JP3619022B2 - Color electrophotographic image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention forms an electrostatic latent image on an image carrier such as a photosensitive drum such as a color copying machine or a color printer, develops the electrostatic latent image, and transfers the image to a recording material. The present invention relates to an electrophotographic image forming apparatus in which a process cartridge including a developing device is detachable in a color electrophotographic image forming apparatus to be formed.
[0002]
The process cartridge described above is a cartridge in which a charging unit or a cleaning unit, a developing unit, and an electrophotographic photosensitive member are integrally formed, and the cartridge can be attached to and detached from the image forming apparatus main body. In addition, at least one of the charging unit and the cleaning unit, the developing unit, and the electrophotographic photosensitive member are integrally formed into a cartridge that can be attached to and detached from the image forming apparatus main body. Further, the developing means and the electrophotographic photosensitive member are integrated into a cartridge so as to be detachable from the image forming apparatus main body.
[0003]
Further, the charging means that also serves as the cleaning means, the developing means, and the electrophotographic photosensitive member are integrally formed into a cartridge, and the cartridge can be attached to and detached from the image forming apparatus main body.
[0004]
[Prior art]
In an image forming apparatus that forms an image using a two-component developer composed of toner and carrier, toner is replenished by comparing the toner density signal at the time of image formation with a reference toner density, and the toner density is kept constant. Control is taking place. At this time, an electrical signal from a sensor for detecting the toner density is used as a toner density signal and a reference toner density signal. Conventionally, a service person has a toner density signal when the apparatus is installed and when a developer is replaced. It was necessary to initially set the control voltage value and the reference toner density value.
[0005]
[Problems to be solved by the invention]
For this reason, there is a problem that the device cannot be used no matter how rushed until the service person is called and the work is completed.
[0006]
Accordingly, an object of the present invention is to provide a process cartridge in which an image forming apparatus is integrated with a developing unit that is easy for a user to work and an electrophotographic photosensitive drum as an image carrier, and the process cartridge is not used. When it is detected, it automatically initializes various data necessary for toner density control, thereby providing a color electrophotographic image forming apparatus that does not require a service person to be exchanged when replacing a process cartridge.
[0007]
[Means for Solving the Problems]
If a representative invention according to the present application is shown with a number corresponding to the number of the claim, the first invention according to the present application is a color electrophotographic image in which an image is formed on a recording medium with a process cartridge removable. In the forming device,
a. A process cartridge having an electrophotographic photosensitive drum, developing means for developing the latent image formed on the electrophotographic photosensitive drum with toner, and means for storing various initial data is detachably mounted. Mounting means;
b. Means for determining whether the process cartridge is unused;
c. Means for initial setting of various data necessary for toner density control;
d. Means for storing various data set by the initial setting means in the process cartridge;
e . a toner concentration detection sensor for detecting the toner concentration in the developing means;
And when the means for determining that the process cartridge is not used is determined by the operation panel, the user can select whether to perform the initial setting,
When the user selects to perform the initial setting, initial setting of the control voltage value of the toner density signal and the reference toner density value is performed, and the initially set values are stored in the process cartridge. A color electrophotographic image forming apparatus.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a color image forming apparatus according to the present invention will be described in more detail with reference to the drawings.
[0009]
(Embodiment 1)
FIG. 1 shows a configuration diagram of a color image forming apparatus according to Embodiment 1 of the present invention. The color image forming apparatus includes a color reader unit and a color printer unit.
[0010]
[Configuration of color reader unit]
In FIG. 1, an original platen glass (platen) 301 is horizontally provided above the color reader unit, and an original feeder (DF) 302 is provided thereon. Note that there is a configuration in which a mirror surface pressure plate (not shown) is mounted instead of the document feeder 302. Within the first carriage 314, there are light sources 303 and 304, which are halogen lamps, reflectors 305 and 306 for condensing the light from these light sources 303 and 304 on the document, and a mirror 307 for reflecting the reflected light or projection light from the document. It is installed. Further, mirrors 308 and 309 for condensing the reflected light from the mirror 307 onto the CCD 101 via the lens 310 are mounted on the second carriage 315.
