JPH01209264A - Paper jam detecting circuit - Google Patents

Abstract

PURPOSE:To enable a jam of paper and its run out to be promptly detected by mounting each sensor to a position of the paper before its intake and after its discharge and detecting how many number of paper sheets is present between these two sensors. CONSTITUTION:Continuous paper 1 is sucked into a platen 4 from a tractor 2, in this time, an optical sensor 3, mounted to the tractor 2, detects a hole of the paper 1. Next, the continuous paper 1 is discharged passing through between the platen 4 and a pressure roller 5, but an optical sensor 6, mounted to the pressure roller 5, detects the hole of the paper 1. A counter A counts a detecting signal of the optical sensor 3, while also a counter B counts a detecting signal of the optical sensor 6, and a comparator arithmetic circuit fetches a difference amount between values of the counters A, B, detecting what number of sheets of the paper 1 is present between the two optical sensors 3, 6. As the result, when the number of sheets of the paper 1 reaches a certain value not less than the fixed value, an alarm signal is output as the paper jam.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a circuit for detecting a jam of continuous paper.

[Prior Art] Conventionally, this type of paper jam detection circuit has used one sensor.

[Problem to be solved by the invention]

In conventional continuous paper jam detection circuits, paper jams are detected using a single sensor, so there is a drawback that it is difficult to distinguish between a paper jam state and whether the paper feed mechanism has not operated. Ta.

[Means to solve the problem]

According to the present invention, two sensors are installed before and after the continuous paper is sucked into the platen, two counters are installed to count the number of paper feeding holes detected by the two sensors, and two counters are installed at the positions before and after the continuous paper is drawn into the platen. A paper jam detection circuit having a comparison calculation circuit that compares values, detects a paper jam, and outputs a jam alarm is obtained.

〔Example〕

Next, the present invention will be described in detail with reference to the drawings showing one embodiment of the present invention.

Referring to FIG. 1, in one embodiment of the present invention, a continuous sheet of paper 1 is drawn onto a platen 4 by a tractor 2. As shown in FIG.

At that time, the optical sensor 3 attached to the tractor 2
detects holes in paper 1.

The continuous paper 1 is ejected passing between the platen 4 and the pressure roller 5, and an optical sensor 6 attached to the pressure roller 5 detects holes in the continuous paper 1.

Referring to FIG. 2, the counter 7 counts the detection signal of the optical sensor 3, and the counter 8 counts the detection signal of the optical sensor 6. Comparison calculation circuit 9 takes the difference between the values of counters 7 and 8, detects how much paper is between the two optical sensors, and if it exceeds a certain value, issues an alarm signal as a paper jam. .

〔Effect of the invention〕

As explained above, according to the present invention, sensors are installed at positions before paper is sucked in and after paper is ejected, and the paper is detected by detecting how much paper is between the two sensors. If a jam occurs or breaks, it can be detected immediately.

[Brief explanation of the drawing]

1 and 2 are an external view and a block diagram of an embodiment of the present invention. Continuous paper, 2: Tractor, 3: Optical sensor, 4 Nibraten, 5: Pressure roller, 6: Optical sensor, 7
: Counter, 8: Counter, 9: Comparison calculation circuit. Agent Patent Attorney Susumu Uchihara

Claims (1)

[Claims] Two sensors are installed at the positions before and after the continuous paper is sucked into the platen, two counters count the number of paper feeding holes detected by the two sensors, and the values of the two counters are A paper jam detection circuit comprising: a comparison calculation circuit that compares, detects a paper jam, and outputs a jam alarm.