JPS6331355A - Copying device - Google Patents

Abstract

PURPOSE:To obtain an optimum copying state by comparing expected value data based on standard parameters of a test pattern with picture data read from a print sample obtained from the test pattern output to automatically adjust various parameters of a print part. CONSTITUTION:A system controller 23 writes patch data of a density gradation step in a test pattern generator 21 and switches a selecting circuit 22 so that picture data outputted from the test pattern generator 21 is inputted to the print part, and data is printed on a form in accordance with standard process parameters. The obtained print sample is put on a platen, and the exposure is set to a standard value by a scanner part controller 28, and the selecting circuit 22 is switched to the side of the scanner part, and patch data is read by a CCD 7 and is written in a memory circuit 26. The system controller 23 compares picture data with expected value data based on standard parameters of the test pattern to change the conversion characteristic of a density converting circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a copying apparatus that prints based on digitally sampled image signals, and particularly to a copying apparatus that is capable of automatically adjusting image data processing parameters.

[Conventional technology]

For example, there is a copying apparatus shown in FIGS. 3 and 4 as a conventional copying apparatus that performs copy printing from digitally sampled image signals, and includes a platen l on which a document is placed, and an exposure device that irradiates light onto the surface of the document. a lamp 2, a mirror 3.4.5 forming an optical path for reflected light of the irradiated light, and a CCD 7 for receiving the reflected light condensed by a lens 6.
On the other hand, a laser driver 8 that emits a laser beam of a predetermined wavelength, an optical modulator 9 that modulates the laser beam based on the image signal W read by the scanner section, and an optical A rotating polygon mirror 11 that polarizes the output light of the modulator 9 onto a photoreceptor drum 10, a photoreceptor drum 10 that forms an electrostatic latent image by sensing laser light from the rotating polygon mirror, and a photoreceptor drum 10. A charger 12 uniformly charges the photoreceptor on the surface of the drum to give it photosensitivity, a developer 13 develops the electrostatic latent image with toner, and the toner attached to the drum surface by the developer 13 is transferred to the recording paper 14. A transfer device 15 for transferring, a fixing device 16 for fixing the transferred toner on the recording paper surface, and a photosensitive drum 10 after transfer.
A printer section is composed of a cleaner 17 that removes toner remaining on the printer.

In the above configuration, the image signal W read by the scanner section is input to the optical modulator 9 of the printer section, where optical modulation is performed sequentially, and optical dots polarized by the rotating polygon mirror 11 are placed on the photoreceptor drum IO. The electrostatic latent image is formed by projecting a positive charge level on the drum and reducing the level of positive charge on the drum. When the drum surface on which the electrostatic latent image is formed reaches the developing device 13, toner charged to a positive potential adheres only to the surface on which the electrostatic latent image is formed.

Further, as the photosensitive drum 10 continues to rotate and reaches the transfer device 15, the recording paper 14 reaches the transfer device 15 in time with this arrival, and the image is transferred onto the recording paper 14.

The recording paper 14 after the transfer is heated and fixed by the fixing device 16. On the other hand, the photosensitive drum 10, which has been transferred, continues to rotate, and the cleaner 17 removes the toner remaining due to untransferred toner in preparation for the next recording. According to the above copying machine, the image signal W5 read by C0D7 is
Since it has been converted, this image signal W is enlarged/reduced and MTF corrected. Image processing such as cropping, movement, negative/positive reversal, rotation, and compositing can be accomplished electrically.

[Problem that the invention seeks to solve]

However, according to the conventional copying apparatus that performs copy printing from digitally sampled image signals, various parameters for forming electrostatic latent images, such as exposure amount, charge amount, developing bias, etc., cannot be adjusted using conventional analog method copying machines. alike,
The test pattern sheet for adjustment is copied, a human determines the necessary adjustment level from the taken copy, and adjustments are made based on the test butter sheet for adjustment, so there may be differences in the degree of adjustment depending on the person. There is a problem in that the adjustment requires skill, and the digitally sampled image signal is not effectively used for the adjustment.

[Means and effects for solving the problems] The present invention has been made in view of the above, and facilitates adjustment of various parameters for forming an electrostatic latent image to obtain a constant and optimal copying state. Therefore, a test pattern generation circuit is provided that generates a test pattern that serves as the basis for adjustment, and the printer unit compares the expected value data based on the standard parameters of the test pattern with the image data read from the print sample obtained by outputting the test pattern. The present invention provides a copying apparatus that automatically adjusts the various parameters described above.

〔Example〕

Hereinafter, a copying apparatus according to the present invention will be explained in detail.

