JPH04301463A - Printing device - Google Patents

Abstract

PURPOSE:To enhance the quality of printing to a recording paper by forming a leaf spring member as an engaging part with a head frame at the top end of said member and regulating the movement of the head frame, which may be caused by the rotation of a platen roller or by the rotation of a pressure contact release cam. CONSTITUTION:When a recording paper 20 is set in a printing device, a user of the device rotatively manipulates a pressure contact release lever in the C2-direction, thereby rotating a pressure contact release cam 4 in the A1- direction. According to this manipulation, the pressure contact release cam 4 pushes up a head frame 1 with a push-up part 4a of said cam to release a pressure contact state between a thermal recording head 3 and a platen roller 2. Further, in this case, a leaf spring member 7 regulates with its engaging part 7b the movement of the head frame 1, which may be caused by the rotation of the pressure contact release cam 4 in the A1-direction, and maintains accurately the pressure contact-released state between the thermal recording head 3 and the platen roller 2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus that prints a stamp on the above-mentioned recording paper with the recording paper sandwiched between a thermal recording head and a platen roller.

0002

2. Description of the Related Art Conventionally, a printing device of this type has, for example, a recording paper 30 sandwiched between a thermal recording head 13 supported by a head frame 11 and a platen roller 12, as shown in FIG. The thermal recording head 13 is configured to be pressed against the platen roller 12 via the recording paper 30 by the head frame 11 being pressed by the leaf spring member 17 . Also,
The pressure contact between the thermal recording head 13 and the platen roller 12 as described above is released by pushing up the head frame 11 with the push-up part 14a of the pressure release cam 14 provided on the rotating shaft 12a of the platen roller 12. The push-up operation of the pressure release cam 14 is performed by the user of the device rotating the pressure release lever 15 in the E2 direction. When the recording paper 30 is set in the apparatus, the recording paper 30 is placed between the thermal recording head 13 pushed up by the push-up part 14a of the pressure release cam 14 and the platen roller 12, as shown in FIG.
, and then rotate the pressure release lever 15 in the E1 direction to release the thermal recording head 1 as shown in FIG.
Setting of the recording paper 30 is completed by sandwiching the recording paper 30 between the recording paper 3 and the platen roller 12.

[0003] Furthermore, a lid body 41 of an apparatus main body 40 housing the above-mentioned thermal recording head 13 and platen roller 12 is provided.
A regulating protrusion 41a is formed therein. During printing shown in FIG. 3, the regulating protrusion 41a comes into contact with the head frame 11 to regulate the movement of the head frame 11 as the platen roller 12 rotates in the F direction, thereby preventing uneven printing on the recording paper 30. It is designed to prevent
Thermal recording head 13 and platen roller 1 shown in FIG.
2, the head frame 11 is brought into contact with the head frame 11 to restrict the movement of the head frame 11 due to the rotation of the pressure release cam 14 in the F direction, thereby allowing the pressure release cam 14 to normally push up the head frame 11. It is supposed to invite you.

0004

However, in the conventional configuration described above, the regulating protrusion 41a that regulates the movement of the head frame 11 due to the rotation of the platen roller 12 or the pressure release cam 14 is Since it is formed on the lid 41 that can be opened and closed, it is difficult to achieve positional accuracy when assembling the device. Therefore, if the positional accuracy of the regulating protrusion 41a with respect to the head frame 11 is poor, the thermal recording head 13 will have a large amount of wobble during printing, causing uneven printing on the recording paper 30, and the thermal recording head 13 and the platen. When the pressure contact with the roller 12 is released, the movement of the head frame 11 due to the rotation of the pressure release cam 14 cannot be restricted, and in the worst case, it is impossible to maintain the released state between the thermal recording head 13 and the platen roller 12. The problem is that it cannot be done.

[0005]

[Means for Solving the Problems] In order to solve the above problems, the printing device of the present invention performs printing by sandwiching recording paper between a thermal recording head supported by a head frame and a platen roller. By pressing the head frame with a leaf spring member, the thermal recording head is brought into pressure contact with the platen roller via the recording paper, and at the same time, a pressure release cam provided on the rotating shaft of the platen roller is rotated. In a printing device that lifts up a head frame to release the press-contact state between a thermal recording head and a platen roller, the following measures are taken.

That is, the tip of the leaf spring member is formed as an engaging portion with the head frame, and is adapted to restrict the movement of the head frame due to the rotation of the platen roller or the rotation of the pressure release cam. There is.

[0007]

[Operation] According to the above structure, the tip of the leaf spring member that presses the head frame to bring the thermal recording head into pressure contact with the platen roller is formed as an engaging portion with the head frame. As a result, during printing, the movement of the head frame due to the rotation of the platen roller is regulated to prevent uneven printing on the recording paper, and when the pressure contact between the thermal recording head and the platen roller is released, The movement of the head frame accompanying the rotation of the pressure release cam is restricted to ensure accurate release of pressure between the thermal recording head and the platen roller.

[0008]

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. 1 and 2 are longitudinal cross-sectional views showing the printing device of this embodiment, and the direction perpendicular to the plane of the paper indicates the depth of the device, and for convenience of explanation, this direction is referred to as the width of the device. The directions are described below.

