JPH0412875A - Thermal recording apparatus - Google Patents

Abstract

PURPOSE:To almost prevent the position of a heat generating body provided in a thermal head from being moved by setting the position of an urging means away from a contacting point between the thermal head and a platen. CONSTITUTION:A thermal head 22 is urged by an urging means 31 at a position away from a contacting point C with a platen 23. For example, when the thermal head is urged away from the contacting point C at the opposite side of a support shaft, the thermal head 22 is rotated in a clockwise direction around the contacting point C because of the rotation of the platen 23 when a recording paper 20 is sent out, thereby adding an upward force to the supporting shaft. Moreover, when the platen 23 is rotated in a counterclockwise direction, since the point of application of the urging means 31 is at the right side of the contacting point C, the upward force is added to the supporting shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is applicable to thermal recording devices such as printers and facsimile machines in which thermal recording is performed.

[Background of the Invention] Conventionally, in a thermal recording device such as a facsimile, there is a heating element of the thermal head at the contact point between the thermal head and the platen, and a biasing means is provided on a line connecting the contact point and the center of the platen. It was common practice to touch recording paper on a platen to perform thermal printing.

[Problems to be Solved by the Invention] As shown in FIG. 4, in a thermal recording device such as a facsimile machine, when the printing at the time of reception is completed and the empty feeding of the recording paper 20 of a predetermined length is completed, the cutter unit 24 (see FIG. 1), the recording paper 20 is cut. If the next received print is carried out in this state, there will be a blank space between the print position and the cutter unit, which will result in a lot of loss and will be unsightly. rotates in the opposite direction and pulls the leading edge of the recording paper 20 back to the vicinity of the heating element.

The mounting plate 26 of the thermal head 22 that performs printing is attached to the bearing 29 of the frame member 28 of the receiving door 10 (see FIG. 1).
It is swingably suspended on a shaft 30. Therefore, when the platen 23 rotates in the clockwise direction as shown in FIG. 22 is biased against the rotating direction of the platen 23, and the shaft support side of the mounting plate 26 is pushed upward.
It can be raised.

Furthermore, when the platen 23 rotates in the opposite direction to pull back the recorder M20 as shown in FIG. It will be done.

For this reason, the position of the heating element of the thermal head 22 is shifted from the printing position, which has the disadvantage of making the quality of the printed image unstable. In order to solve this problem, it is possible to improve the accuracy of the shaft support and eliminate the distortion of the shaft support of the thermal head 22, but this poses a problem of high cost.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a thermal recording device in which the thermal head is brought into contact with the platen by an urging means, in which the thermal head and the platen are brought into contact with each other. At a position away from the contact point,
This feature is characterized in that the position of the IT force means is set.

[Function] The thermal head 22 is biased by the biasing means 31 at a position away from the contact point C with the platen 23. For example, as shown in FIG. 2, when the contact point C is biased at a position away from the shaft support side, the thermal head 22 is moved to the platen 23 by rotation of the platen 23 when the recording paper 20 is fed out. Since the rotational force acts clockwise using the contact point C as a fulcrum, an upward force (arrow) is applied to the shaft support.

Further, even when the platen 23 rotates counterclockwise, an upward force is applied to the shaft support because the point of action of the biasing means 31 is on the right side of the contact point C.

That is, irrespective of the paper feeding direction of the recording paper 20, a force in the direction of pushing up is applied to the shaft support. Therefore, the heating element position of the thermal head 220 does not move away from the contact point C position with the platen 23, and uniform printing can be obtained.

Further, when the contact point C is pressed at a position away from the shaft support side as shown in FIG. 3, only the downward force acts regardless of the paper feeding direction.

[Embodiment] Next, an embodiment of the thermal recording device according to the present invention, which is incorporated into a Fufunmiri device, will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram of a facsimile machine F incorporating a thermal recording device according to the present invention.

In FIG. 1, the facsimile machine F is composed of a box-type exterior case 1, a transmitting means 2 for reading original images with an optical reading system, and a receiving means 3 for printing and recording incoming image information. There is.

The exterior case 1 includes a lower cover 4 that serves as a housing, a back cover 6 to which a reception tray 5 is attached, site covers 7.7 on both sides (only one is shown), and an operation panel 8 on the top surface. It consists of a transmitting door cover 9 and a receiving door 10 arranged on the rear side of the upper surface.

An operation panel 8 disposed on the slanted upper surface of the outer case 1
As usual, an LCD board (not shown) of a liquid crystal display unit and a panel assembly (not shown) of pushbutton switches such as a numeric keypad are arranged.

The transmitting means 2 includes a document stacker 11 mounted on the upper part of the upper surface of the outer case 1, a separation bat unit 3 that separates biplane documents 12 one by one, and a self-supplying roller 14 that sends the separated documents 12 to an optical system. , a pressure roller 15, a feed roller 16, a paper ejection roller 17, and an optical reading unit 18 disposed below the self-feeding roller 14, which are arranged opposite to each other across the surface on which the document 12 moves, and the document stacker 11
The bi-leaf originals 12 stacked on top are separated one by one, the images are read by an optical reading unit 1, and the images are sent out to a paper discharge port 19.

