark as a test pattern. According to the apparatus of the present invention, such confirmation can be performed extremely easily and with high accuracy.

FIG. 3 is a diagram illustrating in more detail an example of the electrical signal processing device 11 in the apparatus of the present invention. In the case of Fig. 3, image signals Y, M, C, converted into electrical signals from each television camera,
After passing through the regulator 12, BL is sent to the monitor TV 1.
In addition to the signals input to the monitor 4, some other signals can also be sent as image signals to a black and white monitor television 32 by means of a switch circuit 31.
It is necessary to check and adjust whether the relative positional relationship of the images taken by each television camera is correct before starting the plate inspection work. Such confirmation can be performed as follows. First, either one of an electrical signal containing an image signal from a reference TV camera and an electrical signal containing an image signal from another TV camera is input to the signal inversion circuit 35, and the other electrical signal is input to the signal inversion circuit 35. The signal is directly input to the electrical signal synthesis circuit 34. These are switch circuit 3
It can be controlled by 3. The signal inversion circuit 35 is a circuit for inverting an electric signal, and in the case of a positive signal, it inverts it to a negative signal, and in the case of a negative signal, it inverts it to a positive signal.

The electrical signal input to the signal inversion circuit 35 is input to the electrical signal synthesis circuit 34 after being inverted.

In this way, the image signal that has passed through the signal inversion circuit 35 and then entered the electrical signal synthesis circuit 34 and the image signal that has directly entered the electrical signal synthesis circuit 34 are synthesized here and amplified as necessary, and then the black and white monitor television 3
2 and the image is displayed on that screen. By looking at this screen, it can be confirmed whether the relative positions of the images from each television camera are correct. For example, an image signal from a TV camera for the M version is inputted to the electrical signal synthesis circuit 34 after passing through the signal inversion circuit 35, and an image signal from the TV camera for the Y version is directly input to the electrical signal synthesis circuit. When displayed on a monitor TV, the image 3 of the inverted white test pattern for the M version as shown in Figure 5 will be displayed.
6 and the image 37 of the test pattern for the Y version are combined and displayed.

When a white part is displayed on the screen like this, it occurs when the relative positions of the images from the two TV cameras are not adjusted correctly, so it depends on whether the white part is displayed on the screen or not. You can check whether the relative positional relationship of the TV cameras is correct.

In this way, while viewing the screen of the monitor television 32, it can be easily confirmed whether or not the relative positional relationship of the images of the other cameras is correct using the image of one of the television cameras as a reference. If the images from the two television cameras are misaligned, it is necessary to make adjustments to prevent the misalignment. This can be done as follows. The first method is to move the position of the TV camera that has shifted without moving the position of the reference TV camera.

In general, it is better to keep the TV camera fixed so that it cannot be moved, so the accuracy can be improved, so the second method is to correct the image shift electrically without moving the TV camera. It is preferable to adopt the method of This is accomplished by changing the scanning position when scanning the image projected onto the image pickup tube of the television camera with a lens.

When the relative positional relationship of the images from each television camera is properly adjusted, the white pattern will no longer appear on the monitor television.

When the adjustment of one television camera is completed in this way, the adjustment of other television cameras is carried out in the same way, and the adjustment of all the television cameras is completed.

The accuracy can be improved by confirming whether the relative positional relationship of the images obtained by each television camera is correct by increasing the magnification.

FIG. 3 shows an example in which a black and white monitor television 32 is used, but this is because when a color television is used as the monitor, the resolution is reduced due to the large dot pitch on the television screen. This is because it is difficult to confirm the position with high precision.

After the relative positional relationship of the images from each television camera is properly adjusted in this manner, the images are used to confirm the register of the original film as described above. In this case, a color monitor television 14 will be used.

Furthermore, when inspecting halftone dots, it is desirable to magnify 20 times or more, but in such a case, the area projected on the monitor TV 14 will be at the very edge of the original film due to the high magnification. Limited to some. In order to solve this problem, the original film holding plate 1 should be made movable in the X and Y directions. That is, as shown in FIG.
This frame 15 may be attached to another frame 16 so as to be slidable in a direction perpendicular to the X direction (Y direction), or any other appropriate means may be employed. Can be done.

Also, without moving the original film holding plate 1 in the X and Y directions, the television cameras 7, 8, 9, and 10 can be moved.
Alternatively, the television cameras may be moved together in the X and Y directions without changing the relative positional relationship between the television cameras. The television camera can be made movable in the X and Y directions using the same principle as the above-mentioned moving means for the original film holding plate. Note that the movement of the original film holding plate and the television camera in the X and Y directions is not limited to the above-mentioned means, but may be any other means such as the method employed in a universal drafting device such as Drafter (trade name). can be selected and adopted as appropriate. Further, both the original film holding plate and the television camera may be movable.

