JPH0747735A - Ink sheet cassette - Google Patents

Abstract

PURPOSE:To provide an ink sheet cassette constituted so that the discrimination of the colorant of ink is automatically performed by a printer in a printer performing medium contrast recording such as a video printer. CONSTITUTION:A mark 8 wherein the kind and characteristics of the colorant of ink are encoded is provided on the cassette case of an ink sheet cassette 10 and read in a printer to transmit the kind of the colorant of ink to a printer. Since the mark is provided on the cassette case, the printer can read the mark without operating a reading part.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink sheet cassette used in a thermal transfer recording apparatus for printing an image having gradation, and particularly to a change in environmental temperature. The present invention also relates to an ink sheet cassette suitable for a thermal transfer recording apparatus, which is suitable for obtaining an image having a constant halftone density regardless of the change due to the improvement of the ink color material. Various methods have been proposed for recording an image or a character in accordance with a signal from the outside in a communication device, a terminal output device of an electronic computer, or the like. Among them, as a method for recording a multi-tone image by the thermal transfer recording method, for example, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Laid-Open No. 5-69482, an ink sheet having a thermally sublimable ink layer is used, and a necessary energization time is read from a read-only memory (ROM) in which energization time data corresponding to print density is written in advance. There is known a time-controlled gradation recording method in which an ink layer is heated in accordance with the energization time by a read-out method, a thermal head, or the like to transfer the ink onto the surface of a recording sheet. This method is different from the so-called dither gradation method in which one pixel is composed of a plurality of dots and the number of transferred dots is changed to perform gradation expression. Since the gradation is expressed by controlling the temperature of the dots, a good image having smooth gradation can be obtained by a relatively small and inexpensive device. However, in reality, the temperature is not directly controlled, but the amount of heat generated is controlled by the energization time of the thermal head to express a gradation print. Extremely sensitive to temperature. For example, a concentration of 1.
When 0 is obtained, it is assumed that the ROM has an energization time for an ambient temperature of about 25 ° C. When the ambient temperature changes to a range of 10 ° C. to 50 ° C., the image density is reduced by about 0.5 when the ambient temperature is 10 ° C., and the overall print result is very light and has no contrast. Obtained and the ambient temperature is 50 ℃
In the case of, the image density is increased by about 0.5, and the image becomes a black sunken image. That is, a normal printing result may not be obtained depending on the environmental temperature change. However, in the above-mentioned conventional example, sufficient consideration has not been given to such a point. Further, for example, even when the color development sensitivity of the ink changes due to the improvement of the heat sublimation ink color material, the data of the energization time corresponding to the density is written in the ROM, so that the ink sheet after the improvement is improved. On the other hand, printing must be performed using the current-carrying time for the ink before improvement as it is, and recording is performed at a density different from the original design, and normal recording density cannot be maintained. For this reason, there is a problem that a great limitation is imposed on the improvement of the ink. As a means for solving this problem, Japanese Patent Laid-Open No.
