JPH02127061A - Jam detection device for printer - Google Patents

Abstract

PURPOSE:To prevent the generation of huming and ignition effectively by detecting an output signal from a jam sensor and the pulse signal of a constant period output from a sensor output detecting means and installing a jam detector transmitting a jam detecting signal to a signal detecting display means as required. CONSTITUTION:When an output signal S11 is output from a jam sensor 1 and an output signal S13 from the second output port 2C of a micro-processor 2 is not the pulse signal of a constant period, a jam detecting signal S14 is transmitted over a signal detecting displaying means 3 by a jam detector 5. The signal detecting displaying means 3 receives the jam detecting signal S14, and 'blank-form jam generation' is displayed in a display section 4 in the signal detecting display means 3. When the output signal S11 is output from the jam sensor 1 and the pulse period output from the output port 2C of the microprocessor 2 is normal, the jam detecting signal S14 is not output from the jam detector 5. Accordingly, the jamming of a blank form can be detected even when the microprocessor is operated uncontrolledly.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a jam detection device for a printer, and in particular,
The present invention relates to a printer jam detection device for detecting a paper jam in a fixing unit of a printer equipped with a fixing unit.

[Conventional technology]

A conventional example is shown in FIG. In FIG. 2, a microprocessor 52 as a sensor output detection means is provided at the output stage of a jam sensor 51 equipped to detect a paper jam in the fixing section of the printer. A detection display means 53 is provided.

The output signal S of the jam sensor 51 is input to the input port 52a of the microprocessor 52, and the microprocessor 52 periodically outputs the output signal of the jam sensor 51 according to a preset program. When the jam sensor 51 output signal is detected, the jam detection signal s8 is sent to the next stage signal detection display means 53 through the output port 52b. The signal detection display means 53 detects this jam detection signal S! When the paper jam occurs, the display section 54 displays a message indicating that a paper jam has occurred.

Detection of paper jam in the fixing unit was performed as described in 2 above.

[Problem to be solved by the invention]

However, in the above conventional example, since jam detection is performed by the microprocessor program, when the microprocessor goes out of control due to external noise, etc.
Even if a paper jam happens to occur in the fixing section and a signal is output from the jam sensor, the jam cannot be detected and smoke and ignition occur due to heating of the heater or the like in the fixing section.

[Purpose of the invention]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a jam detection device for a printer that can improve the disadvantages of the conventional example and, in particular, can detect a jam even when a microprocessor goes out of control.

(Means for Solving the Problems) The present invention includes a jam sensor that detects a paper jam in a fixing unit, and a jam sensor that periodically monitors the output signal of the jam sensor and detects a jam when the output signal of the jam sensor is detected. The sensor output detection means outputs a signal to the signal detection and display means at the next stage.Then, the output stage between the jam sensor and the sensor output detection means is provided with an output signal from the jam sensor and from the sensor output detection means. A jam detection circuit is provided which detects the output pulse signal of a constant period and sends a jam detection signal to the signal detection and display means as necessary.Thus, the above-mentioned purpose can be achieved. It is something to do.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG.

The embodiment shown in FIG. 1 includes a jam sensor 1 that detects a paper jam in a fixing section (not shown), and a system that periodically monitors the output signal of this jam sensor 1 and detects an output signal 311 of the jam sensor. A microprocessor 2 is provided as a sensor output detection means for outputting a jam detection signal S+Z to a signal detection and display means 3 at the next stage. Then, at the output stage of the jam sensor 1 and the microprocessor 2, an output signal Sll from the jam sensor 1 and a constant cycle pulse signal output from the microprocessor 2,
A jam detection circuit 5 is provided which detects the jam detection signal and sends a jam detection signal to the signal detection and display means 3 as necessary.

To explain this in more detail, the output signal Sll of the jam sensor 1 can be input to the input port 2a of the microprocessor 2, and the microprocessor 2 periodically changes the output signal of the jam sensor 1 according to a preset program. be monitored.

When the output signal of the jam sensor 1 is detected, the jam detection signal StZ is sent to the next stage signal detection and display means 3 through the first output port 2b. When the signal detection and display means 3 receives this jam detection signal, it displays "paper jam occurrence" on the display section 4.

An output signal srs is input from the second output port 2C of the microprocessor 2 to the jam detection circuit 4. The jam detection circuit 4 monitors the microprocessor 2 by constantly detecting this signal SI3. That is, if this output signal S13 is a pulse signal with a constant period, it is determined that the microprocessor 2 is normal;
When the signal SI3 is no longer a constant periodic pulse signal, the microprocessor 2 determines that there is an abnormality. Since the output signal S11 of the jam sensor 1 is also input to the jam detection circuit 5 as described above, the output signal S is output from the jam sensor 1, and the output signal from the second output port 2C of the microprocessor 2 is also input. If 313 is not a constant cycle pulse signal, the jam detection circuit 5 sends a jam detection signal S+4 to the signal detection display means 3.

In response to this jam detection signal SI4, the signal detection and display means 3 displays on the display section 4 that "paper jam has occurred".

Also, here, the jam detection circuit 5 is connected to the jam sensor 1.
If the output signal S is output from the microprocessor 2 and the pulse cycle output from the second output port 2C of the microprocessor 2 is normal, the jam detection signal 314 is not output.

〔Effect of the invention〕

As described above, according to the present invention, the paper jam can be detected even if the sensor output detection means composed of a microprocessor or the like goes out of control when a paper jam occurs in the fixing section due to the function of the jam detection circuit. It is possible to provide a jam detection device for a printer that is unprecedented and excellent in that it can effectively prevent smoke and ignition from occurring due to heating of a heater or the like.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of a conventional jam detection device. 1...Jam sensor, 2...Microprocessor as sensor output detection means, 3...
- Signal detection display means, 5...Jam detection circuit. Patent applicant Japan Electric Co., Ltd. Nippon Electric Data Equipment Co., Ltd.

Claims (1)

[Claims] (1) A jam sensor detects a paper jam in the fixing unit, and the output signal of this jam sensor is periodically monitored, and when the output signal of the jam sensor is detected, the jam detection signal is displayed on the next stage signal detection. In the jam detection device for a printer, the output stage of the jam sensor and the sensor output detection means is provided with an output signal from the jam sensor and an output signal output from the sensor output detection means. 1. A jam detection device for a printer, comprising a jam detection circuit that detects a pulse signal of a constant period and sends a jam detection signal to the signal detection and display means as necessary.