JP2769306B2 - Color electrophotographic recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording a color image by superimposing and recording a plurality of images of different colors on the same recording medium. [0002] In recent years, with the development of color printers and plotters, high quality and large images similar to color printing and color photography have been required, and a plurality of images of different colors are superimposed. Therefore, when a color image is generated, it is an essential condition that the images of the respective colors are aligned with high accuracy in order to obtain a high-quality and large-sized image. [0003] A conventional color electrophotographic recording apparatus will be described with reference to FIG. 9. This apparatus comprises a photoconductive image carrier 1.
, A charger 2, an LED head 3, a developing unit 4, a transfer roller 5, a cleaning unit 6, an eraser unit 7, a transport roller 8, a supply roller 9 for the recording medium 12, and a take-up roller 10. And a sensor 11 for positioning the recording medium 12. The case where a color image is recorded in the above configuration will be described. The image carrier 1, which has been neutralized in advance by the eraser unit 7, is rotated in the direction of the arrow shown in the figure, is uniformly charged by the charger 2, and is An alignment mark to be described later and a latent image of the first color image are formed, and the first color toner is attached to the latent image by the developing device 4. On the other hand, the recording medium 12 is conveyed from the supply roller 9 toward the take-up roller 10, and the alignment mark on the image carrier 1 and the first color image are transferred via the transfer roller 5. [0006] The residual toner is removed from the image carrier 1 after the transfer by the cleaning unit 6 and the residual charge is removed by the eraser unit 7.
Is rewound in the direction of the supply roller 9 from the winding roller 10 to prepare for image recording of the second and subsequent colors. FIG. 10 shows an alignment mark 12a at the beginning.
Is recorded, and then the recording medium 12 on which the first color image 12b is recorded is rewound to start recording the second color image. In this case, the sensor 11 detects the alignment mark 1
When the LED head 3 detects 2a, the image is superimposed by taking a recording timing so that the LED head 3 starts exposing the image of the second color on the image carrier 1, and similarly, a plurality of images of different colors are superimposed. Get an image. Accordingly, the alignment mark 12a is formed in a shape and an interval that enable the sensor 11 to identify the image, and is formed at a position in consideration of the conveyance timing of the recording medium 12 and the renewal timing of the image carrier 1. . However, according to such a configuration, the recording medium 12 expands and contracts due to the influence of the ambient temperature during the transportation of the previous color image, and the transportation of the recording medium 12 Due to slippage in the direction and meandering in the horizontal direction, when an image of the next color is recorded, there is a problem that a positional shift or a color shift occurs. The above-mentioned problem of expansion and contraction can be dealt with by setting a certain allowable range for displacement and color misregistration, but in reality, it can be dealt with by adjusting the production specifications of the recording medium and the atmosphere in the apparatus. The range is not so wide, and in particular, when obtaining a large color image, the positional shift and color shift due to expansion and contraction of the recording medium cannot be ignored. Further, since the problems of slippage in the transport direction of the recording medium and meandering in the lateral direction are dealt with by increasing the precision of the design and manufacture of the apparatus, the apparatus becomes expensive and there is no guarantee that the apparatus will fall within an allowable range. SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and enables a plurality of images of different colors to be accurately positioned on a recording medium regardless of expansion and contraction of the recording medium, sliding or meandering in the transport direction. An object of the present invention is to provide a color electrophotographic recording apparatus which can be superimposedly recorded together and has no color shift. According to the present invention, there is provided an image holding member for holding an image to be recorded on a recording medium having marks formed at predetermined intervals in a conveying direction. A recording station that forms a latent image on the image carrier, and a developing unit that visualizes the formed latent image in a plurality of colors,
A transfer unit that transfers the visualized image to the recording medium, a measuring unit that measures the mark interval, and the number of lines set between the previous marks and the number of lines of the actually recorded image. First control means for detecting an error of the first mark and setting the number of lines between the next marks based on the error so that the number of lines between two consecutive marks becomes a predetermined number of lines ;
Record the mark on the recording medium when recording the image of the first color.
