JPS6228266A - Thermal transfer printer - Google Patents

Abstract

PURPOSE:To transfer-record images with high quality irrespective of temperature variations or scattering of quality of thermal recording materials, by detecting the optical density of an image transferred onto a transfer recording paper, and controlling the heating value of a thermal head according to the magnitude of a detection signal. CONSTITUTION:By a heating value controlling part 9 for the thermal head 4, a heating part 6 located at a position corresponding to a solid image pattern signal inputted from a storage part 10 is driven to generate heat, whereby a dye or the like of a thermal transfer paper 3 forms a rectilinear density detection mark 20 (yellow) extending from the top to the bottom of a right or left marginal part 17 of the transfer recording paper 2. The optical density of the mark 20 is inputted into the part 9 through a density-detecting part 7 and a signal-processing part 8. In the part 9, the optical density is compared with a reference density, and the heating time of the thermal head 4 is set to be shorter or longer (on a continuous basis) according as the detected density is higher or lower than the reference density. The same applies to other-colored detection marks 21, 22. Accordingly, each color image 16 is controlled against the temperature variations during formation thereof.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thermal transfer printer, and more specifically, the present invention relates to a thermal transfer printer. The present invention relates to a thermal transfer printer such as a facsimile machine that performs thermal recording using a thermal head capable of obtaining high density.

[Prior art and its problems]

Conventionally, facsimile machines and other general thermal transfer printers that have a recording section that uses a thermal head consisting of a plurality of heating element dots are susceptible to environmental temperature changes, temporal temperature changes of the thermal head base material during printing, and Due to variations in the characteristics of the heat-sensitive material of the thermal transfer paper, the amount of heat-sensitive transfer material transferred onto the transfer paper changes due to heating of the heat-sensitive transfer paper by the thermal head, and as a result, the transferred image formed on the transfer paper There is a problem in that the concentration of

Conventionally, a method to solve this problem was to use the fact that the amount of heat generated by a thermal head depends on the amount of power supplied to generate heat in the thermal head and the energization time of the thermal head. Measure the temperature of the thermal head by attaching a temperature sensor such as , for example, and shorten the energization time by 10% every time the head rises by 5 degrees Celsius, or respond to the temperature signal obtained from a thermistor. The amount of heat generated by the thermal head was always controlled to be constant using a power control method that controlled the amount of power supplied to the thermal head.

However, all such control methods depend on the temperature of the thermal head base material and simply keep the amount of heat generated by the head constant, so they are completely incapable of dealing with variations in the thermal material of thermal transfer paper. However, density unevenness in the transferred recorded image on the transfer paper still occurred.

[Purpose of the invention]

The present invention was devised in view of the problems of the prior art described above, and its purpose is to provide high-quality products that are not affected by environmental temperature changes, thermal head temperature changes, variations in heat-sensitive materials, etc. It is an object of the present invention to provide a thermal transfer printer capable of obtaining transferred recorded images.

[Summary of the invention]

That is, the present invention provides a thermal transfer printer that transfers pigments or dyes from thermal transfer paper onto transfer paper using a thermal head, and includes a 4-degree detection section for detecting the optical intensity of an image transferred onto transfer paper; gg '19 The present invention is directed to a thermal transfer printer characterized by having a heat generation amount control section that controls the heat generation amount of a thermal head according to the magnitude of a signal output from a 19 degree detection section.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a schematic diagram showing the basic configuration of a thermal transfer printer of the present invention. As shown in the first diagram, the thermal transfer printer 11 of the present invention includes a gripper 12 for holding the transfer paper 2.
a rotatable platen rubber roll 1, a thermal head 4 having a heat generating part 6 on a base 5, and the heat generating part 6 being removably attached to the platen rubber roll l; Thermal transfer paper 3 is movably stretched between the head 4 and the transfer paper 2 wound around the surface of the platen rubber roll 1 by an unwinding roll 14 and a winding roll 15, and the transfer paper 2. a density detection unit 7 disposed opposite the platen rubber roll 1 to detect the optical reflection density of the transferred recorded image formed thereon; and a signal processing unit that processes signals output from the density detection unit 7. The heat generation unit 8 controls the amount of heat generated by the thermal head 4 based on the magnitude of the signal obtained from the signal processing unit 8, and also controls the heat generation units 6, which are arranged in large numbers in the axial direction of the platen rubber roll 1, in accordance with the transferred image pattern signal. It is composed of a heat generation amount control section 9 for a thermal head that selectively generates heat, and a storage section 10 in which a solid image pattern to be transferred and formed on the margin of the transfer paper 2 is stored.

