JPH10217529A - Image-recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To print images at high speed without causing heat wrinkles or improper discharge of papers, by detecting a temperature of a thermal head having a plurality of heat-generating elements, setting a printing start temperature when printing can be started on the basis of a value of the print quantity and controlling starting/stopping of the printing on the basis of the temperatures. SOLUTION: In a thermal transfer color printer 2, when image data of one plane is received from a computer 1 via an interface 100, a CPU 21 calculates a value of the print quantity and stores the calculated value in a memory 24. Before printing is started for every color, the CPU 21 reads a temperature of a thermal head with the use of a temperature-measuring device 25, and moreover calculates from the value of the print quantity stored in the memory 24 a printing start temperature when printing can be started and compares with the temperature of the thermal head. When the temperature of the thermal head is lower than the printing start temperature, the printing for every color is started. When the temperature of the thermal head is higher, it is detected as a printing failure, and the printing is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer image recording apparatus, such as a sublimation method and a melting method, used for obtaining an output image from a visual device such as a personal computer, a video, and a television.

[0002]

2. Description of the Related Art A thermal transfer image recording apparatus prints one or more lines of printing data (hereinafter, referred to as an area) on a printing paper by a thermal head, feeds the printing paper to the next area, and prints again. It is a device that repeats. This apparatus has a problem that, when printing is performed continuously, the thermal head is heated to a high temperature, and problems such as hot wrinkles and defective paper discharge occur. As a countermeasure against this, in the conventional device, Attach a temperature measuring device near the thermal head and monitor the temperature. 2. When the temperature measuring device detects a temperature at which a problem occurs in the thermal head, the CPU incorporated in the image recording device interrupts printing. 3. When the temperature measuring device detects a temperature at which the thermal head cools and printing can be started (hereinafter referred to as a set temperature), the CPU starts printing. That technology was used.

[0003]

The set temperature has been set low and constant so as to minimize the occurrence of problems. Therefore, the CPU did not start printing until the thermal head cooled to the set temperature regardless of the size of the printing amount of the data to be printed. For this reason, there was a disadvantage that the printing time was long.

The present invention has been made to solve this drawback.

[0005]

In order to solve the above-mentioned problems,
In the image recording apparatus of the present invention, in the invention according to claim 1, a thermal head 23 having a plurality of heating elements, a temperature measuring device 25 for detecting a head temperature of the thermal head 23, and a printing amount calculated from the printing amount A print startable temperature setting means for setting a printable start temperature at which printing is started based on the value.

According to a second aspect of the present invention, in the image recording apparatus according to the first aspect, a temperature measuring device for detecting a temperature of the thermal head, and a temperature for comparing the measured temperature with the print startable temperature. A printing means for performing printing if the measured temperature is lower than the print startable temperature by the comparing means and the temperature comparing means, and stopping printing when the measured temperature is higher than or equal to the print startable temperature; Means.

According to a third aspect of the present invention, in the image recording apparatus according to the second aspect, the thermal head 23 for performing printing for each area has a print amount of each pixel corresponding to the heating element in an area to be printed next time. The total sum is used for the printing amount value. According to a fourth aspect of the present invention, in the image recording apparatus according to the second aspect, the thermal head 23 that performs printing for each area has the largest printing amount among the pixels corresponding to the heating elements in the area to be printed next time. A large value is used as the print amount value.

According to a fifth aspect of the present invention, in the image recording apparatus according to the second aspect, means for dividing the area to be printed next time by the thermal head 23 for performing printing for each area into several blocks; And means for calculating the sum of the printing amounts of the respective pixels, and means for using the largest value of the sum of the printing amounts as the printing amount value.

