JPH10214018A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the temperature of an exposure optical system and a contact glass from excessively rising in accordance with the fluctuation of an environment by detecting the temperature in the exposure optical system after a main switch is turned on and controlling the driving of a cooling means according to the detected temperature. SOLUTION: When the main switch is turned on in order to energize the respective parts of an image forming device, the fixing lamp of a fixing device 32 is turned on and the temperature of a fixing roller is detected by a temperature sensor 39 arranged close to the fixing roller at the same time. Then, when the detected temperature is equal to or under a set value, a power source is judged to be turned on from a cooling state. Next, the detection output of a temperature sensor 36 arranged near the contact glass 15 is read. According to this output value, the driving of the cooling fan 38 cooling the inside of the exposure optical system is controlled. Besides, it is judged whether a copying action can be executed or not. When it can be executed, a printing switch is turned on and the level of the detection output of the sensor 36 is judged. When the fixing temperature is equal to or over the set value, the driving of the fan 38 is controlled based on the detection output value of the sensor 36 detected at the last time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine and a printer, and more particularly to an apparatus for preventing an excessive rise in temperature in an optical system.

[0002]

2. Description of the Related Art Conventionally, as a countermeasure against overheating of a contact glass or an exposure optical system of a copying machine or the like, a detection output of a temperature sensor provided near the contact glass is compared with a predetermined temperature level, and a temperature of the contact glass is measured. When the value is higher, the copying interval may be lengthened, the copying operation may be stopped, and the driving of the cooling fan may be controlled. In addition, a thermal fuse is connected to the exposure lamp, and when an abnormality occurs, the thermal fuse is blown and measures are taken to prevent the contact glass and the exposure optical system from overheating.

For example, Japanese Patent Application Laid-Open No. 61-261,753 discloses a technique for detecting the temperature of an original glass and controlling the copy mode (exposure time copy interval) and the operation of a cooling fan according to the detected level. Have been. See also
In Japanese Patent Application Laid-Open No. 3-156735, the cooling means is driven by predicting a rise in the temperature of the document table based on the operation mode of the document scanning, a temperature sensor detecting the temperature of the document table, or various data obtained from the apparatus. A controlling technique is disclosed. Further, as a publicly known technique, a technique of detecting the temperature in the exposure optical system and controlling the driving of the cooling means when the detected temperature becomes a certain value or more, or detecting the temperature in the exposure optical system and detecting the detected temperature There is a method in which the copy operation is stopped when the value exceeds a certain value.

[0004]

However, in the above-mentioned prior art, when the temperature of the contact glass becomes high, there is a problem that the copy interval is lengthened and the copy operation is stopped, so that the productivity is reduced. Further, in the method of driving the cooling fan when the detection output of the temperature sensor provided near the contact glass reaches or exceeds a predetermined temperature level,
The temperature sensor provided near the contact glass and the temperature fuse connected to the exposure lamp may have different degrees of temperature rise, and the fuse may be blown even though it is not abnormal. If the operating temperature of the cooling fan is set low in order to prevent this, the operating time of the cooling fan becomes longer, and the dirt on the optical mirror is accelerated by dust and the like in the outside air. is there.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and it is possible to prevent the contact glass and the exposure optical system from overheating without lowering the productivity of an image forming apparatus such as a copying machine. It is an object to provide a simple image forming apparatus.

[0006]

In order to achieve the above object, an image forming apparatus according to the present invention irradiates a document with an exposure lamp and reflects a reflected light image from the document. In an image forming apparatus having an exposure optical system for exposing a photoreceptor, a cooling unit for cooling the inside of the exposure optical system, and a temperature sensor for detecting a temperature in the exposure optical system, a main switch was turned on. The apparatus further comprises means for controlling the drive of the cooling means in accordance with the temperature detected by the temperature sensor immediately after.

According to a second aspect of the present invention, the drive control means sets a control temperature for controlling the drive of the cooling means as the detected temperature of the temperature sensor in the optical system becomes lower immediately after the main switch is turned on. It is characterized by being set low.

