JPH05155081A - Printer - Google Patents

Abstract

PURPOSE:To detect trouble such as paper jamming, etc., by an inexpensive constitution. CONSTITUTION:A voltage monitor circuit 28, which monitors the driving voltages of a picking motor 8, carrier motor 13 and paper feeding motor 16, is provided, and when trouble such as paper jamming, etc., is generated, the output voltage of a power source 27 is reduced by the operation of a current restricting circuit 25, and the driving voltages of respective motors are reduced, and a reset signal is input from the voltage monitor circuit 28 to a central operation process unit 17 by the reduction of the driving voltages. When a reset signal is input in the central operation process unit 17, the motions of a printing head 10, the picking motor 8, carrier motor 13 and paper feeding motor 16 are stopped, and all the printing motions stop, and by this action, trouble such as paper jamming, etc., can be surely detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, and more particularly to a printer capable of detecting a trouble such as a paper jam.

[0002]

2. Description of the Related Art Some printers are capable of detecting troubles such as paper jams. For example, in a printer for continuous paper, photo sensors are provided opposite to paper feed holes formed at both ends in the width direction of the continuous paper,
The photo sensor can detect a paper jam by monitoring the passing state of the paper feed hole. Also,
A printer for cut sheets is provided with a plurality of sensors in the sheet feeding direction, and these sensors can detect the paper jam by monitoring the tip position of the cut sheet.

[0003]

However, the conventional structure as described above has a problem in that an expensive sensor such as a photo sensor is required and the cost is high.

An object of the present invention is to provide a printer capable of detecting troubles such as paper jams with a low cost structure.

[0005]

SUMMARY OF THE INVENTION According to the present invention, in a printer for feeding a recording paper or transporting a print head by operating a motor, the power for monitoring the drive power of the motor and detecting a trouble by the change of the drive power. The feature is that a monitoring circuit is provided.

[0006]

According to the present invention, a trouble such as a paper jam can be easily detected by the power monitoring circuit.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A printer to which the present invention is applied will be described below with reference to the drawings. In this printer, as shown in FIG. 1, a paper feed cassette 3 for accommodating the recording paper 2 is mounted inside a printer case 1 and a printing mechanism 4 is provided so that the recording paper 2 in the paper feed cassette 3 is The recording paper 2 is fed to the printing mechanism 4 for printing, and after printing, the printed recording paper 2 passes through the paper discharge port 5 formed in the printer case 1 and the printer case 1 is printed.
It is designed to be discharged to the outside.

The paper feed cassette 3 can be detachably attached and detached through a loading port 6 formed in the printer case 1, and the recording paper 2 can be replenished as needed. A picking roller 7 is provided above the paper feeding cassette 3, and the recording paper 2 is taken out from the paper feeding cassette 3 by the picking roller 7. The picking roller 7 is adapted to be driven by a picking motor 8 shown in FIG.

The printing mechanism 4 is provided with a platen 9 and a print head 10 facing the platen 9, and the recording paper 2 is fed between the print head 10 and the platen 9 for printing. It is supposed to be served. The platen 9 is extended in a direction orthogonal to the paper feeding direction (a direction perpendicular to the paper surface in FIG. 1) via a fixing means (not shown). The print head 10 is mounted on a carrier 11, and is integrally driven with the carrier 11 so as to run in a direction orthogonal to the paper feed direction. The carrier 11 is supported via a pair of guide shafts 12 so as to be movable in a direction orthogonal to the paper feeding direction, and is driven by a carrier motor 13 shown in FIG.

In the vicinity of the printing mechanism 4, a paper feed roller 14 is provided on the upstream side and a paper discharge roller 15 is provided on the downstream side, and the recording paper 2 taken out from the paper feed cassette 3 is a paper. The printing mechanism 4 by the feed roller 14
The recording paper 2 that has been fed to and printed on is ejected to the outside of the printer case 1 by the paper ejection roller 15 through the paper ejection port 5. The paper discharge roller 14 and the paper feed roller 15 are driven by the paper feed motor 16 shown in FIG.

