JPH0825654A - Image processing method - Google Patents

Abstract

PURPOSE:To form a correct tone crush data optionally and simply by the operation of a user based on a guidance display. CONSTITUTION:The tone correction mode is set manually based on a display, and a given pattern is formed based on the setting and the formed pattern is guided to be mounted on a manuscript stand. The given pattern is read, and the tone correction data is formed based on an image data obtained by the reading.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing method for generating gradation correction data.

[0002]

2. Description of the Related Art Conventionally, standard tone correction data has been fixed to that set at the time of factory shipment.

The gradation correction is manually changed by the user using the density correction key by the user or the operation unit.

[0004]

However, since the density correction is manually performed in the past, there is a problem that a high level of knowledge and skill is required to set an appropriate density correction.

Further, there is a problem in that it is necessary to carry out trial printing many times before setting the proper density correction, which takes time.

The present invention has been made in view of the above points, and an object of the present invention is to allow a user to arbitrarily and easily generate appropriate gradation correction data by operating based on a guidance display. And

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points. The gradation correction mode is manually set based on the display, and a predetermined pattern is formed based on the setting. It is characterized in that the predetermined pattern is guided to be placed on a document table, the predetermined pattern is read, and gradation correction data is generated based on the image data obtained by the reading.

[0008]

EXAMPLES The present invention will be described in detail below based on examples.

FIG. 1 is a block diagram showing the configuration of an ink jet recording apparatus according to an embodiment of the present invention. In FIG.
Reference numeral 101 is a color image sensor for reading an original,
After being amplified to a predetermined value by the amplifier 102, it is converted into a digital image signal by the A / D converter 103.

The sensor sensitivity and the white level of the digital image signal are corrected by the shading correction of 104.

Reference numerals 105, 106, and 107 are signal adders for adding outputs corresponding to the filters of the color image sensor 101 in a predetermined section, and 108 is an image for converting a digital color image signal into a color and a density equivalent to those of a document. It is a processing unit.

Reference numeral 109 is a γ correction unit that is a part of the image processing unit 108 for adjusting the characteristics relating to density conversion, and 112 is a binarization circuit that converts a multi-valued signal into a binary value so that printing can be performed by the head. The signal binarized by the circuit is converted by the head driver 113 into a signal suitable for printing given to the heads 114 to 117.

Further, the heads 114, 115, 116, 11
7 is controlled to a constant temperature by the temperature control unit 118.

Reference numeral 110 denotes these signal adders 105, 10
6, 107, a γ correction unit, a pattern generation unit 119, a head driver 113, and a temperature control unit 118. The calculation control unit 119 is a pattern generation unit for generating a predetermined print pattern.

Reference numeral 111 is a display section 111 'for displaying the state of the apparatus as will be described later and an operation section for performing operations.

The paper exchange detection unit 119 is a pattern generation unit for generating a reference pattern, and 120 is a binarization circuit 112.
Is a switch circuit for switching and selecting the output of the pattern generator 119 and supplying the output to the head driver 113.

Next, the operation of the embodiment configured as described above will be described.

In this embodiment, in order to measure the bleeding rate of the paper, it is necessary to keep the printing conditions other than the recording paper constant. Therefore, for example, the arithmetic control unit 110 instructs the temperature control unit 118 to set the temperature so that the temperature of the print head is set to a predetermined value, and the temperature control unit 118 causes the print head 11 to set.
4, 115, 116, 117 are controlled to a predetermined temperature. After the voltage and pulse width applied to the print heads 114 to 117 are set to predetermined values, the pattern generator 119 is instructed to generate a signal for printing a pattern as shown in FIG. , Changeover switch circuit 1
20 is selected on the pattern generation section 119 side. In this state, at least three lines are printed for each color. In this embodiment, the printing of three lines or more is performed because the printing result is read by the image sensor 101 as described below. For example, when printing only one line, the printing width and the image sensor reading width are 1 :. This is because it corresponds to 1 because it is practically impossible to place the print result in parallel with the moving direction of the image sensor when the print result is read by the image sensor.

