JPS58168382A - Printing device - Google Patents

Abstract

PURPOSE:To print out variable density signals such as TV video signals with variable density, by variablly controlling the heating variable of a heat-sensitive head in accordance with the density. CONSTITUTION:An analog video signal from a device 20 is stored in a data storage device 22 through an A/D converter 21. Data from the data storage device 22 are sent to a data comparator 25 in a variable density data generating device 23 and compared with an output from a data counter 26. An output from the comparator 25 is sent to a shift register circuit 27 and the output of the shift register circuit 27 is applied to transistors TR1-TRn controlling power supply to the resistors R1-Rn of the heat-sensitive head through gates G1-Gn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing device, and in a thermal transfer printing device, by having a configuration in which the amount of heating of a thermal head can be variably controlled according to the density, it is possible to print, for example, a TV video signal. It is an object of the present invention to provide a printing device capable of printing signals with shading in shading.

The principle of a thermal transfer printing device is shown in Figure 1 a+b.
As shown in FIG. 2, the recording paper 1 and the transfer paper 2 are brought into close contact with each other and are fed between the pressure roller 3 and the thermal head 4, and a current is applied to each resistor R, FL2, . . . , Rn of the thermal head 4. When the transfer paper 2 is heated, the hot-melt ink 2' applied to the transfer paper 2 is melted, and the hot-melt ink 2' is attached to the recording paper l, and the recording paper printed in this way is The paper is cut into a suitable shape to become a printed matter, and the unnecessary transfer paper passes through a guide roller 5 and is wound up on a winding roller 6 for disposal.

Resistances R, ·L, · of the thermal head 4 of such a printing device
・To control the current for +Rn, first send the respective data corresponding to the resistances R, , R, . After that, each data is individually extracted and sent to the latch circuit 8, and then a data transfer pulse is applied to the latch circuit 8 to connect each gate G,, G',
, . . . + G n, the data of the thermal head is sent all at once, and a heating pulse is sent to each gate, G,, G,,
・At the same time from +On, driver transistor T
R1I TR” +...+TRn Sends a signal especially according to the data, and each resistor R,, R, 2,...+ R of the thermal head
The printer is configured to generate heat from the thermal head by adjusting the current to the current level, but in printing devices with such control systems, the control circuit is composed of digital elements, and the heating time by the thermal head is always constant. Even for video signals that require a certain degree of shading for a certain period of time T or zero, there is a drawback that intermediate shading cannot be expressed.

The present invention eliminates the above-mentioned drawbacks, and examples thereof will be described below.

FIG. 3 is a block diagram for explaining the control circuit of the printing apparatus according to the present invention, and FIG. 4 is a diagram for explaining the operation.

That is, an analog video signal obtained from a device 2o such as a TV camera or VTII (, etc.) is converted into a digital signal by a width conversion device 21, and this digital signal is sent to a data storage device 22 such as a semiconductor memory, and then Addresses for the required number of pixels are determined and stored.

Then, when a start pulse is added to the address counter 24 of the grayscale data creation device 23 and a reference clock is sent to the address counter 24, the grayscale data creation device 23 starts operating, and the address counter 24 first receives the first address as the data. Data corresponding to the address is sent to the storage device 22, and data corresponding to the address is sent back from the data storage device 22, and this sent back data is sent to the data comparison circuit 25 of the grayscale data creation device 23. At this time, the count of the data counter 26 of the gradation data creation device 23 is set to 1,
A data comparison circuit 25 compares the data sent back from the data storage device 22 and the data from the data counter 26.
If the data from the data storage device 22 is equal to or larger than the data 1 from the data counter 26, a signal of 1 is sent to the shift register circuit 27, and if it is smaller, a signal of 0 is sent to the shift register circuit 27. Then, the address counter 24 measures the resistance R1°R2, . . . of the thermal head.
, Rn is counted, one data transfer pulse is sent to the launch circuit 28. Also, at the same time as sending the first data transfer pulse, the heating pulse is gated G, ,
G,...r Send to G n.

