JPH0544142Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

The present invention relates to a thermal printing device used in facsimile machines and the like, and more particularly to a thermal printing device that passes recording paper between a thermal head and a feed roller and prints while being conveyed by the feed roller.

[Prior art and problems]

In conventional thermal printing devices of this type, the thermal head is always fixed in a fixed position with the thermal head in contact with the feed roller, and the leading edge of the recording paper is passed between the thermal head and the feed roller to set it, or when printing a jammed record. The operation was very inconvenient when removing paper. The purpose of the present invention is to provide a thermal printing device that can easily move the thermal head away from the feed roller with a single touch, detect the state electrically, and adjust the pressing force of the thermal head against the feed roller. There is a particular thing.

[Means to solve the problem]

In the thermal printing device of the present invention, a thermal head holding plate 8 that holds a thermal head 11 is attached to a fixed frame 1 that bears a feed roller 5 in parallel with the feed roller 5. It is attached so that it can rotate freely around a fulcrum. An adjusting screw 14 is provided between the fixed frame 1 and the free end of the thermal head holding plate 8, and a spring 15 is attached to the adjusting screw 14 to urge the thermal head holding plate 8 toward the feed roller 5 side. Attach. Further, a retraction lever 16 that can engage with the thermal head holding plate 8 and rotate it in a direction away from the feed roller 5 against the spring 15 is provided.
It is rotatably mounted on a fixed frame 1, and a switch 22 that is turned on and off by the rotation of the retraction lever 16 is further attached to the fixed frame 1.

[Effect]

The thermal head 11 is moved around the feed roller 5 by a spring 15 acting on the adjusting screw 14.
is pressed against. The pressure contact force can be adjusted using an adjustment screw 14. When the evacuation lever 16 is rotated in a predetermined direction, the thermal head holding plate 8 is moved by the spring 1.
5 in a direction away from the feed roller 5, and a gap is formed between the feed roller 5 and the feed roller 5. This condition is detected electrically by switch 22.

【Example】

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings. FIG. 1 is a perspective view of a thermal printing device A according to the present invention, FIG. 2 is a vertical cross-sectional view of the thermal printing device A installed in a small reception-only facsimile B, and FIG. 3 is a horizontal cross-sectional view. This thermal printing device A is a unit in which the following components are attached to a fixed frame 1 made of a metal plate. Between the side plates 2 at both left and right ends of the fixed frame 1, a horizontally long feed roller 5 having a metal shaft 4 passed through a blanket cylinder 3 is rotatably supported horizontally. A gear 6 fixed to one end of the metal shaft 4 of this feed roller 5
is meshed with a drive gear (not shown) of a feed motor 7 attached to the side plate 2, and the feed roller 5 is rotated by the feed motor 7. A horizontally long metal thermal head holding plate 8 is rotatably attached to the left and right side plates 2 at leg portions 9 hanging from both left and right ends thereof by left and right pins 10 parallel to the axis of the feed roller 5. There is. If the feed roller 5 side is the front side, a horizontally long thermal head 1 is placed in front of this thermal head holding plate 8.
1 is screwed, and the thermal head 11 faces the feed roller 5 in parallel. L-shaped arm portions 12 are provided at right angles to protrude from both left and right ends of the thermal head holding plate 6. Adjustment screws 14 are provided between the tip portions of the left and right arm portions 12 and the L-shaped bent portions 13 provided on the left and right side plates 2, respectively. The adjustment screw 14 passes through a guide hole in the bent portion 13 and is screwed into a screw hole in the tip of the arm portion 12 .
A spring 15 is wound around the adjustment screw 14 between its head and the bent portion 13.
Due to this spring 15, the arm portion 12 is bent at the bent portion 13.
is biased in the direction of approaching . Therefore, the thermal head holding plate 8 is urged toward the feed roller 5 by the spring 15, and tends to press the thermal head 11 against the feed roller 5. This pressing force can be adjusted with adjustment screws 14 for each of the left and right sides. A resin-made retraction lever 16 is rotatably mounted on the side plate 2 on the side opposite to the side driven by the feed motor 7. This evacuation lever 16
is pivotally supported at one end of the metal shaft 4 so as to rotate about the axis of the feed roller 5 as a fulcrum. The retraction lever 16 has a knob 17 at its upper end,
A switch operating section 18 is provided at the lower end, and a cam section 19 and a stopper section 20 are integrally provided at the middle. The cam portion 19 can engage with the front surface of a protrusion 21 protruding from one end of the thermal head holding plate 8 as shown in FIG. It is in a relationship that allows it to engage with the upper edge of the. There is also a switch (micro switch) on the side plate 2.
22 is attached. The switch lever 23 of the switch 22 engages with the switch operation portion 18 of the retraction lever 16 and is operated thereby. When the evacuation lever 16 is tilted forward (to the left in the figure) as shown in FIG.
The cam portion 19 is connected to the protrusion 2 of the thermal head holding plate 8.
1, so the thermal head retaining plate 8
is subjected to the action of the spring 15 regardless of the retraction lever 16. Therefore, the thermal head 11 is pressed against the feed roller 5. At this time, the recording paper 25 pulled out from the recording paper roll 24 in the facsimile B is sandwiched between the thermal head 11 and the feed roller 5, and is conveyed by the rotation of the feed roller 5. A guide plate 27 that forms an oblique paper guide path 26 is attached to the lower side of the fixed frame 1, and the recording paper 25 passing between the thermal head 11 and the feed roller 5 is guided through this paper guide. It is guided to the passage 26 and discharged to the outside of the facsimile B. A cutout window 28 is provided at the center of the upper edge of the guide plate 27, and the guide plate 27 is provided in the cutout window 28.
A switch 29 for paper detection is attached to the paper. The switch lever 30 of this switch 29 is in pressure contact with the feed roller 5 outside the paper guide path 26, and if the recording paper 25 does not enter the guide path 26 and wraps around the feed roller 5 or comes off downward outside the guide path 26, , the switch 29 is turned on by the recording paper 25, and a trouble is detected. On the other hand, when the evacuation lever 16 is tilted backward as shown in FIG. It can be rotated clockwise until it engages the upper edge of the protrusion 21. When the evacuation lever 16 is rotated in this way, the thermal head holding plate 8 is moved by the spring 1
5, the feed roller 5 is rotated in a direction away from the feed roller 5, as shown in FIG.
A gap 31 is formed between the thermal head 11 and the thermal head 11 . Therefore, the leading edge of the recording paper 25 is moved to the feed roller 5.
When passing the recording paper between the recording paper 2 and the thermal head 11, the operation can be easily performed, and
Even if 5 is jammed, it can be easily removed. Moreover, when the evacuation lever 16 is rotated clockwise,
Since the switch lever 23 is pushed down by the switch operation part 18 and the switch 22 is turned on,
The fact that the thermal head 11 is separated from the feed roller 5 can be detected by the control circuit of the facsimile B. In the above, the thermal printing device A of the present invention is incorporated into the facsimile B, but it can also be applied to other OA equipment.

