JPH03136046A - Heat fixing device - Google Patents

Abstract

PURPOSE:To reduce the manufacture cost of the device and to reduce its size by providing an abnormality detecting means which decides the variation of an operation signal to a heating means and detects abnormal operation of a sucking means. CONSTITUTION:The operation of the heating means 31 is controlled according to the detection signal of a temperature detecting means 41 and the heating means 31 heats a recording medium 18 to heat and fix an image on a recording medium. Gas produced when the recording medium 18 is heated is sucked by the sucking means 31 and discharged. When the sucking means 36 is in operation, the variation of the operation signal to be heating means 31 is decided and if the sucking means 36 becomes abnormal not to suck the gas normally, the temperature drop of the heating means 31 decreases and the variation of the operation signal to the heating means 31 becomes less than a specific value, so the abnormal operation of the sucking means 36 is detected. Therefore, the abnormality of the sucking means can be detected without providing any rotation detector, etc., for a suction fan. Consequently, the manufacture cost of the device is reducible and the device is reduced in size.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a heat fixing device used for heat fixing an image formed on a recording medium in a copying machine or the like.

[Prior Art] Conventionally, in various copying machines, when an image formed on developer paper as a recording medium is heated and fixed, for example, while the developer paper is conveyed along a conveyance path, a heater or a fan is used to fix the image. A dryer-type heat fixing device is used, which performs heat fixing by blowing hot air onto the image surface of color developing paper.

Furthermore, when the color developer paper is heat-fixed, a gas having an unpleasant odor is generated from the color developer applied to the base material of the color developer paper, so when the heat fixing device is activated, a gas suction device as a suction means is activated. , the odorous gas is sucked from inside the heat fixing device and discharged to the outside of the copying machine.

Furthermore, if the gas suction device malfunctions, the suction and discharge of odor gas will not be performed normally, so a rotation detector is installed to detect failure of the suction fan of the gas suction device, and a backup suction fan is installed. I was doing a lot of things.

[Problems to be Solved by the Invention] However, the conventional device described above requires a rotation detector and a spare fan in addition to the suction fan of the gas suction device, which increases the manufacturing cost of the device. There was a problem that the device became larger.

This invention was made by focusing on the problems existing in the conventional technology, and its purpose is to improve the speed of the suction means without providing a rotation detector or the like for the suction fan. An object of the present invention is to provide a heat fixing device that can detect an abnormality, reduce the manufacturing cost of the device, and downsize the device.

[Means for Solving the Problems] In order to achieve the above object, the heat fixing device of the present invention includes a heating means for heating and fixing an image formed on color developer paper, and a heating means for heating the color developer paper by the heating means. a suction means for sucking the generated gas; a temperature detection means for detecting the heating temperature of the color developing paper by the heating means; a control means for controlling the operation of the heating means based on a detection signal of the temperature detection means; The apparatus includes abnormality detection means for detecting an abnormal operation of the suction means by determining a change in an activation signal for the heating means when the suction means is activated.

[Function] In the heat fixing device configured as described above, the operation of the heating means is controlled based on the detection signal of the temperature detection means,
The recording medium is heated by the heating means, and the image on the recording medium is heat-fixed. Further, the gas generated when the recording medium is heated is sucked by the suction means and discharged to the outside.

When the suction means is activated, a change in the activation signal for the heating means is determined, and if an abnormality occurs in the suction means and gas suction is not performed normally, the temperature drop in the heating means is reduced. Then, since the change in the operating signal for the heating means becomes less than or equal to a predetermined value, abnormal operation of the suction means is detected.

[Embodiment] Hereinafter, an embodiment of a color copying machine embodying the present invention will be described in detail with reference to the drawings.

As shown in FIG. 2, the main body 1 of the copying machine has a substantially box-shaped structure, and on the top thereof there is a document table glass 2 on which a document can be placed.
A cover 3 that covers the document table glass 2 in an openable and closable manner is provided so as to be movable left and right.

The light source 4 is disposed below the document glass 2 and includes a halogen lamp 5 and a halogen lamp 5 extending in a direction perpendicular to the moving direction of the document glass 2 so as to irradiate the original on the document glass 2 with light. and a reflecting mirror body 6 that reflects the light toward the document table glass 2. By moving the document table glass 2 left and right while the light source 4 is emitting light, the entire document is irradiated with light.

