JPS62280055A - Method for measurement of density characteristics in gradation printer - Google Patents

Abstract

PURPOSE:To enable acquisition of a relation between recording density and applied energy, by a method wherein the recording of a specific time is carried out by applying uniform energy or a specific energy correcting an unevenness of temperature in the main scanning direction to be anticipated to each of a plurality of recording elements arranged in the main scanning direction. CONSTITUTION:A first recording process in which recording for a specific time is carried out not less than once in the sub-scanning direction on image receiving paper 11 in a state where the same energy is applied to each of a plurality of heating elements 13a arranged in the main scanning direction, a second and the third recording processes in which the heating elements are divided into a plunality of groups and the recording of a specific time is carried out in the sub-scanning direction on the image receiving paper in a state where stepwise different energy is applied to respective groups, and the measuring process in which the density or the reflectance of each part corresponding to each group of the recording pictures obtained on the image receiving paper by the second recording process is measured, are possessed. By execution of the third recording process just after execution of the first recording process and the second recording process, a relation between the recording density and the applied energy under that temperature conditions of a thermal head 13 which is most near to actual use conditions is obtained and a required density can be obtained by adjusting the applied energy.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Industrial Application Field The present invention relates to a gradation printer used for hard copying images of televisions, video systems, etc. The present invention relates to a method for measuring density characteristics that can easily obtain a relationship between recorded density or reflectance.

Conventional technology Thermal transfer method modulates the energy applied to the heating element by 3 bars.

By doing so, it is possible to record gradation, and it is easy to convert to color, and it is quiet and easy to maintain.
It is attracting attention as a gradation printer for use in offices to make hard copies of halftone images from televisions and video systems.

Generally, when performing color recording using a thermal transfer method, as shown in FIG. Thermal head 3 is arranged in a straight line.
is pressed against the platen roller 4 through the ink sheet 2 and the image receiving paper 1, and energy corresponding to the density information of the color to be recorded is applied to each heating element to generate heat, thereby recording one line by thermal transfer. Let it happen. At the same time, the image receiving paper 1 and the ink sheet 2 are conveyed in the direction of the arrow a to complete recording of one page using the first color ink.

Next, the image receiving paper 1 is pulled back in the direction of the arrow so that the recording start position is at the heating element position, and then the thermal head 3 is pressed again to transport the image receiving paper 1 and the ink sheet 2 in the direction of the arrow a. One page is recorded using the second color ink, and one page is similarly recorded using the third color ink, thereby completing the recording of a color image using the subtractive color mixing method.

However, in order to obtain the desired recording density, it is necessary to obtain the relationship between the recording density and the applied energy. Therefore, the main scanning direction is divided into a plurality of groups, and recording of a predetermined length in the sub-scanning direction is performed with different applied energy for each group.

When this pattern is recorded at different positions on the receiver paper for each color, a pattern including a plurality of different density blocks for each color is obtained as shown in FIG. Next, the density of each inclusion density block of this pattern is measured using a densitometer. In the manner described above, the relationship between applied energy and recording density as shown in FIG. 9 is obtained for each color.

Problems to be Solved by the Invention However, in the case of a thermal transfer method, the temperature of the thermal head increases near the heating element to which a large amount of energy is applied, and even if recording is performed with the same applied energy, the temperature of the thermal head differs. In this case, the recording density will also be different. Therefore, with the above pattern, each time each color is recorded, the difference in applied energy for each block causes a temperature difference in the main scanning direction on the thermal head, and the recording density and applied energy under a constant temperature condition for each color are It had the disadvantage of not being able to establish a relationship with Also, when recording actual images,
Since the temperature of the thermal head changes as shown in FIG. 10 while recording one page, the temperature of the thermal head closest to the actual usage conditions is T1. However, with the above pattern, the recording density can only be obtained when the temperature of the thermal head is between T2 and T1.
At the same time, this method also has the drawback that a relationship between recording density and applied energy that is useful for recording actual images cannot be obtained.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a means for solving the above-mentioned problems by applying the same energy to a plurality of heating elements arranged in the main scanning direction. Record the specified time 1
The first recording step is performed more than once, and the heating element is divided into a plurality of groups, and recording is performed for a predetermined time in the sub-scanning direction on the receiver paper while applying different energy in stages to each group. Similar to the second recording process, the recording element is divided into a plurality of groups, and a predetermined amount of energy is applied to each group in a predetermined direction in the sub-scanning direction on the image receiving paper. a third recording step for recording time; and a measuring step for measuring the density or reflectance of each portion of the recorded image obtained on the receiver paper in the second recording step, which corresponds to each of the groups; By executing the second recording process after executing the first recording process, and executing the third recording process immediately after executing the second recording process, the thermal head is closest to the actual usage conditions. The relationship between the recording density and the applied energy under the temperature conditions can be obtained and used as data for controlling the applied energy to obtain a desired density.

