JPH0692187B2 - Stamper with pressing force adjustment function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of use) The present invention relates to a stamper that presses a stamp portion against a recording sheet to perform printing, and more specifically, a function of optimally adjusting the force for pressing the stamp portion against the recording sheet. It relates to a stamper equipped with.

(Prior Art) For example, as a stamper (printing device) for printing a date, a company seal, etc. on a copy made by a copying machine, a swing member that holds a stamp portion and is swingably supported, and a recording sheet have been conventionally used. It is known that an opposing member is disposed so as to face the stamp portion with the stamp member interposed therebetween, and an urging means that urges the swinging member in a direction in which the opposing member presses the stamp portion. ing. In this type of stamper, generally, a cam plate rotated by a motor causes the swing member to swing, thereby performing printing. That is, the cam plate sets the swinging member to a standby position where the stamp portion is separated from the facing member when no print instruction is given, and when the print instruction is given, the swing member is rotated by a predetermined amount and separated from the swing member. As a result, the swinging member swings by the biasing force of the biasing means, and the stamp portion presses the facing member via the recording sheet to print on the sheet.

In the stamper having the above structure, it is essential to set the pressing force of the stamp portion to the facing member (that is, the pressing force to the recording sheet) to an optimum value in order to perform clear printing. Recently, there is also provided a stamper in which the stamp portion is composed of a thermal head, and the thermal head is pressed against a recording sheet via an ink donor sheet. It is desirable to set. For that purpose, it is necessary to optimally set the timing at which the cam separates from the swing member and the timing at which the cam stops. That is, if the cam continues to rotate even after the cam is separated from the rocking member, the rocking of the rocking member is obstructed by the cam. No urging force is applied, and in either case, printing failure occurs.

Therefore, conventionally, the position sensor detects that the swinging member is at the standby position so that the swinging member accurately waits at this position, and when a print instruction is given, the motor is rotated by a predetermined rotation angle. When the cam is rotated, the timing at which the cam separates from the swing member and the timing at which the cam stops are strictly defined.

(Problems to be solved by the invention) However, the above-mentioned position sensor has individual component tolerance variations, and it is extremely difficult to mount it at a predetermined position with high accuracy. Also, from the viewpoint of the torque load of the motor, after the stamper is assembled, It was necessary to strictly adjust the mounting position of the position sensor and the mounting angle of the cam, and the work was very troublesome.

Therefore, an object of the present invention is to provide a stamper capable of adjusting the pressing force of the stamp portion on the recording paper without requiring such troublesome work.

(Means and Actions for Solving Problems) A stamper having a pressing force adjusting function of the present invention includes a swing member holding a stamp portion as described above, an opposing member,
In the stamper including the urging means, the cam and the position sensor, a stepping motor is used as a motor for driving the cam, and the stepping motor detects a detection signal from the position sensor indicating that the swing member is in the standby position. A control circuit for receiving the signal stops the rotation when the signal is input, and rotates a predetermined number of steps when a print instruction is issued. Is characterized in that it can be changed arbitrarily.

(Examples) Hereinafter, the present invention will be described in detail based on examples shown in the drawings.

1 and 2 show a stamper having a pressing force adjusting function according to an embodiment of the present invention. As shown in FIG. 2, the recording sheet 10 is conveyed between the sheet guides 11 by the sheet conveying rollers 12 from the left side to the right side in the figure. An opening 13 is formed in a part of the paper guide 11, and an opposed roller 14 is provided therein. This opposing roller 14
Is arranged at a right angle to the paper conveyance direction, and the recording paper 10 being conveyed moves on the facing roller 14. The opposing roller
A paper detection sensor 15 that detects passage of the recording paper 10 is provided on the upstream side of the paper conveyance direction. The paper detection sensor 15 is composed of, for example, a known photoelectric sensor or the like, and the paper detection signal S1 generated by the sensor 15 is used.
Is input to the control circuit 16 described in detail later.

On the upper side of the opposed roller 14, a swing member 18 is disposed which is swingably supported around a swing shaft 17. The swing member 18 is biased by a coil spring 19 in the direction of arrow A in FIG. Further, a thermal head 20 as a stamp portion is fixed to one end of the swinging member 18, and the thermal head 20 is a roller facing the roller when the swinging member 18 swings in the direction of arrow A by the urging force of the spring 19. Pressed to 14. The thermal head 20 and the opposing roller 14
An ink donor sheet 21 is stretched between and by a known mechanism. In the vicinity of the other end of the swinging member 18, a cam 22 having a shape in which a part of the disc is cut out is slidably contacted. This cam 22 receives a drive control signal from the control circuit 16.
It is rotated by the stepping motor 23 that receives S2.
A detection end 24 is fixed to the swing member 18 near the swing shaft 17, and this detection end 24 is detected by, for example, a photoelectric position sensor 25. The detection signal S3 of the position sensor 25 is input to the control circuit 16. Further, to the control circuit 16, a step number change instruction signal S4 is input from the motor rotation angle setting switch 26, and a print instruction signal S5 is input from the print mode setting switch 27.

