JP2003098883A - Image forming device - Google Patents

Abstract

(57) [Summary] [Problem] An oil heater for heating silicon oil,
Equipped with a thermistor that detects the temperature of the silicone oil.In controlling the temperature of the silicone oil, the time after the oil heater is turned on is measured, and the temperature of the silicone oil does not rise until a predetermined time is reached. When the detected temperature is within the temperature range between the ambient temperature and the oil heater temperature, it is determined that the oil level is insufficient, and a display and warning are issued, eliminating the need for a conventional sensor for detecting the remaining level of silicon oil. Become. SOLUTION: Separation oil applied to the heating and pressing roller for improving the releasability between a heating and pressing roller provided in a heating and pressing fixing device and a transfer material.・ A separation oil heater that heats the separation oil. Oil temperature detecting means for detecting the temperature of the separated oil. Environmental temperature detecting means for detecting the ambient temperature of the image forming apparatus; Oil heater temperature detecting means for detecting the temperature of the separated oil heater. An oil temperature detecting means after a predetermined time has elapsed after the separation oil heater is turned on.

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 for forming an image on a transfer material by applying heat and pressure to a toner image formed on the transfer material with a heating and pressure fixing device, and particularly to heating. The present invention relates to a heating / pressurizing roller provided in a pressurizing device, and an image forming apparatus capable of adjusting the temperature of separated oil for improving the releasability between the roller and the transfer material.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a toner image is transferred onto a transfer material by a photosensitive drum, and then heated and pressed by a fixing heat roller using a temperature sensor such as a thermistor. By doing so, image formation is performed. Further, at that time, the toner is melted due to the image on which the toner is transferred on the transfer material passing through the fixing heat roller, so that the adhesive action is exerted between the heat roller and the transfer material, and the heat is applied. There was a possibility that the transfer material would be wrapped around the roller. As a countermeasure,
Apply oil such as silicone oil to the heat roller,
The release property between the heat roller and the transfer material was improved. Furthermore, due to the temperature dependence of the viscosity of the silicone oil applied to the heat roller, the amount of silicone oil applied to the heat roller varies depending on the temperature of the silicone oil, and as a result, the oil of the image on the transfer material that is heated and pressed by the heat roller is fixed. Since the amount of glue was not fixed, the glossiness of the output image was difficult to be uniform. Therefore, it has been attempted to heat the silicone oil to keep the viscosity of the oil constant and to stabilize the coating amount.

[0003]

Conventionally, as a means for detecting the remaining amount of oil in the oil pan for storing the above-mentioned silicone oil, the height of the oil level is detected to judge whether the remaining amount of oil is present or absent. It was Then, it is necessary to use at least one sensor such as a photo interrupter in order to detect the height of the oil surface at this time.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an image forming apparatus according to a first aspect of the present invention uses a toner to form a latent image formed on a photoreceptor. After development, the toner image on the photoconductor is transferred onto the transfer material, and the image is formed on the transfer material by applying heat and pressure with a heat and pressure fixing device. Separation oil applied to the heating and pressure roller for improving the releasability between the heating and pressure roller and the transfer material provided in the pressure fixing device, and a separation oil heater for heating the separation oil. And an oil temperature detecting means for detecting the temperature of the separated oil, the separated oil heating heater is turned on, the temperature of the oil temperature detecting means does not rise even after a predetermined time has passed, and the oil at that time Predetermined temperature of temperature detection means The image forming apparatus according to claim 2, wherein when the temperature is within the range, a warning is displayed to indicate that the remaining amount of oil is low, and the image forming apparatus according to claim 2 detects the ambient temperature of the image forming apparatus. Means and an oil heater temperature detecting means for detecting the temperature of the separated oil overheat heater, and the predetermined temperature range is a range of a detected temperature of the environmental temperature detecting means and a detected temperature of the oil heater temperature detecting means. The image forming apparatus according to claim 3, wherein when the temperature of the oil temperature detecting means is not within a predetermined temperature range, the image forming apparatus displays and warns that the oil temperature detecting means is abnormal. With the above, it becomes possible to detect the remaining oil level and display that fact.
By issuing a warning, a sensor for detecting the remaining amount of silicone oil is not required.

