JPS6315876Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a magnification measuring device that represents the ratio of the original image to the finished image when the sizes of the original image and the finished image are different during printing plate making, etc. This invention relates to a magnification measuring device for printing plate making which can perform sufficient measurement even in a relatively bright place without the need for.

As color scanners that can perform color separation and shading at the same time have been put into practical use, photoengraving technology has come to be used more and more in the printing process.

In addition to the above-mentioned features, photoengraving techniques such as color scanners have the advantage of being able to arbitrarily create images that are enlarged or reduced in size over a relatively wide range of document sizes. It is necessary to measure how many times (or what fraction) the finished image size is as compared to the original size, and proceed with the plate-making work based on the measurement.

Therefore, conventionally, two points on the image of the manuscript were selected, the distance between the two points was measured with a ruler, a caliper, etc., and then the distance between the two corresponding points on the layout paper was measured in the same way. A method has been adopted in which the magnification is calculated by dividing the numerical values obtained through these measurements.

However, with this method, the magnification calculation work is completely manual, so the work efficiency is poor, and there are many errors and reading errors associated with dimension measurement, making it difficult to calculate the magnification accurately. The drawback was that it was difficult.

Therefore, in order to eliminate the drawbacks of such manual methods, a magnification measuring device using an enlarger having a projection magnification display function as shown in FIG. 1 has come into use.

In FIG. 1, 1 is a base, 2 is a projection lens, 3 is a document holder, 4 is a lamp house, 5 is a column, 6 is a magnification display, 7 is a document (film),
8 is a layout mount, and the entire magnification measuring device is indicated by M.

The projection lens 2, document holder 3, and lamp house 4 are held by a support 5 attached to the base 1, and the document 7 mounted on the document holder 3 receives light from a light source provided in the lamp house 4. The image of the pattern is projected by a projection lens 2 onto a layout board 8 placed on the surface of the base 1.

Also, at this time, the projection lens 2, document holder 3, and lamp house 4 are configured to be movable up and down along the support 5, so that an image of the image of the document 7 can be created, similar to a well-known photo enlarger. can be reduced or enlarged to any size over a predetermined range and projected onto the layout mount 8.

Further, the moving positions of the projection lens 2 and document holder 3 along the support column 5 at this time are configured to be measurable by a linear encoder, and the distance between the surface of the layout mount 8 and the projection lens 2 and the distance between the document holder A magnification determined by the ratio of the distance between the projection lens 3 and the projection lens 2 is calculated and displayed on the magnification display 6.

Therefore, according to this magnification measuring machine M, a document is set in the measuring machine, and an image is projected onto a layout board in a dark room, and the projected image is adjusted so that the pattern drawn there matches the projected image. By changing the size of the images and reading the projection magnification when they match, you can easily find the required magnification. Since there is no need to measure with a ruler or caliper, you can find the magnification with high accuracy. .

However, this method using a magnification measuring machine has the disadvantage that sufficient workability cannot be obtained because the measuring work, including setting the original on the measuring machine, must be carried out in a dark room.

The purpose of the present invention is to provide a magnification measuring device for printing plate making that eliminates the above-mentioned drawbacks of the prior art, reduces the occurrence of measurement errors and measurement errors, does not require a darkroom, and provides high workability. .

In order to achieve this purpose, the present invention combines the images of both the original image and the layout mount image in the same optical path, superimposes the images on the transmission screen in this same optical path, and forms the images on the transmission screen. It is characterized by the fact that the magnification is measured by matching the images above.

Embodiments of the magnification measuring device according to the present invention will be described below with reference to the drawings.

FIG. 2 shows an embodiment of the present invention, in which 9 is a projection lens, 10 is a half mirror, 11 is a transmission screen, 12 is a copy film on a layout mount, 13, 1
4 is a light source, 15 is a linear encoder, and 16 is an arithmetic circuit. Note that the projection lens 2, magnification display 6, document 7, etc. are the same as in the conventional example shown in FIG.
Further, 7' is a projected image of the original 7 on the transmission screen 11, and 12' is a projected image of the copy film 12 as well.

The projection lens 9 functions to project the image of the copy film 12 onto the transmission screen 11.

The half mirror 10 is inserted into the optical path in which the image of the copy film 12 is projected by the projection lens 9, and bends the optical path in which the image of the document 7 is projected by the projection lens 2 in the same direction as the optical path projected by the projection lens 9.
It functions to synthesize these two optical paths.

The transmission screen 11 is made of frosted glass or frosted glass and a condenser lens (Fresnel lens).
This is a well-known device consisting of a half mirror 10, which is used to synthesize the image, and which is provided in the subsequent optical path, and functions to form the projected image of the original 7 and the projected image of the copy film 12 on the same plane.

The copy film 12 is coated in advance so that the patterns such as figures drawn on the layout mount (same as the layout mount 8 in the conventional example shown in FIG. 1) for adjusting the magnification can be seen through transmitted light. The layout mount was photographed on film and made into a transparent copy.

The light sources 13 and 14 are, for example, tungsten lamps,
It consists of a xenon discharge lamp, etc., and functions to illuminate the original 7 and copy film 12 with the required amount of light.

The linear encoder 15 functions to detect the position of the original 7 in the direction of the arrow a, and to generate data using electrical signals.

The arithmetic circuit 16 inputs the data from the linear encoder 15, calculates the ratio of the distance between the projection lens 2 and the transmission screen 11 along the optical axis, and the distance between the projection lens 2 and the original 7, It functions to calculate data representing magnification. Note that this calculation can be easily performed by searching a table using data from the linear encoder 15. Also, at this time, the magnification of the copy film 12 and its projected image 12' is given by the ratio of the distance to the projection lens 9, but this magnification must be factored into the above calculation as a constant in advance. .

The following operation will be explained.

When the copy film 12 on the layout mount and the original 7 are set and the light sources 13 and 14 are turned on, respective projected images 12' and 7' are formed on the transmission screen 11.

When the original 7 is moved in the direction of the arrow a, the size of the image 7' on the screen 11 changes, and when the original 7 is moved in the direction of the arrow b, the image 7' on the screen 11 changes in the direction of the arrow B. When the document 7 is moved in the direction of the arrow c, the image 7' moves in the direction of the arrow C, respectively.

Therefore, when measuring the magnification, the transmission screen 11 is observed, the image 12' of the layout sheet formed by the copy film 12 and the image 7' of the original 7 are examined, and the image 7'
Move the original 7 in the direction of arrow a to change the size of image 7', and then adjust the size of image 7' in the directions of arrows b and c so that the part to be trimmed and the predetermined part of image 12' on the layout sheet correctly match. Adjust the positions of the images 7' by moving them, and when they match, look at the display 6 and the magnification will be displayed there. At this time, the arithmetic circuit 16 is provided with an output data latch circuit and a latch switch, and the image 7'
Operate the switch when and 12' match,
The display of magnification data may be latched.

Therefore, according to this embodiment, since the transmission screen 11 can adjust the correspondence between the image of the original and the image of the layout sheet, it is possible to measure the magnification even in a fairly bright place. This eliminates the need for indoor operations.

In the above embodiment, the image 12' is projected using the copy film 12 on the layout mount, but if a sufficient amount of light can be obtained as the light source 13, the copy film 12 can be directly replaced with By placing the layout mount at the position of this copy film 12 and illuminating it with the light source 13 from above, the image 12' of the layout mount is created in the same manner as the real magic lantern.
may be projected onto the transmission screen 11.

Furthermore, the magnification data that is the output of the arithmetic circuit 16 may not only be input to the magnification display 6 and displayed, but may also be directly input to a scanner or the like.

As explained above, according to the present invention, the magnification can be immediately measured by simply observing the images of the layout sheet and the original projected on the transmissive screen in a bright place and adjusting the state of coincidence of those images. Therefore, it is possible to eliminate the drawbacks of the prior art, and easily provide a magnification measuring device that does not require work in a dark room and has excellent operability.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a conventional example of a magnification measuring device, and FIG. 2 is an explanatory diagram showing an embodiment of the magnification measuring device according to the present invention. 1, 9...Projection lens, 6...Magnification display, 7
... Original, 10 ... Half mirror, 11 ... Transparent screen, 12 ... Copy film on layout mount, 13, 14 ... Light source, 15 ... Linear encoder, 16 ... Arithmetic circuit.

Claims (1)

[Scope of utility model registration request] A magnification measuring device for printing plate making that determines magnification by matching a projected image of a document pattern with a pattern on a layout mount includes a first projection optical system for projecting an image of a pattern on the original; a second projection optical system for projecting a pattern image; a means for combining the projection optical axes of the first and second projection optical systems onto the same optical path; and combined projection light on the same optical path. A magnification measuring device for printing plate making, characterized in that a transmission screen is provided for obtaining an image formed by the transmission screen, and the magnification is measured by matching the pattern image of the original and the layout sheet on the surface of the transmission screen. .