In the printer constructed as described above,
As shown in FIG. 2, the picking motor 8, the print head 10, the carrier motor 13, and the paper feed motor 16 are connected to a central processing unit 17, and the central processing unit 17 controls the operation of the print head and each motor. It has become. The picking motor 8 is connected to the central processing unit 17 via a picking motor drive circuit 18 and a picking motor control circuit 19. Print head 1
0 is connected to the central processing unit 17 via the head drive circuit 20 and the head control circuit 21. The carrier motor 13 is connected to the central processing unit 17 via a carrier motor drive circuit 22 and a carrier motor control circuit 23. The paper feed motor 16 is a paper feed motor drive circuit 24.
It is also connected to the central processing unit 17 via the paper feed motor control circuit 25. A picking signal and print data are input to the central processing unit 17 during printing, the picking motor 8 is operated by the input of the picking signal, and the print head 10, the carrier motor 13, and the paper feed motor 16 are operated based on the print data. It is designed to be controlled.

The print head 10 has a current limiting circuit 26.
The picking motor 8, the carrier motor 13, and the paper feed motor 16 are connected to the power source 27 via the voltage monitoring circuit 28 and the current limiting circuit 26.

The current limiting circuit 26 limits the output current of the power supply 27 to a predetermined value or less by lowering the output voltage of the power supply 27 when the output current of the power supply 27 exceeds a predetermined value. The current limiting circuit 26 limits the output current of the power source 27 so that the output voltage of the power source 27 drops when a trouble such as a paper jam occurs. That is, the picking motor 8, due to a trouble such as a paper jam,
The load on the carrier motor 13 or the paper feed motor 16 increases, and the power source 27 is used to maintain the rotation of the motor.
Is increased, the output voltage of the power supply 27 is lowered by the action of the current limiting circuit 26. Note that the picking motor 8, the carrier motor 13, or the paper feed motor 1 may be caused by a trouble such as a paper jam.
When the load of 6 increases, the picking roller 7 is locked by a paper jam or the like, the carrier 11 is locked by a paper jam, or the paper feed roller 14 or the discharge roller 15 is locked by a paper jam or the like. It was when I locked it.

The voltage monitoring circuit 28 includes a picking motor 8,
The drive voltage of the carrier motor 13 and the paper feed motor 16 is monitored, and a reset signal is output to the central processing unit 17 when the output voltage of the power supply 27 decreases due to a trouble such as paper jam and the drive voltage of each motor decreases. It is supposed to do. From the voltage monitoring circuit 28 to the central processing unit 17
When the reset signal is input to the print head 10, the picking motor 8,
The operations of the carrier motor 13 and the paper feed motor 16 are stopped. A comparator is applicable as this type of voltage monitoring circuit 26.

Next, the operation will be described. When a trouble such as a paper jam occurs, the load of at least one of the picking motor 8, the carrier motor 13, and the paper feed motor 16 increases, and the output current of the power supply 27 is increased to maintain the rotation of the motor. Increase. When the output current of the power supply 27 increases, the output voltage of the power supply 27 decreases due to the function of the current limiting circuit 26, and the drive voltage of the picking motor 8, the carrier motor 13, and the paper feed motor 16 decreases, and this decrease of the drive voltage causes the output voltage of the power supply 27 to decrease. Voltage monitoring circuit 28
A reset signal is input to the central processing unit 17 from. When the reset signal is input to the central processing unit 17, the print head 10, the picking motor 8, the carrier motor 13 and the paper feed motor 16 are stopped from operating, and all the printing operations are stopped. The trouble of can be detected reliably.

