JP2000098736A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately control the stop positions of respective developing units without increasing the manufacturing cost and the cost of parts and to realize an excellent developing action by deciding the correction value of the detected position of a rotating position detection means by using reference position display parts respectively arranged at a developing unit fitting member and a developing device supporting member and using this correction value when the respective developing units are moved to a developing position. SOLUTION: By a CPU 120, a value counted by a pulse counter 123 until an angle recognition member 104 arranged at the rotary developing unit 100 is detected by an optical sensor 107 fitted to a machine frame is compared with a prescribed value counted when an error is not caused in the fitting position and the detecting accuracy of the sensor 107 previously stored in a memory 121 and difference between them is calculated as the correction value. Then, when a digital color copying machine is actually used, the correction value is stored in the memory of a CPU controlling the action of a rotary developing device 18 as the correction value used when the developing device 18 is driven to be rotated to the developing position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device used in an image forming apparatus such as an electrophotographic copying machine or a printer, and more particularly to a developing device in which a plurality of developing devices are arranged along a circumferential direction around a rotation axis. The present invention relates to a rotary developing device configured to rotate and move the plurality of developing devices around a rotation axis.

[0002]

2. Description of the Related Art Conventionally, as a developing device used for an image forming apparatus such as an electrophotographic copying machine or a printer of this kind,
For example, as shown in FIG. 15, developing devices 201K, 201Y, 201M, and 201C of four colors of black (K), yellow (Y), magenta (M), and cyan (C) are arranged around a rotation axis 202. The developing units 201K, 201Y, 201 of these four colors are arranged along the circumferential direction.
M, 201C are rotated about the rotation axis 202, and the developing units 201K, 201Y, 201M,
201C is sequentially moved to a development position facing the photoconductor drum 200, so that four colors of black (K), yellow (Y), magenta (M), and cyan (C) are sequentially formed on the photoconductor drum 200. Are developed by the developing units 201K, 201Y, 201M, and 20 of the corresponding colors.
Rotary developing device 2 configured to be developable at 1C
01 has been proposed and has already been commercialized.

The rotary type developing device 2
01 includes four developing devices 201K, as shown in FIG.
A cylindrical rotary developing unit 203 in which 201Y, 201M, and 201C are arranged around a rotation shaft 202
Is rotated by a driving gear 206 attached to a rotary motor 205 via a gear 204 on the developing unit attached to an end in the axial direction of the developing unit 201K.
Are rotated so as to be sequentially switchable to a developing position facing the photosensitive drum 200.

At this time, the rotary developing device 2 is used.
In FIG. 16, an angle recognition member 207 made of a metal plate is attached to a part of the rotary developing unit 203 as shown in FIG.
The optical sensor 210 is attached to the image forming apparatus via a mounting plate 209, and the angle sensor 207 attached to the rotary developing unit 203 is detected by the optical sensor 210 attached to the machine frame 208 of the image forming apparatus. As a result, the four developing devices 201K, 201
It is configured to perform angle recognition for stopping Y, 201M, and 201C at predetermined positions.

The rotary type developing device 2
01, the angle recognizing member 207 attached to the rotary developing unit 203 includes four developing devices 201K and 201.
When the rotary developing unit 203 is driven to rotate by the rotary motor 205, the angle recognition member 207 attached to the rotary developing unit 203 is used as a reference for the position in the rotation direction of Y, 201M, and 201C.
Optical sensor 21 mounted on machine frame 208
0, the four developing devices 201K, 20
Recognize the positions of the rotation directions of 1Y, 201M, and 201C,
Developing devices 201K, 201Y, 201M, 20 to be developed
1C is rotated and moved to a developing position opposed to the photosensitive drum 200.

[0006]

However, the prior art described above has the following problems. That is, in the case of the rotary developing device 201,
As shown in FIG. 16, the machine frame 2 of the image forming apparatus
08 for attaching optical sensor 210 to plate 2
09, the mounting error of the optical sensor 210 with respect to the plate 209, the error of the detection position and the sensitivity variation of the optical sensor 210 itself, and the mounting error of the angle recognition member 207 mounted on the rotary developing unit 203. Etc. inevitably exist. Therefore, the mounting error of the plate member 209 and the optical sensor 210
The mounting error of the optical sensor 210 itself, the variation in the detection position and the sensitivity variation of the optical sensor 210 itself, and the mounting error of the angle recognition member 207 are accumulated, and the stop positions of the developing devices 201K, 201Y, 201M, and 201C are directly changed. The angle varies, and each of the developing devices 201K, 201Y,
This appears as a deviation of the MSA (magnet setting angle) of the magnet rolls arranged in the developing rolls 201M and 201C with respect to the photosensitive drum 200.
Thus, each of the developing units 201K, 201Y, 201
When the MSA of the M and 201C magnet rolls is shifted, for example, each of the developing devices 201K, 201Y, 201
There is a problem that an edge effect appears strongly in the development characteristics of M and 201C, which causes variation and deterioration of image quality.

Therefore, it is necessary to improve the mounting accuracy so as to reduce an error generated in the plate member 209, the optical sensor 210, or the detection position of the optical sensor 210, or to use a high-precision optical sensor 210. However, in this case, there is a new problem that manufacturing costs and parts costs are increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. It is an object of the present invention to provide a stopping position of each developing unit without increasing manufacturing costs and parts costs. It is an object of the present invention to provide a rotary type developing device capable of controlling the image quality with high accuracy and capable of developing good image quality.

