JPH04290765A - Thermal printer - Google Patents

Abstract

PURPOSE:To confirm normality or abnormality in operation of a sheet feeding mechanism of a thermal printer with which printing is made, using rolled-up recording paper. CONSTITUTION:The present device is equipped with a sheet feeding roller 3 that feeds rolled-up recording paper 5, a gear 2 that drives said roller 3 and a motor 1, and is so constructed that the revolution of the aforementioned gear 2 is monitored by a revolution-monitoring sensor 4. Since the revolution of the gear 2 is monitored by the sensor 4, the motor 1 can be prevented from being broken when any emergency happens to the sheet feeding mechanism.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer that prints using a roll of recording paper.

0002

[Prior Art] Conventionally, thermal printers that use cut-shaped recording paper generally use a sensor to detect the end of the recording paper (paper end) when the paper feed mechanism cannot be driven due to some kind of load. It is determined whether the paper feeding mechanism is operating normally or not. The reason why the paper feed mechanism is not driving properly may be due to a paper jam due to recording paper, etc. In this case, a drive signal is input to the paper feed motor, but the motor itself cannot be driven, so in some cases This may lead to damage to the motor.

Specifically, if the paper feed mechanism is normal, it is possible to check whether the paper has been conveyed correctly by turning on the paper end sensor each time a sheet of cut paper is printed. . Further, when the paper feed mechanism is abnormal, the paper end sensor remains OFF even after printing one sheet of cut paper, so it can be confirmed that the recording paper is not being conveyed correctly.

0004

[Problems to be Solved by the Invention] However, in a thermal printer that uses a roll of recording paper, the paper end sensor must print until the end of one roll of the roll of recording paper; Even if the paper feeding mechanism becomes abnormal, it cannot be confirmed. In addition, a method of pre-printing markings that can be detected by a paper end sensor on each page of rolled recording paper increases the cost of rolled recording paper, and each page is printed by the user using the printer. Since the length of the recording paper is not determined, there have been problems such as the inability to use general-purpose roll-shaped recording paper.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, it is an object of the present invention to provide a thermal printer that can confirm whether the paper feeding mechanism is normal or abnormal even when recording paper is in the form of a roll.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the thermal printer of the present invention includes a paper feed roller for feeding a roll of recording paper, and a paper feed roller for rotating this paper feed roller. A configuration comprising a gear and a motor for rotating the gear, a sensor for monitoring the rotation of the gear, and a paper feed motor drive control means for controlling the drive of the motor based on a signal from the sensor. It is.

[0007]

[Operation] In a printer using roll-shaped recording paper, the present invention uses a sensor to monitor the rotation of a gear for driving the paper feed roller that carries in or out the recording paper, thereby preventing paper jams. This is to prevent damage to the motor by confirming that the paper feed mechanism is not operating properly due to the cause.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of the present invention, in which 1 is a paper feed motor, 2 is a paper feed gear that meshes with a gear 1a attached to the rotating shaft of this motor 1, and 3 is rotated by this gear 2. A paper feeding roller; 4 is a rotation monitoring sensor for the paper feeding gear 2; 5 is a roll of recording paper; 6 is a microcomputer that controls the drive of the motor 1 based on the signal from the rotation monitoring sensor 4; 7 is a rotation monitoring sensor 4; This is a waveform shaping circuit that shapes the signal waveform from.

Protection of the paper feed motor of the thermal printer configured as above will be explained using the configuration diagram in FIG. 1, the flowchart in FIG. 2, and the signal waveform diagram from the rotation monitoring sensor of the paper feed gear in FIG. 3. do.

When carrying in or out recording paper, the paper feeding motor 1 is driven by the paper feeding motor driving means of the microcomputer 6. When the paper feed motor 1 is driven, the paper feed gear 2 rotates, and the paper feed roller 3 rotates, thereby feeding the recording paper. The signal of the rotation monitoring sensor 4 of the paper feeding gear 2 at this time is as shown in FIG.
It can be confirmed that the paper feed mechanism is normal. Here, if a paper jam or the like occurs between the paper feed roller 3 and the rolled recording paper 5, the paper feed roller 3 will not be able to rotate. When the paper feed roller 3 becomes unable to rotate, the paper feed gear 2 and the paper feed motor 1 also become unable to rotate at the same time. In this case, the signal from the rotation monitoring sensor 4 that monitors the rotation of the paper feeding gear 2 is as shown in FIG. 3, and it can be confirmed that the paper feeding mechanism is abnormal. When it is confirmed that the paper feeding mechanism is abnormal, the paper feeding drive signal outputted from the microcomputer 6 is turned off, thereby preventing the paper feeding motor 1 from being damaged.

The above operation is shown in a flowchart as shown in FIG. Further, an example of the rotation monitoring sensor 4 is shown in FIG. When the paper feed gear 2 rotates, the rotation monitoring sensor 4
The signal output from the microcomputer 6 via the waveform shaping circuit 7 is a pulsed signal as shown in FIG. This is because the light from the photosensor 8 is transmitted or blocked through the through hole 2a provided in the paper feeding gear 2. On the other hand, when the paper feeding gear 2 does not rotate, the signal has no pulse as shown in FIG. This is because the light from the photosensor does not pass through the through hole 2a provided in the paper feed gear 2, nor is it blocked, and the paper feed gear 2 stops in either state.

According to the configuration of the above embodiment, it is possible to check whether the paper feeding mechanism of the printer is operating normally or not by monitoring the signal from the rotation monitoring sensor of the paper feeding gear. can.

[0013]

Effects of the Invention As described above, the present invention can improve the normal operation of the paper feeding mechanism even in printers using roll-shaped recording paper.
Abnormalities can be confirmed, and if an abnormality occurs, the drive of the paper feed motor is stopped, thereby preventing damage to the motor.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a thermal printer according to an embodiment of the present invention.

[Figure 2] Flowchart showing the protection of the paper feed motor in the same printer

[Figure 3] Waveform diagram showing signals from the rotation monitoring sensor of the paper feed gear in the same printer

[Fig. 4] A configuration diagram showing an example of a rotation monitoring sensor in the same printer.

[Explanation of symbols]

1 Paper feed motor 2 Paper feeding gear 3 Paper feed roller 4 Rotation monitoring sensor 5 Rolled recording paper 6. Microcomputer

Claims (1)

[Claims] Claim 1: A paper feed roller for feeding a roll of recording paper, a gear for rotating this paper feed roller, and a motor for rotating this gear, and the rotation of the gear is monitored. What is claimed is: 1. A thermal printer comprising: a sensor for controlling a thermal printer; and a paper feed motor drive control means for controlling drive of the motor based on a signal from the sensor.