According to the type of ink applied to the ink sheet, the type information of the ink sheet is described as a mark on the shaft around which the ink sheet is wound, and the mark is read by the thermal transfer recording device. There is known a thermal transfer recording apparatus that prints with an optimum density by applying thermal energy. However, in the method of writing marks on the ink shaft, the mark reading means on the side of the thermal transfer recording device needs to rotate together with the rotation of the ink shaft. Therefore, a means such as a brush is required for transmitting the information obtained by reading the marks to the main body of the thermal transfer recording apparatus, and no consideration has been given to cost increase due to this and occurrence of an error due to abrasion of the brush. An object of the present invention is to provide a thermal transfer recording apparatus capable of stably and accurately performing gradation expression of a multi-gradation image such as a video image regardless of environmental temperature change and ink color material change. To provide the ink sheet cassette. The above-mentioned object is an ink sheet cassette for accommodating a roll-shaped ink paper coated with thermal transfer ink, wherein information on the type and characteristics of the ink sheet incorporated therein is described above. It is achieved by what is described on the ink sheet cassette. By reading the information about the type and characteristics of the ink sheet on the ink sheet cassette with the thermal transfer recording device, stable multi-gradation printing suitable for the color material can be obtained. An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows an outline of a thermal transfer recording apparatus for recording by the thermal transfer recording system. The recording sheet 2 wound around the drum 1 is superposed on the ink sheet 3 and pressed against the drum 1 by the thermal head 4. As the drum 1 rotates, the recording sheet 2 and the ink sheet 3 pass under the thermal head 4, and an amount of ink corresponding to the heat generated by the thermal head 4 is transferred from the ink sheet 3 to the recording sheet 2 to produce multi-gradation. Is recorded. At this time, information on the relationship between the energization time of the ink sheet 3 and the print density is detected from the mark provided on the ink sheet cassette shown in FIG. 2 by the reading means such as the optical sensor 5 prior to recording. Stored in memory. At the time of recording, first, the temperature information from the temperature detecting means such as the temperature sensor 6 attached to the thermal head 4 for measuring the environmental temperature and the stored information are input to the calculating means such as a microcomputer, and the thermal head 4 The data for controlling the heat generation amount of, for example, the energization time is calculated. FIG. 1 shows an example of the layout when the mark 8 is provided on the ink sheet cassette 10 according to the present invention. The ink sheet cassette 10 has an ink sheet supply shaft 11 and an ink sheet take-up shaft 12 rotatably supported therein, and as shown in the drawing, is placed between the ink sheet supply shaft 11 and the ink sheet take-up shaft 12. The ink sheet 3 is sprinkled around. On the surface of the ink sheet cassette 10, a mark 8 which encodes information about the energization time of the thermal transfer ink 9 and the environmental temperature characteristic of the print density is attached, and is made by a method such as engraving or printing. That is, the information about the thermal transfer ink 9 is read by the optical sensor 5 from the mark 8 when the ink sheet cassette is mounted. FIG. 3 shows an example of changes in the relationship between the print density of the thermal transfer ink 9 on the recording sheet 2 and the energization time of the thermal head 4 depending on the environmental temperature 14. Thermal head 4
When the thermal transfer ink 9 is a sublimable dye, the relationship between the energization time to the recording sheet 2 and the print density on the recording sheet 2 is generally 0 ° C to 60 ° C.
Practically, it is approximated by a straight line passing through a certain fixed point 13 at a temperature of the order. That is, the relationship between the energization time of a certain thermal transfer ink and the print density is represented by the coordinates of the fixed point 13 and the slope 15 of the straight line for each environmental temperature. [Table 1] [Table 2] Utilizing this property, Tables 1 and 2 show an example of information on the characteristics of the thermal transfer ink 9 recorded on the mark 8 of the ink sheet 3 or the ink sheet cassette 10. The coordinates of the fixed point 13 are X, Y, and the ambient temperature T
Assuming that the slope 15 of the straight line in is a _T , the relationship between the energization time t and the print density D is expressed by [Equation 1]. ## EQU1 ## D = a _T. (t-X) + Y That is, the mark 8 has the coordinates of the fixed point 13 and the characteristics of the cyan, magenta, and yellow thermal transfer inks 9 at several environmental temperatures. The slope of the straight line is shown. As a method of describing the characteristics of the thermal transfer ink 9, the coordinates of a fixed point, the slope of the characteristic straight line at a certain environmental temperature, and the temperature change rate of the slope may be used. The description format can be selected from a bar code format, an analog format proportional to a numerical value, a digital format in which a numerical value is converted into a bit, and the respective formats may be combined. FIG. 4 shows a block diagram of a thermal transfer recording apparatus for recording by the thermal transfer recording system according to the present invention. Thermal transfer ink 9 marked with marks 8 on the ink sheet 3 or ink sheet cassette 10.