[0005]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a schematic configuration of a digital image forming apparatus as an example of the image forming apparatus according to the present invention.

First, the configuration and operation will be described with reference to the drawings.

The image forming apparatus shown in FIG. 1 includes a reader unit 1 on the upper portion of the main body of the apparatus and a printer unit 2 on the lower portion.

The reader unit 1 includes a document table glass 101 on which documents are stacked, a document pressing plate 102 for pressing the stacked documents from above, a light source 103 for illuminating the image surface of the document, and a light source 1.
03, a mirror stand 133 for scanning an original, a plurality of mirrors 104 and lenses 105 for guiding the reflected light from the image surface,
The photoelectric conversion / image processing unit 106 performs photoelectric conversion on the reflected light from the document by the CCD 301 and performs various image processing on the obtained electric signal. Further, the photoelectric conversion / image processing unit 106 has an image processing function of performing A / D conversion, shading correction, masking correction, scaling, LOG conversion, and the like on the photoelectrically converted electric signal.

The operation of the reader unit 1 having the above-mentioned configuration is as follows.

The originals are stacked on the original table 101 with the image surface thereof facing downward, and the original pressing plate 102 is placed over the originals.
Hold down with. The mirror stand 133 moves while illuminating the light from the light source 103, and scans the image surface of the document. The reflected light image from the image plane is formed on the CCD 301 of the photoelectric conversion / image processing unit 106 via the plurality of mirrors 104 and the lens 105, and is photoelectrically converted into an electric signal here. The image signal which has become an electric signal is sent to the next printer unit 2 after being subjected to various kinds of image processing.

As shown in FIG. 1, the printer unit 2 converts the image signal sent from the reader unit 1 into a signal for driving a laser, a laser control unit 304, a laser element 108, and a laser on the surface of the photosensitive drum. An image forming unit including a polygon scanner 109 that scans with light and a photosensitive drum 112, and a fixing unit 1 disposed on the most downstream side.
20 is a main component.

Further, the above-mentioned image forming section is provided with a photosensitive drum 112 which is rotatably supported in the direction of the arrow, and the photosensitive drum 11 which is arranged around the photosensitive drum 112 in the order of its rotation.
2 a primary charger 113 for uniformly charging the surface, a developing device 110 for developing an electrostatic latent image on the photosensitive drum 112, and a transfer charger 1 for transferring a toner image on the photosensitive drum 112 to a transfer material.
19, a cleaner 116 for removing the transfer residual toner on the photosensitive drum 112, a cleaner blade 117, an auxiliary charger 115 for removing the charge, and a pre-exposure lamp 114 for removing the residual charge.

Further, the developing device 110 includes a developing roller 11
1 is provided, and the developing roller 111 rotates in the opposite direction to the photosensitive drum 112 to develop a toner image on the photosensitive drum 112.

The transfer material on which the toner image is transferred is
The pre-fixing belt 118 conveys the transfer material to the fixing unit 120, where the fixing rollers 121 and 122 rotate to convey the transfer material, and the transfer material is pressurized. Finally, the transfer material after fixing is discharged to the paper discharge tray 126 outside the apparatus main body via the conveying roller 123 after fixing.

The feeding / conveying unit for feeding the transfer material has a transfer material conveying path, and the paper feeding cassettes 127 and 128 and the paper feeding roller 12 are provided on the most upstream side in the transfer material conveying direction.
It is provided with a paper feeding device having 9, 130, conveyance rollers 131, 132, and the like.

In addition to this paper feeding device, a multi-paper feeding device 125 is provided. Since the paper feeding path is straight, the multi-paper feeding device 125 can feed various transfer materials having different properties such as material and size to the image forming unit.

An environmental sensor 150 is arranged on the bottom surface of the image forming apparatus. The environmental sensor 150 is arranged at a place where the influence of a fixing heater inside the apparatus is small in order to detect the environmental temperature of the apparatus. .

Next, FIG. 2 shows a block diagram of the image forming apparatus of the present invention.

All the devices are controlled by the CPU 306. The CPU 306 mainly plays a role of driving each load in the apparatus, collecting and analyzing information of sensors and exchanging data with the operation unit 305, that is, a user interface in addition to the image processing unit 107 and the laser driving unit 304 described above. Is responsible for Further, the CPU 306 stores a ROM (not shown) in which programs for executing various sequences related to the above-described image forming sequence are stored.
Also, a RAM for storing rewritable data that needs to be temporarily or permanently stored is connected. The RAM includes, for example, a high voltage controller 312 described later.
The high voltage setting value, various data described later, image formation command information from the operation unit 305, and the like are stored.

Data exchange with the shading correction unit 303, the image processing unit 107, the laser control unit 304, and the operation unit 305, which is the first role of the CPU 306, will be described. The image of the original document photoelectrically converted by the CCD 301 is converted into digital image data by the next A / D conversion unit 302 and input to the shading correction unit 303. The shading correction unit 303 is controlled by the CPU 306 and performs black level offset adjustment and white level shading correction including the characteristics of the light source 103 on the input image data. The image data after shading correction is input to the image processing unit 107, and masking correction, scaling, repeat, composition, and various decoration processes (shading, shading, shading, shadowing, etc.) are performed.

The CPU 306, in addition to sending the specification setting value data of each section necessary for these image processing, receives signals from each section, for example, a document image density signal, etc. The laser control unit 304 is controlled to make settings for optimal image formation. The laser control unit 304 optimally controls the laser on the basis of the definition of the image size for forming an image and the image-processed digital video data, that is, in this device, it is necessary to perform the PWM processing of the laser emission. Make settings. The operation unit 305 obtains information such as the copy magnification and the density setting value set by the user, and also the state of the image forming apparatus, for example, the number of images formed, information as to whether or not an image is being formed, and occurrence of a jam. Data is sent to show the location and the like to the user.

Next, the driving of each load in the apparatus, which is the second role, and the information collection analysis of the sensors will be described. In this device, a motor 316, a DC load 317 such as a clutch / solenoid, and various sensors 315 such as a photo interrupter and a micro switch are arranged at various places inside the device. That is, the transfer material is conveyed and each unit is driven by appropriately driving the motor 316 and each DC load 317, and various sensors 315 monitor the operation. Therefore, the CPU 306 controls each motor 316 by the motor control unit 310 based on signals from the various sensors 315, and at the same time, causes the DC load control unit 311 to control the DC of the clutch / solenoid or the like.
The load 317 is operated to smoothly advance the image forming operation. In addition, by sending various high voltage control signals to the high voltage controller 312, various high voltages suitable for the primary charger 113, the auxiliary charger 115, the transfer charger 119, and the developing roller 111, which are various chargers included in the high voltage unit 318, are generated. Is being applied.

As a third role, the CPU 306 inputs the output signal of the thermistor inside the fixing device 120 and controls the driving of the fixing heaters 320 and 321 and the oil heater 201. The fixing roller 12 in the fixing device 120 described above.
Fixing heaters 320 and 321 for heating the rollers and an oil heater 201 for heating oil to be applied to the fixing rollers are incorporated in the first and the second 122, respectively. Each heater is ON / OFF controlled by a fixing heater controller 313 and an oil heater controller 319. The fixing heater control unit 313 and the oil heater control unit 319 are connected to a primary power source 324 for supplying primary power to the heaters, and the triac 606 inside the fixing heater control unit 313 and the oil heater control unit 319 turns on / off the power supply. It is turned off. Further, the upper and lower fixing rollers 121 and 122 have fixing heater thermistors 322 and 323 for measuring the roller surface temperature, the oil heater 201 has an oil heater thermistor 324 for measuring the surface temperature, and further the temperature of the fixing oil 209 is measured. An oil thermistor 204 for controlling the temperature is provided, and the CPU 306 controls the fixing heater controller 313 and the oil heater controller 319 based on the temperature data.

Next, the area around the fixing unit 120 will be described with reference to FIG. Inside the fixing rollers 121 and 122, fixing heaters 320 and 321 for heating the rollers are provided, and halogen heaters are generally used for the fixing heaters 320 and 321. Fixing heater 320,
The ON / OFF control of the 321 is performed by the CPU 3 as described above.
06 via the fixing heater controller 313.
Further, ON / OFF of the fixing heaters 320 and 321 is controlled so as to reach the specified temperature based on the temperature measured by the fixing heater thermistors 322 and 323 for temperature monitoring which are attached in contact with the rollers. Further, the fixing unit 120 is coated with silicone oil for the purpose of improving the releasability between the upper fixing roller 121 and the transfer material, and the oil coating unit is 124. The oil application unit 124 includes the oil roller 20.
8 and silicone oil 209 (hereinafter abbreviated as oil), an oil pan 205 for storing the oil, and an oil heater 20 for adjusting the oil temperature for keeping the viscosity of the oil constant.
1. Installation of oil heater 201 and oil heater 2
Heater sheet metal 202 for indirectly transmitting the heat of 01 to the silicon oil 209, an oil heater thermistor 203 for measuring the temperature of the oil heater 201, and an oil thermistor 204 for measuring the temperature of the oil inside the oil pan 205. It is composed of oil application rollers 206 and 207 for applying an appropriate amount of oil to the upper fixing roller. Further, the oil heater 201 is ON / OFF controlled by the CPU 306 via the oil heater control unit 319.

FIG. 5 shows the oil heater controller 319 of the present invention.
2 is a circuit diagram showing an embodiment of FIG. Oil heater control unit 3
19, the output signals of the oil heater thermistor 203 and the oil thermistor 204 are respectively amplified by the amplifier circuit 60.
1 and 602, and the A / D converters 603 and 604 convert the resistance value change of each thermistor according to the temperature change of the oil heater 201 and the fixing oil 209 into a voltage value, and then input it as a digital value to the CPU 306, respectively. To be done. The CPU 306 outputs an oil control signal 610 based on this temperature data to output the oil heater 2 described later.
ON / OFF control of 01 is performed. A primary power source 324 for supplying primary power to the oil heater 201 is connected to the oil heater control unit 319, and a triac 606 is driven by a control signal 610 from the CPU 306 to turn ON / OFF the primary power supply. Further, there is an abnormality detection circuit inside the triac 606, and when the triac is short-circuited, the detection signal 611 is output to the EX-OR circuit 608. In the EX-OR circuit 608, when the abnormality detection signal 611 is input (logic is H) even though the oil control signal 610 is OFF (logic is L), the output becomes L and the abnormality signal is sent to the CPU 306. Simultaneously with outputting 609, the transistor 607 is turned off, and the relay 605 forcibly turns off the supply of the primary power to the oil heater 201. Further, the oil heater control unit 319 performs an abnormality detection to the CPU 306 based on the signals from the oil heater thermistor 203 and the oil thermistor 204 to detect an abnormality output of each thermistor such as when the thermistor is dropped or the thermistor is disconnected. At the same time as outputting the signal, the power supply to the oil heater 201 is forcibly cut off.

Next, the operation of the image forming apparatus of the present invention will be described with reference to the flowchart of FIG.

FIG. 4 is a flow chart of the oil remaining amount detecting sequence of the present invention. First, the oil temperature To is measured by the oil thermistor 204, and when To exceeds the predetermined oil setting temperature Tos, the drive of the oil heater is turned off (S502), and the oil temperature To is changed to the oil setting temperature Tos. In the following cases, the oil heater 201 is turned on (S503). When the oil temperature To is higher than Tos and the oil heater 201 is off, the heater on time tHON is 0 (S5
10) If To is lower than Tos and the oil heater 201 is on, the heater on time tHON is counted (S504). Then, next, tHON is compared with a predetermined oil rising time tHS (S50
5). This oil rising time is normally the oil heater 201.
This is the time required from when the oil is turned on to when the oil temperature starts to rise, and is determined by the heat capacity of the system including the wattage of the oil heater and members for transferring heat from the oil heater to the oil. Here, if tHON has not reached the oil rise time tHS, the oil temperature To and the minimum oil temperature ToL are compared (S506). Here, the initial value of ToL after the oil heater is turned on is Tos. T
If o is lower than ToL, set ToL = To (S
507) Change the minimum oil temperature ToL. And T
When o is equal to or higher than ToL, S507 is skipped, and it is determined whether the oil temperature To has started to rise (S50).
8). It should be noted that, here, as the determination of the oil temperature rise, it is determined that the oil temperature To rises when the oil minimum temperature ToL rises by 3 degrees, and the temperature rise range is set to 3 degrees. It is possible to change the temperature range in consideration of tHS. Then, if it is not confirmed in S508 that the oil temperature has risen, S50 is again set.
Returning to step 1, the above-mentioned control for detecting the remaining oil amount is performed. When this control is repeated and tHON increases at S504 and tHON reaches tHS at S505, that is, when there is no oil temperature increase of +3 degrees within the preset time tHS, the oil temperature To is the environmental temperature of the device. TUL and above,
It is determined whether the temperature is within the range of the oil heater temperature TUH or lower (S511). Oil temperature To is TUL or higher, TUH
In the following cases, it is displayed that the remaining amount of oil is small (S512) and a warning is issued (S514). If the oil temperature To is not higher than or equal to TUL and lower than or equal to TUH, a thermistor abnormality such as disconnection or short circuit of the thermistor is displayed (S513) and a warning is issued (S514).

If it is confirmed in S508 that the oil temperature has risen, the heater ON time tHON is set to 0 (S
510), tHON becomes 0 in S510 each time the above-described oil remaining amount detection control is repeated, tHON in S505 does not reach tHS, and normal operation without warning is executed.

[0030]

As described above, according to the present invention, the oil heater for heating the silicone oil and the thermistor for detecting the temperature of the silicone oil are provided, and the oil heater is turned on during the temperature control of the silicone oil. If the temperature of the silicon oil is not increased until the predetermined time is reached by measuring the subsequent time and the temperature detected by the thermistor is within the predetermined ambient temperature range, it is judged that the remaining oil amount is insufficient and displayed. Also, it becomes possible to issue a warning, and the conventional sensor for detecting the remaining amount of silicone oil is unnecessary.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a digital image forming apparatus of the present invention.

FIG. 2 is a block diagram of an image forming apparatus of the present invention.

FIG. 3 is an explanatory diagram of a fixing unit of the present invention.

FIG. 4 is a flowchart of an oil remaining amount detection sequence of the present invention.

FIG. 5 is a circuit diagram showing an embodiment of an oil heater control unit of the present invention.

Continued front page    F term (reference) 2H027 DA11 DA12 DA38 DE07 GB02                       GB08 HA02                 2H033 AA21 AA36 BA45 BA46 BB17                       CA07 CA08 CA57                 3K058 AA12 AA97 BA18 CA12 CA22                       CA61 CB02                 4F040 AA05 AB08 AC01 BA12 CB23                 4F042 AA03 BA19 CA03

Claims (3)

[Claims] 1. A transfer material by developing a latent image formed on a photoreceptor with toner, transferring the toner image on the photoreceptor onto a transfer material, and then applying heat and pressure with a heat and pressure fixing device. An electrophotographic image forming apparatus for forming an image on an image forming apparatus, wherein the heating / pressurizing roller is provided in order to improve the releasability between the heating / pressurizing roller and the transfer material. The separation oil to be applied, the separation oil heating heater for heating the separation oil, and the oil temperature detecting means for detecting the temperature of the separation oil are provided, and the separation oil heating heater is turned on, and the separation oil heating heater is turned on for a predetermined time. If the temperature of the oil temperature detecting means does not rise and the temperature of the oil temperature detecting means at that time is within a predetermined temperature range, an image indicating that the remaining amount of oil is low is displayed and a warning is given. Forming equipment. 2. An environmental temperature detecting means for detecting an ambient environmental temperature of the image forming apparatus and an oil heater temperature detecting means for detecting a temperature of the separated oil overheat heater, wherein the predetermined temperature range is the environmental temperature. The image forming apparatus according to claim 1, wherein the temperature is within a range of a temperature detected by a detection unit and a temperature detected by the oil heater temperature detection unit. 3. An image forming apparatus, wherein when the temperature of the oil temperature detecting means is not within a predetermined temperature range, it is displayed and a warning is given that the oil temperature detecting means is abnormal.