JPH03215061A - Detection system of direction for sheet introduction - Google Patents

Abstract

PURPOSE:To enable a single photosensor to detect in which part a sheet is introduced, front or rear by providing a constitution in which a sensor lever having two holes is rotated by a printing sheet which is transported and the rotation is detected by the photosensor. CONSTITUTION:If a printing sheet 1 is transported from the front, a sensor lever 3 having two holes rotates centered around a sensor shaft 2. A sheet presence detection part becomes located in the position of one of the holes 4 of the sensor lever 3, then the sensor lever 3 becomes separated from the photosensor 6 which now detects 'no sheet is present' and the photosensor detects 'sheet is present' from 'no sheet is present'. If the sheet 1 is transported from the rear, the hole 4, of the sensor lever 3, which is located at the sheet presence detection part 6 before the introduction of the sheet and another hole 7 pass through the sheet presence detection part of the photosensor 6 continuously, when the sensor lever 3 becomes separated from the photosensor 6. Then the photosensor 6 detects 'no sheet is present', 'sheet is present', 'no sheet is present' and 'sheet is present' in that order. Thus a single photosensor 6 can detect in which part the sheet 1 is introduced, front or rear.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a paper feeding direction detection method, and more particularly to a paper feeding direction detection method in which the paper feeding direction is detected using one paper detection sensor.

[Conventional technology]

Conventionally, in this type of paper feed direction detection method, it has not been possible to detect the paper feed direction using a single paper detection sensor.

[Problem to be solved by the invention]

The above-described conventional paper feed detection method has the disadvantage that it increases costs because it cannot be detected unless a paper detection sensor is attached to each paper feed path.

[Means to solve the problem]

The paper feed direction detection method of the present invention uses a paper feed drive motor as a drive source, and uses a gear fixed to the motor shaft of the drive source and a power transmission means that engages with the gear to create a cylindrical cylinder that performs printing backup and paper feed. In a printer having a feed roller in the shape of a shape, when printing paper is fed from the front by the power transmission means, the sensor shaft is held so as to freely rotate. A sensor lever attached thereto and having two holes drilled at equal distances from the sensor shaft is rotated around the sensor shaft by the fed printing paper, and the sensor lever is held between the sensor levers and the paper is fed. Previously, the paper presence/absence detection section is located at the position of one hole of the sensor lever, and the sensor lever moves away from the photo sensor which detects "no paper", and detects "no paper" → "paper present". Furthermore, when the printing paper is fed from the rear by the power transmission means and the sensor lever leaves the photo sensor, the hole in the sensor lever located in the paper presence/absence detecting section is opened before the paper is fed. Both holes, ie, the other hole, successively pass through the paper presence/absence detecting section of the photosensor, and detect "no paper" → "paper present" → "no paper" → "paper present". This results in the above 2
The present invention is characterized in that one of the photosensors can detect whether the paper is fed from the front or the rear using a type detection method.

〔Example〕

1 to 3 are configuration diagrams of an embodiment of the present invention.

This paper feed direction detection method uses a paper feed drive motor as the drive source, and uses a gear fixed to the motor shaft of the drive source and a power transmission means that engages with the gear to perform printing backup and paper feed. In a printer having a shaped feed roller, a sensor shaft 2 is held so as to freely rotate when printing paper 1 is fed from the front by the power transmission means as shown in FIG.
A sensor lever 3, which is mounted so as to freely rotate on the sensor shaft 2 and has two holes equally spaced from the sensor shaft 2, is rotated about the sensor shaft 2 by the fed printing paper 1. , when the sensor lever 3 is held in place and before the paper is fed, as shown in FIGS. 1(a) and (b).
As shown in the figure, the paper presence/absence detection section 5 is located at the position of one hole 4 of the sensor lever 30, and the sensor lever 3 moves away from the photo sensor 6 which detects "no paper", and the state changes from "no paper" to "no paper". When the printing paper 1 is fed from the rear by the power transmission means as shown in FIG. 3, when the sensor lever 3 leaves the photo sensor 6, the Both the hole 4 of the sensor lever 3 and the other hole 7 located in the paper presence/absence detection section 6 are connected to the paper presence/absence detection section 5 of the photosensor 6.
are detected in the order of "No paper" → "Paper present" → "No paper" → "Paper present". This feature allows the single photosensor 6 to detect whether the paper 1 is fed from the front or the rear using the two detection methods described above.

〔Effect of the invention〕

As described above, the present invention has the advantage that it is possible to detect whether the paper is fed from the front or the rear using the one photo sensor using the two detection methods described above.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are front views of an embodiment of the present invention,
The side view, FIGS. 2 and 3 are configuration diagrams of the same embodiment. 1...Paper, 2...Sensor shaft,
3... Sensor lever 4, 7... Hole,
5...Paper presence/absence detection section, 6...Photo sensor.

Claims (1)

[Claims] A printer that uses a paper feed drive motor as a drive source and has a cylindrical feed roller that backs up printing and feeds paper by means of a gear fixed to the motor shaft of the drive source and a power transmission means that engages with the gear. When the printing paper is fed from the front by the power transmission means, the paper is attached to the sensor shaft, which is held so as to rotate freely, and is placed at an equal distance from the sensor shaft. A sensor lever having two holes drilled therein is rotated around the sensor shaft by the fed printing paper, and the position of one hole in the sensor lever is determined before the paper is fed. The sensor lever moves away from the photosensor where the paper presence/absence detection section is located and detects "no paper", and "no paper" and "with paper" are detected in that order, and the printing paper is moved from the rear to the power transmission means. When the sensor lever leaves the photosensor, both the hole in the sensor lever located in the paper presence/absence detection section and the other hole are closed before the paper is fed. The photosensor continuously passes through the paper presence/absence detection section and detects "no paper,""paperpresent,""nopaper," and "paper present" in this order, and thereby the two types of detection methods described above detect the paper in the front and back. A method for detecting the feeding direction of paper, characterized in that one of the photosensors can detect which direction from the rear the paper is fed from.