[0009]

According to a first aspect of the present invention, a plurality of developing devices are arranged along a circumferential direction around a rotation axis, and the plurality of developing devices are arranged around a rotation shaft. By detecting the rotational positions of the plurality of developing devices, a desired developing device is moved to a developing position facing the image carrier, and the electrostatic latent formed on the image carrier is moved. In a developing device for visualizing an image, a developing device mounting member for mounting the plurality of developing devices along a circumferential direction around a rotation axis, provided on the developing device mounting member,
An angle recognition member for recognizing an angle of the developing device mounting member in a circumferential direction; a developing device supporting member rotatably supporting the developing device mounting member via a rotating shaft; and a developing device supporting member. A rotational position detecting means for detecting a rotational position of the developing device mounting member by detecting an angle recognizing member provided on the developing device mounting member; and a rotational position detecting means provided on the developing device mounting member and the developing device support member, respectively. A reference position display unit that displays a reference position for performing alignment in the rotation direction of the two, using a reference position display unit provided on each of the developing device mounting member and the developing device support member, The correction value of the detection position of the rotation position detection means is determined, and the correction value is used when each developing unit is moved to the development position.

Further, in the developing device according to the present invention, the developing device mounting member is rotated after the positions of the reference position indicating portions provided on the developing device mounting member and the developing device support member are adjusted. The rotation amount of the developing unit mounting member is detected by the rotation amount detecting unit until the rotation amount detecting unit detects the angle recognition member provided on the developing unit mounting member, and the developing amount detected by the rotation amount detecting unit is detected. 2. The developing device according to claim 1, wherein a difference between a rotation amount of the container mounting member and a predetermined value is set as a correction value.

Further, according to a third aspect of the present invention, the operation of determining the correction value is performed at the time of assembling an image forming apparatus provided with the developing device.
3. The developing device according to item 1.

According to a fourth aspect of the present invention, the operation of determining the correction value is performed after the use of the image forming apparatus having the developing device is started. 3. The developing device according to item 1.

[0013]

The developing device according to the present invention determines the correction value of the detected position of the rotational position detecting means by using the reference position display sections provided on the developing device mounting member and the developing device support member, respectively. Since the values are used to move each developing device to the developing position, even if there is an error in the mounting position or the like in the rotation position detecting means or the like, the developing device mounting member and the developing device supporting member are respectively provided. Using the provided reference position display unit, a correction value for the detection position of the rotation position detection means is determined, and this correction value is used when each developing unit is moved to the development position. The stop position of each developing unit can be controlled with high accuracy without increasing the image quality, thereby enabling development with good image quality.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows a multi-transfer digital color copier as an image forming apparatus to which a rotary developing device according to an embodiment of the present invention is applied.

In FIG. 2, reference numeral 1 denotes a main body of the digital color copying machine, and an automatic document feeder 2 for automatically transporting originals 2 one by one onto a platen glass 3 Document feeder 4 (Auto D
document feeder) is provided. Also, at the upper end of the digital color copier main body 1,
An image reading device 5 (Image) for reading an image of the original 2
Input Terminal). The image reading device 5 illuminates the image of the original 2 placed on the platen glass 3 with the light source 6 and also reflects the reflected light image of the original 2 on the first and second scanning mirrors 7 and 8 and the imaging lens. 9 to scan and expose the CCD sensor 10 via
The CCD sensor 10 is configured to read the color material reflected light image of the document 2 at a predetermined dot density (for example, 16 dots / mm).

The color material reflected light image of the original 2 read by the image reading device 5 is, for example, original reflectance data of three colors of red (R), green (G), and blue (B) (8 bits each). As an image processing device 11 (Image Process)
The image processing apparatus 11 transmits the reflectance data of the document 2 to the predetermined data such as shading correction, positional deviation correction, lightness / color space conversion, gamma correction, frame erasure, color / movement editing, and the like. Image processing is performed.

The image data subjected to the predetermined image processing by the image processing device 11 as described above includes four data of black (K), yellow (Y), magenta (M), and cyan (C) (each 8 bits). ROS12 (Raster Output S)
The ROS 12 performs image exposure using a laser beam LB in accordance with original color material gradation data.

In the ROS 12, as shown in FIG.
By modulating the semiconductor laser 13 in accordance with the original color material gradation data, a laser beam LB is emitted from the semiconductor laser 13 in accordance with the gradation data. The laser beam LB emitted from the semiconductor laser 13 is deflected and scanned by a rotary polygon mirror 14 and is scanned and exposed on a photosensitive drum 16 via a reflection mirror 15.

The photosensitive drum 16 on which the laser light LB is scanned and exposed by the ROS 12 is driven to rotate at a predetermined speed in a direction indicated by an arrow by a driving means (not shown). The surface of the photosensitive drum 16 is
After being charged to a predetermined potential by the charging scorotron 17 in advance, the laser light L
An electrostatic latent image is formed by scanning and exposing B. The electrostatic latent image formed on the photosensitive drum 16 is
Black (K), yellow (Y), magenta (M), cyan (C) four color developing units 18K, 18Y, 18M, 1
The toner image is sequentially developed by a rotary type developing device 18 provided with an 8C, and a toner image of a predetermined color is obtained.