According to a sixth aspect of the present invention, in the image recording apparatus according to the second aspect, in order to determine the print start possible temperature, a relationship between the print amount value and the print start possible temperature is determined by a look-up table. And a storage means for storing the data in the memory means.
According to a seventh aspect of the present invention, in the image recording apparatus according to the second aspect, in order to determine the print start possible temperature, the relationship between the print amount value and the print start possible temperature is stored in the form of a function in a memory means. It has a configuration characterized by having storage means for storing.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a configuration diagram showing an embodiment of the present invention. In this embodiment, the printer 2 is a thermal transfer type color printer.
Computer 1 and printer 2 are interface cables
It is connected by 100 and exchanges image data and control signals. The operations performed by the CPU 21 are as follows.
Heat is generated in the thermal head 23 to print an area. The image data to be printed is temporarily stored in the memory 24, and each control parameter is held. Interface 2
2 causes the computer 1 to exchange image data and control signals. The print data is sent to the thermal head 23, printing is performed, and then a paper feed is performed. The temperature measuring device 25 always measures the temperature of the thermal head 23. Further, the CPU 21 performs various arithmetic processes used for control.

If data forming an image is, for example, YMC data, each of Y, M, and C is a plane (platform).
ne). In the second embodiment, two examples will be described: a first embodiment in which a print amount value (described later) is calculated for each plane, and a second embodiment in which a print amount value is calculated for each area. FIG. 2 is a flowchart illustrating a processing procedure of the CPU 21 according to the first embodiment. Hereinafter, the description will be made with reference to both FIG. 1 and FIG.

In FIG. 2 S 1, the CPU 21 receives one plane of image data from the computer 1 via the interface 100. Next, in S2, the CPU 2
1 performs a printing amount value calculation process. The printing amount value in the first embodiment is an amount calculated based on the printing amount for one plane, and will be described later in detail. The printing amount is the amount of YMC data itself if the data forming the image is, for example, YMC data. The density of the recording paper as a result of printing has a monotonically increasing relationship with an increase in printing amount.

Various definitions are conceivable for the printing amount value.
Here, three types of definitions are described. A value obtained by adding all the print amounts of the individual pixels constituting the plane is called a total print amount. The first definition is to set the total print amount as a print amount value. In this case, an average print amount may be used instead of the total print amount. If the number of pixels is fixed, the total print amount and the average print amount are proportional and equivalent. The second definition is to define the largest value among the print amounts of the respective pixels as the print amount value. The third definition is that the plane to be printed next time by the thermal head 23 is divided into several blocks, the sum of the printing amounts of the respective pixels in each block is calculated, and the largest value among them is determined as the printing amount. Use for values. In this case, similarly to the first definition, an average may be used instead of the sum. The first definition is the most accurate value for measuring the printing amount, but it takes time to calculate. The second definition is used when it is desired to reduce the processing time. The thermal wrinkles of the paper by the thermal head 23 often occur partially, and in that case, the third definition is effective. Which of these to select may be determined according to the processing time of the CPU or the like.

The calculated print amount value is stored by the CPU 21 in the memory 24 of the printer main body. In the color printer of the present embodiment, three colors of Y, M and C are separately printed. CP
U21 reads the temperature of the thermal head using the temperature measuring device 25 in FIG. 2 and S3 before printing is started for each color. Next, in S4, the CPU 21 calculates a print startable temperature of a printable temperature from the print amount value stored in the memory 24. In step S5, the CPU 21 compares the print startable temperature with the thermal head temperature.
If the temperature of the thermal head is lower than the temperature at which printing can be started, the CPU 21 determines that printing is possible, and starts printing by color in S6. If the thermal head temperature is higher than the print startable temperature, it is determined that printing is not possible,
Return to S3. In S7, the CPU 21 determines whether or not all the planes have been printed. If there is any unprinted plane, the CPU 21 requests the computer 1 for data of the next plane in S8. If the printing of all the planes has been completed, the operation is terminated.

Next, a second embodiment will be described. FIG. 3, S
In 1, the CPU 21 receives one plane of image data from the computer 1 via the interface 100. Next, in S2, the CPU 21 extracts print data for one area to be printed at one time by the thermal head from print data for one plane. Next, in S3, the CPU 21 performs a printing amount value calculation process. As in the first embodiment, any one of the above-described three types is applied to the printing amount value. The calculated print amount value is stored in the memory 24 of the printer main body by the CPU 21. In S4 before printing the area, the CPU 21 determines the temperature of the temperature measurement device 25.
Read the temperature of the thermal head using. Next, in S5, the CPU 21 calculates a print startable temperature of a printable temperature from the print amount value stored in the memory 24. CP
U21 compares this print startable temperature with the thermal head temperature in S6. The thermal head temperature is
If the temperature is lower than the print startable temperature, the CPU 21 determines that print is possible, and starts printing an area in S7. If the temperature of the thermal head is higher than the temperature at which printing can be started, it is determined that printing is not possible, and the process returns to S4. CPU 21
Determines in S8 whether all areas have been printed,
If there is an unprinted area, data of the next area is prepared in S9. If all the areas have been completed, that is, if printing of one plane has been completed, the CPU 21 determines in S10 whether or not all the planes have been printed. Request data of the next plane. If the printing of all the planes has been completed, the operation is terminated.

