JPH01130965A - Automatic paper thickness control device - Google Patents

Abstract

PURPOSE:To enable correct position adjustment of a printing head by enlarging the deflection value of a head position detecting rod under the pressure of the printing head upon a platen by using an enlargement mechanism, and detecting the position of the printing head after enlargement to determine the position of the printing head. CONSTITUTION:A printing head position detecting rod 2 is installed on a shaft 6, and therefore, it deflects to a shaft 6 twisting direction through the contact of the printing head with a platen 3. When an eccentric rod 5 coupled with a drive motor is turned clockwise, the printing head 1 is so designed as to approach the platen 3. Immediately before the printing head 1 hits the platen 3, the head position detecting rod 2 touches the platen 3. Nevertheless, the eccentric rod 5 continues to rotate, resulting in the deflection of the head position detecting rod 2 to a twisting direction. Then the tip of a deflection enlarging rod 7 moves to the enlargement value of a deflection at the tip of the head position detecting rod 2 to m/l. This movement is detected by the position detecting element 4, so that a position where the printing head 1 hits the platen 3 can be detected to the enlargement precision of X l/m. Consequently, the positions of the printing head and the platen can be determined precisely, and adjusted with high accuracy.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an automatic paper thickness control device, and more particularly to an automatic paper thickness control device that automatically adjusts the distance between the platen of a printing device and a print head to an optimum value. .

[Prior Art] Conventionally, the automatic paper thickness control device in this type of printing device presses the print head against the platen with the force of a spring, and then moves the print head back by a certain amount based on the position of the print head. The distance between the platen and the print head was ensured.

[Problems to be Solved by the Invention] In the conventional automatic paper thickness control device described above, the print head hits the platen using the force of a spring, and the adjustment is made using that position as a reference. The disadvantage is that the viscous resistance of the mechanical part changes depending on the change, so the speed of the print head when it collides with the platen varies, and as a result, the amount of deflection of the platen changes, causing the position of the print head to vary when it collides with the platen. there were. This means that the distance between the platen and the print head will vary as the temperature changes.

[Means for Solving the Problems] The present invention was made to solve the above-mentioned conventional problems.As a means for solving the problems, the present invention automatically sets the distance between the platen and the print head to an optimum value In an automatic paper thickness control device for a printing device that is adjusted to The deflection amount of the head position detecting rod due to the pressing of the print head against the platen is magnified by an enlarging mechanism, and the expanded position is detected by a position detecting element to determine the position of the print head.

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

FIG. 1 is a side view of an automatic paper thickness control device according to an embodiment of the present invention.

The automatic paper thickness control device of this embodiment automatically controls the distance between the platen 3 and the print head 1 to an optimum value, and the print head 1 is mounted on a carriage 8. The carriage 8 is rotatably supported by a shaft 9 on the platen 3 side, and engaged with the eccentric rod 5 on the opposite side. The eccentric rod 5 is rotated eccentrically by a drive motor (not shown) to rotate the carriage 8 up and down about a shaft 9. The print head 1 moves its tip to the platen 3 as the carriage 8 rotates up and down.
It is designed so that it comes into contact with the

The distance between the print head 3 and the platen 1 is adjusted using a head position detecting rod 2, a deflection enlarging frame 7 as an enlarging mechanism, a position detecting element 4, and the like. The head position detection rod 2 has its tip protruding slightly in front of the tip of the print head 1. In addition, this head position detection rod 2
is attached to the shaft 6, and is bent in the direction of twisting the shaft 6 when the print head 1 comes into contact with the platen 3.

The deflection magnifying frame 7 is configured to magnify the deflection of the head position detection rod 2 and transmit it to the position detection element 4.

The position detection element 4 detects the deflection after enlargement to detect and adjust the position of the print head 1.

When the eccentric rod 5 connected to the drive motor is rotated clockwise, the print head 1 approaches the platen 3. Just before the print head 1 hits the platen 3, the head position detection rod 2 hits the platen 3. Even when the head position detecting rod 2 hits the platen 3, the eccentric rod 5 continues to rotate, and the head position detecting rod 2 deflects the shaft 6 in the twisting direction.

Then, the tip of the deflection magnifying frame 7 moves with the deflection of the tip of the head position detecting rod 2 magnified to m/Il (here, the length of the head position detecting rod 2 is 1, and the length of the deflection magnifying frame 7 is ). The movement of the tip of the deflection magnifying frame 7 is detected by a position detection element 4 such as a photo sensor, and the print head 1 is
It is possible to detect the position where the platen 3 hits the platen 3 by multiplying by 11/m.

[Effects of the Invention] As explained above, the automatic paper thickness control device of the present invention uses an enlarging mechanism to enlarge the amount of deflection of the head position detection rod caused by pressing the print head against the platen, and uses a position detection element to detect the enlarged position. Since the position of the print head is determined by detection, it is possible to accurately determine the position of the print head and the distance between the platen by slowly pressing the head position detection rod against the platen and magnifying the deflection to detect it. I can do it,
Accurate position adjustments can be made at any time.

[Brief explanation of the drawing]

FIG. 1 is a side view of an automatic paper thickness control device according to an embodiment of the present invention. 1: Print head 2: Head position detection rod 3: Platen 4: Position detection element 5: Eccentric rod 6: Axis 7: Deflection magnification frame

Claims (1)

[Claims] In an automatic paper thickness control device for a printing device that automatically adjusts the distance between the platen and the print head to the optimum value, the print head can be brought into contact with the platen by motor drive, and A head position detection rod is provided slightly forward, and the amount of deflection of the head position detection rod caused by the printing head being pressed against the platen is magnified by an enlarging mechanism, and the expanded position is detected by a position detection element to detect the position of the print head. An automatic paper thickness control device characterized by determining a position.