The toner image formed on the photosensitive drum 16 is transferred onto a transfer material 21 such as a transfer sheet held on a transfer drum 20 disposed adjacent to the photosensitive drum 16 by a transfer scorotron. Due to the charging of 22, the images are sequentially transferred in multiple layers. As shown in FIG. 2, the transfer material 21 is fed from one of a plurality of paper feed cassettes 23 to 27 stored in the lower part of the copying machine main body 1 by a paper feed roll 28, or The transfer material 21 is fed from a manual feed tray 29 disposed on a side surface outside the main body 1 by a feed roller 30, and the fed transfer material 21 is transferred by a transfer roll 20 and a registration roll 32 to the transfer drum 20.
Are respectively conveyed to the surface of the sheet at a predetermined timing. Then, the transfer material 21 is transferred to the transfer drum 20 by charging of the electrostatic attraction corotron 33 and pressing of the attraction roll 34.
The transfer drum 2 is electrostatically attracted to the surface of the transfer drum 2.
0 surface. In addition to the non-standard-size transfer paper such as a postcard, a transparent OHP sheet or the like for an overhead projector can be fed from the manual feed tray 29, and an image can be formed on the OHP sheet or the like. ing.

The transfer material 21 on which the toner images of a predetermined number of colors are sequentially transferred from the photosensitive drum 16 is separated from the surface of the transfer drum 23 by discharging the corotron 35 for separation. 36, fixing device 3
The toner image is fixed on the transfer material 21 by heat and pressure by the fixing device 37, and is discharged onto a discharge tray 39 by a discharge roll 38, thereby completing the color image copying process.

Further, when a color image is formed on both sides of the transfer material 21, the transfer material 21 having the color image fixed on one side is not discharged onto the discharge tray 39 as it is, The transfer direction of the transfer material 21 is changed by the provided switching plate 40 to the lower double-sided conveyance path 4.
Switch to 1. Then, the transfer material 21 conveyed to the two-sided conveyance path 41 is temporarily put on the intermediate tray 45 in a state where the transfer material 21 is turned upside down by the conveyance rolls 42 and the switching plates 43 and 44 provided in the two-sided conveyance path 41. The transfer material 21 is transferred from the intermediate tray 45 to the transfer drum 23 by the paper feed roll 46 and the transport roll 31.
, The color image is copied on both sides of the transfer material 21.

2, reference numeral 47 denotes a cleaner for cleaning the surface of the photosensitive drum 16, reference numeral 48 denotes a pair of discharging corotrons for removing the charge of the transfer drum 20, and reference numeral 49 denotes a cleaner for cleaning the surface of the transfer drum 20. Are respectively shown.

FIG. 3 shows a developing device according to an embodiment of the present invention. This developing device is used, for example, as a rotary developing device 18 of a digital color copying machine configured as described above.

As shown in FIG. 3, the rotary type developing device 18 has the same configuration and includes four developing devices 18K, 18Y, 18M,
18C, these four developing units 18K, 1
The developing units 8Y, 18M, and 18C are attached to the developing device holder 51 formed of a substantially cylindrical frame at symmetric positions different from each other by 90 degrees about the rotation shaft 50.
The four developing units 18K, 18Y, 18M, and 18C are:
As described above, black (K), yellow (Y), magenta (M), and cyan (C) developers are stored, respectively. The four developing devices 18K, 18Y, 18
Needless to say, the order of the colors M and 18C and the colors of the developer to be contained may be different from the above order and colors.

The rotary type developing device 1
Reference numeral 8 denotes four developing devices 18 by a driving mechanism described later.
A developing device mounting member 51 holding K, 18Y, 18M, and 18C is rotatable in the direction of the arrow, and the developing devices 18K, 18Y, and 18M containing toner of a predetermined color to be developed by this driving mechanism. , 18C, as shown in FIG. 3, are sequentially rotated and moved to a developing position opposed to the photosensitive drum 16, thereby enabling development of a predetermined color. Further, the four developing devices 18K, 18Y,
18M and 18C can be stopped by moving to a predetermined position such as a home position other than the developing position by a driving mechanism.

As shown in FIG. 4, the developing devices 18K, 18Y, 18M, and 18C of the developing device 18 of the rotary type have a photosensitive drum 1 at an opening of a developing device housing 52.
6, a first screw auger 55 as a stirring and conveying member provided along a partition wall 54 at the lower rear side of the developing roll 53, and The second screw auger 56 and the first and second screw augers 5
5 and 56, the toner T is agitated while being sequentially conveyed.
And a carrier C, and a toner supply member disposed at an intermediate portion on the back side of the developing device housing 52 and serving as a connecting / conveying member for conveying toner T supplied from a toner supply device described later. The main part of the screw auger 59 is formed. Each of the developing units 18K, 1
8Y, 18M, and 18C, inside the developing device housing 52, a developer tank 61 in which a two-component developer 57 including a toner T of a predetermined color and a carrier C which is a magnetic particle is stored.
It has become.

As shown in FIG. 4, the developing roll 53 is composed of a cylindrical developing sleeve 62 having a diameter of, for example, 18 mm, which rotates in the direction of the arrow, and a magnet roll 63 fixedly disposed inside the developing sleeve. The surplus developer 57 is scraped off by the spike regulating member 64 disposed above the developing sleeve 62, and a predetermined amount of magnetic brush is formed on the outer peripheral surface. The developing roller 53 having a predetermined amount of a magnetic brush formed on the surface thereof conveys the developer 57 to the developing area where the photosensitive drum 16 faces the photosensitive drum 16 as the developing sleeve 62 rotates.
The electrostatic latent image formed on the surface 6 is developed with toner of a predetermined color. Note that a plurality of magnetic poles having a predetermined polarity are disposed at predetermined positions on the outer periphery of the magnet roll 63 disposed inside the developing sleeve 62 in order to obtain predetermined development characteristics and developer transport characteristics. .

