JPH0222676A - Device for driving fan motor for page printer - Google Patents

Abstract

PURPOSE:To restrain noise produced in a printing standby condition and to reduce considerably the noise produced in a printer by detecting the temperature of a thermal fixing device by means of a temperature detecting circuit, and controlling the rotational speed of a fan motor according to the detected temperature. CONSTITUTION:The detecting signal of the temperature detecting circuit 12 is applied to the processing circuit 24 of a control circuit 16; the processing circuit 24 judges the temperature of a heating roller 11 by using the detecting signal of the temperature detecting circuit 12. The output data of the processing circuit 24, employing the judged result as its content, is given to a decoder 26; and one of the drivers 28-1, 28-2, and 28-3 is driven in response to a decode output from the decoder 26. In the case of the judgement that the detected temperature of the heating roller 11 is about 140 deg.C, the processing circuit 24 ascertains that printing is on standby; the driver 28-1 is driven, and the fan motor 14 is rotated at low speed. Since fan noise is restrained in the standby condition, the noise caused by page printer is made far less.

Description

[Detailed Description of the Invention] [Summary] The purpose of the present invention is to provide a device for driving a fan motor of a page printer that can improve the quietness of the page printer, and to detect the temperature of a heat fixing device. It is comprised of a detection circuit and a motor control circuit that suppresses the rotation speed of the fan motor according to the detected temperature.

[Industrial Field of Application] The present invention relates to a device for driving a fan motor of a page printer.

Since page printers consume a large amount of current, a single motor is used to prevent the temperature inside the printer from rising.

[Prior Art] Conventionally, a fan motor is always rotated at a constant speed, so that the number of rotations is the same even when the page printer is on standby for printing and during printing.

[Problems to be Solved by the Invention] Therefore, the noise generated by the fan motor is generated during printing standby as well as during printing, and the quietness of the page printer is impaired.

The present invention has been made in view of the above-mentioned conventional problems,
The purpose is to provide a fan motor drive device for a page printer that can suppress noise during printing standby and improve the quietness of the printer.

[Means for Solving the Problems] In order to achieve the above object, the device according to the present invention has the following features:
The temperature detection circuit 12 and the motor control circuit 16 shown in FIG. controlled.

[Function] Approximately 80% of the heat generated inside the page printer is generated by the heat fixing device 10, and its temperature is low when the page printer is on standby for printing, and high during printing.

In the present invention, the rotation speed of the fan motor 14 is controlled according to the temperature of the heat fixing device 10, so the fan motor 14 is rotated at a low speed during printing standby when the temperature of the heat fixing device 10 is low, and during printing, the fan motor 14 is rotated at a low speed. It becomes possible to rotate this at high speed.

[Embodiments] Hereinafter, preferred embodiments of the apparatus according to the present invention will be described based on the drawings.

In the figure, an AC power source 20 is connected to a heat roller 11 of a thermal fixing device 10, and the heat roller 11 is energized by the AC power source 20 via a power conversion circuit 18.

The heat fixing device 10 is provided with a thermistor 21 whose resistance value changes depending on the temperature of the heat roller 11.

In the temperature detection circuit 12, a detection signal corresponding to the temperature of the heat roller 11 is obtained from the resistance value of the thermistor 21, and the power conversion circuit 18 is controlled by the energization control circuit 22 in accordance with this detection signal.

As a result, the amount of current (applied voltage) to the heat roller 11 is adjusted according to the temperature of the heat roller 11, and the temperature is controlled in a direction that matches the set temperature.

As a result, the heat roller 11 reaches a high temperature (approximately 190° C. in this embodiment) while the printer is printing, and a lower temperature (approximately 140° C. in this embodiment) while waiting for printing.

Further, the detection signal of the temperature detection circuit 12 is transmitted to the motor control circuit 1.
6, and the processing circuit 24 uses the detection signal of the temperature detection circuit 12 to detect the heat roller 11.
temperature is determined.

The output data of the processing circuit 24 containing the determination result is given to the decoder 26, and the decoded output of the decoder 26 drives one of the drivers 28-1, 28-2, and 28-3.

Furthermore, the output voltage of the driver 28-1 is applied to the fan motor 14.
The output voltage of the driver 28-2 and 28-3 is supplied through a resistor 30-1 with a low resistance value and a resistor 30-2 with a high resistance value, respectively.

Therefore, the fan motor 14 is controlled to the highest rotation speed when the driver 28-1 is driven, is controlled to the lowest rotation speed when the driver 28-3 is driven, and is controlled to the lowest rotation speed when the driver 28-2 is driven. When the engine is rotated, the rotation speed is controlled to two intermediate rotation speeds.

Here, if it is determined that the detected temperature of the heat roller 11 is approximately 140° C., the processing circuit 24 confirms that printing is on standby.

As a result, the driver 28-3 is driven and the fan motor 14 is rotated at a low speed.

Further, when it is determined that the detected temperature of the heat roller 11 is approximately 190, the processing circuit 2 indicates that printing is in progress.
Confirmed in 4.

This drives the driver 28-1 and rotates the fan motor 14 at high speed.

In this way, the fan motor 14 rotates at high speed during printing when the temperature of the heat roller 11 is high and a large amount of air is required to be blown, but during standby for printing when the temperature of the heat roller 11 is low and hardly any air is needed. , the fan motor 14 is rotated at low speed.

Therefore, according to this embodiment, the air blown by the fan motor 14 is adjusted as necessary, and the amount of air blown is reduced during printing standby.

Therefore, it is possible to suppress fan noise during printing standby and further improve the quietness of the page printer.

Furthermore, according to this embodiment, the temperature detection system of the heat roller 11 is also used as the energization control system, so that an increase in manufacturing costs can be suppressed.

Note that the energization control circuit 22 is omitted and the energization control circuit 2
It is also preferable to have the processing circuit 24 carry out the energization control according to 2.

[Effects of the Invention] As explained above, according to the present invention, the speed of the fan motor is controlled according to the temperature of the heat fixing device, so the fan noise 5 is suppressed during printing standby, making page linking even quieter. It is possible to increase it.

[Brief explanation of the drawing]

The figure is an explanatory diagram of the configuration of the embodiment. 1011・ 11　・・ 12・・ 14・・ 16・・ 18・・ 20・・ 21　・・ 22・・ 24・・ 26・・ 28-1° 30-1° ・Heat fixing device, ・Heat roller, ・Temperature detection circuit, ・Fan motor, ・Motor control circuit, ・Power conversion circuit, ·AC source, ・Thermistor, ・Electrification control circuit, ・Processing circuit, ·decoder, 28-2.28-3... 30-2...Resistor. driver,

Claims (1)

[Claims] A temperature detection circuit (12) that detects the temperature of a heat fixing device (10).
); and a motor control circuit (16) that controls the rotational speed of the fan motor (14) according to the detected temperature.