As shown in FIG. 1, the printing device according to this embodiment includes a head frame 1 and a platen roller 2, which extend in the width direction of the device, in a main body 10 of the device.

The head frame 1 is provided with a thermal recording head 3 supported on the surface facing the platen roller 2, and at both ends of the head frame 1 in the width direction, rotation of the platen roller 2 is provided. Support parts 1a, 1a are formed to support the shaft 2a (only the support part 1a at one end in the width direction of the device is shown in the figure).

The platen roller 2 has a rotating shaft 2a.
is supported at both ends thereof so as to be rotatable in the A1-A2 direction with respect to the device main body 10, and a push-up portion 4a is formed on one end side of this rotation shaft 2a to form a substantially egg-shaped pressure contact. A release cam 4 is provided.

The pressure release cam 4 has a gear portion formed on its outer periphery, and this gear portion meshes with a gear 6 provided on the pressure release lever 5, which will be described later, to release the pressure release lever 5. It is designed to be rotated in the A1-A2 direction as the rotation operation is performed.

The pressure release lever 5 is rotatable in the C1-C2 direction about the fulcrum B and is attached to the main body 1 of the apparatus.
0, and a gear 6 meshed with the gear portion of the pressure release cam 4 described above is integrally attached to the fulcrum B thereof.

Further, on the back side of the head frame 1, a plate spring member 7 is disposed to bring the thermal recording head 3 and the platen roller 2 into pressure contact during printing. One end of the leaf spring member 7 is fixed to the device main body 10, while a pressing protrusion 7a for pressing the head frame 1 is formed on the other end. , is formed as an engaging portion 7b that engages with the head frame 1.

In the above configuration, the recording paper 20 is placed inside the apparatus.
When setting, as shown in FIG. 2, the user of the device rotates the pressure release lever 5 in the C2 direction, thereby rotating the pressure release cam 4 in the A1 direction. As a result, the pressure release cam 4 pushes up the head frame 1 with its push-up portion 4a, and releases the pressure contact state between the thermal recording head 3 and the platen roller 2. Also, at this time,
The plate spring member 7 releases the pressure contact release cam 4 by its engaging portion 7b.
The movement of the head frame 1 accompanying the rotation in the A1 direction is regulated to maintain an accurate release state between the thermal recording head 3 and the platen roller 2.

Next, the recording paper 2 stored in a recording paper cassette (not shown) is placed in the gap between the thermal recording head 3 and the platen roller 2 whose pressure contact state has been released as described above.
0 in the D direction, and then move the pressure release lever 5 to C1.
By rotating the pressure release cam 4 in the A2 direction, the recording paper 20 is sandwiched between the thermal recording head 3 and the platen roller 2 as shown in FIG.

Then, as described above, the thermal recording head 3 with the recording paper 20 sandwiched between it and the platen roller 2 is energized, and the platen roller 2 is rotated in the A1 direction to move the recording paper 20 in the D direction. By sending out the sheets, printing is performed on the recording paper 20 one after another. At this time, the leaf spring member 7 presses the head frame 1 with its pressing protrusion 7a to press the thermal recording head 3 to the platen roller 2 via the recording paper 20, and The joint portion 7b restricts the movement of the head frame 1 as the platen roller 2 rotates in the A1 direction, thereby improving the quality of printing on the recording paper 20.

[0018]

Effects of the Invention As described above, in the printing device of the present invention, the tip of the leaf spring member is formed as an engaging portion with the head frame, and the leaf spring member is configured to have a flat spring member that is connected to the head frame when the platen roller rotates or the pressure release cam rotates. This configuration is designed to restrict movement of the head frame.

As a result, during printing, the movement of the head frame due to the rotation of the platen roller is restricted, and the quality of printing on the recording paper is improved, and when the pressure contact between the thermal recording head and the platen roller is released, the movement of the head frame is restricted. This has the effect that the movement of the head frame accompanying the rotation of the pressure release cam is regulated, leading to accurate release of pressure between the thermal recording head and the platen roller.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing a state in which a thermal recording head and a platen roller are in pressure contact with each other, which constitute a printing apparatus of the present invention.

FIG. 2 is a longitudinal sectional view showing a state in which the thermal recording head and the platen roller are released from pressure contact.

FIG. 3 is a longitudinal sectional view showing a state in which a thermal recording head and a platen roller are in pressure contact with each other, which constitute a conventional printing device.

FIG. 4 is a longitudinal sectional view showing a state in which the thermal recording head and the platen roller are released from pressure contact.

[Explanation of symbols]

1 Head frame 2 Platen roller 2a Rotation axis 3 Thermal recording head 4 Pressure release cam 7. Leaf spring member 7b Engagement part 20 Recording paper

Claims (1)

[Claims] 1. A printing device that performs printing by sandwiching recording paper between a thermal recording head supported by a head frame and a platen roller, wherein the head frame is pressed by a leaf spring member. The thermal recording head is brought into pressure contact with the platen roller via the recording paper, and the head frame is pushed up by the rotation of the pressure release cam provided on the rotating shaft of the platen roller, thereby releasing the pressure contact between the thermal recording head and the platen roller. In the printing device, the tip of the leaf spring member is formed as an engaging portion with the head frame, and restricts movement of the head frame due to rotation of the platen roller or rotation of the pressure release cam. A printing device characterized by: