JP2518083Y2 - Printer print head gap adjustment device - Google Patents

Description

[Detailed Description of the Invention] [Outline] A print head gap adjusting device for a printer that automatically adjusts the gap between a paper guide provided in front of the print head and the platen prior to printing. It can be done in a short time, and at that time, the distance between the printing paper and the paper guide, which is in close contact with the platen, is set to a predetermined amount in order to prevent a strong force from being applied to the surface of the printing paper. At this time, the paper detection switch provided on the paper guide unit so as to be turned on by being pressed by the surface of the print paper, and usually the paper detection switch is fixed to the paper guide unit, and the paper detection switch is And a switch fixing means for releasing the fixed state when the printing paper is pushed by a force larger than a predetermined force.

[Industrial applications]

The present invention relates to a print head gap adjusting device for a printer, which automatically adjusts the gap between a platen formed in front of the print head and a platen prior to printing.

Printing sheets of various thicknesses are used in the printer. Therefore, the distance between the paper guide and the platen also needs to be adjusted before printing according to the thickness of the printing paper.

[Conventional technology]

FIG. 6 shows a conventional printer. 51 is a platen with which the printing paper 100 is in close contact. 52 is a print head. 53 is a paper guide attached in front of the print head 52. Reference numeral 54 designates the print head 52 and the paper guide 53 integrally, in the direction of arrow A,
That is, it is a drive motor that drives the platen 51 toward or away from it.

A paper detection switch 55 is fixed on the front of the paper guide 53 so as to allow a slight business trip.
The detection signal from 55 is input to the control unit 59 for controlling the operation of the drive motor 54.

FIG. 7 shows the operation of the above-mentioned conventional printer. When the printing paper 100 is sucked into the printing unit, the drive motor 5
By rotating 4 in the forward direction, the paper guide 53
Move in the direction of approaching. And the paper detection switch
When 55 is pressed in close contact with the print paper 100, the switch is turned on and a paper detection signal is sent to the control unit 59. In this state, the printing paper 100 is sandwiched between the platen 51 and the paper guide 53, and the space (paper gap) between the paper guide 53 and the printing paper 100 is zero.

When the paper detection signal is input, the control unit 59 first stops the drive motor 54 and then immediately reverses the drive motor 54 to form a predetermined space between the print paper 100 and the paper guide 53.

[Problems to be solved by the device]

As described above, in the conventional printer, the paper detection switch 55 is fixed to the paper guide 53. Therefore, the print paper 100 is strongly pressed by the switch 55 when the paper is detected. Generally, the paper detection switch 55
To turn on the switch, it is sufficient to press the switch with a comparatively light force, but there is a certain delay from the time the paper detection switch 55 is turned on until the drive motor 54 stops, so the drive force during that time causes the paper Detection switch 55 is print paper
It is strongly pressed against the surface of 100.

Such an operation is not preferable from the viewpoint of durability of the paper detection switch 55, and when copy paper is used as the printing paper 100, the second paper and the second paper or less are pressed at the portion where the paper detection switch 55 is pressed. Has the drawback of becoming dirty.

Further, in the conventional device as described above, the drive motor 54 is normally rotated → stopped → by the time the predetermined paper gap is normally rotated.
Since it has to be operated in reverse, there is a drawback that it takes time to set the interval.

The present invention solves such a conventional drawback, and provides a print head gap adjusting device for a printer, which can set the gap in a short time and at the same time does not apply a strong force to the surface of the printing paper. With the goal.

[Means for solving the problem]

In order to achieve the above-mentioned object, a print head gap adjusting device for a printer according to the present invention, as shown in FIGS. 1 and 2 for explaining an embodiment, includes a platen 1 to which a printing paper 100 is closely attached, Print head 2 facing platen 1
A paper guide 3 provided in front of the platen 1, a gap adjusting means 4 for changing the gap between the platen 1 and the paper guide 3, a printing paper 100 in close contact with the platen 1, and the paper guide 3. The paper detection switch 5 provided on the paper guide 3 and normally the paper detection switch 5 so as to be pressed by the surface of the printing paper 100 and turned on when the distance between them reaches a predetermined amount. Switch fixing means 6 is provided which is fixed to the paper guide 3 and the paper detection switch 5 is released from the fixed state when the paper detection switch 5 is pressed from the print paper 100 side by a predetermined force or more. To do.

