JPS63153164A - Serial thermal printer - Google Patents

Abstract

PURPOSE:To realize bilateral recording with sufficient recording density, by adjusting and holding the angle of thermal head such that the center of pressing of a scanning thermal head facing with the surface of a recording medium matches with the center of heating face of heating element in the thermal head. CONSTITUTION:A thermal carrier 2 causes scanning of a thermal head 1 with the angle thereof with respect to recording medium 12 being adjusted and held at the adjusted level. A solenoid 7 is excited to push up A thermal head supporting base 3 by means of a plunger 8 so as to press the thermal head 1 against a pressure disc 11 or the recording medium 12. Than the thermal head supporting base 3 is rotated by a rotary motor 6 through a rotary shaft supporting board 5 And a base rotary shaft 4 by an angle theta1 around the base rotary shaft 4 or it is reset so as to enable shifting of the central heating point of a heating element 13 by the amount of l/2theta in the scanning direction when the thermal head 1 rotates in any one scanning direction of S1 or S2. Consequently, the center of the heating element can be matched with the center of pressing of the thermal head against the pressure disc regardless of the scanning direction of thermal head, resulting in bilateral recording having sufficient recording density.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a serial type thermal printer that prints by scanning a thermal head in the recording line direction of a recording medium, and particularly relates to a serial type thermal printer that can print in both directions. .

[Conventional technology]

FIG. 4 shows a part of a cross section of a thermal head 41, a platen 11, and a recording paper 1 of a conventional example of this type of thermal printer.
2 is an explanatory diagram showing the positional relationship with No. 2.

The thermal head 41 includes, on an alumina substrate 42, a glaze layer 431, a heating resistor layer 44, a conductor layer 45 for forming wiring and electrodes. #A wear protection layer 46 is configured, and printing is performed by pressing the recording paper 12 against a large or flat platen 11. In the case of a thermal transfer type, an ink ribbon is further sandwiched between the recording paper 12 and the head 41.

(Problems to be Solved by the Invention) The conventional thermal printer described above is set so that the center of the heating resistor coincides with the center C of the contact surface between the platen or recording paper and the thermal plate when stationary. When such a thermal head is scanned in the direction of the recording line and recorded, the center of compression of the thermal head against the platen is shifted in the scanning direction of the recording line with respect to the center C of the contact surface, so that sufficient recording cannot be achieved. Since the density cannot be obtained, a method is used in which the center of one heating resistor is shifted in the scanning direction of the recording line with respect to the center C of the contact surface between the platen and the thermal head when they are stationary.

That is, as shown in FIG.
Either shift the center of the heating resistor 1 in the scanning direction of the recording line (usually about 50 to 100 μs), or move the thermal head 61 at an angle θ with respect to a plane parallel to the pressure ill, as shown in FIG. A method of installing the device at an angle (usually the angle θ is about 2 to 3 degrees) is used, but with these methods, the scanning direction of the recording line is limited to one direction, making it impossible to record in both directions for the purpose of high-speed recording. It has the disadvantage of being.

[Means for solving problems]

In the serial type thermal printer of the present invention, the pressure center of the thermal head during scanning on the surface of the recording medium is aligned with the center of the heating surface of the heating resistor of the thermal head.
It has head angle setting means for adjusting and maintaining the angle of the thermal head surface with respect to the recording medium surface.

[Effect]

Therefore, the center of pressure of the thermal head against the recording medium and the center of the heat generating surface of the heat generating resistor can be made to coincide with each other, not only in one scanning direction but also in any direction, so that sufficient recording density can be obtained in both directions. Records can be achieved.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory diagram showing a schematic configuration of a thermal head 1 included in an embodiment of a serial type thermal printer of the present invention, and a head carrier 2 that supports the thermal head 1 and adjusts and holds the angle of the thermal head 1 with respect to a platen 11. , Figure 2 (a
) and (b) are diagrams showing the contact positional relationship between the heating resistor 13 and the recording medium 12 in the embodiment of FIG. 1.