According to the present invention, by performing the first and third recording steps, the second recording step can be performed with the temperature of the thermal head closest to the actual usage conditions and kept constant in the main scanning direction. , it is possible to obtain a relationship between recording density and applied energy, which is useful as data for controlling applied energy to obtain a desired density.

EXAMPLE Hereinafter, a method according to a first example of the present invention will be explained with reference to the accompanying drawings.

FIG. 2 is a basic configuration diagram of a gradation printer. In Fig. 2, reference numeral 11 indicates image receiving paper, and 12 indicates a support such as a PET film, and on the surface facing the image receiving paper 11, ink that becomes fluid when heated is applied to one page of each color, such as yellow, magenta, and yellow. Ink sheets are painted in order, 13 is a line-type thermal head in which heating elements 13a are linearly arranged in the main scanning direction, 14 is a platen roller around which image-receiving paper 11 is wound, and 16 is a platen roller that wraps the tip of image-receiving paper 11. This is a paper holder that is held between the

Next, the operation of this gradation printer will be explained using FIG. 2. Before starting recording, at a position facing the heating element 13a,
The recording start position of the image receiving paper 11 and the recording start position of the first color yellow ink on the ink sheet 12 have arrived, and the thermal head 13 and the ink sheet 12 are in a state separated from the platen roller 14 (13' and 12'). . At the start of recording, 13% of the heating elements are on the ink sheet 12.
Then, the thermal head 13 is moved in the direction of arrow C by means not shown so as to come into pressure contact with the platen roller 14 via the image receiving paper 11. Next, energy corresponding to the density information for one line of yellow is applied to each heating element 13a to generate heat, and the yellow ink is heated and the image receiving paper 11 is heated.
Perform the transfer on top. At the same time, the image receiving paper 11 is moved line by line in the direction of arrow d by a driving means (not shown) in synchronization with the density information. At this time, the ink sheet 12 is conveyed in the direction of arrow θ by the frictional force with the image receiving paper 11 at the position where the thermal head 13 and the platen roller 14 are in pressure contact with each other, and is wound up while applying tension by means not shown. When one page of recording is completed using the yellow ink in this manner, the conveyance of the image receiving paper 11 is temporarily stopped and the image receiving paper 11 is transferred to the server 9.

The thermal head 13 and the ink sheet 12 are separated from the platen roller 14 by moving the printing press 13 in the direction of arrow f. (States 13' and 12') After this, the ink sheet 12 is conveyed in the direction of arrow e until the recording start position of the magenta ink of the two-color edge comes to a position facing the heating element 13a, and the image receiving paper 11 is 13! It is moved in the direction of arrow d by a drive means (not shown) until the recording start position is at a position opposite to L. In this way, the receiving paper 11
is moved to the recording start position, and the magenta ink recording state for two colors is started. Thereafter, the thermal head 13 and the ink sheet 12 are pressed against the platen roller 14 to record one page of magenta ink on the yellow ink record image. Thereafter, recording with cyan ink of three colors is performed in the same manner to complete the recording of a color image using the subtractive color mixing method.

