JPS62293111A - Evaluation system for printing quality - Google Patents

Abstract

PURPOSE:To speedily and easily obtain high-accuracy printing quality test data and to evaluate and analyze printing quality accurately and properly by providing an image formation part, a computer part, and an image processor. CONSTITUTION:A paper to be measured is fixed on the fixed table 11a of the X-Y measurement stage 11 of the image formation part 10 and a fitting rack 11b for a CCD camera 12 is moved to detect an image within a desired printing range. The computer part 20 stores data inputted from the image formation part 10 through the image processor 30 in the internal memory of a main body 21 and performs arithmetic processing to display the result on a display device 22 and also print out it on a printer 23 as a hard copy. The processor 30 processes the image output of the camera 12 so that it can be monitored on a monitor device 15, converts and stored the image output in the form of image data to be sent to the computer part 20, and transfers it on the basis of an instruction from the computer. Thus, various operations are carried out automatically under the control of the computer part 20 to evaluate the printing quality properly and accurately without reference to the font.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention The present invention relates to a print quality evaluation system for evaluating the print quality of various printers.

BACKGROUND ART It is extremely important to evaluate the print quality when printing using various printers, that is, the print quality, in the manufacturing and adjustment process of printers.

This is because if there is a factor in the print head, platen, printing paper, ink ribbon, feed mechanism, etc. that degrades print quality, the product cannot be considered to be an appropriate product unless this factor is removed. In addition, when testing print density, conventional evaluations based on a Machess densitometer rely heavily on visual perception, and tests can only be performed on specific character types, but there is a demand for more precise testing.

The purpose of the present invention is to perform an evaluation test based on absolute white (magnesium oxide) and a relative evaluation specific to the paper being tested, and is not limited to character type, and furthermore, does not require special skill. An object of the present invention is to provide a print quality evaluation system that can perform print quality tests with high accuracy and high speed.

This object is achieved by providing a printing quality evaluation system having the construction according to the claims, namely an x-y measuring table in which an image detection device for forming an image signal on a measuring table is automatically aimed at the character position to be measured. an image forming unit having a memory of a predetermined storage capacity and performing calculations for evaluating print quality according to a predetermined procedure; and a computer unit that processes and monitors the output of the image detection device for forming image signals. This is achieved by a print quality evaluation system having an image processing device that enables and transfers images to the computer section.

According to the printing quality evaluation system according to the present invention, highly accurate printing quality test data can be obtained easily and quickly, and operability is improved, so that accurate and appropriate printing quality evaluation and evaluation can be performed without requiring a high degree of skill. Analyzes associated with this become possible. In this case, each data has high reproducibility and arbitrary data can be easily stored.

The print quality evaluation system according to the present invention will be explained below with reference to the attached drawings showing examples.

FIG. 1 is a block diagram showing the basic configuration of a print quality evaluation system according to the present invention. In the figure, the print quality evaluation system includes an image forming section 10 and a computer section 20.

The image forming unit 10 includes an X-Y measurement stage 11, a CCD camera 12, an X-axis near scale counter 13, a Y-axis near scale counter 14, a monitor 15, a sub-control box 16, and an operation switch 17. .

The computer section 20 includes a computer main body 21, a CRT
It is composed of a display 22 and a printer 23.

An image processing device 30 is interposed and connected to transmit and receive signals between the image forming section IO and the computer section 20.

In this embodiment, a sheet of paper whose printing quality is to be measured is fixed on the fixed table lla of the X-Y measurement stage 11, and the desired measurement is performed by moving the mounting frame 11b of the CCD camera 12 in the X-axis direction and the Y-axis direction. Detects the image of the printing area. Fine adjustment of the range in this case is performed using the X-axis and Y-axis fine adjustment handles 11c and lid. In this embodiment, the fixed table lla is formed using an electrostatic adsorption plate to prevent errors caused by bending or wrinkles of the paper.

The X-axis near scale counter 13 and the Y-axis near scale counter 14 output the displacement amount of each axis as a digital value, and send it to the sub-control box 16.

The operation switch 17 controls start, stop, and
The sub-control box 16 is controlled by clearing or the like.

The CCD camera 12 used has a predetermined number of pixels and a predetermined resolution. In this example, the number of effective pixels is 510.
vx492 'Te'josu, H(& degree 350 vx
380' is used.

The computer section 20 is composed of a main body 21, a CRT display 22 and a printer 23 connected to the main body 21, stores data inputted from the image forming section 10 via the image processing device 30 in a built-in memory, and stores data inputted from the image forming section 10 via the image processing device 30. Performs calculation processing for each test based on the required program. The results can be displayed on the display 22 and output as a hard copy using the printer 23.

The image processing device 30 processes the image output of the CCD camera 12 so that it can be monitored on the monitor 15, converts and stores the image data to the computer section 20, and transfers the image data based on instructions from the computer.

According to the print quality evaluation system according to the present invention, first, it is selected whether to use the white color based on the Macbeth density (absolute white color) as the reference or the printed sample paper as the reference. In the latter case, print results printed by various printers are placed on a fixed table lla, and the CCD camera 12 is automatically aligned with the character position to be evaluated for print. In this case, the monitor 15 is adjusted so that the center of gravity of the characters is at the center of the monitor screen.
The image signal obtained by the above process is processed appropriately to perform a print quality test. The tests covered here include print density tests, character shape/area tests, density slope tests, and line segment size tests. Note that the center of gravity of a character is calculated by counting the number of effective pixels representing a certain character and calculating the total area Sl.
The intersection point of each line is obtained by scanning each of the X and Y axes to find a line where the area of each axis is 1/2.

FIG. 2 is a flowchart showing the operation of the print quality evaluation system according to the present invention.

Once the device is ready and powered on, the system program starts. The flow differs depending on whether data already stored in the file is to be processed and evaluated or new measurements are to be made. In the former case, the flow differs depending on whether the evaluation is related to printing accuracy or printing quality. Furthermore, the flow of measurement differs depending on whether the measurement is for evaluating printing quality or for evaluating printing accuracy.

Each test and/or evaluation is automatically performed through each of these steps.

By automatically performing each of these operations under the control of the computer section, it becomes possible to appropriately and accurately evaluate print quality regardless of the character type without requiring special skill.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of a print quality evaluation system according to the present invention. FIG. 2 is a flowchart showing the measurement and evaluation operations of the print quality evaluation system according to the present invention. The correspondence of the main reference symbols in the figure is as follows. lO: Image forming section 11: X-Y measurement stage 12:
CCD camera 13: X-axis near scale counter 14: Y-axis near scale counter 15: Monitor 16: Sub-control box 17: Operation switch 20: Computer section 21: Computer main body 22: CRT display

Claims (1)

[Scope of Claim] A print quality evaluation system that captures a desired portion of a print sheet to be evaluated placed on a measurement table as an image signal, and measures and evaluates the image signal according to a predetermined program, comprising: The image detection device for image signal formation is
An image forming unit that has an X-Y measurement table that automatically aims at the character position to be measured, and a computer that has a memory with a predetermined storage capacity and performs calculations for evaluating print quality according to a predetermined procedure. and an image processing device that processes the output of the image signal forming image detection device to make it monitorable and transfers it to the computer section.