JP2840584B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for forming an image on a recording medium.

[0002]

2. Description of the Related Art In recent years, there has been a remarkable spread and development of color copying apparatuses, and there are many types of printer engines for realizing an ink jet system, a thermal transfer system, a silver halide photographic system, and an electrophotographic system. Among them, the electrophotographic method has been remarkably popularized due to its advantages of high speed and high image quality.

FIG. 9 is a cross-sectional view showing an example of this type of image forming apparatus. In particular, a color original is color-separated for each pixel and read digitally as an electric signal. A full-color print image is obtained by a photographic method. A indicates an image reading unit, and B indicates an image printing unit.

[0004] The configuration and operation will be described below.

In the image reading section A, a color original 1 is irradiated by an original exposure lamp (illumination lamp) 2, and a color reflected light image reflected from the color original 1 is formed on a color image sensor 3. Color image sensor 3 (CC
A color image signal that has been subjected to color separation for each pixel by a D color line sensor) is subjected to signal processing in a color signal processing circuit 4 and input to an image processing circuit 5 through a cable 25.

The image processing circuit 5 sends the digital image signal to the image printing section B after color correction by digitizing the input signal and digital image processing of the color signal. The semiconductor laser 8 is modulated by the semiconductor laser drive unit 7 in accordance with the image data sent to the image printing unit B via the cable 6, and is modulated by the polygon mirror 9 onto the photosensitive drum via the mirror 10. To form a single-color latent image which has been color-separated. The formed latent image is supplied to the developing device 2
In steps 1 to 24, visualization (development) is performed, and color separation toner images are sequentially formed on the photosensitive drum 11. 14 is a transport belt, 20 is an exposure lamp, and 19 is a charger.

On the other hand, the copy paper is fed from the cassette 17 or the cassette 18, wound around the transfer drum 12, and the toner is transferred to the copy paper in synchronization with the above-described color separation toner image. As shown in this figure, since only one color image is formed in one image forming process, the color separation process of the original is performed for the number of toner colors, that is, yellow (Y), magenta (M), The processes of cyan (C) and black (K) are repeated four times, and the processes of latent image formation, development, and transfer corresponding to each color component are also repeated in synchronization with each color separation.

In this way, the separation claw 1 is rotated four times to complete the transfer of four colors while being wound around the transfer drum 12.
3, the copy paper is peeled off, and the heat and pressure fixing rollers 15, 16
Then, the toner image on the copy paper is fixed and discharged outside the apparatus, and one full-color copy is completed. That is, in the case of this type of color copying apparatus, FIG. 10 is used to realize a further higher speed by performing each process of each color separation image, Y, M, C, and K by overlapping each other. Such a four-drum type color image forming apparatus has also been proposed.

FIG. 10 is a sectional view showing an example of a four-drum type color image forming apparatus. The structure and operation will be described below.

A color document 1 placed on a document table is illuminated by an illumination lamp 2 and a CCD color line sensor 3 is provided.
Is the same as that in FIG. 9 until the color separation image is read by the CPU and the digital image processing is performed by the image processing circuit 5 via the color signal processing circuit 4 and the cable 25.
After that, one page of the full-color image signal is stored in the memory device 2.
6 temporarily.

That is, as will be described later, in this type of apparatus, a plurality of photosensitive drums (image forming units) are juxtaposed,
This is because, in order to form images of a plurality of colors at the same time, it is necessary to store images at least for the distance between adjacent image forming units.

On the other hand, the image forming section independently controls the photosensitive drums 29 to 32 for each component, magenta (M), cyan (C), yellow (Y), and black (K).
It has primary chargers 41-44, developing devices 33-36, transfer chargers 37-40, and cleaner devices 62-65, and detects the leading edge of the paper as the paper fed from the cassette advances. When the image signal is detected by the (ITOP sensor) 67, the image signal for each color component already stored in the memory device 26 is read out at an appropriate timing by a timing control circuit (not shown) in synchronization with the leading edge signal of the paper. After the signal processing in the second digital image processing unit 27, the magenta (M) image is obtained by converting the light beams modulated by the semiconductor lasers 50, 57 to 59, etc. into the polygon mirror 28, the reflection mirror 4 and the like.
Reflected by 5-49, 51-53, 54-56,
After irradiating the photosensitive drum 29 to form a latent image, the developing device 33 develops magenta toner, and the transfer charger 3
7, a magenta image of the first color is formed on the copy paper. Subsequently, in the second, third, and fourth stations, cyan (C), yellow (Y), and black (K) are similarly developed with high accuracy, transferred, and then fixed by the fixing rollers 15 and 16. One copy is completed. 61 is a cassette, and 66 is an interface circuit.