FIG. 1 is a schematic configuration diagram of a density characteristic measurement image in a first embodiment of the present invention recorded by the gradation printer having the configuration shown in FIG. In Figure 1, 10 - Y1 to Y5 are images recorded with yellow ink, the first color ink, M1 to M5 are images recorded with magenta ink, the second color ink, and C1 to 05 are images recorded with the third color ink. This is an image recorded by 7 uninking. Of these, Yl, Y,...

Y3 and Ml, M2. M3 and C,,C2,C
3 is a portion recorded by uniformly applying maximum energy in the main scanning direction, and Y4. M4. C4 is a portion recorded by uniformly applying energy of half the maximum energy in the main scanning direction, and Y52M5. C5 divides the main scanning direction into 10 equal parts,
Apply energy that is 1/10 of the maximum energy to the block Yl (or J or C1), and apply energy that increases by 1/10 of the maximum energy to each block of y10 (or JJ or Cl0). This is the part I recorded.

3A, B, and C are diagrams showing the results of measuring the reflection densities of each of 10 blocks of Y52M5 and C5 in the density characteristic measurement image of FIG. 1 using a Macbeth densitometer. When performing gradation recording on an actual image, create a table of applied energy 11...-full range corresponding to the density information from this figure in advance, and control the applied energy based on this table to obtain the desired value. Obtain the concentration of

FIG. 4 is a diagram showing the temperature change of the thermal head 13 when recording the density characteristic measurement image shown in FIG. The average temperature of the thermal head 13, m, when energy of about 60% of the maximum energy is applied uniformly for one page in the main scanning direction, which is the most frequent, is Y style, T5, or C5 in Fig. 1. ) Thermal head 1 near heating element 13fL used for recording blocks of
3, n is the heating element 1.3 used for recording the block of y SO (or T5- or C:0) in Figure 1.
& is a graph showing the temperature of the nearby thermal head 13, respectively. In addition, a indicates the temperature change during recording of one page each with the first color ink, b the second color ink, and C the third color ink, and 11.12, 13, 14.15 on the time axis are respectively Y, (or Ml or C,), T2(-!
or T2 or C2) + Y3 (or T3 or C3)
, T4 (still T4 or C4).

It shows the time during which part T5 (or T5 or C5) is recorded. From b and c in Figure 4, the temperature difference between m and n disappears at t5, so T5(
It can be seen that the temperature unevenness in the main scanning direction caused by recording at T5 (or T5) is evened out during recording at T5 (or C5). Further, from 1 in FIG. 4, it can be seen that the temperature of the thermal head 13, which is most frequently used in actual images, is T1, but at t5, m and n have reached T1, and at T5. It can be said that the temperature of the thermal head 13 when recording T5 and C5 is close to the actual usage conditions. Therefore, the relationship between recording density and applied energy in FIG. 3 obtained from each block of Y52M5 and C5 in FIG. 1 is data under conditions closest to actual usage conditions.
This can be used as optimal data for controlling applied energy to obtain a desired concentration.

As described above, according to the first embodiment of the present invention, recording for a predetermined period of time is performed in the sub-scanning direction on the image receiving paper one or more times while applying uniform energy in the main-scanning direction. Thus, the relationship between recording density and applied energy under conditions closest to actual usage conditions can be obtained.

A method according to a second embodiment of the present invention will be explained below with reference to the accompanying drawings.

In the density characteristic measuring method of the second embodiment, the basic configuration and operation of the gradation printer for recording are the same as those shown in FIG. FIG. 6 is a schematic configuration diagram of a density characteristic measurement image in a second embodiment of the present invention recorded by the gradation printer having the configuration shown in FIG.