The operation of the stamper having the above structure will be described below.
The swinging member 18 before printing with the thermal head 20
Is set to a standby position shown in FIG. 3, that is, a position where the thermal head 20 is separated from the opposing roller 14 as described later. When the print instruction signal S5 is input from the print mode setting switch 27, the control circuit 16 receives the paper detection signal S1 from the paper detection sensor 15 (that is, after detecting the leading end of the recording paper 10 to be conveyed). ) After a lapse of a predetermined time, the drive control signal S2 is sent to the stepping motor 23, and the stepping motor 23 is rotated counterclockwise in FIG. 3 by a predetermined number of steps. As a result, the cam 22 is set to the rotational position shown in FIG. 2, that is, the rotational position away from the rocking member 18, so that the rocking member 18 rocks in the direction of arrow A in FIG. . Therefore, the thermal head 20 includes the ink donor sheet 21 and the recording paper 10.
It is pressed against the opposing roller 14 via. At this time, the thermal head 20 is operated to generate heat by a known method,
The heat causes the ink of the donor sheet 21 to be melted, and the ink prints predetermined contents such as characters and company seals on the recording paper 10.

Next, a signal indicating the end of printing is input to the control circuit 16 from, for example, a sensor (not shown) that detects the printing operation of the swing member 18, and when the control circuit 16 receives this signal, the stepping motor 23 is operated as described above. On the contrary to the case, rotate it clockwise. Then, the cam 22 pushes the swing member 18, and the swing member 18 swings in the direction opposite to the arrow A direction in FIG. Swing member 18
Returns to the standby position shown in FIG. 3, the position sensor 25 detects the detection end 24 and sends the detection signal S3 to the control circuit 16, whereupon the stepping motor 23 is stopped. By repeating the above-described operation, predetermined contents are printed and recorded on the recording papers 10 that are successively conveyed.

Here, the mounting position of the position sensor 25 is often slightly different for each stamper due to variations in component dimensions and the like. If there is an attachment error of the position sensor 25, the standby position (state shown in FIG. 3) of the rocking member 18 that is detected and regulated by the position sensor 25 will be different for each stamper. If so, the rocking member
Even if the number of rotation steps of the stepping motor 23 at the time of printing operation of 18 is set to a predetermined value, the timing at which the cam 22 is disengaged from the swing member 18 and the timing at which the cam 22 is stopped are different, so the thermal head 20 It becomes impossible to set the pressing force of the recording paper 10 to the desired value. That is, cam 22
If the cam continues to rotate even after being separated from the rocking member 18, the rocking of the rocking member 18 is hindered by the cam 22.
If is stopped before it is completely separated from the swinging member 18, a predetermined biasing force is not applied to the swinging member 18, and in either case, printing failure is caused.

Therefore, in this apparatus, a motor rotation angle setting switch 26 is provided, and the switch 26 can change the number of rotation steps of the stepping motor 23 during printing operation. The motor rotation angle setting switch 26 is composed of, for example, a known DIP switch, and while operating the switch 26, the step number change instruction signal S4 is input to the control circuit 16 and the set value of the step number in the control circuit 16 is set. Is continuously changed. For example, in the printing operation, if the cam 22 further rotates too much even after it is disengaged from the rocking member 18 to prevent the rocking of the rocking member 18, the number of steps is reduced, and conversely, the cam 22 rocks. When the swing member 18 is stopped before it completely comes off the member 18 to prevent the swing member 18 from swinging, the number of steps is increased. In this way, by adjusting the number of rotation steps of the stepping motor 23, that is, the rotation angle of the cam 22, the mounting position error of the position sensor 25 is compensated, and the pressing force of the thermal head 20 on the recording paper 10 is set to a desired value. It becomes possible to set.

In the embodiment described above, the stamp portion is composed of the thermal head 20, but the present invention is not limited to a stamper having such a stamp portion, and printing is performed using a printing body to which ink is applied, for example. It is also applicable to stampers that perform

(Effect of the Invention) As described in detail above, according to the stamper having the pressing force adjusting function of the present invention, the pressing force of the stamp portion on the recording paper can be adjusted to an optimum value, so that the printing can be performed neatly. it can. Moreover, in the device of the present invention, the pressing force is adjusted electrically instead of by mechanical adjustment, so the adjustment work is significantly simpler than in the prior art.

[Brief description of drawings]

FIG. 1 is a perspective view showing an apparatus according to an embodiment of the present invention, and FIGS. 2 and 3 are schematic side views showing states of the apparatus according to the embodiment during printing and waiting for printing, respectively. 10 …… Recording paper, 14 …… Counter roller 16 …… Control circuit, 18 …… Rotating member 19 …… Coil spring, 20 …… Thermal head 22 …… Cam, 23 …… Stepping motor 24 …… Detecting end, 25 …… Position sensor 26 …… Motor rotation angle setting switch

Claims (1)

[Claims] 1. A swinging member which holds a stamp portion and is swingably supported, a facing member which is disposed so as to face the stamp portion with a recording paper sandwiched therebetween, and the stamp portion is provided on the facing member. Urging means for urging the oscillating member in a pressing direction, a standby position in which the stamp portion is separated from the facing member and rotated by a stepping motor, and a position for pressing the oscillating member. A cam that swings between the two, a position sensor that outputs a detection signal when the swing member is in the standby position, and the stepping motor is stopped when the detection signal is input from the position sensor. And a control circuit for rotating the motor by a predetermined number of steps when a print instruction is given, and a motor rotation angle connected to the control circuit for arbitrarily changing the number of steps. Stamper with a pressing force adjusting function consisting of a constant section.