In such an apparatus, as described above, there are four drum stations for forming each color component image, four laser beam generators for forming a latent image,
Further, four optical systems for accurately irradiating each photosensitive drum with each laser beam are also required.

On the other hand, in a high-precision full-color copying machine,
Position accuracy for superposition of each color component image is 100 to 1
It needs to be 50 μm or less, and it is very difficult to adjust each component for image formation with such accuracy. Even if the adjustment can be made, for example, a positional shift due to thermal expansion of each component due to a temperature change, a positional shift due to reproducibility of machine positional accuracy after a jam processing, a drum scratch, a defect in a developing device, etc. The position adjusted by the component replacement or the like immediately shifts, and once shifted, it is practically impossible for the user to adjust it.

Therefore, in order to make such adjustments automatically, for example, as shown in FIG. 11, a mark for registering each color component magenta, cyan, yellow and black is printed on the transfer belt at a fixed interval time. Is read by two sensors, for example, CCDs 80 and 81 at the back and front sides, and the amount of deviation, inclination, and the like in the main scanning and sub-scanning directions at each printing station are detected, and the next There has been proposed an apparatus that automatically corrects deviations in the sub-scanning direction and the main scanning direction by using such correction means.

[Automatic Correction in Sub-scanning Direction] FIGS. 12A and 12B are timing charts showing the timing of forming marks for registration in this type of image forming apparatus. FIG. (B) corresponds to the mark forming timing for registration in the main scanning direction.

As shown in FIG. 12A, in the sub-scanning direction, the number of lines is counted by a counter circuit (not shown) from the rise of the output signal ITOP from the ITOP sensor 67 for detecting the leading edge of the copy sheet. after counting t _m times in magenta, after counting t _c time in cyan, after counting t _y time in yellow, after counting t _k time in black, the output signals MTOP, CTOP, yTop, the KTOP signal generated , and by sending the image signal from the rising edge of each signal, based on the timing mark of the resist combined as described above (e.g., mark #) is detected by the sensor 80, 81, by determining the count value t _m ~t _k Good.

[Automatic correction in the main scanning direction] FIG.
, Each signal MBD, CBD, YBD, KBD
Are detection signals of laser beams for forming magenta, cyan, yellow, and black latent images, and each signal is a reference signal for determining a main scanning position of an image at each position. Each color image is a detection signal MB of a laser beam.
It is determined by enable signals MEN, CEN, YEN, KEN generated after pixel counts x _m , x _c , _xy , x _k from D, CBD, YBD, KBD respectively.
In this case, the respective values may be appropriately determined based on the positions where the above-described marks are detected by the sensors 80 and 81.

For automatic correction of inclination, for example, for magenta, automatic correction is realized by inclining the reflection mirrors 45, 46, 47 by actuators not shown.

[0020]

When the sensors 80 and 81 read the pattern transferred onto the transfer belt in this manner, registration deviation can be detected. However, FIGS. 13 (a) and 13 (b) As shown in (1), since the transfer belt and the black toner do not have a reflection region in any wavelength region, it becomes impossible to identify the pattern formed by the black toner on the transfer belt.

That is, magenta, cyan, and yellow toners are 400 to 500 nm and 500 to 60 nm, respectively.
Since it absorbs light having wavelengths of 0 nm and 600 to 700 nm, conversely speaking, it has a reflection region at other wavelengths, but the black toner has no reflection region at any wavelength.

On the other hand, since the transfer belt reflects only in the infrared region, by disposing an infrared cut filter in front of the sensors 80 and 81, the above-described magenta, cyan, and cyan are removed.
Although the yellow mark can be read, the black mark has no reflective area in any area,
There is a problem that the two cannot be distinguished, and as a result, the registration deviation of the black station cannot be detected.