The image signal read by the optical reading unit 18 is transmitted to the other party using a communication line.

The receiving means 3 includes a recording paper storage chamber 21 that stores a roll of recording paper 20 in a freely fed-out manner, and a thermal device that prints and records image information transmitted to the recording paper 20 that is fed out from the recording paper storage chamber 21. a cut 22 and a platen 23;
It is composed of a cutter unit 24 that cuts the recording paper 20 on which the received information is printed and recorded into a predetermined length. (received from the discharge port 25) and sent out onto L, -5.

FIG. 2 is a configuration diagram showing an example of a thermal recording device incorporated into a facsimile machine F.

In this FIG. 2, the thermal head 22 is fixed to a mounting plate 26 with high accuracy, and a bracket 27 is provided on the top surface of the mounting plate 26 in the longitudinal direction of the reception door.
is suspended from the lower surface of the frame member 28. Specifically, a pair of bearings 29 and 29 are vertically installed on the lower surface of the frame member 28.
A shaft 30 is supported between them, and the shaft 30 is supported parallel to the axis of the platen 23.

The thermal head 22 has a contact point C with the platen 23.
The biasing means 31 is biased at a position deviated from the shaft support side (a position deviated from the normal line).

The heat generating part of the thermal head 22 is connected to the platen 2.
The relative positional relationship between the two is selected so that the contact point C on the circumferential surface of No. A recording paper 2o is interposed between the platen 23 and the thermal gutter 22, and the printed recording paper 2o
The rear end of is cut by the cutter unit 24. The recording paper 20 is sent out and pulled back by the rotation of the platen 23.

The top surface of the mounting plate 26 of the thermal ＼t 22 and the reception door 1
A coil spring serving as a means 31 for biasing the thermal head 22 toward the platen 23 is attached between the thermal head 22 and the platen 23 at a position away from the contact point C between the platen 23 and the thermal head 22. This biasing means 31 may be a leaf spring.

When the recording paper 20 is fed out, as the platen 23 rotates clockwise, the thermal head 22 uses the contact point C as a fulcrum, and a force (indicated by the arrow in the figure) that pushes up the bracket 27, which is the shaft support, acts on the thermal head 22. . Furthermore, when the recording paper 2o is pulled back, since the biasing means 31 is provided near the tip of the thermal head 22, it pushes the bracket 27 upward even when the platen 23 is reversed (rotated counterclockwise). , a lifting force acts.

That is, regardless of the direction in which the recording paper 20 works, -
A similar force (force in the direction of pushing up the shaft support) will act on the shaft. Therefore, the position of the orbiting body of the thermal head 22 does not deviate from the contact point C position with the platen 23, and uniform printing can be obtained.

FIG. 3 is a configuration diagram showing a second embodiment of the thermal recording apparatus according to the present invention.

In FIG. 3, the platen 23 is urged at a position away from the contact point C between the thermal head 22 and the platen 23 toward the shaft support side.

In this configuration, since the biasing means 31 is located between the shaft support and the contact point C, when the recording paper 20 is fed out, the thermal head 22 applies a force that tries to pull down the shaft support using the contact point C portion as a fulcrum. (arrow shown) acts.

Further, when the recording paper 2o is pulled back, a force that tends to pull down the shaft support of the mounting plate 26 acts, causing it to tilt in the same manner as described above, so that uniform printing can be obtained.

[Effects of the Invention] As described above, the tactile recording device according to the present invention has a tactile recording device in which the tactile recording device according to the present invention is arranged such that the tactile recording device of the 11-force means is placed vertically away from the contact point between the thermal head and the platen on the shaft support side or on the side opposite to the shaft support side. Since the thermal head is in a fixed position, a force always acts on the shaft of the thermal head in a constant direction regardless of the direction in which the recording paper runs.Therefore, the position of the heating element provided on the thermal head hardly changes. Therefore, even if the precision of the members of the shaft support of the thermal head is not required as in the past, uniform printing can be obtained and the cost of vertical installation can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a thermal recording device according to the present invention incorporated into a facsimile machine, FIG. 2 is a configuration diagram showing a first implementation example, FIG. 3 is a configuration diagram of another embodiment, and FIG. FIG. 5 is a configuration diagram of a conventional example. F...Facsimile machine C...Contact 3...Receiving means 10 ・ ・ ・ 1 word Tore 20...Recording paper 22φ・Thermal head 23・Platen 24・Cutter unit 26・...Mounting plate 27...Bracket 28...Frame member 30...Shaft 31...Biasing means

Claims (1)

[Claims] (1) In a thermal recording device in which the thermal head is brought into contact with the platen by a biasing means, at a position away from the contact point between the thermal head and the platen,
A thermal recording device characterized in that the position of the urging means is set.