JPS63256474A - Printing head gap adjusting mechanism for printer - Google Patents

Abstract

PURPOSE:To eliminate the need for a paper thickness adjusting operation carried out by the user and to contrive the prevention of time loss and of a trouble due to misadjustment, by adjusting a printing head gap according to the thickness of a recording paper detected by a linear sensor. CONSTITUTION:At an initial position where a recording paper 4 is absent, a platen 8 and a printing head 5 are spaced most apart from each other. A pinch roller 23 and a paper-supporting roller 25 are in contact with each other, so that a linear sensor 21 stores this position into a controlling part as the initial position. When the paper 4 is present, a scale shaft 22 is moved in the direction of an arrow D, so that the sensor 21 outputs the moving quantity to the controlling part as a movement signal. Upon receiving the movement signal, the controlling part decodes the signal, and outputs a predetermined pulse corresponding to the thickness of the paper to a pulse motor 34. The pulse sent from the controlling part actuates the motor 34 to rotate a guide shaft 3 in the direction of an arrow G, whereby the head 5 is moved to the side of the paper 4, and is enabled to perform printing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a print head gap adjustment mechanism for a printer that is capable of automatically adjusting the gap between recording paper and a print head (hereinafter referred to as head gap).

[Prior Art] In general, dot impact printers print dots by pressing an ink ribbon against recording paper using the print wire of the print head, but in order to maintain good print quality, the interaction between the recording paper and the print head is important. It was necessary to adjust the gap to a specified gap.

Therefore, adjustment has been made by providing a gap adjustment mechanism using a lever operation or the like.

[Problems to be solved] The print head gap adjustment mechanism of the conventional printer described above requires manual adjustment such as lever operation, so the user must perform the adjustment work directly, which places a burden on the user. In addition, there were many other problems, such as a loss of time until finding an appropriate head gap and malfunctions due to adjustment errors.

[Means for Solving Problems] The present invention has been made in order to solve the above-mentioned conventional problems.As a means for solving the problems, the print head gap adjustment mechanism of the printer of the present invention is designed to A print head that performs printing; a distance 11 between the print head and the recording paper;
The apparatus is configured to include a carriage that enables adjustment, a motor that rotates the eccentric shaft to adjust the distance 1lII, and a linear sensor that detects the thickness of the recording paper and controls the rotation of the motor.

[Example] Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a print head gap adjustment mechanism according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes a carriage, and the carriage 1 moves along a pair of guide shafts 2.3 arranged in parallel in the vertical direction in directions (arrow B, Move back and forth in direction C). This carriage 1
A print head 5, a card holder 6, etc. are arranged in the printer, and an ink ribbon 9 that is fed in the moving direction of the platen 8 and the carriage 1 is arranged corresponding to the print head 5, and these constitute a printing mechanism. ing.

The print head 5 performs printing using a print wire, but since it is conventionally well known, a description thereof will be omitted.

The card holder 6 is made of transparent plastic and is disposed below the print head 5 so as to be interposed between the recording paper 4 and the ink ribbon 9. Since the opening 16 is provided in the center of the card holder 6, the print head 5 can print on the recording paper 4.

The guide shaft 3 is supported by an eccentric bearing 32 rotatably disposed on a side plate 31 to form an eccentric shaft. A driven gear 33 is disposed on the eccentric bearing 32 and meshes with a drive gear 36 fixed to an output shaft 35 of a pulse motor 34 to transmit rotation of the pulse motor 34 to the guide shaft 3. Since the guide shaft 3 rotates eccentrically by the eccentric bearing 32, the carriage 1 swings about the guide shaft 2, but the print head 5 disposed on the carriage 1 makes a substantially linear vertical movement.

The home sensor 37 detects the initial rotational position of the guide shaft 3, and the initial position is determined by a sensor plate 38 disposed on the driven gear 33. On the other hand, recording paper 4
The paper thickness is detected by a linear sensor 21 whose one end is fixed to the side plate 31. A scale shaft 22 is pivotally supported near the other end of the linear sensor 21 so as to be slidable in the vertical direction (in the direction of arrow E). A pressing roller 23 is rotatably disposed at the lower end of the scale shaft 22 and is attached to the side plate 3.
The paper receiving roller 25 is rotatably supported on a shaft 24 fixed to the paper receiving roller 25.

Next, the operation of the print head gap adjustment mechanism having such a configuration will be explained.

First, when there is no recording paper 4, the pulse motor 34 rotates in the downward direction of the arrow until the home sensor 37 detects the sensor plate 38, thereby setting the rotational position of the guide shaft 3 to the initial position. This initial position is between platen 8 and print head 5.
This is the state where they are at their maximum distance. Also, the pressing roller 23
Since the paper tray and the roller 25 are in contact with each other, the linear sensor 21 stores this position as an initial position in a control section (not shown). When the recording paper 4 is present, the recording paper 4 passes between the pressing roller 23 and the paper receiving roller 25, so that the pressing roller 42 moves in the direction indicated by the arrow by the thickness of the recording paper 4. That is, since the scale shaft 22 moves in the direction indicated by the arrow, the linear sensor 21 sends the amount of movement to the control unit as a movement signal. When the control section receives and receives this movement signal, it decodes the movement signal and sends a predetermined pulse to the pulse motor 34 corresponding to the paper thickness. Pulse motor 3
4 rotates the guide shaft 3, which is rotated in the direction of arrow G by the pulse sent from the control section, so that the print head 5 moves toward the recording paper 4 and becomes ready for printing.

[Effects of the Invention] As explained above, in the present invention, the print head gap is adjusted according to the paper thickness of the recording paper detected by the linear sensor, so that the print head gap can be automatically adjusted appropriately. Therefore, it is possible to eliminate the paper thickness adjustment operation by the user and to prevent malfunctions due to time loss or adjustment errors.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention. 1: Carriage 3: Guide shaft as an eccentric shaft 4: Recording paper 5: Print head 21: Linear sensor 32 two eccentric bearings 34: Pulse motor

Claims (1)

[Claims] A print head that prints on recording paper via an ink ribbon, and a print head that is mounted with the print head and moves back and forth in a direction perpendicular to the feeding direction of the recording paper and swings via an eccentric shaft to perform recording with the print head. A carriage capable of adjusting the distance between sheets, a motor rotating the eccentric shaft to adjust the distance, and a linear sensor detecting the thickness of the recording sheet and controlling the rotation of the motor. Features printer print head gap adjustment mechanism.