[0011]
Further, the substrate 311 on which the CCD 101 is mounted, elements other than the CCD 101 shown in FIG. 2 and the binary conversion unit 201, video signal count units 220, 221, 222, and 223 shown in FIG. 3, delay units 202, 203, 204, and 205. And a digital image processing unit 312 including an interface (I / F) unit 313 with other IPUs.
[0012]
The first carriage 314 is moved at a speed V and the second carriage 315 is moved at a speed V / 2 by being mechanically moved by the driving means 316 in the direction perpendicular to the electrical scanning (main scanning) direction of the CCD 101. Then, the entire surface of the document is scanned (sub-scanning).
[0013]
FIG. 2 is a block diagram showing a detailed configuration of the digital image processing unit 312.
[0014]
In the figure, a document on the platen glass 301 reflects light from light sources 303 and 304, and the reflected light is guided to the CCD 101 and converted into an electrical signal. When the CCD 101 is a color sensor, even if the RGB color filters are mounted inline in the order of RGB on the 1-line CCD, the R-filter, G-filter, and B-filter are arranged for each CCD by the 3-line CCD. The filter may be on-chip, or the filter may be configured separately from the CCD.
[0015]
Then, the electrical signal (analog image signal) is input to the image processing unit 312, and clamp & Amp. & S / H & A / D unit 102 samples and holds (S / H), clamps the dark level of the analog image signal to the reference potential, and amplifies it to a predetermined amount (the above processing order is not limited to the notation order), and A / D-converted and converted into, for example, an RGB 8-bit digital signal.
[0016]
The RGB signal is subjected to shading correction and black correction by the shading unit 103, and then, when the CCD 101 is a three-line CCD in the stitching & MTF correction & document detection unit 104, the stitching processing differs in the reading position between lines. The delay amount for each line is adjusted according to the reading speed, and the signal timing is corrected so that the reading positions of the three lines are the same. In the MTF correction, the reading MTF changes depending on the reading speed and the variable magnification. Then, the original detection detects the original size on the original platen glass 301.
[0017]
The digital signal whose reading position timing is corrected corrects the spectral characteristics of the CCD 101 and the spectral characteristics of the light sources 303 and 304 and the reflectors 305 and 306 by the input masking unit 105. The output of the input masking unit 105 is input to the selector 106 which can be switched with a signal passing through the external I / F 114.
[0018]
The signal output from the selector 106 is input to the color space compression & background removal & LOG conversion unit 107 and background removal unit 115. After the background is removed, the signal input to the background removal unit 115 is input to the black character determination unit 116 that determines whether the document is a black character in the document, and generates a black character signal from the document. The color space compression & background removal & LOG conversion unit 107 to which the output of the other selector 106 is input determines whether the image signal read by the color space compression is within a range that can be reproduced by the printer. If not, the image signal is corrected so that it can be reproduced by the printer. Then, background removal processing is performed, and RGB signals are converted to CMY signals by LOG conversion.
[0019]
In order to correct the signal and timing generated by the black character determination unit 116, the timing of the output signal of the color space compression & background removal & LOG conversion unit 107 is adjusted by a delay 108. The moire removal unit 109 removes the moire from the two types of signals, and then the magnification processing unit 110 performs magnification processing in the main scanning direction.
[0020]
In the UCR & masking & black character reflecting unit 111, the signal processed by the scaling processing unit 110 is a CMYK signal generated by UCR processing, and the masking processing unit corrects the signal to the output of the printer and corrects the black character. The determination signal generated by the determination unit 116 is fed back to the CMYK signal.
[0021]
The signal processed by the UCR & masking & black character reflection unit 111 is subjected to density adjustment by the γ correction unit 112 and then smoothed or edge processed by the filter unit 113. The signal processed as described above is converted from an 8-bit multilevel signal to a binary signal by the binary conversion unit 201 shown in FIG. This conversion method may be a dither method, an error diffusion method, or an improved error diffusion method.
[0022]
[Configuration of color printer section]
In FIG. 1, a Y image forming unit 317 that forms a yellow image, an M image forming unit 318 that forms a magenta image, a C image forming unit 319 that forms a cyan image, and a K that forms a black image. The image forming unit 320 includes photosensitive drums 342, 343, 344, 345, chargers 321, 324, 327, 330, LED units 210, 211, 212, 213, developing units 322, 325, 328, 331, auxiliary charging, respectively. Devices 360, 361, 362, and 363 are provided. The chargers 321, 324, 327, and 330 include charging sleeves 370, 371, 372, and 373, respectively, and the developing devices 322, 325, 328, and 331 include developing sleeves 355, 356, 357, and 358, respectively. Yes.
[0023]
Since each configuration is the same, the Y image forming unit 317 will be described in detail, and description of the other image forming units will be omitted.
[0024]
The Y image forming unit 317 is provided with a photosensitive drum 342 around which a charger 321, an LED unit 210, a developing unit 322, an auxiliary charger 360 and the like are arranged. Here, as shown in FIG. 9, the photosensitive drum 342, the charger 321, and the developer 322 are an integrated process cartridge 390.
[0025]
The process cartridge 390 is detachable from the image forming apparatus main body 14. In this attachment / detachment method, a guide member (not shown) is provided in the image forming apparatus main body 14, and a guide (not shown) provided in the process cartridge 390 is guided by the guide member. The process cartridge 390 includes a memory EEPROM 374.
[0026]
In these operations, first, the photosensitive drum 342 is charged by the auxiliary charger 360 and the charger 321. Next, a latent image is formed on the surface of the photosensitive drum 342 by light from the LED unit 210 driven by the LED drive 206 (207, 208, 209) shown in FIG. 3, and a toner image is formed by developing with the developing device 322. To do.
[0027]
The developing device 322 includes a developing sleeve 355 for developing by applying a developing bias. As shown in FIG. 1, a transfer charger 323 is disposed below the developing device 322 with the transfer belt 333 interposed therebetween, and discharge is performed from the back of the transfer belt 333 so that the toner image on the photosensitive drum 342 is transferred to the transfer belt. The image is transferred to a recording paper on 333.
[0028]
After this transfer, the toner remaining on the photosensitive drum 342 is once taken into the charger 321, the electrostatic characteristics are changed, and the toner is returned to the photosensitive drum 342 again. The developing unit 322 collects and reuses the toner.
[0029]
Next, a procedure for forming an image on recording paper or the like will be described. The recording paper stored in the paper feed cassettes 340 and 341 is supplied onto the transfer belt 333 by the paper feed rollers 336 and 337 one by one by the pickup rollers 338 and 339. The transfer belt 333 is disposed below the Y image forming unit 317, the M image forming unit 318, the C image forming unit 319, and the K image forming unit 320 and is driven by the transfer belt roller 348 in the direction indicated by the arrow.
[0030]
The leading edge of the recording paper fed to the transfer belt 333 is detected by a paper leading edge sensor 347. The detection signal of the paper leading edge sensor 347 is sent from the printer unit to the color reader unit, and is used as a sub-scanning synchronization signal when a video signal is sent from the color reader unit to the printer unit.
[0031]
Thereafter, the recording paper or the like is conveyed by the transfer belt 333, and toner images are formed on the surface in the order of YMCK in the image forming units 317 to 320.
[0032]
The recording paper or the like that has passed through the K image forming unit 320 is separated from the transfer belt 333 after being neutralized by the neutralization charger 349 to facilitate separation from the transfer belt 333. A peeling charger 350 is provided adjacent to the charge eliminating charger 349, and image disturbance due to peeling discharge when the recording paper or the like is separated from the transfer belt 333 is prevented.
[0033]
The separated recording paper or the like is charged by the pre-fixing chargers 351 and 352 and then the toner image is thermally fixed by the fixing device 334 and then discharged after the toner image is fixed in order to compensate for the toner adsorption force and prevent image distortion. The paper is discharged onto a paper tray 335. The transfer belt 333 is neutralized by an internal / external neutralizer 353.
[0034]
Next, a method for initially setting the control voltage value of the toner density signal and the reference toner density value and storing them in the process cartridge 390 when the process cartridge 390 which is a feature of the present invention is not used will be described in detail.
[0035]
When the process cartridge 390 is attached to the image forming apparatus main body 14, the memory EEPROM 374 is coupled to the control device of the apparatus main body 14.