Next, the print result is read by the image sensor 101. First, the user sets the print result so that it is substantially parallel to the moving direction of the print head and the moving direction of the image sensor 101, and causes the image sensor 101 to read it. Therefore, first, according to the ratio of the colors of Red, Green, and Blue of the print result obtained by reading one line,
After determining which head is printing, all the read data obtained by the next one-line reading is added and averaged, and the density of the density is compared with the predetermined reference value, that is, the reference value generated by the pattern generation unit 119. Determine the difference. After performing this operation for the four heads, the image processing unit 108
The correction curve of the γ correction unit 109 is corrected.

Here, the reference value may differ depending on the type of each ink, but in this embodiment, the ratio of the printed area is 25% as can be seen from FIG. This is to prevent ink from mixing with each other. In this embodiment, the print result is discriminated based on the density, and the print ratio is controlled by the arithmetic control unit according to the discriminated print result.

When the bleeding rate of the recording paper is increased, the printed dot diameter is increased and the density is increased. On the other hand, when the bleeding rate is small, the printed dot diameter is small and the density is low.

FIG. 3 shows an example showing the correction characteristic of the γ correction unit 109 for making the density of the printed result constant regardless of the bleeding rate. When the one-dot broken line is the normal correction characteristic, the output data becomes lighter when the correction characteristic is corrected as shown by the solid line, and when the dot diameter is larger than the reference, the correction is performed in this way. On the contrary, if the correction characteristic is corrected as shown by the dotted line, the output data becomes darker, and if the dot diameter is smaller than the reference, correction is performed in this way.

Next, the timing for reading the result of printing the reference pattern as described above will be described. An example of such a time is a recording paper replacement time.

FIG. 4 shows the structure of the detection unit for automatically detecting the paper exchange.

Reference numeral 301 is a roll paper to be printed, and 30
Reference numeral 2 denotes a shaft for pressing the roll paper 301, which freely rotates. Reference numeral 103 denotes the arithmetic control unit shown in FIG. 1, which detects the remaining amount and replacement of roll paper. Reference numeral 304 denotes a roll paper remaining amount detection rod for detecting the remaining amount of roll paper, which is biased in the arrow direction by a member 309 extending from the shaft 302. 308
Is the rotation axis of 309. Reference numeral 305 denotes a photosensor array for detecting the position of the roll paper remaining amount detection rod 304.
A sensor processing unit 306 processes a sensor signal.

The roll paper 301 is used in the detection unit configured as described above, the change in the amount of paper is detected from the output of the photosensor array, and the remaining amount of paper is grasped to detect the paper It is possible to determine that the roll paper 301 has not been replaced even when the roll paper has been removed such as when jammed, and it is possible to prevent erroneous detection that the paper has been replaced just by removing the roll paper. , It is possible to grasp the paper exchange automatically and accurately.

FIG. 5 is a flow chart showing the operation of the above-mentioned detection unit, and FIG. 6 shows the operation unit display at that time.
Shown in

In FIG. 5, it is first detected whether or not the roll paper has been removed (S1), and if the roll paper has been removed as a result of this detection, it is determined whether or not the amount of roll paper has changed. (S3) If the amount of roll paper has changed, it is assumed that the roll paper has been replaced and the display shown in FIG. 6i) is displayed on the display unit of the operation unit 111 in FIG.

Then, after a predetermined time, it is displayed as to whether or not the print correction is performed as shown in FIG. 6ii) (S7). In response to this display, the user touches either part A or B with his / her hand to input an instruction as to whether or not to perform print correction to the arithmetic control unit 103 via the operation unit 111. As a result, when an instruction to perform print correction is issued, the print correction operation described later is performed (S9).

Further, in S1, S3, and S7 described above, N
When the flow branches to the position indicated by O and when the print correction operation ends, the display shown in FIG. 6v) is displayed on the operation unit 111.

Next, the operation in step S9 shown in FIG. 5 will be described with reference to FIG.

In FIG. 7, first, head temperature control and head voltage, pulse width, etc. are set to specified values before forming a predetermined pattern at f4-3, and then the pattern generation section 119 shows the same as shown in FIG. The predetermined pattern is printed (f4-4).

