JPS62227776A - Paper jam detecting mechanism - Google Patents

Abstract

PURPOSE:To ensure that a paper jam can be speedily discriminated, recording can be started and a blank part can be inexpensively reduced, by providing a rotation-detecting mechanism on a platen or on an end face of the platen to detect the rotation of the platen itself. CONSTITUTION:A thermal head 1 is oscillatably supported on a main body, and a platen 2 is supported on the main body through a shaft so that it is driven to rotate. A recording material 3 is automatically supplied, and after the leading end thereof is passed between the head 1 and the platen 2, the head 1 is pressed against the platen 2 to clamp the recording material 3. The platen 2 is provided with a rotation-detecting disk 5 integrally on an end face thereof, and the rotation of the disk 5 is detected by a transmission-type optical sensor 6. The disk 5 is provided with slits 5a at regular angular intervals, for generating signals of the sensor 6. When the recording material 3 is jammed (a), the head 1 is pressed against the platen 2 without clamping the material 3 therebetween. Therefore, the rotation of the platen 2 is stopped due to frictional resistance between it and the head 1, and outputting of the signal from the sensor 6 is stopped, whereby the paper jam can be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a paper jam detection mechanism for a recording apparatus equipped with a thermal head and a platen.

(Summary of the Invention) The present invention is capable of sandwiching the leading edge of an automatically fed recording material between a thermal head and a platen, transporting the recording material by rotationally driving the platen, and transporting the recording material to the thermal head. In a recording apparatus that performs thermal recording, whether or not the leading edge of the recording material is held between the thermal head and the platen is detected by rotation of the platen.

(Prior Art) Conventionally, the paper jam detection mechanism in this type of device has mostly been based on a reflective optical sensor. FIG. 3 is a schematic diagram showing the embodiment, and the thermal head 1
The recording material 3 held between the platen 2 and the platen 2 is conveyed in the b direction by the rotational drive of the platen 2 (direction a). The leading edge of the transported recording material 3 was detected by a reflective optical sensor 1/4, and it was confirmed that the recording material 3 was held between the thermal head 1 and the platen 2.

(Problems to be Solved by the Invention) In the conventional technology, due to the method described above, paper jam occurs during the period from the platen 2 shown in FIG. 2 until the leading edge of the recording material 3 reaches the optical sensor 4. Since detection is not possible and recording is not possible to protect the thermal head 1, the length L shown in Figure 3 is
There was a problem in that the part became a blank space.

(Means for solving the problems) In order to solve the conventional problems, the present invention provides
Alternatively, a rotation detection mechanism is provided on the end face of the platen to detect rotation of the platen itself.

(Function) If the recording material that is supposed to be conveyed while being sandwiched between the thermal head and the platen is not sandwiched and becomes a paper jam, the thermal head and the platen come into pressure contact, and the y of the pressure contact surface
XX The rotation of the platen stops due to the low resistance.

When the recording material is held between the thermal head and the platen, the recording material is automatically fed and is transported as it is by the rotational drive of the platen, and the platen also continues to rotate.

From the above, paper jams are detected by detecting the rotation of the platen.

(Example) Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, a thermal head 1 is swingably held in a main body (the main body is not shown), and a platen 2 is pivotally supported by the main body and rotationally driven (the driving source is not shown). The leading edge of the fed sheet passes between the thermal head 1 and the platen 2, and the thermal head 1 comes into pressure contact with the platen 2, sandwiching the recording material 3 therebetween.

Since the platen 2 is rotationally driven by a drive means (not shown), the recording material 3 is conveyed as it is.

The platen 2 is integrally provided with a rotation detection plate 5 on its end face, and a transmission type optical sensor 6 detects the rotation of the rotation detection plate 5, which rotates as the platen rotates. Rotation detection 51
115 is provided with slits 5a at equal intervals for generating signals for the transmission type optical sensor 6, but if the slits 5a are treated with a coating with a different reflectance, etc. It is also easy to apply.

Heat is applied from a thermal head 1 to a recording material 3 conveyed by a platen 2 at any time to perform thermal recording.

If the automatically fed recording material 3 jams its leading edge on the end surface of the thermal head 1 or the platen 2 as shown in FIG. It comes into contact with pressure.

As a result, the platen 2 stops rotating due to frictional resistance with the thermal head 1, and the signal from the optical sensor 6 for rotation detection provided on the end face of the platen 2 is lost.
It is possible to detect paper jams and make a noise.

(Effects of the Invention) As described above, the present invention makes it possible to determine whether or not a recording material is sandwiched between the thermal head and the platen by detecting the rotation of the platen. It is possible to judge a jam and start recording, and it has the effect that it is possible to reduce the margin area at a low cost, which was difficult with the conventional technology.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the main parts of the paper jam detection mechanism according to the embodiment of the present invention, FIGS. 2A and B are sectional views of the main parts when a paper jam occurs, and FIG. FIG. 3 is a sectional view of main parts showing a jam detection mechanism. 1...Thermal head 2...Platen 3...Recording material 5...Rotation detection plate 6...Transmission type optical sensor Applicant Seiko Electronics Co., Ltd. Resistance sensor 14 +s-sage perspective view 1c] A.
B-Bouten Meso~Otomakura Kommemensei no Ube~'
Floor plan Figure 2

Claims (1)

[Claims] It is equipped with at least a line-type thermal head (hereinafter referred to as the thermal head) and a platen roller (hereinafter referred to as the platen) that is rotatably supported by the main body, and the recording material such as automatically fed paper is transferred to the thermal head. In a thermal recording device that conveys and records by pressing the platen, a rotation detection mechanism is provided at one end of the platen to detect whether or not the recording material is held between the thermal head and the platen by rotation of the platen. A paper jam detection mechanism characterized in that it recognizes the paper jam.