The density detection section 7 is composed of light B (not shown) for irradiating the transferred recorded image formed on the transfer paper 2 and a photodiode or other photoelectric conversion element (not shown). There is. A plurality of photoelectric conversion elements having high sensitivity are provided for each color such as cyan, magenta, yellow, and black that form a transferred recorded image, or one photoelectric conversion element is provided and Alternatively, the most suitable filter may be automatically switched and set.

Next, the thermal transfer paper 3 and transfer paper 2 used in the thermal transfer printer 11 of the present invention are shown, but are not limited thereto, and other sublimable dyes are fixed on a support such as PET with a binder. Either a heat-sensitive transfer paper using a sublimation method or a heat-sensitive transfer paper using a method in which wax and pigment or dye are fixed on a support and the wax and pigment are transferred simultaneously can be used.

The ink composition for forming a thermal transfer layer having the following composition was applied to a 9 μm thick PET whose back side was heat-resistant treated at a dry weight of 1.0 g/
A thermal transfer paper was obtained by coating and drying to obtain a heat-sensitive transfer paper.

[Cyan ink]

Disperse dye KST-B-136 (manufactured by Nippon Kayaku Co., Ltd.)...4 parts by weight Ethyl hydroxyethyl cellulose (manufactured by Vercules)...6 parts by weight Methyl ethyl ketone... 45 parts by weight toluene...
・・・・・・・1 part by weight of 45 parts [Magenta ink] Disperse dye KST-Red-B (manufactured by Nippon Kayaku Co., Ltd.) ・・・・・3 parts by weight Ethyl hydroxyethyl cellulose (manufactured by Vercules Co., Ltd.) ...6 parts by weight Methyl ethyl ketone...45 parts by weight Toluene...
......45 parts by weight [yellow ink] Disperse dye PTY-52 (manufactured by Mitsubishi Kasei Corporation) ......1 part by weight Ethyl hydroxyethyl cellulose (manufactured by Vercules) ...・6 parts by weight methyl ethyl ketone 45 parts by weight toluene
...... 45 mm section Next, using 150 μm synthetic paper (Yupo FPG-150 manufactured by Tamago Yuka Co., Ltd.) as a base material, an ink composition for forming a receptor layer having the following composition was applied per inch on this surface. The coating was applied and dried in a reverse roll method using a 54-line gravure roll to obtain a transfer paper.

Polyester resin: 10 parts by weight Amino-modified silicone resin: 0.3 parts by weight Epoxy-modified silicone resin: 0.3 parts by weight Methyl ethyl ketone/toluene/cyclohexanone (weight ratio 4) : 4 : 2) ...90 parts by weight Next, the operation of the thermal transfer printer 11 of the present invention will be explained. Here, a case will be described in which a full-color image is output in three-color printing using thermal transfer paper in which cyan, magenta, and yellow color areas are sequentially formed in the longitudinal direction.

First, the transfer paper 2 is placed in the grip part 12 of the platen rubber roll 1.
Wrap the transfer paper 2 around the platen rubber roll 1 while holding the edge 15 on the gripping side.

Then, the platen rubber roll 1 rotates counterclockwise to a printing start position, and at the same time, the thermal transfer paper 3 moves rightward to a position where a predetermined first color (yellow) covers the heat generating part 6 of the thermal head 4.

Next, the thermal head 4 rises and presses the transfer paper 2 and the thermal transfer paper 3 against the platen rubber roll 1.

Then, the heat generation amount control section 9 of the thermal head causes the heat generating section 6 located at a position corresponding to the solid image pattern signal inputted from the storage section 10 to generate heat. As a result, the dye, etc. on the thermal transfer paper 3 is transferred to the transfer paper 2, and a solid yellow density detection mark 20 is formed on the grip side edge 15 of the transfer paper 2, as shown in the second diagram. .

In the second figure, arrow A is the axial direction of the platen rubber roll 1 when the transfer paper 2 is wound around the platen rubber roll 1, and arrow B is the circumferential direction of the platen rubber roll 1.