According to a third aspect of the present invention, the drive control means detects the temperature of the temperature sensor in the exposure optical system immediately after turning on the main switch in the vicinity of a fixing roller of a fixing device. When the temperature detected by the temperature sensor for detecting the temperature of the fixing roller provided is equal to or lower than a set value, it is detected that the operation is started from the cooling state.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram showing an embodiment of an image forming apparatus according to the present invention. As shown,
Around the drum-shaped photoreceptor 11, in the order of the image forming process,
Charging corona charger 12, slit exposure device 13,
An eraser 14, a developing device 24, a corona charger 28 for transfer, a corona charger 29 for separation, a separation claw 30, a cleaning device 34, and a static eliminator 35 are arranged.

In this apparatus, a latent image is formed on the photoreceptor 11 by the slit exposure device 13, the latent image is visualized by the developing device 24, and the latent image is formed on the paper fed from the paper feeding unit 25 via the paper feeding roller 26. The image is transferred by the transfer corona charger 28 to the separation corona charger 29 and the separation claw 3.
At 0, the sheet is separated from the photoreceptor 11, sent to the fixing device 32 to fix the image, and discharged to the paper output tray 33. In the fixing device 32, a temperature sensor 39 is provided near the fixing roller.
Is provided. The photoconductor 11 after the paper is separated
Is removed by the cleaning device 34 to remove the residual toner, and the charge is removed by the charge remover 35 to prepare for the next image forming operation.

The slit exposure device 13 includes an exposure lamp 16 provided immediately below a contact glass 15, first, second, and third reflection mirrors 17, 18, and 19, an imaging lens 20, and fourth, fifth, and sixth lenses. It has reflection mirrors 21, 22, and 23. The exposure lamp 16, the first, second, and third reflection mirrors 17, 18, and 19 constitute a first carriage, and the fourth, fifth, and sixth reflection mirrors 21, 22, and 23 constitute a second carriage. doing.

A temperature sensor 36 is provided near the contact glass 15, a temperature fuse 37 is provided near the exposure lamp 16, and a cooling fan 38 for cooling the inside of the optical system. The cooling fan 38 for cooling the inside of the exposure optical system drives and controls the cooling fan 38 for cooling according to the detection output of the temperature sensor 37 provided in the vicinity of the contact glass 15, thereby increasing the temperature of the optical system and the contact glass 15. Can be prevented.

FIG. 2 is a flowchart showing the operation of the image forming apparatus according to this embodiment. First, when a main switch is turned on to energize each part of the image forming apparatus (step 1), a fixing lamp of the fixing device 32 is turned on, and at the same time, a temperature sensor 39 provided near the fixing roller is provided.
To detect the temperature of the fixing roller, and set value T (for example, 40
° C) or less, it is determined that the power is on from the first cooling state in the morning, and the process proceeds to step 3 (step 2). Next, the temperature sensor 3 provided near the contact glass 15
Then, the detection output x is read and the cooling fan 38 for cooling the inside of the exposure optical system is driven and controlled according to the output value (step 3). Further, it is determined whether or not a copy operation is possible (step 4). If it is impossible, the process returns to step 2, and if possible, the print switch is turned on (step 5).
The process proceeds to step 6 in which the level of the detection output x of the temperature sensor 36 is determined. If the fixing temperature is equal to or higher than the set value T in step 2, the process proceeds to step 7 in which the driving control of the cooling fan 38 is performed based on the detection output value x ′ of the temperature sensor 36 detected last time, thereby changing the environment. Can also respond.

In this embodiment, the read value of the detection output x of the temperature sensor 36 is divided into three levels, and the temperature at which the cooling fan 38 for cooling the inside of the exposure optical system is driven is set as shown in Table 1 below. (Steps 6, 8, and 9).

[Table 1] Level detection output value Cooling fan drive temperature Level 1 Lower temperature or lower x + y1 Level 2 Intermediate temperature range x + y2 Level 3 Upper temperature or higher x + y3 That is, if the detection output x of the temperature sensor 36 is level 1 in step 6, It is detected that the operation has started from the cooling state as in the morning, and the process proceeds to step 8. If it is level 2, the process proceeds to step 9, and if it is level 3, the process proceeds to step 10.
The cooling fans 38 are turned on, and it is determined in step 11 whether a predetermined copy process (job) has been completed. If not completed, the process returns to step 6; The operation returns to the state of waiting for the operation.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention, the temperature at which the cooling fan 38 is driven is set as shown in the following Table 2 based on the above-described three levels of the detection output x of the temperature sensor 36.

