JPH085200B2 - Thermal recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal recording apparatus for recording desired images or characters on recording paper according to an electric signal applied to a thermal recording head.

2. Description of the Related Art In recent years, thermal recording devices have been used in printers, digital copiers,
Although it is used in facsimiles and the like, clear recording cannot be performed unless dedicated recording paper is used. Therefore, a thermal recording device has been devised which can perform clear recording on plain paper without using a dedicated recording paper.

An example of the above-described conventional thermal recording device will be described below with reference to the drawings.

FIG. 2 shows a block diagram of a conventional thermal recording apparatus. In FIG. 2, reference numeral 1 is a transfer drum, on the surface of which a transfer layer 12 made of a flexible material is formed.
A thermal head 2 faces the transfer drum 1 via the ink sheet 3. The thermal head 2 and the ink sheet 3 are normally separated from the transfer drum 1, but are pressed against the transfer drum 1 when recording. A heater 4 is energized and controlled by a thermistor 5 and a temperature control circuit 6 provided in contact with the surface of the transfer layer 12 to heat and keep the surface of the transfer layer 12 at a predetermined temperature.
A recording sheet 7 is conveyed between the pressure roller 8 and the transfer drum 1. A cleaning device 9 is provided in contact with the transfer layer 12. The operation of the heat-sensitive recording apparatus having the above structure will be described below.

First, when a recording command is input, the thermal head 2 is pressed against the transfer drum 1 via the ink sheet 3. The thermal head 2 melts the ink applied on the ink sheet 3 according to the recording signal, and the ink image 31 is formed on the surface of the transfer layer 12.
To form. The ink image 31 is moved in the direction of the arrow and transferred onto the recording paper 7 between the pressure contact roller 8 and the transfer drum 1. At this time, the transfer layer 12 formed on the surface of the transfer drum 1
Since the ink image 31 has flexibility, the ink image 31 is faithfully transferred to the paper surface of the recording paper 7 so that clear recording can be performed. The transfer layer is not transferred to the recording paper 7.
The ink image 31 remaining on the surface of 12 is removed from the transfer layer 12 by the cleaning device 9 (for example, JP-A-62-248669).

However, in the above-described configuration, when the temperature of the recording sheet 7 is lowered, the ink image 31 is not sufficiently transferred to the recording sheet 7 and a transfer failure occurs, or when the type of the ink sheet 3 is different, the recording is performed. Since the energy required for printing differs, there is a problem in that the printing quality deteriorates, such as variations in printing density.

In view of the above problems, the present invention provides a heat-sensitive recording apparatus capable of high-quality recording without transfer failure or print density fluctuation.

Means for Solving the Problems In order to solve the above problems, the thermal recording apparatus of the present invention is provided with a structure for controlling the temperature of the transfer drum surface according to the temperature of the recording paper and the type of the ink sheet.

Effect The present invention can correct the recording state by referring to the temperature of the recording sheet and the type of the ink sheet with the above-described configuration, and thus high-quality recording without transfer failure or print density fluctuation can be performed.

EXAMPLE A thermal recording apparatus according to an example of the present invention will be described below with reference to the drawings.

FIG. 1 shows a block diagram of a thermal recording apparatus in an embodiment of the present invention. In FIG. 1, a transfer drum 1 has a silicone rubber layer 12 formed on the outer circumference of an aluminum tube 13. 2 is a thermal head and a transfer drum 1
Having a large number of heating element rows 21 arranged in the width direction of
It faces the transfer drum 1 via the ink sheet 3.
The thermal head 2 and the ink sheet 3 are normally separated from the transfer drum 1, but are pressed against the transfer drum 1 when recording. Also, the ink sheet 3 is stored in the ink cassette 32 for easy replacement,
A detection port 33 for determining the type of the ink sheet 3 is provided. The ink sensor 34 is provided so as to face the detection port 33. A heater 4 is energized and controlled by the temperature control circuit 6 to keep the surface of the silicone rubber layer 12 heated. A thermistor 5 is provided in contact with the surface of the silicone rubber layer 12. 7 is a recording sheet, and a pressure roller 8
And the transfer drum 1. A cleaning device 9 is provided in contact with the silicone rubber layer 12. A thermistor 101 is provided so as to contact the recording paper 7. A thermistor 102 is provided inside the device and detects the environmental temperature inside the device.

The operation of the thermal recording apparatus configured as described above will be described below with reference to FIG. First, the recording operation will be described.

When the recording command is input, the thermal head 2 is pressed against the transfer drum 1 via the ink sheet 3. The thermal head 2 melts the ink applied on the ink sheet 3 by energizing the heating element 21 according to the recording signal,
An ink image 31 is formed on the surface of the silicone rubber layer 12. When the formation of the ink image 31 is completed, the thermal head 2 is separated from the transfer drum 1. The ink image 31 is moved in the direction of the arrow, and the recording paper 7 is moved between the pressure roller 8 and the transfer drum 1.
Is transferred to At this time, since the silicone rubber layer 12 formed on the surface of the transfer drum 1 has flexibility, the ink image 31 is faithfully transferred along the surface of the recording paper 7, so that clear recording should be performed. You can Recording paper 7
The ink image 31 not transferred onto the surface of the silicone rubber layer 12 and remaining on the surface of the silicone rubber layer 12 is removed from the silicone rubber layer 12 by the cleaning device 9.

Next, a method of controlling the temperature of the surface of the silicone rubber layer 12 will be described.