In FIG. 6, from Yl to T5. M, to T5. O
, to C5 are the same as the density characteristic measurement images of the first embodiment shown in FIG. The density characteristic measurement image in the second embodiment of the present invention is different from that of Y62M6 in FIG. C
As shown in T5.6. T5. Same as C5, set the main scanning direction to 1.
0 equal parts, and (10-1
) and the point where a flock of Y2o-il 4 .\-1 (or T6 !, or C6) was applied, and Y,, T8. T5 + T4 r as shown in T9 (or T7.T8.M, or C,,C8,C,)
T5 (”! or T3.T4.T5 or C3, C4,
The point is that the same pattern as C5) is further provided. Here T6. The length of the T6°C6 block in the sub-scanning direction is Y5
9M5°Shorter than C5. FIG. 6 is a diagram showing the temperature change of the thermal head 13 when recording the density characteristic measurement image of FIG. 5. 1 in the figure is similar to 1 in FIG. The temperature of the frequently used thermal head 13, m is the temperature of the thermal head 13 near the heating element 13a used for recording the block of Yl (or J or C) in FIG. 6, and n is y in FIG. It is a graph showing the temperature of the heating element 13 and the nearby thermal head 13 used for recording a block containing ; C shows the temperature change during recording of one page each with the third color ink, and 11.1., .1. on the time axis.
．． 14,15. 16,1. ．． 18,1. Haso 16 base.

Yl (or Ml or C1), T2 (or T2 or C2), T3 (t or T3 or C3) + Y
4 (or T4-i or C4), T5 (or T5 or C5).

T6 (or T6 or C6), Y, (t or T7 or C7) + YB (frozen or T8 or 08), Y, (or M, 4 or C2) indicates the recording time. There is. From a, b, and c in Figure 6, at t, m
Since there is no temperature difference between and n, T5 (or T
Temperature unevenness in the main scanning direction caused by recording from T6 to T8 (or from T6 to T8 or C6)
Y by recording from C8).

It can be seen that when recording (or M, Sword or C9), it is leveled uniformly. ¥1: Since the temperature difference between m and n disappears even at t5, the temperature unevenness in the main scanning direction caused by recording Y, (t or M,) is from M to T4 (!J or From C4 to C4), T5 (
It can be seen that when recording 05), the smoothing is done uniformly. Regarding the matter, from 1 in Fig. 6, t5 and t, and m and n in odor both reach T1, and since T1 is the temperature of the thermal head 13 most frequently used in actual images, T5° T5. C5 and Y, , T9. C,
It can be said that the temperature of the thermal head 13 when recording is close to the actual usage conditions. Therefore, T5 in FIG. The concentration characteristics obtained from each block in T5 and C5 are data under conditions closest to actual usage conditions, and can not only be used as optimal data for controlling the applied energy to obtain the desired concentration. , Y, , M, and C9 overlapped blocks can also be used to obtain density characteristics when ink colors are mixed.

As described above, according to the second embodiment of the present invention, recording for a predetermined period of time is performed at least once in the sub-scanning direction on the image receiving paper while applying uniform energy in the main-scanning direction, and By applying a predetermined energy to each block to correct temperature unevenness in the main scanning direction, multiple relationships between recording density and applied energy under conditions closest to actual usage conditions can be obtained from one page of recording. be able to.

In both embodiments, gradation preset 17 of the thermal transfer method is used.

Although the above mentioned printer is used, the same effect can be obtained by using a thermal method, an energized thermal method, etc. as long as the temperature of the head changes during recording.

In both embodiments, a paper holder is used as a means for transporting the image receiving paper in the sub-scanning direction, but it goes without saying that other methods may be used for transporting the image receiving paper.

Further, in both embodiments, a pattern was used in which the applied energy was divided into 10 stages and recorded, but the same effect can be obtained even if a pattern in which the applied energy is divided into stages other than 10 is used.

Further, in both Examples, the evaluation using the density was performed in the measuring process of the recording section, but the evaluation may also be performed by measuring the reflectance.

In both examples, when recording was performed for a predetermined period of time with the applied energy being uniform in the main scanning direction, the maximum energy and 1/2 of the maximum energy were applied.
Depending on the recording speed, the thickness of the maximum energy, the thermal characteristics of the head, etc., the same effect can be obtained even if other magnitudes of energy are used.

