JPH0348868A - Color printer - Google Patents

Abstract

PURPOSE:To facilitate and ensure the confirmation of a color reproducing range by providing the color printer with a multiplexer which switches from a ROM for color reproducing range confirmation to single pattern reading or page memory reading and obtains printing data. CONSTITUTION:When a single pattern printing mode is selected, a microprocessor MPU reverses a control signal, which is supplied to the multiplexer 3, to select the reading data of a single pattern generating ROM 1. Then, the MPU prints by using a held single pattern printing mode control program. That is, when a recording paper comes to a prescribed position, the MPU accesses to the ROM 1 to carry out address renewal and data reading at a prescribed cycle. When the printing for one page is finished, the MPU reverses the control signal, which is supplied to the multiplexer 3, selects the page memory reading data side, and thereby preparing for the following printing. The ROM stores a single pattern, which consecutively varies a density from the lowest to highest, for every primary color. In this constitution, the color reproducing range can be easily and securely confirmed.

Description

[Detailed Description of the Invention] [Summary] Regarding a method for checking color reproducibility of a color printing device, ink,
The purpose is to make it easy and reliable to check the color reproduction range when the loft of consumables such as toner changes, and to print multi-tone colors by overlapping two or more colors according to the given printing information. In the color printing apparatus, the color printing apparatus includes a simple pattern storage means for generating simple pattern data that continuously changes the density from the lowest density to the highest density for at least all the primary colors, and reading from the simple pattern storage means. The apparatus further comprises a control means for supplying the simple pattern data to the printing means and causing the printing means to print.

[Industrial Field of Application] The present invention relates to a color printing device, and more particularly to a color printing device having a function of generating a test pattern for checking the color reproduction range.

[Conventional technology]

In a color printing device, the ink sheets used in the toner thermal transfer method used in the electrophotographic method, and the color materials and recording paper used in the inkjet method are consumables, so it is the responsibility of the user to replenish or replace these consumables. There are many. These consumables may have slightly different characteristics depending on the manufacturing loft, and as a result, the color of the output printed matter may change slightly.

Conventionally, even when these consumables are replenished or replaced, there is no specific confirmation method, so the following two methods have been used.

One is that a rectangular area contains primary colors (three pigments used for color printing, Y (yellow), M (magenta: reddish-purple), C (cyan: blue-green), and secondary colors (- Basic colors created by overlapping colors; K (black), R (red), C (
This is a method of evaluating whether printing is in normal colors using what is called a "patch" printed at the maximum density of green) and B (blue).

The other method is to print a natural picture such as a portrait or a landscape picture and confirm that it can be printed normally.

[Problem to be solved by the invention]

In the case of color printing devices, color reproducibility is an extremely important item. However, when natural images are used for confirmation or evaluation as in the conventional method, the following disadvantages occur.

■The colors used in natural paintings do not use the absolute range of colors that can be expressed.

■In natural paintings, there are few primary colors and many superimposed colors are used, so when the color of a printed matter changes, it is not easy to determine which secondary color has changed.

■If the tones of a natural painting are dark, it will be difficult to tell even if the colors change slightly.

Also, for patches with only maximum density, you can punch them out.

The horizontal axis of the figure is the ink density (OD: optical density), and the vertical axis is the subjective evaluation value (how it feels). The subjective evaluation value is determined based on the following criteria.

Subjective evaluation value 5: Satisfied Subjective evaluation value 4: -'satisfied Subjective evaluation value 3: Tolerable level Subjective evaluation value 2: Slightly dissatisfied Subjective evaluation value 1: Totally dissatisfied.

In the figure, the solid line is the subjective evaluation value of the patch, and the maximum density (for example, the density of gradation 256 when the gradation is expressed in 8 bits) is determined by the optical density (OD
) is a solid line connecting the subjective evaluation values of patches printed with settings such as

The subjective evaluation value of a patch is a subjective evaluation value that combines all the punches of the primary color and secondary color.

In the figure, (1) to OCD indicate the subjective evaluation values of images printed with the maximum density set to several levels of optical density in the printing of 10 types of natural images.

As shown in the figure, even if the maximum density is the same, the evaluation value varies considerably depending on the pattern of the natural image, and the evaluation value of the patch does not have a specific relationship with the evaluation value of the natural image. That is,
The evaluation value for punching is sometimes stricter (lower evaluation value) than the evaluation value for natural images, and sometimes it is lenient (higher evaluation), so it is impossible to deal with it.

The problem to be solved by the present invention is to solve these conventional problems and to provide a color printing device that allows easy confirmation of color reproducibility and has a function of generating an accurate test pattern.

[Means to solve the problem]

FIG. 1 is a block diagram showing the configuration of the present invention.

In figure (a), 1 is a simple pattern storage means,
To generate simple pattern data in which the density of at least all primary colors is continuously changed from the lowest density to the highest density.

A page memory 2 stores print information sent from a host computer or the like.

Reference numeral 3 denotes a switching means, which switches between the read data of the page memory 2 storing print information and the continuous data of the simple pattern storage means 1.

Reference numeral 4 denotes a successive output control circuit, which reads out the page memory 2 and the simple pattern storage means 1.

Note that the control means 20 includes a continuous control circuit 4 and a switching means 3.
, a microprocessor 8, and the given print information or simple pattern storage means 1 through the switching means 3.
The color scale information stored in is applied to the print head drive circuit of the printing means 20 to perform printing.

FIG. 1(b) is a diagram showing an example of a color scale printed with a simple pattern.