The present invention has been made to solve the above-mentioned problems, and the first to fourth inventions according to the present invention provide an image forming apparatus having an optical image having a different optical characteristic from an underlying image on an image carrier. Another object of the present invention is to provide an image forming apparatus capable of accurately measuring reflected light of a mark image on an image carrier by forming a mark image having optical characteristics different from that of the base image in a multiplex manner.

[0024]

According to a first aspect of the present invention, there is provided an image forming means for forming images of a plurality of colors different from each other on an image carrier, and an optical system of the image carrier among the plurality of colors. Forming a base image of a color having an optical characteristic different from the target image on the image carrier, and forming a mark image of a color having an optical characteristic different from the base image on the base image by multiplexing the mark image. And a measuring means for measuring reflected light of the mark image formed on the base image. In a second invention according to the present invention, the control unit further controls the image forming unit to form the mark images of the plurality of colors on the image carrier. In a third aspect according to the present invention, the control unit further controls an image forming operation by the image forming unit using a measurement result of the measuring unit. According to a fourth aspect of the present invention, the image forming means has a plurality of image forming stations for forming images of different colors on the image carrier.

[0025]

According to the first aspect of the invention, a base image of a color having optical characteristics different from the optical characteristics of the image carrier among a plurality of different colors is formed on the image carrier, and the base image is The control unit controls the image forming unit so as to multiplex and form a mark image of a color having different optical characteristics on the base image, and the reflected light of the mark image formed on the base image is measured by the measurement unit. Even when the measured optical characteristics of the mark image substantially match those of the image carrier, the reflected light of the mark image on the image carrier can be accurately measured. In the second invention, the control unit further controls the image forming unit to form the mark images of the plurality of colors on the image carrier, and the mark images of different colors on the image carrier. Can be accurately measured. In the third invention, the control unit further controls an image forming operation by the image forming unit using a measurement result of the measuring unit, and forms an image based on a mark image reflected light measurement result on an image carrier. Can be performed. In a fourth aspect, the image forming means has a plurality of image forming stations for forming images of different colors on the image carrier, respectively, and forms the image on the image carrier by the plurality of image forming stations. It is possible to accurately measure the reflected light of the mark image to be formed.

[0026]

FIG. 1 is a cross-sectional view illustrating the structure of an essential part of an image forming apparatus according to an embodiment of the present invention. The same reference numerals as in FIG. 10 denote the same parts.

In this figure, reference numeral 27a denotes a registration correction pattern generation control unit which outputs a video signal output from the registration correction pattern generation control unit 27a to a laser driver 27b and outputs the video signal via each laser scanning optical system. An electrostatic latent image corresponding to the registration correction pattern is formed at a desired position on each of the photosensitive drums 29 to 32.

In the image forming apparatus having the above-described configuration, when the pattern forming means (each of the first to fourth stations) starts a predetermined registration pattern forming process on the photosensitive member, the control means (this embodiment). Then, the registration correction pattern generation control unit 27a) precedes the pattern transfer of a color developer (black in this embodiment) that matches the spectral reflection characteristics of the transport member (transfer belt in this embodiment) that forms the registration pattern. The multi-transfer of color spread transfer using a color developer having a spectral reflection characteristic different from the spectral reflection characteristic and pattern transfer of a color developer matching the spectral reflection characteristic of the conveying member is controlled, and the spectral reflection characteristic of the conveying member is controlled. A pattern of a matching color developer is transferred onto a color spread transfer area by a color developer having different spectral reflection characteristics (yellow in this embodiment). When the registration pattern of each color transferred to the conveying member in this way is detected by the detection means (sensors 80 and 81), timing control means (also used by the digital image processing unit 27). Individually controls the image forming timing based on the output of the detecting means to perform registration of each color.

As for the multiple transfer control, the registration correction pattern generation control section 27a sets the enable signal YESNB to "H level" twice for the laser driver 27b in accordance with a timing chart shown in FIG. As a result, the yellow toner is solidly transferred to the immediately preceding yellow station (third station) in the transfer area of the registration correction pattern for black formed on the photosensitive drum 32 and transferred to the transfer belt.

Then, a registration correction pattern developed with the developed black toner (the first image in the present embodiment) is superimposed and transferred onto the yellow solid area (specific portion) transferred with the yellow toner underlay, Furthermore, the developed registration correction pattern for black can be detected with good discrimination by the sensors 80 and 81 after being transported.