In this thermal recording device, the surface of the silicone rubber layer 12 is constantly heated and kept at about 60 to 70 ° C., and the temperature in the device gradually rises until it reaches a certain temperature. As a result, the temperatures of the thermal head 2 and the ink sheet 3 rise, and the print density fluctuates. Therefore, it is necessary to suppress the print density fluctuation by adjusting the recording energy. Therefore, the temperature inside the device (hereinafter referred to as the environmental temperature) is detected by the thermistor 102.

Further, since the recording paper 7 is normally fed from the outside of the apparatus by manual feeding or a cut sheet feeder, the temperature of the recording paper 7 does not match the environmental temperature, and when the temperature of the recording paper 7 is low, the silicone is used. The ink image 31 on the surface of the rubber layer 12 is not sufficiently transferred to the recording paper 7, causing a transfer failure. Therefore, it is necessary to adjust the temperature of the ink image 31 during transfer. Therefore, the temperature of the recording paper 7 is detected by the thermistor 101.

The ink sheet 3 is a single color ink sheet which is usually composed only of black ink, a color ink sheet which is composed of three colors of yellow, magenta and cyan, or four colors of ink in which black is added, and a multi-time ink sheet which can be used many times. There are types such as ink sheets, and in order to perform good recording when using each ink sheet, it is necessary to adjust the recording energy according to the ink sheet used. Therefore, the ink cassette 32 is provided with a detection port 33 for determining the type of the ink sheet 3, and the ink sensor 34 refers to the detection port 33 to determine the type of the ink sheet 3.

The ink image during transfer 31
As a means for adjusting the temperature and adjusting the recording energy, a means for controlling the temperature of the surface of the silicone rubber layer 12 is used to correct the recording state. Specifically, the temperature control circuit 6 refers to the outputs of the thermistors 101 and 102 and the ink sensor 34, for example, to refer to a temperature table prepared in advance, and to correct the recording state of the silicone rubber layer.
The temperature of the surface of the silicone rubber 12 is determined, and the temperature of the surface of the silicone rubber layer 12 is referred to by the thermistor 5, and the energization of the heater 4 is controlled so as to be equal to the temperature of the previously determined temperature. Adjust the temperature of the surface of layer 12.

As described above, according to the present embodiment, the temperature of the recording paper 7,
By providing means for detecting the environmental temperature and the type of the ink sheet 3 and controlling the temperature of the surface of the silicone rubber layer 12, it is possible to correct the recording state and perform high-quality recording without transfer defects or density fluctuations. .

Although the ink cassette 32 is provided with the detection opening 33 as a means for discriminating the type of the ink sheet 3 in the embodiment, a reflection tape is provided in the ink cassette 32, a detection mark is formed on the ink sheet 3 itself, or The type of the ink sheet 3 may be determined by providing a changeover switch and manually changing over the switch.

Further, although the thermal head 2 and the ink sheet 3 are used as the means for forming the ink image 31 on the surface of the silicone rubber layer 12, an energized recording head and an energized recording sheet may be used.

Further, the cleaning device 9 is a means for removing the ink image 31 remaining on the silicone rubber layer 12 after transferring the ink image 31 to the recording paper 7, but a means for removing the ink image 31 by reattaching it to the ink sheet 3 is used. You may use.

As described above, the present invention corrects the recording state by detecting the temperature of the recording paper, the environmental temperature, the type of the ink sheet, and controlling the temperature of the surface of the transfer drum, and the temperature of the recording paper is corrected. It is possible to perform high-quality recording without transfer defects or density fluctuations, regardless of the environmental temperature and the type of ink sheet.

[Brief description of drawings]

FIG. 1 is a block diagram of a thermal recording apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional thermal recording apparatus. 1 ... Transfer drum, 2 ... Thermal head, 3 ... Ink sheet, 32 ... Ink cassette, 33 ... Detection port, 34 ...
... Ink sensor, 4 ... Heater, 6 ... Temperature control circuit, 7 ... Recording paper, 8 ... Pressure contact roller, 5, 101, 102
...... Thermistor.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Ikeda 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Reference JP-A-61-272174 (JP, A) JP-A-3-227254 (JP, A) JP 62-248669 (JP, A) JP 63-89359 (JP, A) JP 2-200456 (JP, A)

Claims (2)

[Claims] 1. An intermediate transfer medium, a heater for heating the intermediate transfer medium, a thermal recording head pressed against the intermediate transfer medium via an ink sheet, and a thermal recording head pressed against the intermediate transfer medium via a recording sheet. Pressure contact roller, temperature detecting means A for detecting the temperature of the recording sheet, temperature detecting means B for detecting the temperature of the surface of the intermediate transfer medium, and heat retention of the surface of the intermediate transfer medium by the output of the temperature detecting means A. A thermosensitive recording apparatus comprising: a temperature control unit that determines the temperature and controls the heater so that the temperature detected by the temperature detection unit B becomes equal to the heat retention temperature. 2. An intermediate transfer medium, a heater for heating the intermediate transfer medium, a thermal recording head pressed against the intermediate transfer medium via an ink sheet, and a thermal recording head pressed against the intermediate transfer medium via a recording sheet. Pressure contact roller, type detection means for detecting the type of the ink sheet, temperature detection means for detecting the temperature of the surface of the intermediate transfer medium, and the temperature of the intermediate transfer medium surface is determined by the output of the type detection means. And a temperature control means for controlling the heater so that the temperature detected by the temperature detection means becomes equal to the heat retention temperature.