18...-7 In the second embodiment, Y←" or J or OS
) blocks and corresponding main scanning direction positions were provided, but
T6. Y52M5. for T6.06. A similar effect can be obtained by applying energy of another magnitude to correct the temperature unevenness in the main scanning direction that is expected in C5 recording.

In addition, in the second embodiment, two recording sections for each color (T5, T5.
C5 and Y, , T9. C,), but from T6 to T
8. T8 from town. If you add a part that corrects temperature unevenness in the main scanning direction in the same way as C6 to 08, it is possible to provide three or more recording parts for each color in one page that can obtain density characteristics close to actual usage conditions. can.

In addition, in both embodiments, the ink recording order is yellow, magenta, and cyan, but a different order may be used, and although the ink types are three colors, it goes without saying that colors other than the three colors may be used.

Effects of the Invention 19 bases/' The present invention provides a state in which a predetermined energy is applied to a plurality of recording element pots arranged in the main scanning direction to correct uniform or expected temperature unevenness in the main scanning direction. By recording for a predetermined period of time, the temperature of the head is kept as close as possible to the actual usage conditions and is constant in the main scanning direction.Then, the recording elements are divided into multiple groups, and the temperature is adjusted step by step for each group. The relationship between recorded density and applied energy is useful as data for controlling the applied energy and obtaining the desired density by measuring the density of each block obtained by recording for a predetermined time with different energies applied. can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a density characteristic measurement image of a method for measuring density characteristics in a gradation printer according to the first embodiment of the present invention, FIG. 2 is a side view showing the basic configuration of the gradation printer, and FIG. Y5 in the density characteristic measurement image of FIG. A density characteristic diagram showing the results of measuring the reflection density of 10 blocks each of M5 and C5 with a Macbeth densitometer. Figure 4 is a temperature characteristic diagram showing the temperature change of the thermal head when recording the density characteristic measurement image of Figure 1. 6 is a schematic configuration diagram of a density characteristic measurement image in the second embodiment of the present invention, and FIG. 6 is a temperature characteristic showing the temperature change of the thermal head when recording the density characteristic measurement image of FIG. 6. 7 is a side view showing the basic configuration of a conventional gradation printer, FIG. 8 is a schematic configuration diagram of a density characteristic measurement image in a conventional gradation printer, and FIG.
A density characteristic diagram showing the results of measuring the density of each encompassing density block shown in the figure using a densitometer. Figure 10 is a temperature characteristic diagram showing the temperature change of the thermal head when recording the density characteristic measurement image of Figure 8. It is. 11... Image receiving paper, 12... Ink sheet, 13... Thermal head, 14...
・Platen roller. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure Y5' Attachment C5・ Figure 2/l Receiving paper Figure 3 θ/23456 //Y/θ Figure 4 Figure 5 Figure 7 Figure 8 ■] Madder meat Figure 9 Figure 10 - Amber eyes Second color Satsumi colored shellfish 1 hour

Claims (3)

[Claims] (1) In a gradation printer, a first recording step in which recording is performed for a predetermined period of time in the sub-scanning direction on the receiver paper one or more times while applying the same energy to each of a plurality of recording elements arranged in the main-scanning direction. a second recording step of dividing the recording element into a plurality of groups and performing recording for a predetermined time in the sub-scanning direction on the receiver paper while applying different energy stepwise to each group; and a measurement step of measuring the density or reflectance of each portion of the image recorded on the image receiving paper in the second recording step, which corresponds to each group, and after performing the first recording step, the second recording step is performed. 1. A method for measuring density characteristics in a gradation printer, characterized by performing a recording step of: (2) Similar to the second recording step, the recording elements are divided into a plurality of groups, and recording is performed for a predetermined time in the sub-scanning direction on the image receiving paper while applying different energy stepwise to each group. Density characteristic measurement in a gradation printer according to claim 1, which has a third recording step, and is characterized in that the third recording step is executed immediately after executing the second recording step. Method. (3) The gradation printer according to claim 2, wherein the recording time in the sub-scanning direction in the third recording step is shorter than the recording time in the sub-scanning direction in the second recording step. Method for measuring concentration characteristics in