Next, the platen rubber roll l further rotates counterclockwise and when the density detection mark 20 reaches a position facing the density detection section 7, the optical reflection density of the density detection mark 20 is detected by the density detection section 7 and the signal processing The generated heat is taken into the heat generation control section 9 of the thermal head via the section 8 . Then, the calorific value control unit 9 compares the captured optical reflection density with a pre-stored reference layer density. When the optical reflection density value is larger than the reference density value, the heat generation time (current application time) of the thermal head 4 is set short, the supply IT is set large, or the supply voltage is set low, or vice versa. When the reflected density value is smaller than the reference density value, the heating time is set longer, the supply current is set higher, or the supply voltage is set higher.

Next, when an image signal is inputted by an image signal supply means (not shown), the heat generation amount control section 9 of the thermal head selects the heat generation section 6 located at the position corresponding to the image signal, and energizes the heat generation section 6 set in advance as described above. Heat is generated by time, supply current, or supply voltage, and a transferred recorded image of the first color (yellow) is formed on the transfer paper 2. Note that during the formation of the transferred recorded image, the platen rubber roll 1 sequentially rotates counterclockwise.

Similarly, the second color (magenta) and the third color (cyan)
In both cases, solid density detection marks 21 and 22 are first formed on the edge portion 15 of the transfer paper 2 on the gripping side. Thereafter, the optical reflection density of the density detection marks 21 and 22 is detected by the density detection unit 7, and based on the result of comparing the detected value and the reference density value, the amount of heat generated by the thermal head 4, that is, the energization time,
The supply current or supply voltage is set, and transfer printing is performed in accordance with the image signal input from the image signal supply means.

Through the above-described operations, density detection marks 20, 21, and 22 and a full-color image 16 are formed on the transfer paper 2 as shown in the second diagram.

In the above embodiment, once a density detection mark is transferred and formed on the edge 15 of the gripping side of the transfer paper 2 in advance, and once the heat generation amount of the thermal radar 4 is set according to the density of the mark, After that, the amount of heat generated is fixed until the transfer recording of one color is completed, but the present invention is not limited to this. For example, as shown in the third figure, the amount of heat generated is A straight line density detection mark 2 extends from the upper end of the margin section 17 (the edge section 15 on the gripping side) to the lower end.
0.21.22 is transferred and formed, and the ? of the degree detection mark is continuously pressed even while recording the image 16. ; the amount of heat generated by the thermal head 4 may be controlled continuously or intermittently according to the detected density value. In this case, since the amount of heat generated is controlled with respect to changes in the environmental temperature and changes in the temperature of the thermal head itself during the formation of each color image 16, a higher quality transferred image can be obtained. In FIG. 3, arrow A is the axial direction of the platen rubber roll 1 when the transfer paper 2 is wound around the platen rubber roll 1, and arrow B is the circumferential direction of the platen rubber roll 1.

[Effect of idea]

As described above, the thermal transfer printer of the present invention controls the amount of heat generated by the thermal head by detecting the optical reflection density of the image transferred onto the transfer paper 2. It is possible to prevent deterioration such as one-degree unevenness in the transferred image due to temperature changes in the thermal head or variations in the heat-sensitive material due to heat transfer, and it is possible to always obtain a constant high-quality image.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the basic configuration of the thermal transfer printer of the present invention, and FIGS. 2 and 3 are plan views of a transfer paper 2 on which an image has been formed using the thermal transfer printer of the present invention. 1... Platen rubber roll 2... Transfer paper 3... Thermal transfer paper 4... Thermal head 6... Heat generating part 7... ...Density detection section 8 ...Signal processing section 9 ...Heat generation control section 11 ...Thermal transfer printer 12 ...
・Gripping part 15...marginal part

Claims (1)

[Claims] In a thermal transfer printer that uses a thermal head to transfer pigments or dyes from thermal transfer paper onto transfer paper, there is a density detection section for detecting the optical density of the image transferred onto the transfer paper, and a density detection section that detects the optical density of the image transferred onto the transfer paper. A thermal transfer printer comprising: a heat generation amount control section that controls the heat generation amount of a thermal head according to the magnitude of a signal generated by the thermal transfer printer.