FIG. 2 is a circuit block diagram for explaining a main configuration of the registration correction pattern generation control unit 27a shown in FIG. 1. The configuration and operation will be described below with reference to FIG.

FIGS. 3A and 3B are diagrams for explaining the operation of the registration correction pattern generation controller 27a shown in FIG. 2, wherein FIG. 3A shows the timing of generation of the registration correction pattern, and FIG. An example is shown below.

In FIG. 2, reference numeral 85 denotes a bit counter.
The number of pixels after the generation of the horizontal synchronization signal HSYNC is counted. 90 to 93 are comparators, not shown
Each output is set to “H level” at a timing when the count value set in the registers 86 to 89 by the PU or the like matches the value of the bit counter 85. , Each value X
When 1, Y1, X2, and Y2 are set, the output of the J / K flip-flop 94 becomes “H level” at the value X1 pixel, becomes “L level” at the value Y1 pixel, and The output is “H level” at the value X2 pixel.
And becomes “L level” at the Y2 pixel. Accordingly, the output of the OR gate 96 is provided to the enable signal ENB (1) as shown in the timing chart of FIG.
To N) are obtained.

Note that 1 to N indicate the number of lines, 1 corresponds to the first line, 2 corresponds to the second line, and N corresponds to the signal generated on the Nth line. Reference numeral 200 denotes a color spread control signal, which is a registration correction pattern generation control unit 27a shown in FIG.
Generated and output. 201 is an enable signal input,
Enable signal MENB (enable signal CENB, Y
ENB and KENB are also input) from the registration correction pattern generation control unit 27a.

A pattern ROM 99 is a pattern shown in FIG. 3B (for example, pattern "#" in this embodiment).
Is stored, and the pattern "#" is read out according to the address generated by the address counter 97 and the address counter 98. V
D1,2, VDK, K + 1, VDL, L + 1, VDM,
M + 1, VDN, N + 1 are line numbers 1, 2, K, K
This is a video signal for forming a pattern corresponding to +1, L, L + 1, M, M + 1, N, N + 1.

These video signals VD1, VD2, VDK,
K + 1, VDL, L + 1, VDM, M + 1, VDN, N
By outputting +1 to the OR gate 100 at a predetermined timing, an electrostatic latent image corresponding to the pattern shown in FIG. 3B is formed on the photosensitive drums 29 to 32, and each toner stored in the developing unit (not shown) And the image is transferred onto a transfer belt to be conveyed. 101 is an AND gate.

Hereinafter, the pattern transfer process will be described with reference to the timing chart shown in FIG.

FIG. 4 is a timing chart for explaining the timing of forming the registration correction pattern 27a shown in FIG.

As shown in this figure, a predetermined time t _m , t _c , t _y , t _k (however, transfer is started) from the rise of the output signal ITOP from the ITOP sensor 67 which is the reference shown in FIG. When laser exposure for image formation is started for each drum at the timing of (conveyance of the belt is constant), the four colors are exactly overlapped on the transfer belt or on the printing paper. Therefore, in order to form the magenta, cyan, yellow, and black patterns on the transfer belt as shown in FIG. 5, the magenta, cyan, yellow, and black patterns have a predetermined time t _m and a predetermined time t _c −, respectively.
(3/2) delta (although, delta represents the time required for pattern printing), the predetermined time t _y - (5/2) Δ, the predetermined time t _k
It is sufficient to print at the timing of-(7/2) Δ.

FIG. 5 is a schematic view showing a pattern transfer state in the image forming apparatus according to the present invention.
The images are transferred one by one so as to face predetermined positions in the width direction orthogonal to the V transport direction. The shaded area in the figure is a color spread area where yellow transfer has been performed in the third station (for yellow), and corresponds to a state in which the pattern formed in the fourth station is superimposed and transferred on this color spread area.

As shown in FIG. 4, a predetermined time t has elapsed from the rise of the output signal ITOP from the ITOP sensor 67.
_m , predetermined time t _c − (3/2) Δ (where Δ indicates the time required for pattern printing), predetermined time t _y − (5 /
2) delta, the predetermined time t _k - at timing (7/2) delta elapsed, and output is read out pattern data stored in the pattern ROM99 through the OR gate 100 to the laser driver 27b shown in FIG. 1 Thus, the registration correction patterns of the respective magenta, cyan, and yellow stations are transferred to the transfer belt VV.