On the other hand, as shown in FIG. 5, the first and second screw augers 55 and 56 have rotary shafts 65 and 66 which are driven at low speed by a drive motor via a drive gear (not shown). It is composed of conveying blades 67 and 68 formed spirally in the longitudinal direction of the rotating shafts 65 and 66. The transfer blades 67, 68 of the first and second screw augers 55, 56 have transfer blades 67 for receiving the developer 57 at one end thereof.
a, 68a are provided short. The first screw auger 55 has its transport blade 67 made of a non-magnetic stainless steel material (non-magnetic SUS304) or a synthetic resin member (a material to which toner does not easily adhere, such as polycarbonate). It is not affected. Then, the first and second screw augers 55 and 56 transport the developer 57 in the developer tank 61 while stirring the developer 57 in the direction of the arrow, as shown in FIGS. In a state where the developer 57 has been transported to the ends of the second screw augers 55 and 56, an opening 69 provided in the partition wall 54,
The transfer of the developer 57 is carried out via 70, and the developer 57 is circulated and conveyed while being stirred.

As shown in FIG. 4, the toner supply screw auger 59 is disposed at an intermediate portion on the rear side of the developing device housing 52. As shown in FIG. 5, the screw auger 59 for supplying toner is provided with a second screw auger 5 from outside the one end of the developing device housing 52.
Along the longitudinal direction of the second screw auger 5
6 is arranged to the vicinity of the other end. A return screw auger 59a formed at a fine pitch in the opposite direction is formed short at the downstream end of the toner supply screw auger 59 in the transport direction, and is conveyed by the toner supply screw auger 59. The supplied toner T is reliably supplied into the developing device housing 52. As shown in FIG. 5, the screw auger 59 for supplying toner is driven to rotate by a gear 72 provided at an end of a rotating shaft 71 meshing with a driving gear 74 attached to a driving motor 73. It has become so. The drive motor 73 is fixedly mounted on a support frame 75 of a digital color copying machine, corresponding to a developing position where a developing unit faces the photosensitive drum 16. Further, a gear 7 attached to the end of the rotating shaft 71 of the screw auger 59 for supplying toner is used.
2 is provided in each of the developing devices 18K, 18Y, 18M, and 18C, and is provided in each of the developing devices 18K, 18Y, 18M, and 1C.
The gear 72 is configured to mesh with a drive gear 74 attached to a drive motor 73 when the 8C moves to the developing position.

The screw auger 59 for toner supply
4 and 5, is covered by a cylindrical member 76. An opening 77 is provided at one end of the cylindrical member 76 so that toner can be supplied from a toner supply device 80 described later. And at the other end,
Second screw auger 56 in developer housing 52
A large opening 78 for supplying toner is provided at the top of the printer.

FIG. 6 shows a toner supply device used in a rotary developing device according to an embodiment of the present invention.

The toner supply device 80 is provided for each of the developing devices 18K, 18Y, 18M, and 18C from the upper portion to the rear surface of the rotary developing device 18.
Each toner supply device 80K, 80Y, 80M, 80C
As shown in FIGS. 1 and 7, the corresponding black (K),
The toner cartridges 81K, 81Y, 81M, and 81C are provided as toner storage containers that store toner of each color of yellow (Y), magenta (M), and cyan (C). These toner cartridges 81K, 81Y, and 81C are provided.
M and 81C are housed in the upper part of the rotary multicolor developing device 18 in the digital copying machine main body 1 as shown in FIGS.

As shown in FIG. 7, the toner cartridge 81 is formed in a cylindrical shape and contains a predetermined amount of toner T of a predetermined color. Further, inside the toner cartridge 81, a toner transport agitator 82 for stirring and transporting the toner T is provided. As shown in FIGS. 6 and 9, the toner transport agitator 82 The cartridge 80 is rotatably driven by a cartridge motor 84, which is a drive motor including a synchronous motor and the like attached to a frame 83 on the back side of 80. The toner cartridge 81 includes:
As shown in FIG. 8, the digital color copier main body 1 is mounted by being inserted into a predetermined position from the near side. When the toner cartridge 81 is inserted to a predetermined position of the digital color copying machine main body 1 by rotating the handle 85 provided on the front surface of the toner cartridge 81 by a predetermined angle, The shutter (not shown) of the toner cartridge 81 is opened so that the toner T can be supplied from a toner supply opening 86 provided at a lower part on the back side. The toner cartridge 81
The toner transport agitator 82 disposed therein has a large toner transport capability, and if toner is present in the toner cartridge 81, the toner transport agitator 82 is driven for a predetermined time to provide a sufficient amount of toner. The amount of toner can always be supplied from the toner supply opening 86.