FIG. 1 shows a circuit configuration that is an embodiment of the present invention, and the third
Although the explanation of the same parts as those in FIG. One density conversion circuit converts the density, a dither processing circuit 20 binarizes the density-converted image signal into 8 cycles and outputs it to the laser driver 8 of the printer section, and a desired test pattern that becomes the basis for adjustment. A test pattern generation circuit 21 that generates a test pattern, a selection circuit 22 that switches between the output from the test pattern generation circuit 21 and the image signal output from a part of the scanner, and a selection circuit 22 that switches between the output from the test pattern generation circuit 21 and the image signal output from a part of the scanner, the test pattern generation, the operation of the scanner section, the data after printing and the test pattern. System controller 23 that controls and calculates comparison with expected value data, etc.
, a main scanning counter 24 and a sub-scanning counter 25 for selecting the address of data read by the scanner section, a memory circuit 26 for storing data read by the scanner section, a system controller, a scanning counter, etc. It is composed of a clock 27 that provides a reference time to the printer, a scanner section control device 28, a printer section sequence control device 29, and a printer section process control device.

In the above configuration, the operation of parameter adjustment will be described below. Note that parameter adjustment includes adjustment modes such as density reproduction parameters, image and paper registration adjustment parameters, and copy parameters, but since they are common in principle, the density reproduction parameter adjustment will be explained as an example.

First, prior to adjustment, the system controller 23 writes patch data of density gradation steps as shown in FIG. 2 into the test pattern generator 21. This density patch data is written in steps from the lowest density level to the highest density level that can be reproduced by the printer section. Next, the system controller 23 sets the charging current, developing bias, etc. in the printer section process control device 30 to standard values, switches the selection circuit 22, and inputs the image data output from the test pattern generator 21 to the printer section. After making the settings, the printer section is operated in the same sequence as during normal copying operation, and the test pattern generator 21 is triggered at a predetermined timing to output the density punch data to the printer section (the test pattern generator (The data output speed matches the image data input speed from the scanner unit.) This density patch data is binarized by the dither processing circuit 20, subjected to halftone gradation, and input to the laser driver 8. As described above, a test pattern having density gradation is printed on paper using standard process parameters.

Next, the system controller 23 instructs the operator to place the obtained print sample on the platen 1 and start copying, and at the same time sets the exposure amount to the standard value in the scanner controller 28. and switches the selection circuit 22 to the scanner section side. Here, the system controller 23 determines the part of the print sample patch data to be read, and controls the main scanning counter 24 and the sub-scanning counter 25.
Enter the address on the paper where the desired patch data exists.

Then, the scanner section is operated and the patch data is actually read by the CCD 7, and near the desired patch data, the main scanning counter 24, sub-scanning counter 25
If one loss occurs, writing to the memory circuit 26 is enabled.
The patch data of the print sample that has been read and actually read is written into the memory circuit 26 (an example of the measured data is shown in FIG. 2).

When one scan of the scanner section is completed, the system controller 23 reads the data from the memory circuit 26, compares it with the expected value data based on the standard parameters of the test pattern, and stores the difference between the two data.

The above operation is executed repeatedly (in this example, in order to save pixel memory, only memory for a few pixels is prepared and the scanner section is operated repeatedly, but this operation is not necessary in a system with page memory. ), the system controller 2
3, the conversion characteristic of the density conversion circuit is changed, and FIG. 2 illustrates the density conversion curve before and after modification. ) Furthermore, the operation for the scanner unit is repeated to match the expected value data with the image data of the actual print sample. If the adjustment cannot be made by adjusting only the density conversion characteristics, the printer section process control device 30 is instructed to adjust the charging current, etc., and the print sample collection operation is repeated from the beginning to perform the adjustment.

An example of density reproduction parameter adjustment has been shown above. In the registration adjustment, etc., a thin line pattern is generated from the test pattern generation circuit 21, and the time from the start of scanning the print sample to the detection of the thin line pattern is measured.
Adjustment is performed by setting adjustment values in the printer section sequence control device 30.

〔Effect of the invention〕

As explained above, according to the copying apparatus of the present invention, a test pattern generation circuit is provided that generates a test pattern as a basis for adjustment, and expected value data based on standard parameters of the test pattern and a print sample obtained by outputting the test pattern are provided. Since the various parameters of the printer section are automatically adjusted by comparing the image data read from the image data read from the image data, it is possible to easily adjust the various parameters for forming an electrostatic latent image, and to maintain a constant and optimal copying state. Obtainable. Furthermore, the digitally sampled image signal can be effectively used to adjust various parameters for forming the electrostatic latent image.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a control section and an image processing section according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of density reproduction parameter adjustment,
FIG. 3 is a block diagram showing a scanner section of a conventional copying machine, and FIG. 4 is a block diagram showing a printer section of a conventional copying machine. Explanation of symbols 1...Platen, 2...Exposure lamp, 7...
・CCD, 8...Laser driver, 11・
...Rotating polygon mirror. Patent applicant: Fuji Xerox Co., Ltd. Agent: Patent attorney: Shin Matsuhara 2: Same: Seiji Muraki: same: Atsushi Ueshima - Figure 3 Figure 4

Claims (1)

[Scope of Claims] A copying apparatus that converts image information obtained by optically scanning the surface of a document into an electrical signal, performs image processing on the electrical signal, and then outputs it to a printer section, comprising: a test pattern generation circuit that generates a test pattern signal that is the basis for parameter adjustment in image processing;
A copying apparatus comprising: a selection circuit that selects data of the test pattern signal and image data of a test sample obtained from the test pattern signal; and a memory circuit that stores the image data.