By making the original film holding plate and/or the television camera movable in this way,
Even at high magnification, the registration of four colors at any position can be instantly confirmed.

In FIG. 1, a light source unit 17 is provided on the opposite side of the original film from the television camera, and the light from the light source unit 17 is directed to the original film 2, 3, 4, 5.
passing through TV cameras 7, 8, 9, and 1 respectively.
It's starting to go to 0. In this case, if the magnification is large and a portion is to be photographed, it is sufficient that the light is effective in that portion, and the light is prevented from shining on the extra portion and scattering, making it difficult to see the monitor. It is desirable to provide a light-shielding plate 18 that blocks light from the rest while leaving only the necessary parts.

Note that when moving the television camera, the light sources 19, 20, 21, 2 housed in the light source section 17
It is desirable that the light shielding plate 18 also moves together with the television camera, and in this case, the light shielding plate 18 may also move together.

Furthermore, although FIG. 1 is an explanatory diagram of the case where transmitted light is used, it is not necessarily necessary to use transmitted light, and reflected light may also be used. To utilize the reflected light, for example, the surface on which the original film is placed on the original film holding plate may be made white or other color, and the light source section should naturally be located at the position for the reflected light source.

In the present invention, the registration is confirmed on the monitor TV screen, but Y is a color that is difficult to see.
RL erases other colors, so it is not a desirable color for checking registration. To solve this problem, it is preferable to provide an adjustment volume so that each hue and density can be changed independently.

In the present invention, it is preferable to provide a switch so that either a positive type film or a negative type original film can be used, so that either type of original film can be used for inspection. The details of this switching are already known and will not be discussed further here.
It is also possible to switch between continuous tone separation film and halftone separation film as the original film, and such technology is already well known. Therefore, I will not explain it further.

As described above, the present invention simplifies registration confirmation.
This speeds up the process and improves the efficiency and accuracy of film inspection, and improves the efficiency of proof printing by improving registration accuracy. It also reduces material costs by reducing the number of reprints due to registration errors during proofing. Can be done.

Further, according to the present invention, it is possible to extremely easily check whether the relative positional relationship between the television cameras is correct, and therefore the position adjustment of each television camera can be speeded up.

Furthermore, the efficiency of proof printing is improved and misregistration in printing is reduced, so that it is possible to improve the efficiency of printing.

Conventionally, the registration of the original film was left up to the retoucher, so there were constant problems with registration errors during proof printing and final printing.However, with the present invention, it is possible to quickly inspect the plate using an inexpensive device, and it is possible to eliminate registration errors. In addition to drastically reducing the trouble caused by this method, it is also highly effective in interlacing flat nets and checking for duplicates of letters, etc.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a film inspection device of the present invention, FIG. 2 is an explanatory diagram of an example of an original film holding plate in the device of the present invention, and FIG. 3 is a schematic explanatory diagram of a film inspection device of the present invention. FIG. 4 is a more detailed explanatory diagram of the electrical signal processing device in which a test pattern film is set; FIG.
The figure shows an example of a television screen for checking the relative positional relationship of each television camera. 1...Original film holding plate, 2, 3, 4, 5...
...Original film, 6...Bakyum hole, 7, 8,
9, 10...TV camera, 7', 8', 9', 1
0'...zoom lens, 11...electric signal processing device, 12...adjuster, 13...matrix, 1
4... Monitor TV, 15, 16... Frame, 17
...Light source section, 18... Light shielding plate, 19, 20, 2
1, 22... Light source, 2', 3', 4', 5'... Test pattern film, 30... Register pin,
31, 33...Switch circuit, 34...Electric signal synthesis circuit, 35...Signal inversion circuit.

Claims (1)

[Claims] 1. An original film holding plate for holding a plurality of printing original films, a plurality of television cameras for taking images of each original film held on the holding plate, and the plurality of television cameras. an electrical signal processing device for displaying electrical signals from the original film in a composite manner on a monitor television in correspondence with each color of the original film; and an image of each original film is displayed based on the electrical signals processed by the electrical signal processing device. The electrical signal processing device further includes a signal inverting circuit for inverting an electrical signal from at least one of the plurality of TV cameras, and an inverted electrical signal passing through the circuit. and an electrical signal synthesis circuit for synthesizing electrical signals from other arbitrary television cameras that do not pass through the inversion circuit; 1. A film inspection apparatus comprising: a switch circuit for sending signals to an electrical signal synthesizing circuit; and a black and white monitor television for displaying a synthesized image based on the electrical signals synthesized by the electrical signal synthesizing circuit.