[For production]

The color printing device of the present invention continuously prints densities from the lowest density (white) to the highest density for seven colors (R, G, B) in all primary colors (preferably Y, M, C, and R, G, and B). The read data of the simple pattern storage means 1 which stores the changed simple pattern data and the page memory 2 which stores the print data sent from a total of 17 hosts, etc., or the continuous data of the simple pattern storage means 1. Printing means 10
A control means 20 is provided to cause printing to be performed by applying a control means 20 to print a color scale that varies from the lowest density to the highest density for at least all the primary colors.

According to the color scale of the present invention, the current color reproduction range of a color printing device can be easily confirmed.

FIG. 2 shows experimental data of subjective evaluation values when using the color scale of the present invention. In the figure, the solid lines indicate the subjective evaluation values of the color scale, and (1) to θω indicate the subjective evaluation values of 10 types of natural images as in the figure.

As is clear from FIG. 2, there is a specific relationship between the subjective evaluation value of the color scale shown by the solid line and the subjective evaluation value of the natural image. In other words, the evaluation value of Colors/R is more severe than any natural image (evaluation value is low), but it is by no means too severe (the lowest evaluation value of various natural images at each density (very close) (It's direct.) This means that by using a color scale, you can not only see physical changes, but also things that are close to the amount of change that humans feel.

[Embodiment] FIG. 3 is a diagram 1 showing the main part configuration of an embodiment of the present invention.

The control circuit of the color printing device of this embodiment is basically the same as that of a conventional color printing device, but the difference is that a simple pattern is stored for checking the color reproduction range. This is achieved by providing a generation ROM 1 and a multiplexer 3 which can switch the print data to either continuous data of a simple pattern or data read from the page memory 2.

In normal printing operations, print data from the host computer is input via the data input interface 6.
The data is written into the page memory 2 by the write control circuit 5 in response to a write command from a microprocessor (MPU) that controls the entire printing apparatus (not shown). Page memory 2
When the damage to the page memory 2 is finished, the MPU gives a read command to the successive output control circuit 4, and the successive output control circuit 4 reads out the page memory 2.

The successive data is manually input to the multiplexer 3, and since the read data of the page memory 2 is selected by the control f'iI signal from the multiplexer 3, the successive data is Y.

The M and C print head dryers are manually operated.
Printing is done.

The printing operation of a simple pattern (color scale) is performed as follows. From the front panel switch (not shown),
When the simple pattern printing mode is selected, M P tJ
First, the control signal applied to the multiplexer 3 is inverted so that read data of the simple pattern generation ROM 1 is selected.

Thereafter, the MPU performs a printing operation according to the simple pattern printing mode control program held therein. That is,
According to the print sequence, when the recording paper reaches a predetermined position, access to the simple pattern generation ROMI is started, and address updating and data reading are performed sequentially at a predetermined cycle.

When the printing of one page is finished, the printing sequence is finished, the control signal given to the multiplexer 3 is inverted to select the read data side of the page memory, and the simple pattern printing operation is finished to prepare for the next printing.

In the above operation example, the control signal applied to the multiplexer 3 is inverted after printing of one page is completed, but the control signal to the multiplexer 3 may be switched immediately after printing the last line of the simple pattern.

This makes it possible to print the natural image on the same page as the color scale and check it on both the color scale and the natural image.

The simple pattern generated in the above example is - Y, M, so that the entire secondary and secondary colors can be seen.

This is a color scale in which the gradation level is successively increased from the lowest density (white) of the seven colors R, G, and B to the highest density (maximum gradation level).

In this color scale, it is important to change the density continuously and linearly, but the relationship between the gradation level and the recording density in terms of -C is as shown in Figure 4. - Slowness of L curve, saturation on high concentration side. Therefore, in this embodiment, the line width (number of lines) of each gradation level is adjusted to make it appear as a linear change. That is, in the middle straight line part of gradation levels 1 to 255, there are 4 trees/1 floor! In the case of the II level, 1 to 3 lines/gradation level are used in the low hell part and the high hell part.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, it is easy to check the color balance and color at each gradation level, and in addition to the amount of physical change, it is possible to obtain an evaluation value that is close to the amount of change that humans perceive. This has a remarkable industrial effect in that it is possible to print a color scale according to the color scale, and it is possible to easily confirm the color even when the lot of consumables such as toner is changed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a diagram showing subjective evaluation values based on the color scale of the present invention, FIG. 3 is a diagram showing the main part configuration of an embodiment of the present invention, and FIG. The figure shows the relationship between gradation level and density, and FIG. 5 shows subjective evaluation values based on patches and natural images. In the figure 1. 1 is a simple pattern storage means (simple pattern generation ROM)
, 2 is a page memory, 3 is a switching means (multiplexer), 4 is a continuation control circuit, 5 is a write control circuit, 6 is a data input interface, 10 is a printing means, and 20 is a control means. (a) Low-Soto High Diagram King Inkstone Review So value to request and enter and enter! The relationship between Nohel and -hen is shown in Figure 5.
15 Sword

Claims (1)

[Claims] 1. In a color printing device equipped with a printing means (10) that performs multi-gradation color printing by superimposing two or more colors according to given printing information, simple pattern storage means (1) for generating simple pattern data that continuously changes density from density to maximum density; and simple pattern data read from said simple pattern storage means (1) to said printing means (10). 1. A color printing apparatus, comprising: a control means (20) for applying and printing. 2. The color printing apparatus according to claim 1, wherein the simple pattern to be printed is created by adjusting the width of each gradation level so that the recording density is linear.