[0036]
First, FIG. 4 shows the configuration of the developing device 322 in the process cartridge 390. The toner replenished from the toner replenishing port 42 circulates in the direction of the arrow in the figure as the stirring screw 41 rotates. When a developing bias is applied, the toner is blown to the photosensitive drum 342 by the rotation of the developing sleeve 355. The toner concentration detection sensor 40 converts the toner concentration in the developing device 322 into an electrical signal, and this signal is input as a toner concentration 45 to the CPU in the apparatus main body 14. The toner density signal 45 is variable by a control voltage 44 from the apparatus main body 14.
[0037]
Next, an initial setting method for the control voltage value of the toner density signal and the reference toner density value will be described with reference to the flowchart of FIG. First, in step S51, the stirring screw 41 and the developing sleeve 355 are rotated for one minute, and in step S52, a developing bias AC component is applied. Next, in S53, the control voltage is automatically adjusted so that the toner density signal becomes 2.5V ± 0.15V. In step S54, the toner density signal is sampled 10 times at intervals of 20 ms, and the average value is determined as a reference toner density value. In step S55, the determined control voltage value and reference toner density value are written in the EEPROM 374 provided in the process cartridge 390. In step S56, the rotation of the agitating screw 41 and the developing sleeve 355 is stopped. In step S57, the developing bias AC component is turned off, and the process ends. These processes are the same for all color process cartridges.
[0038]
Next, the present invention will be described with reference to the flowchart of FIG. In step S61, the color electrophotographic image forming apparatus is turned on. In S62, it is checked whether or not the process cartridge 390 is mounted on the apparatus main body 14. If there is a process cartridge that is not mounted, a display prompting the mounting on the operation panel is displayed in S64. If all color process cartridges are mounted, the process cartridge storage data is checked in S63. Here, if both the toner density signal control voltage value and the reference toner density value are not 0, it is assumed that the initial setting has already been performed. If either one is 0, it is determined that the initial setting has not been performed, and the initial setting is displayed on the operation panel in S65, the initial setting is performed, each data is stored in the process cartridge, and the process ends. Note that the data stored in the process cartridge in S63 is sequentially checked for the process cartridges of all colors.
[0039]
(Embodiment 2)
FIG. 7 shows an operation unit of the color image forming apparatus of the present embodiment. Reference numeral 1001 denotes a touch panel display, which normally displays the number of copies, selected paper size, magnification, and copy density. A reset key 1002 returns the copy mode to the standard mode. Reference numeral 1003 denotes a start key, which starts a copy operation. Reference numeral 1004 denotes a stop key, which interrupts the copy operation. A clear key 1005 returns the copy mode to the standard mode. Reference numeral 1006 denotes a numeric keypad for setting the number of copies.
[0040]
In the check of the data stored in the process cartridge in S63 in the flowchart of FIG. 6, if either the toner density signal control voltage value or the reference toner density value is 0, it is assumed that the initial setting has not been performed and is displayed on the touch panel 1001. A user setting mode screen shown in FIG. On the user setting mode screen, the key A indicating the toner density control initial setting blinks, and the initial setting is executed by pressing this key. When the cancel key is pressed, the normal screen is restored.
[0041]
【The invention's effect】
According to the present invention described above, a color electrophotographic image forming apparatus odor Te, when the process cartridge by the user are integrated with easy developing means and an electrophotographic photosensitive drum work is detected that an unused the user can by automatically Rukoto initialized various data necessary for toner density control by operating, to provide a color electrophotographic image forming apparatus is not necessary to call a service engineer when the process cartridge is replaced to.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a color image forming apparatus according to a first embodiment.
FIG. 2 is a block diagram showing a configuration of a digital image processing unit according to the first embodiment.
FIG. 3 is a block diagram illustrating a configuration of an LED driving unit according to the first embodiment.
FIG. 4 is a configuration diagram of a developing device according to the first embodiment.
FIG. 5 is a flowchart illustrating initial setting of toner density control according to the first exemplary embodiment.
FIG. 6 is a flowchart for explaining the control of the first embodiment.
7 is a diagram illustrating an operation unit according to a second embodiment. FIG.
