JPH0558507A - Paper jam detection circuit - Google Patents

Abstract

PURPOSE:To provide a paper jam detection circuit which can stop automatically a motor in a case in which a document has been jammed between rollers driven in rotation by means of the motor. CONSTITUTION:At a document sending out device such as an image scanner, a fax machine, the drive output signal 102 of a motor drive circuit 110 and a predetermined threshold signal 104 from a threshold generating circuit 113 are compared with each other by means of a comparator 112, and in the case of the drive output signal 102 being larger than the threshold signal 104, it is decided that the motor is in a paper jam under the condition of overload, and the control of the motor drive circuit 110 is made so as to stop the rotation of the motor 111. Accordingly, the damage of a document owing to paper jam caused by the document having been jammed can be prevented effectively.

Description

Detailed Description of the Invention

[0001]

This invention relates to an image scanner,
The present invention relates to a paper jam detection circuit when a document is stuck in a roller in a document sending device such as a fax machine.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing a related configuration of a conventional motor drive circuit and a motor. In the figure, 11
Reference numeral 0 is a motor drive circuit operated by a start / stop signal 101 which is an input signal, and 111 is a motor whose rotation is controlled by a drive output signal 102 of the motor drive circuit 110.

FIG. 4 is a partial block diagram for explaining a mode in which an original is sent by a roller rotated by driving the motor shown in FIG. In the figure, 1 is a document, 2 and 3 are rollers, and 4 is an arrow indicating the feeding direction of the document 1.

Next, the operation when a document is sent using the conventional motor drive circuit shown in FIG. 3 and the motor whose rotation is controlled by the conventional motor drive circuit will be described. When the start signal of the start / stop signal 101, which is an input signal, is input to the motor drive circuit 110, the motor drive circuit 11
0 operates and the drive output signal 102 of the motor drive circuit 110 is given to the motor 111,
11 starts operation. When the motor 111 starts rotating, the rollers 2 and 3 are rotationally driven by the motor 111, and the document 1 sandwiched between these rollers 2 and 3 is fed in the feeding direction indicated by the arrow 4.

Then, when the operation of sending the original 1 is completed,
The stop signal of the start / stop signal 101 is input to the motor drive circuit 110, and the motor drive circuit 110 receives the stop signal.
Drive output signal 102 is applied to the motor 111, the motor 111 stops its rotation. Here, the start / stop signal 101 is 2 for start / stop.
The drive output signal 102 of the motor drive circuit 110 is a voltage signal given to the motor 111 and is an analog value.

[0006]

Since the conventional motor drive circuit and the related structure of the motor are configured as described above, the motor drive circuit 110 for controlling the rotation of the motor 111 simply replaces the motor 111. Or rotate it,
Or it only controls whether or not to rotate it,
Therefore, for example, in a document feeding device such as an image scanner or a fax machine, a document 1 such as paper sandwiched between rollers 2 and 3 which is driven to rotate by a motor 111 is fed in a feeding direction indicated by an arrow 4. When the document 1 is jammed between the rollers 2 and 3 while the roller 2 and 3 are rotating, there is a problem in that the rotational driving of the rollers 2 and 3 cannot be automatically stopped.

The present invention has been made to solve the above problems, and when a document is fed while being sandwiched between rollers which are rotationally driven by a motor, the document is jammed between the rollers. An object of the present invention is to obtain a paper jam detection circuit that can automatically stop the motor if it does.

[0008]

SUMMARY OF THE INVENTION A paper jam detection circuit according to the present invention uses a comparator to compare a drive output signal of a motor drive circuit which varies depending on a load state of a motor and a predetermined threshold signal from a threshold generation circuit. In comparison, if the drive output signal of the motor drive circuit is larger than the threshold value signal, it is judged that the motor is in the paper jam of the overload state and the motor drive circuit is controlled so as to stop the rotation of the motor. is there.

[0009]

In the paper jam detection circuit according to the present invention, when the motor is overloaded, it is controlled so as to stop the rotation of the motor by detecting the drive output signal of the motor drive circuit. The rotation of the motor can be automatically stopped.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a block diagram showing a configuration of a paper jam detection circuit according to an embodiment of the present invention. In the figure, 110
Is a motor drive circuit operated by a start / stop signal 101 which is an input signal, and 111 is a motor drive circuit 1
10, a motor whose rotation is controlled by the drive output signal 102, 113, a threshold value generation circuit that generates a predetermined threshold value signal 104, 112, a drive output signal of the motor drive circuit 110 that varies depending on the load state of the motor 111 102
And a predetermined threshold signal 1 from the threshold generation circuit 113
Reference numeral 04 is a comparator, and 103 is a comparison output signal generated based on the comparison result of the comparator 112.