The information regarding the characteristic of is detected by the reading unit such as the optical sensor 5 and is stored in the data RAM 40. This information is input to the arithmetic unit 16 such as a microcomputer. At the time of printing, temperature detecting means such as the temperature sensor 6 attached to the thermal head 4 detects the ambient temperature, and the detected temperature is converted into data by the A / D converter 21 or the decoder, and the ambient temperature data is stored in a microcomputer or the like. Is input to the arithmetic unit 16. The arithmetic unit 16 calculates the optimum energization time for each gradation necessary for controlling the thermal head 4 from the characteristic data of the thermal transfer ink 9 and the environmental temperature data read by the reading means, and calculates the gamma characteristic random access memory ( The result is written in (hereinafter abbreviated as γ-RAM) 17. The image data is digital data of several bits according to the required number of gradations and is stored in the memory 1 by an input device (not shown) in advance.
8 are arranged, and the density gradation number is assigned to the halftone circuit 1.
9 reads and uses the data in the γ-RAM 17 to transfer an ON signal to the head drive 20 for each gradation for each energization time, and the thermal head 4 transmits an appropriate energization time according to the signal. Heat is generated by energizing with. The driving mechanism 41 for rotating the drum 1 to convey the paper is instructed to operate by the control computer 42, and returns information about the paper conveyance such as the printing color and the number of printing lines to the control computer 42. The control computer 42 instructs the memory 18 of the address of the line to be printed next stored in the memory 18, and also instructs the arithmetic unit 16 of the timing of the γ-RAM content update. FIG. 5 shows some examples of the reading means. FIG. 5A shows a means for reading the magnetic mark 22 applied to the ink sheet 3 with the magnetic head 23, and FIG.
Is an electrode 25 attached to the surface of the ink sheet cassette
Then, the means for selecting and reading the combination of the electrical contacts 24 is shown, and FIG. 5C shows the means for selecting and reading the micro switch 27 by the notch 26 made in the ink sheet cassette. As described above, according to the present invention, in the thermal transfer recording apparatus, the printing conditions are set so that the printing density becomes about 1.0 at the ambient temperature of about 25 ° C., for example. At this time, when the environmental temperature changes from 10 ° C to 50 ° C, the image density is reduced by about 0.5 at the lower temperature side than 25 ° C, and the overall white and non-contrast printing result is obtained. However, when the color density of the thermal transfer ink was improved, there was a problem that the printing density was increased by about 0.5, and the printing result was blackened all over, and it was very susceptible to the environmental temperature. If you print under the same printing conditions as with the thermal transfer ink of, the recording will be performed at a density different from the original design due to the change in the color development sensitivity of the ink, and the normal recording density cannot be maintained. To solve the problem that there is a great limitation on the improvement of color materials, and to always obtain a stable print density as designed, regardless of the ambient temperature or any thermal transfer ink. It is possible to provide an ink sheet cassette capable of reliably transmitting necessary information to a thermal transfer recording device that enables the information.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an example of an ink sheet cassette. FIG. 2 is a schematic diagram of a thermal transfer recording apparatus to which an embodiment of the present invention is applied. FIG. 3 is a characteristic diagram showing temperature characteristics of an ink coloring material. FIG. 4 is a block diagram of a thermal transfer recording device. FIG. 5 is a diagram showing an example of a reading unit. [Explanation of Codes] 3 ... Ink sheet, 8 ... Marker, 10 ... Ink sheet cassette.

Claims (1)

[Claims] 1. An ink sheet cassette for storing roll-shaped ink paper coated with thermal transfer ink, characterized in that information such as the type and characteristics of the built-in ink sheet is described on the ink sheet cassette. cassette. 2. The ink sheet cassette according to claim 1,
An ink sheet cassette characterized in that information about the ink sheet is coded and described using an optically readable mark on the ink sheet cassette. 3. The ink sheet cassette according to claim 1,
Encoding information about the ink sheet to provide holes, cutouts or protrusions on the ink sheet cassette,
An ink sheet cassette characterized by being described by the pattern.