The exposure table 7 is disposed at the center of the interior of the copying machine body 1, and between the light source 4 and the exposure table 7 are a filter 8 for adjusting the color tone of the copied image and a lens 9 for condensing light. is supported by the mounting plate 10, and the lens 9 and the exposure stage 7
A pair of reflective mirrors 11 for adjusting the optical path length and focus are mounted between the mounting plate 12 and the mirror 11. I [Supported by nodal function. Light reflected from the original after being irradiated onto the original is guided to the lower surface of the exposure table 7 via the filter 8, lens 9, and reflection mirror 11.

The cartridge 13 is removably housed inside the copying machine main body 1, and a take-up shaft 14 is rotatably supported near the side thereof. Long microcapsule paper 15
is housed in a wound state in a cartridge 13, and its surface is provided with microcapsules containing a dye for color copying.

By the rotation of the plurality of feed rollers 16, the microcapsule paper 15 is pulled out from the cartridge 13 and wound around the winding shaft 14. On the way, the microcapsule paper 15 passes through the lower surface of the exposure table 7. A portion is exposed to light to form a latent image of the document.

A cassette 17 is removably attached to the main body 1 of the multifunction machine below the exposure table 7, and the cassette 17 houses a developer paper 18 as a recording screw having a certain size. The pressure developing device 19 is disposed between the exposure table 7 and the winding shaft 14, and the exposed portion of the microcapsule paper 15 and the color developing paper 18 are brought into pressure contact within this pressure developing device, thereby forming microcapsules. A color image based on the latent image on paper 15 is formed on developer paper 18. The size discrimination device 20 is disposed in the copying machine main body 1 facing the cassette 17, and the size discrimination device 20 reads the size of the discrimination protrusion 17a provided on the cassette 17, and determines the size of the developer paper 18. The size of is determined.

The feed roller 21 and the paper guide 22 are connected to the cassette 17.
The developing paper 18 is provided between the roller 21 and the pressure developing device 19, and as the feed roller 21 rotates, the color developing paper 18 is transferred to the pressure developing device 19 along a paper guide 22. However, the Jl roller 23 is provided on the paper feeding side of the pressure developing device 19, and the developer paper 18 is separated from the microcapsule paper 1 by this peeling roller 23.
It is peeled off from 5. The heat fixing device 24 is disposed on the paper sending side of the peeling roller 23, and after the image formed on the developer paper 18 is fixed by heat in the heat fixing device 24, the developer paper 18 is discharged onto the tray 25. be accommodated.

Now, when making a color copy using the copying machine configured as described above, after placing the original on the document glass 2, when the start button (not shown) is operated, the document glass 2 moves to the right side. The document is moved to the position @, and the left end of the document is placed opposite the halogen lamp 5 of light #4, and then the halogen lamp 5 is turned on. In this state, the document table glass 2 is returned to the left and the irradiation of the document with light is completed.

During this light irradiation, the microcapsule paper 15 is moved toward the winding side on the exposure table 7 at the same speed as the document table glass 2. Therefore, a latent image of the original is formed on the microcapsule paper 15 by the reflected light from the original. Further, the color developer paper 18 is transferred from the cassette 17 to the pressure developing device 19 in synchronization with the return movement of the document platen glass 2 to the left, and the exposed portion of the microcapsule paper 15 is pressed against the color developer paper 18. A color image is formed on the color developer paper 18.

Thereafter, the color developer paper 18 is introduced into the heat fixing device 24 by the feed roller 16 and the like, and is discharged onto the tray 25 with the image fixed therein by heat.

Next, the heat fixing device 24 will be explained in detail.

As shown in FIG. 3, the sheet guide 26
It is arranged at the bottom of the conveyance path No. 8.

A pair of upper and lower feed rollers 27 are rotatably disposed on the paper feed side of the sheet guide 26, and a heat insulating roller 28 is provided adjacent to the feed rollers 27.