As shown in FIG. 6, a reserve tank 87 for conveying the toner supplied from the toner cartridge 81 to the developing device 18 is provided below the rear end of the toner cartridge 81. I have. At the bottom of the reserve tank 87, as shown in FIGS. 6, 9, and 10, two toner storage portions 88a and 8 having a U-shaped cross section are provided.
8b and one toner supply section 88c having a U-shaped cross section located between the two toner storage sections 88a and 88b. The two toner storage portions 88a and 88
A spiral agitator 89a, 89b for transporting the toner while stirring the toner is provided inside each of the toner supply portions 88c, and a screw for transporting the toner while stirring the toner is provided inside one toner supply unit 88c. Auger 89c is provided. These spiral agitators 89a and 89b and screw augers 89c
In the case of, the agitators 89a and 89b in a spiral shape are set to have a larger toner conveying capacity than the screw-type augers 89c. Then, the reserve tank 8
7, the toner T supplied from the toner cartridge 81.
While the toner is conveyed so as to be circulated while being stirred by spiral agitators 89a and 89b provided in the two toner accommodating portions 88a and 88b, a part thereof is provided in the toner supply portion 88c. As shown in FIG. 6, the developer 18 is conveyed by a screw-shaped auger 89c, and from a toner outlet 90 provided on the bottom surface of the toner supply unit 88c via a toner supply tubular member 91.
Is supplied with toner.

As shown in FIGS. 6 and 10, on the side wall of the area 92 of the reserve tank 87 where the toner T is supplied from the toner cartridge 81, as shown in FIGS. Is attached.

The toner supply tubular member 91 is shown in FIG.
As shown in FIG.
7 is located below the toner outlet 90,
The other end provided with the opening 94 facing downward is arranged so as to supply the toner T to the developing device 18 (not shown). A screw-shaped auger 9 for transporting the toner T is provided inside the toner-supplying tubular member 91.
5 are provided.

Incidentally, two spiral agitators 89a and 89b provided in the reserve tank 87 of the toner supply device 80 and one screw auger 8 are provided.
9c and a screw-shaped auger 95 provided in the toner-supplying tubular member 91, as shown in FIG. 6 and FIG. Each gear 9
It is designed to be rotationally driven via 7a to 97d and a gear (not shown).

FIG. 11 is a configuration diagram showing a driving mechanism of a rotary type developing device according to this embodiment.

As shown in FIG. 11, the rotary type developing device 18 comprises four developing devices 18K, 18Y, 18
M and 18C are cylindrical rotary developing units 10 as developing device mounting members provided around the rotation shaft 50.
0 is rotated by a drive gear 103 attached to a rotary motor 102 such as a pulse motor via a gear 101 on the developing unit attached to an end of the developing unit 18K. , 18
Y, 18M, and 18C are configured to be rotationally moved so as to be sequentially switched to a developing position facing the photosensitive drum 16. The rotary motor 102 may be, for example, a rotary developing unit 100 with 2400 pulses.
Is set so as to make one rotation.

At this time, the rotary type developing device 1
8 is the rotary developing unit 1 as shown in FIG.
00, an angle recognition member 104 made of a metal plate is attached, and a plate member 106 for attachment to a machine frame 105 as a developing device support member of a digital color copying machine.
The optical sensor 107 attached to the machine frame 105 detects the angle recognizing member 107 attached to the rotary developing unit 103.
It is configured to perform angle recognition for stopping 8K, 18Y, 18M, and 18C at predetermined positions.

The rotary type developing device 1
8, the angle recognizing member 104 attached to the rotary developing unit 100 includes four developing units 18K, 18Y, 1
8M and 18C, the rotary developing unit 100 is rotated by a rotary motor 102 when the rotary developing unit 100 is rotated.
0 passes through the optical sensor 107 attached to the machine frame 105 so that the four developing devices 18K, 18Y, 18M, 18
Developing devices 18K, 18Y, which recognize the position of C and develop
18M and 18C are rotated and moved to a developing position facing the photosensitive drum 16.

For example, as shown in FIG. 12, the rotary developing device 18 is a black developing device 18K.
The home position is a position 45 degrees clockwise from the black developing device 18K, which is an intermediate position between the black developing device 18C and the cyan developing device 18C. Recognition member 1
04 is the center O of the photosensitive drum 16 and the developing unit 10
It is attached at a position forming an angle of 36 degrees with respect to a straight line L connecting the center O ′ of 0. An optical sensor 107 for detecting a home position for detecting the angle recognition member 104 attached to the rotary developing unit 100
Is also attached to the machine frame 105 at a position at an angle of 36 degrees with respect to a straight line connecting the center of the photosensitive drum 16 and the developing unit 100.

By the way, in this embodiment, a developing device mounting member for mounting a plurality of developing devices along a circumferential direction around the rotation axis, and a developing device mounting member provided on the developing device mounting member. An angle recognition member for recognizing an angle in a circumferential direction; a developing device supporting member rotatably supporting the developing device mounting member via a rotation shaft; and the developing device mounting member provided on the developing device supporting member. A rotational position detecting means for detecting a rotational position of the developing device mounting member by detecting an angle recognizing member provided in the developing device mounting member and a developing device supporting member; A reference position display section for displaying a reference position for performing the alignment in the developing device mounting member and the developing device support member. There are, to determine the correction value of the detected position of the rotational position detecting means, and the correction value is configured to use when moving the developing units to a developing position.

That is, in this embodiment, FIG.
(A) and FIG. 13, four developing devices 18K,
The reference position is displayed on a disk-shaped frame 110 disposed at an axial end of the rotary developing unit 100 as a developing device mounting member on which the rotary members 18Y, 18M, and 18C are mounted around the rotation shaft 50. Small hole 11 as part
1 is drilled. The hole 111 is provided in the photosensitive drum 1
6 on the straight line L connecting the center O ″ of the developing roll 63 of the yellow developing unit 18Y as a reference developing unit and the center O ′ of the rotary shaft 50 of the rotary developing unit 100. Have been.

