KR19980015684A - Temperature and humidity detection device of electrophotographic apparatus - Google Patents

Abstract

The present invention relates to an electrophotographic image forming apparatus and an electrophotographic image forming apparatus, in which a temperature sensor and a humidity sensor are installed around a drum to detect changes in dry bulb temperature and wet bulb temperature, respectively, A developing device 2 for attaching toner to the electric latent image of the photosensitive drum 1; a transferring device 3 for transferring the toner to the paper; A temperature sensor 5 provided around the drum 1 for detecting the temperature and humidity around the drum 1 and a humidity sensor 5 for detecting the temperature and humidity around the drum 1, And a controller 7 for receiving the signals of the temperature sensor 5 and the humidity sensor 6 and controlling the heater 4 constitute an apparatus for detecting the humidity of the electrophotographic apparatus.

Description

Temperature and humidity detection device of electrophotographic apparatus

The present invention relates to an electrophotographic apparatus and, more particularly, to an electrophotographic apparatus in which a temperature sensor and a humidity sensor are installed around a drum to detect changes in dry bulb temperature and wet bulb temperature, The present invention relates to a temperature and humidity detecting apparatus for an electrophotographic apparatus.

A general electrophotographic apparatus includes a charging unit for charging a surface of a photoreceptor drum with a predetermined charge when a paper is supplied by a paper feeder, a developing unit for attaching the toner to the electric latent image of the photoreceptor drum, A conveying unit for guiding the conveyance of the image formed by the electrical force of the toner when passing through the transferring unit, the photosensitive drum and the transfer knob, and a conveying unit for conveying the image on the conveyed sheet guided by the conveying unit, .

There are the following two types of devices using the conventional electrophotographic principle.

First, in the case of a compact type, it is determined that the product is used in an office environment at room temperature without adopting a temperature and humidity sensor, and is set in advance under optimum conditions.

Second, in the case of medium and large size high-grade type, only the temperature sensor around the drum is detected to detect the temperature change inside the machine, and this is reflected in the heater installed around the drum to raise the internal temperature so that the optimum condition is maintained. In some cases, a temperature sensor is provided inside the developing unit to compensate for the changed temperature and to reflect the toner concentration control so that the proper amount of toner is replenished and the image density is maintained.

However, in the first case, when the humidity is high, such as extreme temperature or rainy season, moisture is generated on the surface of the drum to damage the image quality and the machine, especially the drum. In the second case, However, it is impossible to prevent an abnormal image from being generated due to moisture absorption of the toner inside the developing device. Further, even when a temperature sensor is provided inside the developing device to adjust the toner supply amount in accordance with the environmental change, there is a problem that it is impossible to cope with the high humidity environment in the summer.

SUMMARY OF THE INVENTION The present invention has been made to solve such conventional problems, and it is an object of the present invention to provide a temperature sensor and a humidity sensor in the vicinity of a drum to detect changes in dry bulb temperature and wet bulb temperature, And an object thereof is to provide an apparatus for detecting the temperature and humidity of an electrophotographic apparatus in order to maintain image quality.

In order to achieve the above object, according to the present invention, there is provided an image forming apparatus comprising: a developing unit for attaching toner to an electric latent image of a photosensitive drum; a transfer unit for transferring toner to the sheet; A temperature sensor and a humidity sensor provided around the developing unit for detecting the temperature and humidity around the drum, and a controller for controlling the heater by receiving signals from the temperature sensor and the humidity sensor, Is a feature of the present invention.

1 is a block diagram of the present invention,

2 is a circuit diagram of the present invention,

Description of the Related Art [0002]

1 ... drum 2 ... developing unit

3 ... Fragment 4 ... Heater

5 ... Temperature sensor 6 ... Humidity sensor

7,

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings.

1 and 2 show an embodiment of the present invention. The developing apparatus 2 includes a developing unit 2 for attaching toner to an electrostatic latent image on the photosensitive drum 1, a transfer unit 3 for transferring toner to the sheet, A temperature sensor 5 provided around the drum 2 for detecting the temperature and humidity around the drum 1; A humidity sensor 6 and a controller 7 for receiving the signals of the temperature sensor 5 and the humidity sensor 6 and controlling the heater 4 constitute an apparatus for detecting the humidity of the electrophotographic apparatus.

A power PCB substrate 8 is provided between the heater 4 and the control unit 7 so that the power of the heater 4 is supplied and cut off.

The temperature and humidity conditions detected by the temperature sensor 5 and the humidity sensor 6 when the electrophotographic apparatus is used are sent to the control unit 7 and the initial The drum 1 and the developing unit 2 are heated by applying power to the heater 4 in the case of low temperature or high humidity which is lower than a predetermined temperature and humidity.

The temperature sensor 5 and the humidity sensor 6 detect environmental changes and continuously send a signal to the control unit 7 so that the drum 1 and the periphery of the developing unit 2 are kept at proper temperature and humidity The control unit 7 turns off the power supply to the heater 4. [

The temperature sensor 5 and the humidity sensor 6 detect changes in the environment of the drum 1 and the developing cartridge 2 and continuously send a signal to the control unit 7 to supply and cut off the power of the heater 4, The periphery of the drum 1 and the developing cartridge 2 heated by the drum 4 can be maintained at a proper temperature and humidity to obtain the best image quality.

The heater 4 may be a heater of a fixing device without being separately provided, and an on / humidity sensor may be used without using the temperature sensor 5 and the humidity sensor 6, respectively.

As described above, according to the present invention, a temperature sensor and a humidity sensor are installed around the drum to detect changes in the dry bulb temperature and the bulb temperature, respectively, and then the heater is heated to maintain the optimum temperature and the optimum humidity so that the best image quality can be maintained .

Claims (1)

A transferring unit for transferring the toner to the paper, a heater for heating the toner to maintain optimal temperature and humidity conditions, and a heater disposed around the drum, A temperature sensor and a humidity sensor for detecting the temperature and humidity around the drum, and a controller for receiving a signal from the temperature sensor and the humidity sensor to control the heater.