JPS60147365A - Rotating amount diagnosing device for platen - Google Patents

Abstract

PURPOSE:To constantly monitor the rotation of a platen and enable to efficiently confirm whether or not the rotation is normal, by a method wherein a plurality of marks provided at a predetermined interval on the same circumference of circle on an end face of a platen are optically read, and are compared with a controlling signal for the rotation of the platen. CONSTITUTION:After fitting a paper onto the platen, a controlling circuit 5 is set in accordance with a required paper-feeding velocity. The circuit 5 provides a motor-driving part 7 with a controlling signal which designates a rotating amount. A platen shaft 10 is rotated by rotating a motor 8, whereby the platen is rotated together with the paper fitted thereon, and a photo-sensor detecting the passage of a reflective plate sends a pulse signal from a sensing circuit 4 to a diagnosing circuit 6. The controlling circuit 5 sends a controlling signal also to the diagnosing circuit 6. The diagnosing circuit 6 diagnoses whether or not the pulse signal from the photo-sensor accords with the controlling signal from the controlling circuit 5, and issues an alarm signal when both of the signals disaccord with each other. Accordingly, it can be diagnosed with favorable workability whether the rotating amount of the platen conforms to the designated amount.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a platen rotation amount diagnostic device, and features
The present invention relates to a device for self-diagnosing whether a platen for feeding paper in accordance with the timing of printing is rotating correctly by placing paper and rotating it in a printing unit of a printer, typewriter, etc.

[Prior art]

In printers and typewriters, paper is fed in the printing section by fixing and holding the paper on a platen.
This is done by rotating the platen. The rotation of the motor is transmitted through gears according to the instructions of the rotation control circuit, and the platen is rotated, but due to various reasons, including gear defects, the platen may not rotate as instructed. . In this way, the platen will not rotate properly, the paper feeding speed will become uneven, the timing of printing will be off, and the printed characters will overlap.
There was an inconvenience that the blank space was bright.

(Object of the Invention) The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to constantly detect the rotation of the platen and check whether it is normal or not with good workability.

[Structure of the invention]

In order to achieve the above object, the present invention includes a plurality of marks arranged at predetermined intervals on the same circumference of one end face of a platen, and a plurality of marks arranged near the end face, and optically detects the marks. A sensor for reading the ζ mark, a sensing circuit for generating a signal to be intercepted by the sensor for each layer that the mark passes through, and a sensing circuit for generating a signal to be output by the sensor for each layer that the mark passes through, and It is equipped with a diagnostic circuit for comparing a control signal, a signal, and the pulse signal to be applied to the motor drive unit to determine the pulse signal.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a platen rotation amount diagnosing device according to an embodiment of the present invention will be described in detail with reference to the drawings.

This platen rotation amount diagnostic device is installed in the printing section of a typewriter, and consists of 32 reflective plates 2 arranged at equal intervals on the same circumference on one end surface of the platen 1.
, a photo sensor 3 disposed to detect passage of the reflection plate, a sensing circuit 4 for processing a signal from the photo sensor 3 and sending it out as a pulse signal of a predetermined shape,
A control signal (CMD signal) issued by the control circuit 50 for specifying the rotation amount of the motor is compared with the pulse signal 1,
S for determining whether the platen rotation is normal or not.
It is composed of a disconnection circuit 6.

゛The photosensor 3 consists of a normal light-emitting element and a light-receiving element, and the light emitted by the light-emitting element is reflected by a reflection plate.
It is configured to be detected by a light receiving element.

Further, this platen 1 is configured such that the rotation of a motor 8 rotated by a motor drive unit 7 which receives a control signal from a control circuit 5 is transmitted to a platen shaft 10 via a gear 9, thereby causing the platen 1 to rotate. .

Next, the operation of this platen rotation amount diagnostic device U will be explained.

``First, after placing a sheet of paper (not shown) on the platen, the control circuit 5 is set according to the required sheet feeding speed.

The control circuit 5 gives a control signal 6 to the motor drive unit 7 to specify the amount of rotation. T In this way, the motor drive section 7 supplies power to the motor 8 in order to rotate it at a desired rotation amount.

On the other hand, the rotation of the motor 8 causes the platen shaft 10 to rotate, and the platen rotates together with the paper placed thereon. - The photo sensor that detects the passage of the reflector as the platen rotates sends a pulse signal to the diagnostic circuit 6 via the sensing circuit 4. □ The control circuit 5 also sends the control signal given to the motor drive unit 7 to the diagnostic enclosure 6.

Therefore, the diagnostic circuit 6 diagnoses whether the pulse signal from the photo sensor matches the control signal from the control circuit, and if they do not match,
A V green signal is emitted from the diagnostic circuit.

Therefore, it is only necessary to inspect the platen rotation mechanism such as the motor when there is a warning.

In this way, whether or not the amount of rotation of the platen is as instructed can be diagnosed with good workability.

In the example, the amount of rotation was detected by using a photo sensor to detect the passage (rotation) of the reflector; however, the detection is not limited to the reflector, and the passage can be detected by an optical sensor. It's fine as long as it's a mark that you can get.

〔Effect of the invention〕

As explained above, the present invention has marks arranged at predetermined intervals on the same circumference of the end surface of the falling platen, and a sensor for optically reading the marks. and a diagnostic circuit for converting the read signal emitted by the sensor into a pulse signal of a predetermined shape and comparing this pulse signal with a control signal emitted to control the rotation of the platen. Therefore, it is possible to constantly check whether the platen is being rotated normally or not with good workability.

[Brief explanation of the drawing]

The figure is an explanatory diagram showing a platen rotation amount diagnosing device according to an embodiment of the present invention.

Claims (1)

[Claims] Marks arranged at predetermined intervals on the same circumference of the end face of the platen, a sensor for optically reading the marks, a read signal from the sensor, and a control signal issued to control the rotation of the platen. A platen rotation amount diagnostic device comprising a diagnostic circuit for comparing the rotation amount of a platen.