Further, the center O of the photosensitive drum 16 is provided on the machine frame 105 of the digital color copying machine body 1.
The rotary developing unit 100 is stopped and is drilled in the frame 110 of the rotary developing unit 100 so that the center O "of the developing roll 63 of the yellow developing unit 18Y as a reference developing unit coincides with the center O". A hole 112 as a reference position display unit is formed at a position corresponding to the hole 111 as the reference position display unit with the same diameter as the hole 111 of the frame 110 of the rotary developing unit 100.

FIG. 1B is a block diagram showing a control circuit of an adjusting device for performing an adjusting operation of the developing device when assembling a digital color copying machine having the developing device according to the present embodiment.

In FIG. 10, reference numeral 120 denotes control means for controlling the operation of the adjusting device for adjusting the developing device 18 at the time of assembling a digital color copying machine having the developing device 18 constructed as described above. CPU, 121
Is a memory such as a RAM for storing correction values and the like detected by the CPU 120 in the adjustment work of the developing device 18, a motor drive circuit 122 for outputting a drive pulse for rotating the rotary motor 102 by a predetermined amount, and a motor 123 5 shows a pulse counter for counting pulses output from the drive circuit 122.

In the above configuration, in the case of the digital copying machine to which the developing device according to the first embodiment is applied, the stopping of each developing device without increasing the manufacturing cost and the component cost as follows. The position can be controlled with high accuracy, and development with good image quality is possible.

That is, in the digital color copying machine according to the first embodiment, as shown in FIG. 2, black (K), yellow (Y), magenta (M), and cyan (C) are formed on the photosensitive drum 16. Are sequentially formed on the photosensitive drum 16, and the electrostatic latent images of the respective colors sequentially formed on the photosensitive drum 16 are developed by the developing devices 18K, 18Y, Developed sequentially by 18M and 18C. Then, the toner image of each color of black (K), yellow (Y), magenta (M), and cyan (C) sequentially formed on the photosensitive drum 16 is transferred to the transfer material 12 held on the transfer drum 20. The transfer material 12 on which the toner images of each of these colors are transferred in a multiplexed manner on the transfer drum 12 is separated from the transfer drum 20 and the fixing device 3
7, and is subjected to a fixing process to copy a color image.

In the above digital color copying machine, the electrostatic latent images of black (K), yellow (Y), magenta (M), and cyan (C) sequentially formed on the photosensitive drum 16 are The corresponding color developing units 18K, 18Y, 18M, 1 of the rotary developing device 18
8C, the developing device 18 of a predetermined color is used.
It is necessary to precisely move K, 18Y, 18M, and 18C to the development position facing photoconductor drum 16. Therefore, as shown in FIG. 11, four developing units 18K, 18Y, 18M, 1
An angle recognition member 104 made of a metal plate is mounted on a cylindrical rotary developing unit 100 in which a rotary shaft 50 is provided around a rotary shaft 50, and a plate member for mounting on a machine frame 105 of a digital color copying machine. 106
The optical sensor 107 is attached via the. Then, the optical sensor 107 attached to the machine frame 105 causes the rotary developing unit 103
By detecting the angle recognizing member 107 attached to the image forming apparatus, angle recognition for stopping the four developing units 18K, 18Y, 18M, and 18C at predetermined positions is performed.

However, the rotary type developing device 1
In the case of No. 8, as shown in FIG.
When assembling a digital color copier equipped with a digital color copier, the mounting error of the plate 106 for mounting the optical sensor 107 to the machine frame 105 of the digital color copier, the mounting error of the optical sensor 107 with respect to the plate 106, or the optical type Inevitably, there are errors in the detection position and variations in the sensitivity of the sensor 107 itself, and errors in mounting the angle recognition member 104 mounted on the rotary developing unit 100.

Therefore, in this embodiment, the following operation is performed as adjustment work after assembling the digital color copying machine at a factory. First,
As shown in FIG. 13, a small hole 111 serving as a reference position display unit provided in the rotary developing unit 100 of the developing device 18 and a reference position display unit provided in the machine frame 105 of the digital color copying machine body 1 are provided. 11B, the holes 111 and 112 are aligned with each other, and a pin P is inserted into these small holes 111 and 112, as shown in FIG. And the machine frame 105 of the digital color copier body 1 are accurately aligned.

At this time, the small hole 111 as a reference position display section provided in the rotary developing unit 100 of the developing device 18 is provided with the photosensitive drum 16 as described above.
Are arranged on a straight line L connecting the center O of the developing roller 63 of the yellow developing unit 18Y as a reference developing unit and the center O ′ of the rotary shaft 50 of the rotary developing unit 100. A hole 112 as a reference position display section provided on the machine frame 105 of the digital color copying machine main body 1 has a center O of the photosensitive drum 16.
And a yellow developing device 18Y as a reference developing device.
When the rotary developing unit 100 is stopped so that the center O "of the developing roll 63 coincides with the center O" of the developing roll 63, the position coincides with the hole 111 serving as a reference position display unit formed in the frame 110 of the rotary developing unit 100. Therefore, when the hole 111 and the hole 112 are aligned with each other, the center O ″ of the developing roll 63 of the yellow developing device 18Y as a reference developing device is aligned with the photosensitive drum 16. Center O and rotary developing unit 1
Since the developing unit 18Y is located on the straight line L connecting the center O 'of the rotation shaft 50 with the developing unit 18Y, it always stops at the predetermined developing position.