A pair of upper and lower feed rollers 29 are connected to the sheet guide 26.
A heat insulating roller 30 is disposed in a rotatable manner on the paper feeding side of the paper feed roller 29, and furthermore, a heat insulating roller 30 is provided in close proximity to the feeding roller 29.

A hot air generator 31 serving as a heating means is disposed facing the upper surface of the sheet guide 26 so as to be located above the conveyance path of the color developing paper 18.

The hot air generator 31 is equipped with a cover 32, and a gold R33 is provided at the lower opening of the cover 32. The heater 34 is disposed within the cover 32 so as to extend in a direction perpendicular to the conveyance direction of the color developing paper 18 and to face the paper feed side wall surface. Blow fan 3 consisting of a cross flow fan
5 is rotatably supported within the cover 32 around an axis parallel to the extending direction of the heater 34, and the blower fan 35 is rotated counterclockwise in FIG. 1 by a motor (not shown). Heat radiation from the heater 34 is caused by the sheet guide 2.
The liquid is sprayed toward the color developing paper 18 on the top of the color developer paper 18 .

As shown in FIGS. 2 and 3, a gas suction device 36 as a suction means includes a casing 37 extending through the main body 1 of the copying machine, and a cover 38 that covers the hot air generator 31 on the inside of the casing 37. are connected. A suction fan 39 is rotatably supported within the casing 37, and is rotated by a motor (not shown) to suck gas generated during heat fixing of the color developer paper 18 through the cover 38. Deodorizing filter 40 filled with deodorizing agent
is removably attached within the outer exhaust part of the casing 37, and the odor and harmful components of the odor gas are absorbed by this deodorizing filter 40.

A thermistor 41 as a temperature detection means is provided inside the cover 32 of the hot air generator 31, and when the hot air generator 31 heats the color developer paper 18, the thermistor 41 detects the heating temperature of the color developer paper 18, and outputs a detection signal. is output.

Next, a control circuit for the heat fixing device 24 having the oval configuration as described above will be explained.

As shown in FIG. 1, a central processing unit (CPU) 42 includes a timer 43 and a counter 44.
42 has a mode selector switch 45 and a start switch 4.
6 and the thermistor 41, the input interface 4
Various signals are input via 7. Further, from the CPU 42, the heater 34 of the hot air generator 231, the blower fan 35,
For the suction fan 39 of the gas suction device 236 and the abnormality indicator 48 for displaying abnormalities in the gas suction device 36,
Activation and deactivation signals are outputted via the output interface 49 and drive circuits 50-53.

The CPU 42 constitutes a control means, and the CPU 42 constitutes a control means.
8, the set temperature under the predetermined mode set by the mode changeover switch 45 and the thermistor 41
For example, in order to bring the temperature detection signal closer to the set temperature by comparing the temperature detection signal from the
) with different on-suncle numbers of actuation signals as shown in
The heater 34 of the hot air generator 31 is controlled to be turned on and off.

Further, the CPU 42 constitutes an abnormality detection means, and when the hot air generator 31 is activated, the suction fan 39 of the gas suction device 36 is activated within a predetermined time measured by the timer 43, and during the operation of the suction fan 39, the suction fan 39 is activated. , the counter 44 counts the number of ON cycles of the activation signal to the heater 34. Then, the CPU 42 compares the count number within a predetermined time with a preset set value, and when the count number is smaller than the set value, that is, an abnormality has occurred in the suction fan 39 and the exhaust inside the hot air generator 31 is When the change in duty of the heater 34 becomes small without the internal temperature decreasing due to insufficient operation, an activation signal is output to the abnormality indicator 48.

Next, the operation of the heat fixing device 24 configured as described above will be explained.

Now, in this heat fixing device, when the developer paper 18 with an image formed on its surface is fed into the conveying path on the sheet guide 26 and the start switch 46 is turned on, the L-coat 34 of the hot air generator 31 is energized to heat the air around it, and a blower fan 35 is rotated by a motor (not shown) to blow hot air onto the surface of the color developer paper 18 from the lower opening of the cover 32. When heating the color developing paper 18, 1. Under the control of the CPU 42, the set gain under a predetermined mode set by the mode changeover switch 45 and the temperature detection signal from the thermistor 41 are compared, and the temperature detection signal from the thermistor 41 is compared, for example, in FIGS.
) The heater 34 is turned on and off by an operation signal having an arbitrary number of on-cycles as shown in (), and the temperature detection signal is maintained at the set temperature. Therefore, the granular resin layer such as a color developer coated on the surface of the base material of the color developer paper 18 is melted, and the image is heat-fixed.