A predetermined time t _y- (7/2) Δ from the rise of the output signal ITOP from the ITOP sensor 67
The registration correction pattern generation control unit 27a
By outputting the color spread control signal 200, the yellow toner color spreads on the pattern transfer area (on the transfer belt VV (the shaded area shown in FIG. 5) by the black toner) for the registration correction of the fourth station (the transfer belt VV). It is as under color) transcription, as well as from the rising of the output signal ITOP from the ITOP sensor 67 the predetermined time t _k -
At the timing of (7/2) Δ elapse, the black pattern for registration correction is transferred to the colored area.

In this way, the transferred pattern for registration correction at each station is identified and detected by the sensors 80 and 81 provided downstream of the transfer belt VV in the transport direction.

FIG. 6 is a flowchart showing an example of a registration correction pattern forming operation in the image forming apparatus according to the present invention. (1) to (13)
Indicates each step.

[0045] First, when detecting the output signal ITOP from the ITOP sensor 67 (1), the timer starts (not shown) (2), when the timer value matches the predetermined time t _m (3), from the pattern ROM99 Based on the output pattern, pattern formation exposure is performed in a magenta station (4), and the pattern is transferred to the transfer belt VV by developing with magenta toner.

Next, the timer value is set to a predetermined time t _c- (3 /
2) If Δ coincides with Δ (5), pattern forming exposure is performed in the cyan station based on the output pattern from the pattern ROM 99 (6), and the pattern is transferred to the transfer belt VV by developing with cyan toner.

Next, the timer value is set to a predetermined time t _y- (5 /
2) If the value matches Δ (7), pattern formation exposure is performed in the yellow station based on the output pattern from the pattern ROM 99 (8), and the pattern is developed and transferred to the transfer belt VV. _y −
If (9/2) coincides with (7/2) Δ, the registration correction pattern generation control unit 27a sends the color control signal 200
Is output to the AND gate 101, pattern formation exposure is performed in the yellow station based on the color spread pattern (10), and development is performed to transfer the color spread pattern to the black pattern transfer area of the transfer belt VV (1).
1).

Next, the timer value is set to a predetermined time t _k- (7 /
2) If the value matches Δ (12), pattern formation exposure is performed in a black station based on the output pattern from the pattern ROM 99 (13), developed, and the black pattern is transferred to the yellow spread area of the transfer belt VV. To end.

In the above embodiment, a four-drum type full-color image forming apparatus has been described as an example. However, developing units 112, 114, 116, and 118 are provided around the photosensitive drum 110 as shown in FIG. The present invention can be applied to an image forming apparatus to be used.

FIG. 7 is a cross-sectional view of a principal part for explaining the structure of an image forming apparatus showing another embodiment of the present invention. Reference numeral 110 denotes a photosensitive drum, and developing units 112, 114, 116 and 118 are arranged in this order in the direction of the arrow. It is arranged in. 111, 113, 1
Reference numerals 15 and 117 denote chargers for uniformly charging the photosensitive drum 110. P is a recording medium.

LM, LC, LY and LK indicate exposure beams.

The operation of FIG. 7 will be described below with reference to FIG.

FIG. 8 is a view for explaining the relationship between the yellow registration correction pattern formed on the photosensitive drum 110 shown in FIG. 7 and the spectral reflection characteristic. FIG. FIG. 8 is a characteristic diagram showing the spectral reflectance of the photosensitive drum 110 shown, in which the horizontal axis represents wavelength, the vertical axis represents reflectance, and FIG. 8B shows the photosensitive drum 11 shown in FIG.
FIG. 9 is a schematic diagram showing a state in which a yellow registration pattern with a color spread (using a black toner) formed at 0 is formed.

The photosensitive drum 110 having the spectral reflection characteristic as shown in FIG. 8A substantially matches the spectral reflection characteristic of the yellow toner shown in FIG.
The yellow mark on the photosensitive drum 110 cannot be detected.

Therefore, at a predetermined timing, the photosensitive drum 1
By transferring the black toner color-adjusted prior to the yellow mark transfer area on the pattern 10, it is possible to reliably identify and detect the yellow pattern in the same manner as described above.