Thereafter, the rotary developing unit 100 of the developing device 18 is moved to the CPU 12 as shown in FIG.
In response to a signal from 0, the rotary drive 102 is driven to rotate by the rotary motor 102 via the motor drive circuit 122, and the angle recognition member 104
Is detected by the optical sensor 107 attached to the machine frame 105 before the motor drive circuit 12
The number of drive pulses output from 2 to the rotary motor 102 is counted by the pulse counter 123.

If there is no error in the mounting position of the angle recognition member 104 provided in the rotary developing unit 100 and the mounting position of the optical sensor 107 provided in the machine frame 105, as described above, 100, the pulse counter 123
Should count equal to a predetermined value.

The CPU 120 counts the count value of the pulse counter 123 until the optical sensor 107 attached to the machine frame 105 detects the angle recognition member 104 provided on the rotary developing unit 100.
The optical sensor 107 is compared with a predetermined count value stored in advance in the memory 121 when there is no error in the mounting position and the detection accuracy of the optical sensor 107, and the difference between them is calculated as a correction value.

When the digital color copier is actually used, the correction value is stored in the memory of the CPU for controlling the operation of the rotary developing device 18 when the rotary developing device 18 is rotated to the developing position. It is stored as a correction value.

More specifically, as shown in FIG. 1B, the rotary developing unit 100 of the developing device 18 is driven by a signal from the CPU 120 to drive the motor driving circuit 1.
The rotary drive 102 is rotated by the rotary motor 102 through the motor 22 and the motor drive circuit 122 detects the angle recognition member 104 provided on the rotary developing unit 100 by the optical sensor 107 attached to the machine frame 105. Is counted by the pulse counter 123, it is assumed that the count value is 950.

On the other hand, if there is no error in the mounting position of the angle recognition member 104 provided in the rotary developing unit 100 or the mounting position of the optical sensor 107 provided in the machine frame 105, as described above, When the unit 100 is rotated, the pulse counter 1
The count value counted by 23 is set to 1000.

In this case, the mounting position of the angle recognition member 104 provided on the rotary developing unit 100 and the mounting position of the optical sensor 107 provided on the machine frame 105 have errors. 1
07 is shifted by 50 pulses in the counterclockwise direction.

Therefore, the CPU 120 sets the predetermined count value of 1000 pulses and the actual detection value of 9 pulses.
The 50 pulses, which is the difference between the 50 pulses, is set as the correction value.

When the digital color copier is actually used, the correction value of 50 pulses is rotationally driven to the developing position of the rotary type developing device 18 in the memory of the CPU for controlling the operation of the rotary developing device 18. This is stored as a correction value when performing.

By doing so, as shown in FIG. 12, the angle recognizing member 104 provided on the rotary developing unit 100 is moved to the home position where the optical sensor 107 provided on the machine frame 105 is detecting. When the rotary developing unit 100 is located, for example, in order to move the black developing device 18K to the developing position, it is necessary to move the black developing device 18K to the developing position by 50 pulses or more than a predetermined number of pulses. Pulse minus the rotary motor 102
May be applied.

By doing so, the angle recognition member 104
Each of the developing units 18K of the rotary developing unit 18 can be improved without increasing the mounting accuracy so as to reduce errors occurring in the detection position and the like of the optical sensor 107 and without using a high-precision optical sensor 107. 18Y, 18
M and 18C can be accurately stopped at the developing position to execute the developing step. Therefore, each of the developing devices 20
Developing roll 53 of 1K, 201Y, 201M, 201C
Drum 1 of magnet roll 63 arranged inside
The MSA (magnet setting angle) for No. 6 can be maintained at an appropriate value, development can always be performed in a good state, and good image quality can be developed.

Second Embodiment FIG. 14 shows a second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals and described. The operation of determining the correction value is not performed at the time of assembling the image forming apparatus provided with the developing device, but after starting the use of the image forming apparatus.

FIG. 14 is a block diagram showing a control circuit of a digital color copying machine provided with the developing device according to the second embodiment.

In FIG. 14, reference numeral 130 denotes a CPU as a control means for controlling the operation of the entire digital color copying machine including the developing device 18, and 131 denotes a CPU 120 which stores parameters for controlling the operation of the entire digital color copying machine. Reference numeral 132 denotes a motor drive circuit that outputs a drive pulse for rotating the rotary motor 102 by a predetermined amount, and 133 denotes a pulse counter that counts pulses output from the motor drive circuit. . And the ROM 131
The correction value obtained according to the first embodiment is stored in advance in.

In the second embodiment, when the optical sensor 107 provided on the machine frame 105 of the digital color copying machine is replaced, for example, in a special mode called a diagnostic mode dedicated to a service engineer, the second embodiment is used. As in the first embodiment, a small hole 111 provided as a reference position display unit provided in the rotary developing unit 100 of the developing device 18 and a hole provided as a reference position display unit provided in the machine frame 105 of the digital color copying machine body 1. The rotary developing unit 100 is rotationally driven in alignment with the position 112, and an operation for obtaining a correction value is executed.