Next, the operation of the paper jam detection circuit according to the embodiment of the present invention shown in FIG. 1 will be described. The start signal of the start / stop signal 101, which is an input signal, is input to the motor drive circuit 110, and
The drive output signal 102 of the motor drive circuit 110 is the motor 1
It is the same as the conventional example shown in FIG. 3 until the motor 111 starts to rotate by being input to 11.

On the other hand, the drive output signal 102 of the motor drive circuit 110 is a voltage signal, and this drive output signal 102 varies depending on the load state of the motor 111. Then, when the motor 111 is overloaded, the voltage value of the drive output signal 102 of the motor drive circuit 110 input to the motor 111 increases. Therefore, the drive output signal 102 of the motor drive circuit 110 input to the comparator 112 and the predetermined threshold value signal 104 from the threshold value generation circuit 113 are compared by the comparator 112, and the drive output signal 102 is If it is larger than the threshold signal 104, it is determined that the motor 111 is in an overload state. That is, it is determined that the paper jam has occurred, the motor drive circuit 110 is controlled by the comparison output signal 103 generated based on the comparison result from the comparator 112, and the rotation of the motor 111 is controlled by the drive output signal 102 of the motor drive circuit 110. Try to stop it.

FIG. 2 is a block diagram showing the configuration of a paper jam detection circuit according to another embodiment of the present invention. Reference numerals 101 to 104, 110 to 113 are the same as those shown in FIG. In the figure, 211 is a time control circuit, and this time control circuit 211 is a motor drive circuit 110.
The control output signal 201 is generated when the driving output signal 102 of FIG. 1 becomes stable, and the control output signal 201 is output to the selection circuit 210 described later. 210 is a selection circuit, and this selection circuit 210 outputs a selection output signal 202 to the motor drive circuit 110.

The operation of the paper jam detection circuit according to another embodiment of the present invention shown in FIG. 2 will be described below. The start signal of the start / stop signal 101, which is an input signal, is input to the motor drive circuit 110, and the drive output signal 102 of the motor drive circuit 110 is input to the motor 111. The drive output signal 102 and the threshold value generation circuit 113 are input. The predetermined threshold value signal 104 from the above is compared by the comparison element 112, and when the drive output signal 102 is larger than the threshold value signal 104, the comparator 11
2 to the output of the comparison output signal 103 shown in FIG.
Is similar to the embodiment shown in FIG.

Further, the start signal of the start / stop signal 101 which is an input signal is input to the time control circuit 211. Drive output signal 102 of motor drive circuit 110
Indicates a voltage value higher than the normal operating voltage at the time of rising, the time control circuit 211 generates the control output signal 201 when the drive output signal 102 of the motor drive circuit 110 stabilizes. The selection circuit 210 is
After receiving the control output signal 201 of the time control circuit 211,
The comparison output signal 103 from the comparator 112 is output as the selection output signal 202 to the motor drive circuit 110 to control the motor drive circuit 110, and the rotation of the motor 111 is stopped by the drive output signal 102 of the motor drive circuit 110. To let

[0016]

As described above, according to the paper jam detection circuit of the present invention, the drive output signal of the motor drive circuit which varies depending on the load condition of the motor is compared with the predetermined threshold signal from the threshold value generation circuit. If the drive output signal of the motor drive circuit is larger than the threshold value signal, it is determined that the motor is overloaded paper jam, and the motor drive circuit is controlled to stop the rotation of the motor. Since it is configured, it is possible to automatically detect the drive output signal of the motor drive circuit and stop the rotation of the motor when the motor is overloaded to effectively prevent damage to the original due to paper jam. Produce the effect.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a paper jam detection circuit according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a paper jam detection circuit according to another embodiment of the present invention.

FIG. 3 is a block diagram showing a related configuration of a conventional motor drive circuit and a motor.

FIG. 4 is a partial configuration diagram for explaining an aspect in which an original is sent by a roller rotated by driving the motor of FIG.

[Explanation of symbols]

 1 Original 2, 3 Roller 4 Arrow 101 Start / Stop Signal 102 Drive Output Signal 103 Comparison Output Signal 104 Threshold Signal 110 Motor Drive Circuit 111 Motor 112 Comparator 113 Threshold Generation Circuit 201 Control Output Signal 202 Select Output Signal 210 Selection circuit 211 Time control circuit

Claims (1)

[Claims] 1. In a document sending device such as an image scanner or a fax machine, a motor drive circuit which is operated by an input signal and controls the rotation of a motor, and a drive output signal of the motor drive circuit which fluctuates depending on a load state of the motor. And a predetermined threshold value signal from the threshold value generating circuit, and the motor based on the comparison output signal generated by the difference between the drive output signal of the motor driving circuit and the threshold value signal. A paper jam detection circuit, comprising: a control unit that controls a drive circuit.