[0056]

As described above, the first embodiment according to the present invention is described.
According to the invention, a base image of a color having optical characteristics different from the optical characteristics of the image carrier among a plurality of colors different from each other is formed on the image carrier, and optical characteristics different from the background image are formed. The control unit controls the image forming unit to form a multiplexed mark image having the color on the base image, and the reflected light of the mark image formed on the base image is measured by the measurement unit. Even if the optical characteristics of the mark image roughly match the image carrier,
The reflected light of the mark image on the image carrier can be accurately measured. According to the second aspect, the control unit further controls the image forming unit to form the mark image of each of the plurality of colors on the image carrier. The reflected light of the mark image can be accurately measured. According to the third invention,
The control unit further controls the image forming operation by the image forming unit using the measurement result of the measuring unit,
An image can be formed in accordance with the measurement result of the reflected light of the mark image on the image carrier. According to the fourth aspect, since the image forming means has a plurality of image forming stations for forming images of different colors on the image carrier, the image forming means is formed on the image carrier by the plurality of image forming stations. The reflected light of the mark image to be formed can be accurately measured. Therefore, the reflected light of the mark image on the image carrier can be measured accurately.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a main configuration of an image forming apparatus according to an exemplary embodiment of the present invention.

FIG. 2 is a circuit block diagram illustrating a main configuration of a registration correction pattern generation control unit illustrated in FIG. 1;

FIG. 3 is a diagram for explaining an operation of a registration correction pattern generation control unit shown in FIG. 2;

FIG. 4 is a timing chart for explaining the timing of forming the registration correction pattern shown in FIG. 3;

FIG. 5 is a schematic diagram showing a pattern transfer state in the image forming apparatus according to the present invention.

FIG. 6 is a flowchart illustrating an example of a registration correction pattern forming processing operation in the image forming apparatus according to the present invention.

FIG. 7 is a cross-sectional view illustrating a main part of a configuration of an image forming apparatus according to another embodiment of the invention.

FIG. 8 is a diagram illustrating the relationship between a yellow registration correction pattern formed on the photosensitive shown in FIG. 7 and spectral reflection characteristics.

FIG. 9 is a cross-sectional view illustrating an example of this type of image forming apparatus.

FIG. 10 is a cross-sectional view illustrating an example of a four-drum type color image forming apparatus.

FIG. 11 is a perspective view showing a mark detection mechanism for registration in this type of apparatus.

FIG. 12 is a timing chart showing the timing of forming marks for registration in this type of image forming apparatus.

FIG. 13 is a spectral reflection characteristic diagram of each color toner.

[Explanation of symbols]

 27 Digital Image Processing Unit 27a Registration Correction Pattern Generation Control Unit 27b Laser Driver 80 Sensor 81 Sensor

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Jun Koide 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Yoshiaki Tahara 3-30-2 Shimomaruko, Ota-ku, Tokyo (56) References JP-A-55-74884 (JP, A) JP-A-61-245177 (JP, A) (58) Fields studied (Int. Cl. ⁶ , DB name) G03G 13 / 01 G03G 15/01-15/01 117 G03G 15/00 303 G03G 21/00 370-540

Claims (4)

(57) [Claims] An image carrier comprising a plurality of different color images on an image carrier.
An image forming means for forming an image, and wherein the optical characteristics of the plurality of colors are different from those of the image carrier.
That said color background image with optical properties image bearing member
And has optical characteristics different from those of the base image.
A color mark image should be formed by multiplexing it on the base image.
An image forming apparatus comprising: a control unit that controls the image forming unit; and a measuring unit that measures reflected light of the mark image formed on the base image . 2. The image processing apparatus according to claim 2, wherein said control means further comprises:
To form a mark image of each of the plurality of colors on the
2. The image forming device according to claim 1, wherein the image forming unit is controlled.
Image forming apparatus. 3. The control means according to claim 1, further comprising:
The image forming operation by the image forming means is performed using the fixed result.
The image forming apparatus according to claim 1, wherein the control is performed.
Place. 4. The image forming means includes:
Multiple images forming images of different colors on the carrier
2. The method according to claim 1, further comprising a forming station.
Image forming apparatus.