The processing procedure of the embodiment in the present invention has been described above. In the following, a method for rapidly determining the print startable temperature in FIG. 2S4 of the first embodiment and FIG. 3S5 of the second embodiment will be described. Will be described. In order to determine the printable temperature of the printable temperature from the printable value, an experiment is performed in advance to determine the relationship between the printable value and the maximum temperature (limit temperature) of the thermal head at which printing is possible. Specifically, printing gray solids (including black solids) of various densities at various head temperatures, recording the thermal head temperature at which a defect begins to occur for each gray solid, and printing image data of the densities, the critical temperature and Create a relationship. The processing time can be shortened by storing the correspondence between the printing amount value and the printable start temperature in the memory 24 and referring to this at the time of printing. There are two ways of storing. That is, it may be stored discretely in the form of a look-up table or continuously in the form of a function.

[0017]

As described above, according to the present invention, by determining the temperature of the thermal head at which printing is started from the printing amount of the image to be printed, heat wrinkles and defective paper discharge do not occur. Can improve the printing speed.

Further, by preparing in advance a relationship between the printing amount value determined from the printing amount and the temperature of the thermal head at which printing can be started with a look-up table or a function for each printer model, the speed can be further improved. Becomes possible. Furthermore, the calculation of the print amount value employs any one of the three types of the sum of the print amounts for each pixel, the maximum value, or the maximum value in the divided block, thereby reducing CPU processing time, heat wrinkles, and the like. Countermeasures are taken accordingly.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an image output apparatus according to the present invention.

FIG. 2 is a processing flow chart according to the first embodiment of the present invention.

FIG. 3 is a processing flow chart according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Computer 2 Printer 21 CPU 22 Interface 23 Thermal head 24 Memory 25 Temperature measuring device 100 Interface cable

Claims (7)

[Claims] A thermal head having a plurality of heating elements; and a print startable temperature setting means for setting a print startable temperature at which printing is started based on a print amount calculated from the print amount. An image recording apparatus characterized by the following. 2. The image recording apparatus according to claim 1, wherein
Temperature measuring means for detecting the temperature of the thermal head,
A temperature comparison unit that compares the measured temperature measured by the temperature measurement unit with the print startable temperature, and performs printing if the measured temperature is lower than the print startable temperature by the temperature comparison unit; and performs the measurement. An image recording apparatus, comprising: a print determining unit that stops printing when the temperature is higher than or equal to the print startable temperature. 3. The image recording apparatus according to claim 2, wherein
An image recording apparatus, wherein a total sum of print amounts of respective pixels corresponding to the heating elements in a region to be printed next time by the thermal head performing printing for each region is used as the print amount value. 4. The image recording apparatus according to claim 2, wherein
An image recording apparatus, wherein the largest value among the print amounts of respective pixels corresponding to the heating elements in a region to be printed next time by the thermal head that prints for each region is used as the print amount value. . 5. The image recording apparatus according to claim 2, wherein
Means for dividing the area to be printed next time by the thermal head which performs printing for each area into several blocks, means for calculating the sum of the printing amounts of respective pixels in each block, and the sum of the printing amounts An image recording apparatus comprising means for using the largest value among the above as the print amount value. 6. The image recording apparatus according to claim 2, wherein
An image recording apparatus comprising: storage means for storing a relationship between the print amount value and the printable temperature in a memory means in the form of a look-up table in order to determine the printable temperature. apparatus. 7. The image recording apparatus according to claim 2, wherein
An image recording apparatus, comprising: storage means for storing a relationship between the printing amount value and the printing startable temperature in a memory in the form of a function in order to determine the printing startable temperature.