FIG. 8 is a diagram showing a user setting mode screen according to the second embodiment.
FIG. 9 is a schematic longitudinal sectional view of a process cartridge.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 14 ... Image forming apparatus main body 40 ... Toner density detection sensor 41 ... Toner stirring screw 42 ... Toner supply port 44 ... Control voltage 45 ... Toner density signal 101 ... CCD
102 ... Clamp & Amp. & S / H & AD unit 103 ... Shading unit 104 ... Connection & MTF correction & document detection unit 105 ... Input masking unit 106 ... Selector 107 ... Color space compression & background removal & LOG conversion unit 108 ... Delay 109 ... Moire removal unit 110 ... Scaling processing unit 111: UCR & Masking & Black Character Reflecting Unit 112 ... γ Correction Unit 113 ... Filter 114 ... External I / F
115 ... Background removal unit 116 ... Black character determination unit 201 ... Binary conversion unit 202-205 ... Delay unit 206-209 ... LED drive 210-213 ... LED unit 220-222 ... Video signal count unit 301 ... Original glass 302 ... Original Paper feeder 303 ... Light source 304 ... Light source 305 ... Reflector umbrella 306 ... Reflector umbrella 307 ... Reflector mirror 308 ... Mirror 309 ... Mirror 310 ... Lens 311 ... Substrate 312 ... Image processing unit 313 ... Interface 314 ... First carriage 315 ... Second Carriage 316 ... Driving means 317 ... Y image forming unit 318 ... M image forming unit 319 ... C image forming unit 320 ... K image forming unit 321 ... Charger 322 ... Developer 323 (326, 329, 332) ... Transfer charger 324 ... Charger 325 ... Developer 327 ... Charger 328 ... Developer 330 ... Charger 331 ... Developer 33 ... transfer belt 334 ... fixer 335 ... discharge tray 336 ... feed roller 337 ... feed roller 338 ... pickup roller 339 ... pickup roller 340 ... feed cassette 341 ... feed cassettes 342-345 ... photosensitive drum 347 ... paper Front end sensor 348... Transfer belt roller 349 .. Static elimination charger 350... Separation charger 351 .. Pre-fixing charger 352 .. Pre-fixing charger 353 .. Internal / external neutralizer 355 to 358 ... Developing sleeve 360 to 363 ... Auxiliary chargers 370 to 373 ... Charging sleeve 374 ... Memory EEPROM
390 ... Process cartridge 1001 ... Touch panel display 1002 ... Reset key 1003 ... Start key 1004 ... Stop key 1005 ... Clear key 1006 ... Ten key

Claims (5)

In a color electrophotographic image forming apparatus in which a process cartridge is detachable and forms an image on a recording medium,
a. A process cartridge having an electrophotographic photosensitive drum, developing means for developing the latent image formed on the electrophotographic photosensitive drum with toner, and means for storing various initial data is detachably mounted. Mounting means;
b. Means for determining whether the process cartridge is unused;
c. Means for initial setting of various data necessary for toner density control;
d. Means for storing various data set by the initial setting means in the process cartridge;
e . a toner concentration detection sensor for detecting the toner concentration in the developing means;
And when the means for determining that the process cartridge is unused , the user can select whether to perform the initial setting from the operation panel,
When the user selects to perform the initial setting, initial setting of the control voltage value of the toner density signal and the reference toner density value is performed, and the initially set values are stored in the process cartridge. Color electrophotographic image forming apparatus. In means the process cartridge to determine whether unused claim 1, characterized by using a control voltage value of the toner density signals stored in the process cartridge and the reference toner density value to determine Color electrophotographic image forming apparatus. 2. The color electrophotographic image forming apparatus according to claim 1, wherein means for initially setting various data necessary for toner density control is automatically performed when the main body is turned on. Color electrophotographic image forming apparatus according to claim 1, characterized in that to indicate that during the execution of the initialization is being initialized to the operation panel. Wherein the process cartridge integrally into a cartridge to a charging section which also serves as a cleaning means and developing means and an electrophotographic photosensitive drum, any of claims 1 to 4 which is detachably mountable to the main assembly of an image forming apparatus A color electrophotographic image forming apparatus according to claim 1.

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