[Table 2] Level detection output value Cooling fan drive temperature Level 1 15 ° C or lower 38 ° C Level 2 15 to 23 ° C 41 ° C Level 3 23 ° C or higher 44 ° C

[0016]

Comparative Example Table 3 below shows a comparison between the temperature in the vicinity of the thermal fuse 37 due to the difference in room temperature between the prior art and the embodiment of the present invention.

Table 3 Room temperature Conventional technology This embodiment 15 ° C. 130 ° C. 117 ° C. 23 ° C. 121 ° C. 115 ° C. 32 ° C. 113 ° C. 110 ° C. In the prior art of Table 2, the value of the temperature sensor provided near the contact glass is equal to or more than the set value. Is reached, the cooling fan is driven regardless of the room temperature.
In this case, the driving time of the cooling fan (the number of copies) differs depending on the room temperature difference. In particular, when the room temperature is low, the temperature near the thermal fuse becomes higher than the fusing temperature before the cooling fan is driven, and abnormality detection may be performed. To prevent this, lower the temperature for driving the cooling fan.
When the temperature is high, the cooling fan operates quickly, and the dirt on the optical mirror is accelerated by dust and the like in the outside air, and an abnormal image may be generated. In the embodiment of the present invention, the driving temperature of the cooling fan is changed according to the room temperature of the use environment in order to compensate for the above-mentioned drawback. As a result, the temperature near the thermal fuse is not affected by the use environment, and the operating time of the cooling fan is controlled in accordance with the use environment, so that the dirt on the optical mirror can be reduced.

[0017]

According to the image forming apparatus of the first aspect, the temperature in the exposure optical system after the main switch is turned on is detected, and the driving of the cooling means is controlled in accordance with the detected temperature. There is an effect that it is possible to prevent the temperature of the exposure optical system and the contact glass from being excessively increased due to environmental fluctuations.

According to the image forming apparatus of the present invention, the temperature in the exposure optical system is detected, and the control temperature for controlling the driving of the cooling means is optimized in accordance with the detected output, so that the exposure lamp is provided. This has the effect of preventing the thermal fuse provided in the vicinity from being blown and preventing the temperature of the exposure optical system and the contact glass from rising excessively.

According to the image forming apparatus of the present invention, after the main switch is turned on, the temperature of the fixing roller is detected,
By detecting that the operation is started from the cooling state when the temperature is equal to or lower than the set value, in addition to the above-described common effects, the temperature in the exposure optical system can be accurately determined, and the detected value of the cooling unit is determined based on the detected value. There is an effect that drive control can be performed to prevent the exposure optical system and the contact glass from being overheated.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a flowchart illustrating an operation of the image forming apparatus according to the exemplary embodiment.

DESCRIPTION OF SYMBOLS 11 Photoreceptor 12 Corona charger for charging 13 Slit exposure device 14 Eraser 15 Contact glass 16 Exposure lamp 17, 18, 19, 21, 22, 23 Reflection mirror 20 Imaging lens 24 Developing device 25 Feeder 26 Paper feed roller 28 Transfer corona charger 29 Separation corona charger 30 Separation claw 32 Fixing device 33 Paper discharge tray 34 Cleaning device 35 Static eliminator 36, 39 Temperature sensor 37 Temperature fuse 38 Cooling fan

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiko Yuki 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Kentaro Matsumoto 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Inside Ricoh Company (72) Inventor Kenji Karashima 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company

Claims (3)

[Claims] An exposure optical system for irradiating a document with an exposure lamp and exposing a reflected light image from the document on a photoreceptor;
In an image forming apparatus having a cooling unit for cooling the inside of the exposure optical system and a temperature sensor for detecting a temperature in the exposure optical system, according to a detected temperature of the temperature sensor immediately after turning on a main switch, An image forming apparatus comprising: means for driving and controlling the cooling means. 2. The control system according to claim 1, wherein the drive control unit sets the control temperature for controlling the drive of the cooling unit to be lower as the detection temperature of the temperature sensor in the optical system immediately after turning on the main switch is lower. The image forming apparatus according to claim 1, wherein: 3. The drive control means detects the temperature of the temperature sensor in the exposure optical system immediately after turning on the main switch and detects the temperature of a fixing roller provided in the vicinity of the fixing roller of the fixing device. An image forming apparatus comprising: detecting an operation start from a cooling state when a temperature detected by a temperature sensor is equal to or lower than a set value.