[Action]

When no force is applied to the paper detection switch 5 from the side of the print paper 100, the paper detection switch 5 moves to the paper guide 3
It is fixed to. Then, when the distance between the printing paper 100 and the paper guide 3 which are in close contact with the platen 1 is narrowed to a predetermined amount, the paper detection switch 5 provided on the paper guide 3 is
The surface of the printing paper 100 is pushed and turned on.

Then, when the paper detection switch 5 is pushed from the print paper 100 side with a force equal to or greater than a predetermined force (a force larger than the force required to turn on), the fixed state between the paper detection switch 5 and the paper guide 3 is released, The paper detection switch 5 is pushed by the print paper 100 and moves without resistance. Therefore, during this time, no force more than the above-mentioned predetermined force is applied to the surface of the printing paper 100.

〔Example〕

 An embodiment will be described with reference to the drawings.

FIG. 2 shows the printing section of the printer, and 1 is a platen with which the printing paper 100 is in close contact. A print head 2 is attached to the carriage 21 and is provided so as to face the platen 1. The carriage 21 moves in the arrow B direction along the stay shaft 22.

A paper guide 3 is attached to the carriage 21 so as to be positioned in front of the print head 2 so as to face the platen 1, and may be considered to be substantially provided integrally with the print head 2.

Reference numeral 4 denotes a drive motor 4 (spacing adjusting means) that drives the carriage 21 in the direction of arrow C in order to change the spacing between the paper guide 3 and the platen 1. A step motor is used as the drive motor 4, and its operation is controlled by the control unit 9. The platen 1 may be moved in the arrow C direction by the drive motor 4.

Reference numeral 5 denotes a paper detection switch provided on the front surface of the paper guide 3 for detecting the printing paper 100, and the details thereof will be described with reference to FIG.

In FIG. 1, an arm 51 is rotatably supported by a hinge 31 provided on the back side of the paper guide 3,
The switch 5b is fixed to the front surface of the arm 51.

A switch push rod 5a is inserted into the hole 32 formed in the paper guide 3. The tip of the switch push rod 5a projects from the front surface of the paper guide 3 to the platen 1 side and is rounded so as not to scratch the printing paper 100. The base end side of the switch push rod 5a is formed thick so as not to protrude from the hole 32, and its end is formed round, and the switch 5b
It is arranged to face the surface. Therefore, the switch push rod 5a is pushed from the print paper 100 side,
Press switch 5b to turn it on.

A permanent magnet (switch fixing means) 6 is fixed to the free end side of the arm 51. An iron piece 61 is fixed to the paper guide 3 side so as to face the permanent magnet 6. The iron piece 61 is screwed into a screw 62 provided upright on the back surface of the paper guide 3, and the mounting height can be arbitrarily adjusted.

With such a configuration, the arm 51 is provided with the switch push rod 5a.
When the permanent magnet 6 is not pressed by the
Adsorbed on 61. However, when the arm 51 is pushed up with a force exceeding a certain level, the permanent magnet 6 is separated from the iron piece 61 as shown in FIG. Further details regarding this will be described in the following description of the operation. An urging spring for urging the switch push rod 5a toward the platen 1 with a slight force may be provided.

Next, the operation of the above embodiment will be described with reference to FIGS.

When the printing paper 100 is sucked into the printing unit, the drive motor 4 is stopped, and as shown in FIG. 3, the space between the platen 1 and the paper guide 3 is maximized. The printing paper 100 is inserted between them. At this time, the permanent magnet 6 at the end of the arm 51 is attracted to the iron piece 61, and the attraction force causes the switch 5b to be fixed to the paper guide 3.

