JPS6076758A - Dew condensation preventive device of electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To prevent surely dew condensation in a copying machine with low electric power consumption by detecting the difference between the internal and external temps. of the copying machine with temp. sensors and starting or stopping automatically a heater for preventing condensation. CONSTITUTION:An internal temp. sensor 3 is provided in a place near an optical system and photosensitive drum in a copying machine and on the other hand, an external temp. sensor 4 is provided in a proper place on the outside of the machine. The values detected with these sensors 3, 4 are respectively amplified by amplifiers 5, 6 in a controller 9 and the difference between both temps. is amplified by a temp. difference amplifier 7 and is inputted to a temp. controller 8. A heater 2 preventing condensation is started when the external temp. rises higher than the internal temp. and conversely the operation of the heater 2 is stopped when the internal temp. rises higher than the external temp. The generation of wasteful consumption of electric power by operating unnecessarily the heater for long time is thus obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a dew condensation prevention device for an electronic copying machine. The present invention relates to a condensation prevention device for an electronic copying machine that controls the operation of a condensation prevention heater.

BACKGROUND OF THE INVENTION In conventional electronic copying systems, copying troubles occur due to condensation in optical systems including lenses and mirrors, photosensitive drums, etc. within a copying machine. Condensation occurs when the room temperature suddenly rises due to combustion type heaters such as kerosene heaters, and it is particularly likely to occur immediately after heating starts in the winter. In such a case, the air around the copying machine is rapidly heated by the heater, and the humidity in the room is sieved by water generated from the combustion of oil, etc.; This air enters the copier and melts on parts within the copier which are still at a much lower temperature than the air, causing condensation on the parts. In order to prevent such condensation on the parts inside the copying machine, a condensation prevention heater is usually installed inside the copying machine. Starts energizing the heater when the main switch to activate the machine is turned off;■
One method is to install a thermistor or the like inside the copying machine and turn on the heater when the Isouchi temperature drop falls below a certain level. However, with this method, the time the heater is energized is very long in any case, and the heater is energized even when the copier is not being used for a long time, especially on holidays, resulting in wasted power consumption. In order to prevent this, the operator of K had to manage the on/off operation of the heater switch as appropriate depending on the situation.

OBJECTS OF THE INVENTION It is an object of the present invention to eliminate the drawbacks of controlling the I @ dew prevention heater in the conventional electronic copying machine as described above, and to achieve prevention of dew condensation within the copying machine reliably and with low power consumption. It is an object of the present invention to provide such a dew condensation prevention device.

Structure of the Invention The above-mentioned object of the present invention is to detect the temperature inside and outside the machine of an electronic copier, and when the temperature outside the machine becomes higher than the temperature inside the machine, activate the heater for preventing dew condensation inside the machine, and reduce the temperature outside the machine to zero. This is achieved by a dew condensation prevention device characterized in that the operation of the heater is stopped when the internal temperature becomes lower than the internal temperature qLe.

The present invention will be described in detail below with reference to the drawings.

In FIG. 1, 1 is a copying machine, and inside the machine there is an optical system that includes a lens 11 and a mirror 12, and a photosensitive drum 1.
6 is stored. If dew condensation occurs on the surface of these scraps, a serious problem will be caused during the exposure and development of the original, resulting in poor quality copies. According to the present invention, an internal temperature detection sensor 6 is installed at a location as close as possible to the optical system and photosensitive drum inside the copying machine.
is installed, and an external temperature detection sensor 4 is installed at a suitable location outside the copying machine. The temperature detected by these temperature detection sensors 6.4 (m) is amplified by two temperature amplification devices 5 and 6 in the controller 9, and the difference between the two is further amplified by a temperature difference amplification device 7. is input to the temperature control device 8.This temperature control rack prevents condensation when there is a difference in temperature between inside and outside the machine, that is, when the temperature outside the machine becomes warmer than the temperature inside the machine. The prevention heater 2 is activated, and if the temperature inside the machine becomes higher than the temperature outside the machine, the heater is stopped. However, it is best to install it as close as possible to the optical system and the photosensitive drum, but it should be installed in a place that is as close as possible to the optical system and the photosensitive drum. Of course, the copying rod/outside temperature detection sensor may detect the ambient temperature at any location near the outside of the copying machine, but it is sufficient to detect the ambient temperature at any location near the indoor heater or heater. A faster response can be obtained by directly detecting the temperature of the copier.In addition, the difference between the outside temperature and the inside temperature of the copier is input to the control device that controls the opening and closing of the switch for the anti-condensation heater. The temperature varies depending on the season, but in winter it is best to open and close the switch of the heater to prevent blisters depending on the temperature difference of about ℃.

In the above explanation, we have described the case where a dedicated dew condensation prevention heater is installed inside the copying machine, but in a heat-fixing type copying machine, the commands from the temperature control device are also applied to the opening and closing of the fuser circuit. The waste heat can be used to replace part or all of the heat generated by the condensation prevention heater.

Effects of the Invention According to the present invention, the temperature detection sensor detects the difference between the inside temperature of the copying machine and the outside temperature, and automatically starts or stops the condensation prevention heater. Therefore, there is no need to operate the heater for an unnecessarily long period of time, resulting in wasted power consumption.Also, since the heater is automatically activated and stopped, there is no need for manpower to manage the heater.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the present invention. Symbols in the figure: 1... Copying machine, 2... Heater for preventing condensation, 6, 4... Temperature detection sensor, 5, 6... Temperature amplification device, 7... Temperature difference amplification device , 8...control device, 9...controller, 11...lens, 12...
・Mirror, 16...Photosensitive P ram.

Claims (1)

[Claims] The internal and external temperatures of the electronic copier are detected, and when the external temperature becomes higher than the internal temperature, the heater to prevent condensation inside the machine is activated, and the external temperature becomes lower than the internal temperature. A dew condensation prevention device for an electronic copying machine, wherein the dew condensation prevention device for an electronic copying machine is characterized in that the operation of the heater is stopped when the heater is activated.