And a second control means for causing the measurement means to be at a position separated from the contact point between the image holding member and the transfer unit by substantially the same distance as the distance from the recording station to the contact point between the image holding member and the transfer unit. characterized in that it is arranged. According to the present invention, it is possible to obtain an electrophotographic recording apparatus capable of performing accurate alignment with a simple configuration even in a recording method having a transfer process. According to the first aspect of the present invention, the first marks are formed at predetermined intervals in the transport direction, and the second at least one row of marks extend in the transport direction. and image carrier only formed or the first mark holds an image to be recorded on the recording medium formed at predetermined intervals in the conveying direction Te, a recording station for forming a latent image on the image holding member, wherein the formed latent image and developing means for variable visual image of a plurality of colors, and a transfer unit that transfers the visualized image on the recording medium, and measuring means for measuring the first mark spacing Detects an error between the number of lines set between the previous marks and the number of lines of the actually recorded image, and based on this error, adjusts the number of lines between two consecutive marks to a predetermined number of lines. First to set the number of lines between the next marks Control means, detecting means for detecting an edge of the second mark or the recording medium and detecting a positional shift in a direction orthogonal to the transport direction of the recording medium; and in the orthogonal direction and a second control means for controlling so as to form by moving the latent image, the meter
Measuring means for transferring the image carrier and the transfer unit from the recording station;
Between the image carrier and the transfer unit by approximately the same distance as the
And the first mark and the second mark are recorded on the recording medium at the same time as the image recording of the first color. The image to be transferred and the position of the expanded and contracted recording paper coincide with the position of the transfer section only by controlling the line interval for recording the image in accordance with the amount of expansion and contraction of the recording paper detected by the mark interval measuring means. And an image matching the expansion and contraction of the recording paper is transferred, and at least the first mark is recorded on the recording medium simultaneously with the recording of the image of the first color. FIG. 1 is a schematic structural view showing one embodiment of a color electrophotographic recording apparatus according to the present invention, and FIGS. 2 and 3 are explanatory views of the principal part. In FIG. 1, reference numeral 21 denotes a photosensitive drum which rotates in a direction indicated by an arrow (sub-scanning direction) and serves as a photoconductive image carrier. Reference numeral 22 denotes a charger for uniformly charging the photosensitive drum 21; Reference numeral 23 denotes an LED head for arranging a plurality of light emitting elements in the width direction (main scanning direction) of the photosensitive drum 21 to emit predetermined dots and recording a latent image corresponding to the dots on the photosensitive drum 21; Is black, cyan, magenta,
Developing units 24a, 24b, 24c, and 24d for independently supplying four yellow toners to the photosensitive drum 21 to develop latent images of the corresponding colors are provided, and also serve as a toner tray. The developing unit 25 includes a transfer roller that superimposes and transfers the images visualized in the respective colors by the developing units 24a, 24b, 24c, and 24d of the developing unit 24 onto the recording paper 33. A cleaning unit for removing toner remaining on the drum 21;
Reference numeral 27 denotes an eraser unit for uniformly removing charges on the photosensitive drum 21. The developing unit 24 and the transfer roller 25
Have a structure that can apply an appropriate bias to improve the efficiency. Reference numeral 28 denotes a transport roller for transporting the recording paper 33 in the direction indicated by an arrow (sub-scanning direction) in synchronization with the rotation of the photosensitive drum 21. Reference numeral 29 denotes a roll of the recording paper 33. Supply roller for continuous supply, 30
Is a take-up roller for the recording paper 33; 31 is an optical sensor for detecting expansion / contraction and slippage in the conveyance direction (sub-scanning direction) of the recording paper 33; 32 is a direction perpendicular to the conveyance direction of the recording paper 33 (main direction). It is an optical sensor for detecting meandering in the scanning direction. The LED head 23 and the optical sensor 31 are arranged at a position equidistant from the contact point between the photosensitive drum 21 and the transfer roller 25 as shown in FIG. Further, the transfer roller 25,
Conveying roller 28, supply roller 29, and winding roller 30
Can rewind the recording paper 33 in the direction opposite to the direction of the arrow shown in the figure. Next, the marks for positioning on the recording paper 33 will be described with reference to FIG. FIG. 3 shows the photosensitive drum 2 on a recording paper 33 on which a first color image 34a is recorded.