Therefore, troubles such as a paper jam can be detected and the cost can be reduced with a low cost structure in which only the voltage monitoring circuit 28 is provided in the circuits of the picking motor 8, the carrier motor 13 and the paper feed motor 16. Further, since a sensor such as a photo sensor conventionally used for detecting a paper jam can be eliminated, the installation space can be effectively used and the degree of freedom in design is improved.

In the above embodiment, the drive voltage of the picking motor 8, the carrier motor 13, and the paper feed motor 16 is monitored and a trouble such as paper jam is detected by the change of the drive voltage. 8. It is also possible to monitor the drive currents of the carrier motor 13 and the paper feed motor 16 and detect troubles such as paper jams based on changes in the drive currents. For example, in FIG.
As shown in FIG. 3, the picking motor 8, the carrier motor 13, and the paper feed motor 16 are provided with a current monitoring circuit 31 for monitoring the drive current of each motor via the current transformer 30. The current monitoring circuit 31 may output a reset signal to the central processing unit 17 when the drive current of the motor increases to detect a trouble such as a paper jam. As shown in FIG. 4, the picking motor 8, the carrier motor 13, and the paper feed motor 16 are provided with a current monitoring circuit 31 for monitoring the drive current of each motor through the current detection resistor 32, and a paper jam or the like is detected. When a trouble occurs and the drive current of each motor increases, the current monitoring circuit 31 may output a reset signal to the central processing unit 17 to detect a trouble such as a paper jam.
When a trouble such as a paper jam is detected by monitoring the drive currents of the picking motor 8, the carrier motor 13 and the paper feed motor 16, the current limiting circuit 26 outputs the output of the power source 27. It is set to operate when the current becomes larger than when a trouble such as a paper jam occurs.

Further, in the above embodiment, when a trouble such as a paper jam occurs, the print head 10, the picking motor 8, the carrier motor 13 and the paper feed motor 16 are stopped to stop all printing operations. However, when the reset signal is input to the central processing unit 17, the central processing unit 17 is set so that the operations of only the picking motor 8 and the paper feed motor 16 are stopped, and trouble such as paper jam occurs. Only the paper feeding operation may be stopped when it occurs. Further, a display device or the like for issuing a warning may be connected to the central processing unit 17 so that when a trouble such as a paper jam occurs, the warning is issued at the same time when the paper feeding operation is stopped or all the printing operations are stopped. Alternatively, when a trouble such as a paper jam occurs, only the warning may be issued without stopping the paper feeding operation and all printing operations.

Further, in the above embodiment, the drive voltage or drive current of the picking motor 8, the carrier motor 13 and the paper feed motor 16 is monitored, and a trouble such as paper jam is detected by the change of the drive voltage or drive current. However, for example, the drive current of only the paper feed motor 16 may be monitored and a trouble such as a paper jam may be detected by the change of the drive current.

Further, in the above embodiment, an example in which the present invention is applied to a printer for cut paper has been described. However, the present invention can of course be applied to a printer for continuous paper or a printer which can use both continuous paper and cut paper. Is.

[0021]

As described above, according to the printer of the present invention, a paper jam or the like is formed at a low cost by simply providing a power monitoring circuit in the circuit of the motor for feeding the recording paper and conveying the print head. It has an excellent effect that troubles can be detected and cost can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a printer to which the present invention is applied.

FIG. 2 is a block circuit diagram of the printer of FIG.

FIG. 3 is a block circuit diagram showing another embodiment.

FIG. 4 is a block circuit diagram showing another embodiment.

[Explanation of symbols]

 8 Picking Motor 13 Carrier Motor 16 Paper Feed Motor 28 Voltage Monitoring Circuit (Power Monitoring Circuit) 31 Current Monitoring Circuit (Power Monitoring Circuit)

Claims (1)

[Claims] 1. A printer for feeding a recording paper or transporting a print head by operating a motor, comprising a power monitoring circuit for monitoring the driving power of the motor and detecting a trouble by a change in the driving power. Characteristic printer.