As described above, after the use of the digital color copying machine is started, the operation of determining the correction value is performed, so that the optical sensor 107 can be replaced or the developing device 18 can be replaced.
Even when the maintenance of the rotary developing unit 100 is performed, the stop position of each developing unit can always be controlled with high accuracy, and the development with good image quality can be performed.

Other structures and operations are the same as those of the first embodiment, and the description thereof is omitted.

[0073]

As described above, according to the present invention,
It is possible to provide a rotary developing device that can precisely control the stop position of each developing device without increasing manufacturing costs and component costs, and that can develop good image quality.

[Brief description of the drawings]

 .

1 (a) and 1 (b) show Embodiment 1 of the present invention.
1 is a configuration diagram illustrating a developing device according to the present invention.

FIG. 2 is a configuration diagram showing a digital color copying machine to which the developing device according to the first embodiment of the present invention is applied.

FIG. 3 is a configuration diagram showing a rotary developing device according to the first embodiment of the present invention.

FIG. 4 is a configuration diagram showing a developing device of the rotary developing device according to the first embodiment of the present invention.

FIG. 5 is a configuration diagram showing the developing device.

FIG. 6 is a partially broken perspective view showing the toner supply device.

FIG. 7 is a sectional view showing a toner cartridge.

FIG. 8 is a configuration diagram illustrating a mounted state of a toner cartridge of the digital color copying machine.

FIG. 9 is a cross-sectional configuration diagram illustrating a toner supply device of the developing device according to the first embodiment of the present invention.

FIG. 10 is a cross-sectional configuration diagram illustrating a reserve tank of the toner supply device.

FIGS. 11A and 11B are configuration diagrams respectively showing a driving mechanism and a positioning mechanism of a rotary developing unit of the developing device according to the first embodiment of the present invention.

FIG. 12 is a configuration diagram showing a control unit of a rotational position of the developing device according to the first embodiment of the present invention.

FIG. 13 is a configuration diagram showing a rotary developing unit of the developing device according to the first embodiment of the present invention.

FIG. 14 is a block diagram showing a control circuit of a developing device according to Embodiment 2 of the present invention.

FIG. 15 is a configuration diagram showing a conventional rotary developing device.

FIG. 16 is a configuration diagram showing a drive mechanism of a conventional rotary developing device.

[Description of sign]

16: photosensitive drum, 18: developing device, 18K, 18
Y, 18M, 18C: developing device, 100: rotary developing unit (developing device mounting member), 102: rotary motor, 104: angle recognition member, 105: machine frame (developing device support member), 107: optical sensor (rotation) Position detecting means), 111: hole (reference position display section), 11
2: hole (reference position display section), 120: CPU, 121:
Memory, 122: motor drive circuit, 123: pulse counter.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsuji Okamoto 2274 Hongo, Fuji Xerox Co., Ltd., Ebina City, Kanagawa Prefecture (72) Inventor Ryuji Hattori 2274 Hongo, Ebina City, Kanagawa Prefecture, Fuji Xerox Co., Ltd. (72) Inventor Hirohisa Kono 2274 Hongo, Ebina-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Mutsu Kikuchi 2274 Hongo, Ebina-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Shino Yokoyama 2274 Hongo, Ebina-shi, Kanagawa Prefecture Address Fuji Xerox Co., Ltd. (72) Inventor Akira Yukita 2274 Hongo, Ebina City, Kanagawa Prefecture F Xerox Co., Ltd. F-term (reference) 2H030 BB24 BB33 2H077 AB12 AC02 AD06 AD13 AD18 BA01 BA08 BA10 DA16 DA24 DA62 DA82 DB10 DB22 DB25 EA03 FA19 FA26 GA12 GA13

Claims (4)

[Claims] A plurality of developing devices arranged in a circumferential direction about a rotation axis, and the plurality of developing devices are rotatable about a rotation axis; and a rotational position of the plurality of developing devices is provided. In the developing device, by detecting a developing device, the desired developing device is moved to a developing position facing the image carrier, and the electrostatic latent image formed on the image carrier is visualized. A developing device mounting member for mounting the developing device in a circumferential direction around the rotation axis; and an angle recognition member provided on the developing device mounting member for recognizing an angle of the developing device mounting member in a circumferential direction. A developing device supporting member that rotatably supports the developing device mounting member via a rotation shaft; and an angle recognition member that is provided on the developing device supporting member and that is provided on the developing device mounting member. The developing unit mounting part A rotation position detecting means for detecting a rotation position of the developing device; and a reference position display unit provided on the developing device mounting member and the developing device support member, respectively, for displaying a reference position for performing alignment in the rotation direction of the two. Using a reference position display unit provided on each of the developing device mounting member and the developing device support member, a correction value of a detection position of a rotation position detection unit is determined, and the correction value is used to set each developing device to a developing position. A developing device for use in moving the developing device. 2. After aligning the positions of reference position display portions provided on the developing device mounting member and the developing device support member, the developing device mounting member is rotated to provide the developing device mounting member. The rotation amount of the developing device mounting member until the rotation amount detecting device detects the angle recognition member is detected by the rotation amount detecting device, and the rotation amount of the developing device mounting member detected by the rotation amount detecting device and a predetermined value. The developing device according to claim 1, wherein a difference between the two is set as a correction value. 3. The developing device according to claim 1, wherein the operation of determining the correction value is performed at the time of assembling an image forming apparatus including the developing device. 4. The developing device according to claim 1, wherein the operation of determining the correction value is performed after the use of the image forming apparatus including the developing device is started.