A case in which the second color image 34b on the first color is superimposed and recorded is shown, and the description of the same members as those in FIG. 1 is omitted. A plurality of registration marks 33a are arranged at both ends of the recording paper 33, which is a continuous paper, outside the image area at predetermined regular intervals in the transport direction and serve as alignment marks in the sub-scanning direction. At least one line mark 33b extending in the transport direction and serving as a mark for alignment in the main scanning direction is formed. The optical sensors 31 and 32 described above are arranged to detect the marks 33a and 33b, respectively. Marks 33a, 33
As described later, b is recorded before recording the first color image, but may be recorded simultaneously with the recording of the first color image. It should be noted that if the recording paper 33 is rolled in advance before the mark recording and expanded and contracted in accordance with the ambient temperature, it is possible to improve the positioning accuracy and the color matching accuracy during image recording. Although the marks 33a and 33b are formed at both ends of the recording paper 33, they may be formed together at one end of the recording paper 33 or may be formed on the back surface.
In the case of the latter back surface, if it is formed near the center, the alignment accuracy is further improved. The marks 33a and 33b may be printed in advance by another printing means, and the meandering may be detected by detecting the left end or the right end of the recording paper 33 without forming the mark 33b. When printing is performed in advance, the marks 33a and 33b are not formed at the time of image recording, so that the image recording time can be reduced. In the above configuration, first, the marks 33a, 3a
3b will be described. In FIG. 1, the photosensitive drum 21 that has been neutralized in advance by the eraser unit 27 rotates in the direction of the arrow shown in the figure, and is uniformly charged by the charger 22, and the marks 33a, 3
The latent image 3b is formed, and the latent image is developed by the developing device 24 with a predetermined color using toner. On the other hand, the recording paper 33 is conveyed from the supply roller 29 to the take-up roller 30 in synchronization with the rotation of the photosensitive drum 21, and the images of the marks 33 a and 33 b on the photosensitive drum 21 are transferred via the transfer roller 25. Transcribed. After the transfer, the photosensitive drum 21 has its remaining toner removed by a cleaning unit 26 and its remaining charge removed by an eraser unit 27. On the other hand, the recording paper 33 is rewound from the take-up roller 30 toward the supply roller 29. To prepare for image recording for the first and subsequent colors. Note that recording paper 3
When rewinding No. 3, rewinding is performed so that the next image recording start position is closer to the supply roller 29 than the optical sensors 31 and 32. In the image recording for the first color and thereafter, the marks 33a and 33b on the recording paper 33 are detected, and the images of the respective colors are aligned and superimposed. Next, referring to FIGS. The matching will be described. FIG. 4 is a registration control circuit diagram for generating a recording trigger signal for starting the LED head 23 in the sub-scanning direction, and FIG. 5 is a timing chart of the main signals. It is assumed that an image signal is input to the LED head 23 from a circuit (not shown) (recording driver circuit). In FIG. 4, reference numeral 31 denotes an optical sensor for detecting the mark 33a of the recording paper 33 as described above, and reference numeral 42 denotes
The optical sensor 31 outputs a Q terminal and a flip-flop having a Q terminal alternately outputting “1” and “0” every time the mark 33a is detected.
A count circuit 44a and 44b for alternately measuring the distance between 3a are provided with respective marks 33a for the LED head 23.
The division circuits 45a and 45b, which alternately calculate the period of the recording trigger signal between them and output the recording trigger signal, use the recording trigger signal of the previous mark 33a to generate the next mark 33a.