When the printing paper 100 is sucked into the printing unit, the drive motor 4 is rotated in the normal direction, and the paper guide 3 and the platen 1 gradually approach each other. Then, as shown in FIG. 4, when the distance T between the surface of the paper guide 3 and the printing paper 100 becomes a predetermined amount T, the tip of the switch push rod 5a is pushed onto the surface of the printing paper 100, Press switch 5b at the end. When the pushing force exceeds F, the switch 5b is turned on. This time,
The printing paper 100 also receives a force of the same magnitude F from the tip of the switch push rod 5a.

When the switch 5b is turned on (that is, when the arm 51 is pushed by the force of F), the permanent magnet 6 and the iron piece 6 are separated from each other.
61 and 61 are set to the strength for maintaining the adsorption state. However, when the switch push rod 5a pushes the arm 51 with a force equal to or greater than a predetermined force, which is a little stronger than the switch 5b turning on, the permanent magnet 6
The attraction force between the iron piece 61 and the iron piece 61 cannot resist it, and the permanent magnet 6 separates from the iron piece 61 as shown in FIG. As a result, the fixed state of the switch 5b and the paper guide 3 is released, and the print paper 100 is in a state in which only an extremely light force equivalent to the weight of the arm 51, the switch 5b, and the switch push rod 5a is applied.

Then, as shown in FIG. 5, the drive motor 4 is
It continues to rotate in the same direction for a while, and stops when the paper gap becomes a predetermined interval t narrower than the previous T.
This completes the setting of the paper gap before printing.

The present invention is not limited to the above embodiment, and for example, the permanent magnet 6 is attached to the paper guide 3 side,
An iron piece may be provided at the tip of the arm 51, or the fixing means may be formed of something other than a permanent magnet. Further, the paper detection switch 5 does not necessarily have to be directly attached to the paper guide 3 itself, but may be attached to a member substantially configured integrally with the paper guide 3, such as the carriage 21.

[Effect of device]

According to the print head gap adjusting device of the printer of the present invention, a large force is not applied to the printing paper when detecting the printing paper, so that dirt does not occur when using copy paper and the paper detection switch is used. Since it does not need to be fixed to the surface of the paper guide, it has an excellent effect such as eliminating a paper jam caused by the print paper being caught in the paper detection switch.

[Brief description of drawings]

FIG. 1 is a partially enlarged view of the embodiment after operation, FIG. 2 is a side view of the embodiment, FIG. 3 is a partially enlarged view of the embodiment, and FIG. 4 is a partially enlarged view of the embodiment during operation. FIG. 5 is a diagram showing the operation of the embodiment, FIG. 6 is a side view of the conventional example, and FIG. 7 is a diagram showing the operation of the conventional example. In the figure, 1 ... Platen, 2 ... Print head, 3 ... Paper guide, 4 ... Space adjusting means, 5 ... Paper detection switch, 6 ... Switch fixing means, 100 ... Printing paper.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Katsuo Sato Inventor, Katsio Sato 1405 Daimaru, Inagi-shi, Tokyo Inside Fujitsu Isotec Co., Ltd.

Claims (1)

(57) [Scope of utility model registration request] 1. A platen (1) with which a printing paper (100) is in close contact, a paper guide (3) provided on the front portion of a print head (2) facing the platen (1), and the platen (1). A space adjusting means (4) for changing the space between the paper guide (1) and the paper guide (3), an arm (51) rotatably attached to the paper guide (3), and an arm (51). A switch (5b) attached to the (51) for outputting a switching signal to the interval adjusting means (4), a printing paper (100) in close contact with the platen (1) and the switch (5b). When the distance between the printing paper (100) and the paper guide (3), which are movably arranged in between and are in close contact with the platen (1), is less than a predetermined amount, the printing paper (100) and the switch (5b). The switch is pressed so that it is sandwiched between The member (5a) and usually the arm (51) are fixed to the paper guide (3), and the arm (51) has a predetermined force larger than the force for turning on the switch (5b). (Five
A print head gap adjusting device for a printer, comprising: arm fixing means (6) for releasing the fixed state when pushed from the platen (1) side by a).