Further, when fixing the color developer paper 18 by heating, the operation shown in the flowchart shown in FIG. 4 is started under the control of the cptr 42, and first, the suction fan 39 of the gas suction device 36 is activated (step S1). Accordingly, when the color developer paper 18 is heated and fixed, the gas having an unpleasant odor generated from the color developer on the color developer paper 18 is sucked through the cover 38.
After the odor and harmful components are absorbed and removed by the deodorizing filter 40, it is discharged to the outside of the copying machine main body 1. Therefore, there is no risk that the odor-filled gas will be exhausted as it is, and the work can be carried out safely.

Further, when the suction fan 39 is operated, the counter 4
4, the number of ON cycles of the activation signal for the heater 34 is counted, and the suction fan 39 is stopped after a predetermined time measured by the timer 43 (steps 82 to S4).
Thereafter, the on-cycle count number is compared with a preset value, and when the count number is smaller than the set value, the abnormality indicator 48 is activated to display an abnormality in the suction fan 39 (step S5, 36).

That is, when the suction fan 39 is operating normally, the air inside the hot air generator 31 is exhausted and the internal temperature tends to decrease, so the on-duty of the activation signal to the heater 34 is increased and the internal temperature decreases. is maintained constant. Therefore, when the suction fan 39 operates normally,
The on-cycle count becomes larger than the set value, and the abnormality indicator 48 is not activated.

On the other hand, if an abnormality occurs in the suction fan 39, the hot air generator 31 is not sufficiently exhausted and the internal temperature does not drop, so the duty change of the operating signal to the heater 34 is reduced, and the When the cycle count becomes less than the set value, the fault indicator 48 is activated.

Therefore, an abnormality in the suction fan 39 can be reliably detected without separately providing a rotation detector for the three suction fans.

Note that the present invention is not limited to the configuration of each of the embodiments described above, and for example, the number of on-cycles counted within a predetermined operating time of the suction fan 39 may be changed to the number of on-cycles counted earlier within a predetermined operating time. The configuration of each part may be arbitrarily changed without departing from the spirit of the invention, such as by comparing the numbers and controlling the heater 34 on and off by DC control, pulse width control, etc. in addition to the AC control in the above embodiment. It is also possible to make it more concrete.

[Effects of the Invention] This invention has the following features:
An abnormality in the suction means can be detected based on a change in the operating signal for the heating means without providing a rotation detector or the like for the suction fan, and the manufacturing cost of the device can be reduced. This has an excellent effect in that the device can be made smaller.

[Brief explanation of the drawing]

Fig. 1 is a control circuit diagram of a heat fixing device embodying the present invention, Fig. 2 is a sectional view showing the entire copying machine, Fig. 3 is a sectional view of the heat fixing device, and Fig. 4 is a suction in a gas suction device. FIG. 5 is a flowchart showing the abnormality detection operation of the fan, and a waveform diagram showing changes in the operating signal with respect to the temperature of the hot air generator. 18... Color developer paper as recording medium, 24... Heat fixing device, 31... Hot air generator as heating means, 34
... Heater, 36 ... Gas suction device as suction means, 39 ... Suction fan, 41 ... Thermistor as temperature detection means, 42 ... CPU forming control means and abnormality detection means, 48... Abnormality indicator.

Claims (1)

[Claims] 1. A heating means (31) that heats and fixes the image formed on the recording medium (18), and sucks gas generated when the recording medium (18) is heated by the heating means (31). a suction means (36); a temperature detection means (41) for detecting the heating temperature of the recording medium (18) by the heating means (31); 31)
control means (42) for controlling the operation of the suction means (36); and abnormality detection for detecting abnormal operation of the suction means (36) by determining a change in the operation signal for the heating means (31) when the suction means (36) is activated. A heat fixing device comprising means (42).