[Effect of the idea]

The present invention has the following effects. The thermal head can be easily moved away from the feed roller with a single touch operation using the evacuation lever, so the leading edge of the recording paper can be easily passed between the thermal head and the feed roller, and jammed recording paper can be removed easily. It also becomes easier. With a simple configuration, it is possible to electrically detect when the thermal head is separated from the feed roller.
It is possible to prevent the recording paper from being conveyed in this state, and also to prevent forgetting to return the thermal head. The pressure force of the thermal head against the feed roller can be easily adjusted using the adjustment screw.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a thermal printing device as an example of the present invention, Fig. 2 is a vertical sectional view of the thermal printing device installed in a small reception-only facsimile, Fig. 3 is a horizontal sectional view, and Fig. 4 is a retraction lever. FIG. 5 is a side view of the device folded forward, and FIG. 5 is a side view of the device folded backward. 1...Fixed frame, 5...Feed roller,
8...Thermal head holding plate, 11...Thermal head, 14...Adjustment screw, 15...Spring, 16...Evacuation lever, 22...Switch.

Claims (1)

[Scope of utility model registration request] In a thermal printing device that passes recording paper between a thermal head 11 and a feed roller 5 and prints while being conveyed by the feed roller 5, a thermal head holding plate 8 that holds the thermal head 11 is mounted on a bearing of the feed roller 5. The thermal head holding plate 8 is mounted on a fixed frame 1 rotatably about a fulcrum parallel to the feed roller 5, and an adjusting screw 14 is provided between the fixed frame 1 and the free end of the thermal head holding plate 8. On the 14th,
Through this, a spring 15 is attached which urges the thermal head holding plate 8 toward the feed roller 5 side, and also engages with the thermal head holding plate 8 to push it away from the feed roller 5 against the spring 15. A feature is that a rotatable evacuation lever 16 is rotatably mounted on the fixed frame 1, and a switch 22 that is turned on and off by the rotation of the evacuation lever 16 is attached to the fixed frame 1. Thermal printing device.