JPH0352618B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the setup performed prior to separation using a color scanner, and in particular to the setup of highlight or shadow points to obtain separations of desired density values or dot percentages. A further object of the present invention is to provide a setup method that allows setup values to be set easily and reliably.

In general, the input aperture size of color scanners is very small (20 mm) in order to improve the resolution of separated plates.
~60μ) has been adopted. This minute aperture is also used during setup so that setup in the scanner can be performed under the same conditions as during resolution scanning. However, since this aperture is minute, it is easily affected by dye particles, dust, etc. in the document, and even a small movement of the scanning spot can cause a large change in the value displayed on the display meter. Therefore, the setting of highlight points or shadow points is very unstable, and it is very difficult to obtain separated plates with the desired halftone dots (or density) in a single color separation operation, and requires considerable skill. is needed.

In order to solve these problems, a method is taken to diffuse or widen the light flux from the light source in the optical path from the document to the photoelectric conversion element in the color scanner, thereby making it possible to stably set the setup value. Attempts have been made to do so.

However, in either method, the scene at the time of setting the conditions and the light intensity at the time of separation scanning are different, so it is necessary to use a conversion table or redo the basic adjustment, and the highlight point or shadow point setting must be changed. Not only was the accuracy poor, but it was also time-consuming.

The present invention solves these problems and provides a setup method that can greatly shorten the time required to set up the decomposition conditions of a color scanner. When performing this in a color scanner, by slightly moving the scanning drum and/or scanning head while shining the light beam from the light source onto the virtual highlight point or virtual shadow point of the document set in the document cylinder. Alternatively, by slightly moving the light flux from the light source to the document, several locations other than the highlight point or shadow point can be set as scanning spots, and then individual scanning spots can be addressed via the scanning head. After extracting the signals to be scanned, calculate the average value from these signals, and then set the scanning spot in the document where the value is the same as or closest to this average value as the highlight point or shadow point, Furthermore, the present invention provides a setup method characterized in that a setup value is determined based on these points.

The present invention will be described in detail below with reference to the drawings, taking the setting of highlight points as an example. Regarding the setting of shadow points, the same idea as for highlight setup can be applied to shadow areas.

FIG. 1 is a schematic explanatory diagram showing an example of a color scanner to which the present invention can be applied, in which 1 is a light source, 2 is an original cylinder, 3 is an original, 4 is a scanning head, 5 is a photoelectric conversion element, and 6 is a log circuit, 7 is an average value circuit, 8 is a color computer, 9 is a lead screw, 10 is a scanning head movement motor, 11 is a cylinder rotation motor, 1
2 is an exposure cylinder, 13 is a motor control unit 1
4 indicates a display meter.

When setting a highlight point, in such a color scanner, a target is first determined as to which part of the document 3 attached to the document cylinder 2 is to be the highlight point. This part is only a rough guide and is not final, and may change depending on the results of subsequent operations. This goal is referred to herein as the virtual highlight set point. The virtual shadow set point is also a target determined in the shadow section for the above purpose.

Subsequently, this virtual highlight point is irradiated with a luminous flux from the light source 1. The light beam irradiated onto the virtual highlight point is reflected by the mirror 30 and reaches the photoelectric conversion element 5. The photoelectric conversion element 5 generates a signal according to the amount of light received, and after being subjected to predetermined processing in the log circuit 6 and color computer 8, the halftone dot (or density) at the virtual highlight point is displayed on the display meter 14. If the virtual highlight point is an appropriate part of the document 3, the subsequent work can be carried out using this displayed value as the highlight setup value. However, to the human eye, there are microscopic differences between what appear to be the same highlighted areas at first glance, and the display on the display meter 14 can change dramatically just by slightly shifting the scanning spot. Put it away. Therefore, by slightly changing the location of the virtual highlight point, the highlight setup value will change, and even if the same document is used for disassembly, it will result in disassembled versions with completely different gradations or An exploded version may be created that does not include the desired halftone dots in the highlights.

Therefore, in the present invention, in order to easily and reliably set highlight points, scanning spots are not only virtual highlight points when setting highlight points, but scanning spots are also set near virtual highlight points. First, a plurality of signals are extracted from these scanning spots via a scanning head. These signals are then
The average value circuit 7 performs processing such as counting, storing, and averaging to obtain an average value. After this average value is processed by the color computer 8, halftone dots (or density) corresponding to the average value are displayed on the display meter 14.

Next, perform setup work in one of two ways.

First, when the displayed value of the previous process is the desired value,
The output signal of the log circuit 6 is changed to be processed directly by the color computer 8 without passing through the average value circuit 7, and the normal setup work is continued. If the displayed value is not the desired value, it is corrected to the desired value using the adjustment knob of the color computer 8, and then the output signal of the log circuit 6 is switched to be processed directly by the color computer 8, and the normal setup work is continued.

Second, a plurality of signals extracted from one scanning spot and nearby scanning spots via the scanning head 4 are
The averaging circuit 7 does not perform averaging processing, but the processing is directly performed within the color computer 8, and the halftone dots (or densities) corresponding to each signal value are displayed on the display meter 14. Next, the operator compares the display on the display meter 14 obtained in this process with the halftone dots (or density) corresponding to the average value displayed in the previous process, and determines whether the value is the same as the average value. The scanning spot in the original document 3 for which the value is the closest or the closest value is determined as the final highlight point. Once the highlight point has been determined, the light beam from the light source 1 is applied to this point, the photoelectric conversion element 5 in the scanning head 4 obtains the desired signal, and then the log circuit 6 and color computer 8 perform the desired processing. Then, the highlight setup value at the highlight point of the document 3 is determined. From then on, you can proceed with the work based on the normal setup procedure.

In the present invention, as described above, it is necessary to extract a plurality of signals from the virtual highlight point and scanning spots in the vicinity thereof, and specifically, the following steps may be performed.

While irradiating the virtual highlight point of the original 3 with the light beam from the light source 1, the original cylinder 2 and/or the scanning head 4 are operated by the cylinder rotation motor 11 or the scanning head movement motor 10 according to a command from the motor control unit 13. to set a plurality of scanning spots, and then the photoelectric conversion element 5
Measure the light multiple times (see Figure 1).

A mirror box 15 is provided in the optical path between the light source 1 and the document 3, and the mirror box 15 or at least one of the fine movement mirrors 17 and 19 in the mirror box 15 is moved by a motor 21 for moving the mirror box.
Alternatively, a plurality of scanning spots can be set by slightly moving the light flux by slightly moving the mirror moving motors 18 and 20, and then photometry is performed multiple times using a photoelectric conversion element (see Figure 2). . In FIG. 2, 16 is a fixed mirror, 22
is a lens, and 23 is a lead screw. Incidentally, the mirror box 15 can be moved to a position out of the light beam when scanning an original.

Since the present invention has the above-described configuration, it is possible to set highlight points or shadow points extremely stably and quickly, which in turn greatly reduces the time required to set disassembly conditions for the scanner. becomes possible.

[Brief explanation of drawings]

FIG. 1 is a schematic illustration of a color scanner that can be used in the present invention, and FIG. 2 is a schematic illustration of a mirror box and its peripheral equipment. 1...Light source, 2...Document cylinder, 3...Document, 4...Scanning head, 5...Photoelectric conversion element, 7...Average value circuit, 8...Color computer, 10...Scanning head movement Motor for use, 11...Motor for cylinder rotation, 13
... Motor control section, 14 ... Display meter, 15 ... Mirror box, 17, 19 ...
Fine movement mirror, 18, 20... Fine movement motor, 21...
Motor for moving the mirror box.

Claims (1)

[Claims] 1. When setting setup values in a color scanner, use the scanning drum and/or scanner while irradiating the light beam from the light source onto the virtual highlight points or virtual shadow points of the document set in the document cylinder. By slightly moving the head or by slightly changing the light beam reaching the document from the light source, several locations other than the highlight point or the shadow point can also be set as scanning spots, and then scanned through the scanning head. The signals corresponding to the individual scanning spots are extracted, the average value is determined from these signals, and the scanning spot in the document for which the value is the same as or closest to this average value is set as a highlight point. or set it as a shadow point,
The setup method further comprises determining a setup value based on these points.