During this period, during the period of f4-3 to f4-4, the display section of the operation section 111 displays the display shown in FIGS. 8i) and ii) to indicate that the printing operation for correction is currently being performed. There is. Next, at f4-5, the operation unit 111 is displayed in FIG.
The message shown in i) is displayed and the message “Please put the print result on the reading unit” is displayed, and the signal for the correction start is waited for. Then, along with the start button, the display of the operation unit 111 is displayed as shown in FIG.
A display indicating that the image density correction is being performed is displayed as shown in v), each data is sampled by the image sensor, and then the γ correction unit is corrected.

After the completion of all the corrections, the flow moves to the step shown in S11 of FIG. 5, and the display shown in FIG.

As another embodiment, it is possible to perform the same correction by using a chart corresponding to a head of a constant color as a reference instead of the pattern generating section 119 in the first embodiment.

First, the correction mode is set before reading the reference chart, and the head temperature, head driver power supply voltage and pulse width are set and controlled.

After the setting is completed, the reference chart is placed on the reading unit, and the reference chart is copied by the reference image processing.

Then, as shown in FIG. 9, the chart and the result of copying as shown in FIG. 10 are set in the reading section, the reference chart and the copy are read by the image sensor, and the difference amount is calculated by the calculation control section. , Γ correction section is corrected.

According to the above embodiment, the pattern generator 11
It is possible to satisfactorily correct the print density without needing 9.

As described above, according to the present embodiment, the bleeding rate is judged by the means for reading the density of the printed matter, and the γ correction characteristic is changed, so that the printing result of the different lots of paper can be obtained. The density difference can be corrected, and the density difference due to the difference in paper can be prevented.

As for the correction of the print density, whether or not the correction is necessary is displayed at the time of exchanging the recording paper so that the user can select it, and the correction is performed only when the user needs it. Therefore, the usability is further improved.

Further, in the above-mentioned embodiment, the user is made to select the correction of the print density, but the present invention is not limited to this.
The print density may be automatically corrected when the replacement of the recording paper is detected.

Further, although the ink jet method is used as the recording method in the above-mentioned embodiments, the present invention is not limited to this, and can be applied to various recording methods such as a thermal transfer method or an electrostatic copying method.

Further, in this embodiment, the characteristics of the γ correction unit 109 are changed to adjust the print density, but the present invention is not limited to this, and other characteristics such as the head temperature may be changed. Alternatively, it may be performed by changing the characteristics of the reading system.

In this embodiment, paper is used as the recording material, but the material is not limited to this, and other materials such as a film made of a synthetic resin called a back print film may be used.

Further, in the present embodiment, the means for detecting the exchange of the paper as the recording material is shown in FIG. 4, but the present invention is not limited to this, and other configurations may be adopted.

[0047]

As described above, according to the present invention, the user operates according to the guidance display,
Appropriate gradation correction data can be arbitrarily and easily generated.

That is, since the correction mode can be manually set, the user can arbitrarily set whether or not to perform the gradation correction mode.

Further, the operation of placing a formed pattern on the platen, which is different from the normal print operation performed in the gradation correction mode, is displayed as a guidance, so that the user can easily operate the operation without hesitation.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a recording apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing an example of a recorded reference pattern.

FIG. 3 is a diagram showing a correction characteristic of a γ correction unit 109.

FIG. 4 is a diagram showing a configuration of a detection unit that detects replacement of recording paper.

FIG. 5 is a flowchart showing the control of the arithmetic control unit 103.

FIG. 6 is a diagram showing a display state performed on a display unit of an operation unit 111.

FIG. 7 is a diagram showing details in S9 of FIG. 5;

FIG. 8 is a diagram showing a display state performed when the flow shown in FIG. 7 is executed.

FIG. 9 is a diagram for explaining another embodiment of the present invention.

FIG. 10 is a diagram for explaining another embodiment of the present invention.

[Explanation of symbols]

 101 image sensor 110 arithmetic control unit 111 operation unit 130 paper replacement detection unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B41J 2/21 H04N 1/407 1/46 B41J 3/00 A 3/04 101 A H04N 1/40 101 E 1/46 Z

Claims (1)

[Claims] 1. A gradation correction mode is manually set on the basis of a display, a predetermined pattern is formed based on the setting, guidance is given that the formed predetermined pattern should be placed on a document table, and the predetermined pattern is read. The image processing method is characterized in that tone correction data is generated based on the image data obtained by the reading.