The head carrier 2 is a device for scanning the thermal head 1 while adjusting and maintaining the angle with respect to the platen 11 or the recording medium 12, and is composed of the following components. That is,
The thermal head support base 3 has the thermal head 1 placed thereon, and one end thereof is rotatably attached to the rotary shaft support plate 5 via the base rotary shaft 4, and when the solenoid 7 of the electromagnetic valve is energized. The zero-rotation shaft support plate 5, which is pushed up by the plunger 8 against the tensile force of the spring 9 and presses the thermal head 1 against the recording medium 12, is rotated by a rotary motor 6, and the thermal By giving the head support base 3 eccentric rotational motion in both directions, the angle of the thermal head support base 3 with respect to the platen 11 or the recording medium 12 can be arbitrarily set. The head carrier 2 is towed by a carrier moving bell (10) and can scan recording lines in both directions. The thermal head 1 has the same configuration as that described in the conventional example, but in FIG. 2(a), printing is performed while the thermal head 1 is scanned in the scanning direction S of the printing line from left to right. FIG. 2(b) shows the case where the scanning direction S2 is the opposite direction, and the angle formed between the thermal head l and the surface of the recording medium 12 is 03 when the scanning direction S1 is, and 03 when the scanning direction S2 is the opposite direction.
When , it is set as O. The angle θ1 is the rotation angle of the thermal head support base 3 around the base rotation axis 4, and at the same time, this angle θ1 is equal to the arc angle of the heating resistor 13 as shown in FIG. Resistor! 3 is the arc angle θ from the glaze apex (point C2)! shall be installed over the range of In this way, in any scanning direction, the center of the heating resistor 13 is on the scanning direction side with respect to the center of contact between the thermal head 1 and the platen 11 or the surface of the recording medium 12 (when stationary) C+, C2. It is possible to set it so that it is shifted by Kakumugi θ. That is, in FIGS. 2(a) and 2(b), the heating resistor 1
In this embodiment, the solenoid 7 is energized, the plunger 8 pushes up the thermal head support base 3, and the thermal head 1 is moved onto the platen 11 or While pressing against the recording medium 12, the thermal head support base 3 is rotated by an angle θ1 around the base rotation shaft 4 via the rotation shaft support plate 5 and the base rotation shaft 4 by the rotary motor 6, or returned to its original position. Therefore, regardless of whether the thermal head l is in the scanning direction S or S2, the center point of the heat generation of the heat generating resistor 13 can be shifted by 01 in the scanning direction.

Next, another embodiment of the present invention will be described.

FIG. 3(a) Vertical or edge type thermal head 31
FIG. 3(b) is an explanatory diagram showing the contact position situation during scanning in the scanning direction S1 from left to right of the head 31.
) is an explanatory diagram showing a similar situation during scanning in the opposite direction S2.8 The heating resistor center C3 of the thermal head 31 in this embodiment is set at the apex of the glaze, but the head carrier 2 similar to the previous embodiment In the scanning direction, the thermal head 31 is tilted by 01 in the scanning direction Sl, and by θ2 (=-01) in the scanning direction S2.

〔Effect of the invention〕

As explained above, the present invention adjusts the angle of the thermal head surface with respect to the recording medium surface so that the center of pressure of the thermal head during scanning on the recording medium surface coincides with the center of the heating surface of the heating resistor of the thermal head. By having a head angle setting means for holding the recording head, the center of the heating element can be aligned with the center of pressure of the thermal head against the platen in any scanning direction, thereby realizing bidirectional recording with sufficient recording density. It has the effect of being able to

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a schematic configuration of a thermal head l and a head carrier 2 that supports the thermal head l of an embodiment of the serial type thermal printer of the present invention, and FIG. 2(a),
(b) is a diagram showing the contact positional relationship between the heating resistor 13 and the recording medium 12 in the embodiment of FIG. 1, and FIG. 3(a),
(b) is a diagram showing the same situation as in FIGS. 2(a) and (b) during scanning of the thermal head 31 of another embodiment, and FIGS. 4 to 6 are recordings of the thermal head in the conventional example. 3 is a diagram showing a contact positional relationship with respect to a medium 12. FIG. 1.31... Thermal head, 2... Head carrier, 3... Thermal head support base, 4... Base rotating shaft, 5... Rotating shaft support plate,
6... Rotating motor, 7... Renoid,
8...Plunger, 9...Spring,
10... Carrier moving belt, 11... Press plate, 12
...Recording medium, 13...Heating resistor, S, , S
2...Scanning direction, Cs r C2,... Contact center. C3...Center of heating resistor, θhθ2...Setting angle. Fig. 2 (a) (b) Fig. 3 (Yokikata ■ Fig. 5 Running 10,000 m Fig. 6

Claims (1)

[Scope of Claims] In a serial type thermal printer that records by scanning a thermal head in the recording line direction of a recording medium, the center of pressure of the thermal head during scanning on the surface of the recording medium and the center of the heating surface of the heating resistor of the thermal head 1. A serial type thermal printer comprising a head angle setting means for adjusting and maintaining the angle of a thermal head surface with respect to a recording medium surface so that the angle of the thermal head surface coincides with that of the recording medium surface.