Thereafter, in the same manner, each time the address counter 24 finishes counting n, the count of the data counter 26 is increased by one, and if the maximum color density is m, the address counter 24 counts n m times. The data comparison circuit 25 compares the number of data counters 26 and the data of each address sent back from the data storage device 22 each time, and the data of the address is
If the number is greater than or equal to the number, a signal of 1 is sent to the shift register circuit 27, and if it is smaller, a signal of 0 is sent to the shift register circuit 27. Then, when the address counter 24 has finished counting the total number n of the resistances R1+R2, . . .
8, and at the same time send a heating pulse to gates G, , G2
Send to ゜+Gn. In this way, address counter 2
If the data of 4 is the maximum concentration m, a pulse current is continuously passed through the resistance of the thermal head for the maximum heating time T, and the maximum concentration is obtained.

In this way, a pulse current proportional to - flows continuously through the resistances of the thermal head R2, . You will be able to do this.

That is, if the number of address counters is 2, for example, as shown in FIG. 4a, the heating time of the resistor of the thermal head is 2. For example, if the number of address counters is m, as shown in Figure 4C, then the heating time of the resistor of the thermal head is T, as shown in Figure 4D, and depending on this heating time, The hot-melt ink on the transfer paper is melted, and shading printing is performed on the recording paper.

Such a gradation display printing device can be made extremely easily and at low cost because the gradation data necessary for printing can be constructed using only digital elements. or R
If comparison data is written in OM10 in advance and the data is given as an address, the configuration is simple, and the printing time is short because it only takes the time required for maximum density.

As described above, the printing apparatus according to the present invention stacks and feeds transfer paper coated with hot-melt ink and recording paper between a thermal head and a pressure roller, and heats the thermal head to transfer the transfer paper. By attaching heat-melting ink to the recording paper, it is possible to perform shading recording by controlling the thermal head so that heating control is performed continuously within a range that does not exceed the printing thermal transfer direction. It has the advantage of being able to print a grayscale image such as a TV video signal in a grayscale display, requiring only a short printing time, and being low cost.

[Brief explanation of the drawing]

1A and 1B are explanatory diagrams of the illumination of thermal transfer printing, FIG. 2 is an explanatory diagram of the control circuit block of conventional thermal transfer printing, and FIG. 3 is a diagram of the control circuit for thermal transfer printing according to the present invention. The control circuit block diagram and FIGS. 4a to 4d are diagrams for explaining the operation. 21...A/D conversion device, 22...data storage device,
23... Grayscale data creation device, 27... Shift register circuit, 28 - Latch circuit, G, , G2.・r G
n...Gate, pasting, R2,..., Rn...Resistance of the thermal head. Patent Applicant: Victor Japan Co., Ltd. Agent Katsumi Utaka 1 Figure (a) 47? Figure 2

Claims (1)

[Claims] ■ Transfer paper coated with heat-melting ink and recording paper are stacked and fed between a thermal head and a pressure roller, and the heat-sensitive head is heated to ink the heat-meltable ink on the transfer paper. In a thermal transfer printing device that prints by adhering it to recording paper, it is possible to record shading by controlling the thermal head so that heating is controlled continuously within a range that does not exceed the heating time required for maximum density. A printing device characterized in that it is configured to ■ In the printing apparatus according to claim 1, an analog signal with shading is converted into a digital signal by A/D conversion, and this digital signal is stored by aligning the position of the pixel of the analog signal with the position of the thermal head. The stored data is read out in accordance with the position of the thermal head, the number of readings is compared with the data at the position of the thermal head, and the relationship between the number of readings and the data at the position of the thermal head is determined based on a predetermined relationship. It converts based on the relationship, and based on this conversion, current is passed through the thermal head for a time depending on the density to heat it.