a correction circuit for alternately correcting the recording trigger signal between a
Is a trigger count circuit for counting the number of pulses of the recording trigger signal, 47a and 47b are AND circuits, and 48 is an OR circuit. The operation of the control circuit according to the above configuration will be described. Each time the optical sensor 31 detects one edge of the mark 33a, the Q and Q terminals of the flip-flop 42 output "1" and "0" to toggle. I do. [0030] The Q and Q terminals, respectively count circuit 43a, which is connected to the enable terminal E of 43 b, thus the optical sensor 31 first marks 33a ₁
Upon detection of the edge with the outputs of the flip-flop 42Q terminal to "1", edge interval (time) shown upper count circuit 43a by the clock signal CL to the edge next mark 33a ₂ T ₁ (signal in FIG. 5 Measure A). At this time, since the image component recording by the LED head 23 has not been performed yet (the same signal B), the count value of the trigger count circuit 46 is “0”, and the correction circuit 4
The correction value of 5a is “0”. Therefore, the number of image component latent image lines N ₁ = N−0 to be recorded on the photosensitive drum 21 to be between the next marks 33a ₂ and 33b ₃ is determined, and the division circuit 44a calculates the following equation τ ₁ = T ₁ / N _{1 is used} to calculate the period τ ₁ of the recording trigger signal corresponding to the number of lines N ₁ . The optical sensor 31 is the Q terminal "0" Q terminal becomes "1" in the flip-flop 42 detects the edge of the next mark 33a _2, shown lower counting circuit 43b is between marks 33a _2, 33a ₃ to measure the time T _2. On the other hand, the dividing circuit 44a at the upper stage
₁ is output, and this signal is output from the AND circuit 4.
7a, the Q terminal is gated during “1”, that is, during the time τ ₂ , and applied to the LED head 23 via the OR circuit 48 and to the trigger count circuit 46 to count the number of pulses. You. The LED head 23 outputs the latent image to the photosensitive drum 2 at the activation timing in the sub-scanning direction by the recording trigger signal.
Thus, the interval between the latent images formed on the photosensitive drum 21 in the sub-scanning direction corresponds to the period τ ₁ of the recording trigger signal. Count circuit 4 in the lower part of the figure
The count value of 3b becomes N ₁ + delta ₁ in accordance with the difference of time T ₁ and T _2. Here, N ₁ + Δ ₁ ≦ T ₂ / τ ₁ <N ₁ + Δ ₁ +1. [0035] That is, by expansion and contraction in the transport direction of the recording paper 33, marks 33a _1, 33a number of lines assumed when recording between ₂ N ₁ and mark 33a _1, 33a number ₂ was actually recorded lines N ₁ + so that the error delta ₁ has occurred between the delta _1. [0036] Therefore, as the correction circuit of the first mark 33a ₁ In 45b the edge and the image components recorded line number 2N between the third mark 33a ₃ edges is _{N + Δ 1 + N 2 =} 2N, the next operation wherein N ₂ = N-delta ₁ in the image component line number N ₂ to be recorded between next mark 33a _2, 33a ₃ is calculated. Further, in the division circuit 44b, the pulse period τ ₂ of the recording trigger signal between the marks 33a ₂ and 33a ₃ is calculated by the operation formula τ ₂ = T ₂ / N ₂ . [0038] This signal is gated during the Q terminal of the flip-flop 42 is then set to "1", i.e. the AND circuit 47b during the time T _3, applied to the LED head 23 via the OR circuit 48 Is done. [0039] Similarly, when the count circuit 43b is ended measurement with respect to time T _3, the trigger count circuit 46
In this case, N ₂ + Δ ₂ (however, N ₂ + Δ ₂ ≦ T ₃ / τ ₂ <N ₂ + Δ ₂ +1) is counted, and the correction circuit 45a exposes between the next marks 33a ₃ and 33a ₄ according to the error Δ _2. the drum 21 is recorded component latent image line number N ₃ calculated by the calculation formula N ₃ = N-Δ _2, further by the division circuit at 45a arithmetic expression _{τ 3 = T 3 / N 3} , next mark 33a _3, 33a ₄ The pulse period τ ₃ of the recording trigger signal for the interval is calculated. To summarize the above operation, the intervals of the registration marks 33a to be recorded at equal intervals in the sub-scanning direction on the recording paper 33 are counted by the counting circuits 43a and 4d.
3b alternately measures each mark interval, detects an error in the sub-scanning direction of the mark interval due to expansion and contraction or slippage of the recording paper 33 by the trigger count circuit 46, and determines the number of image lines to be recorded between the next marks by two. The correction circuits 45a and 45b calculate each line interval so that the number of image lines between consecutive marks is constant (2N), and the recording trigger signal having a cycle corresponding to the number of lines is calculated by the division circuits 44a and 44b.
, And the recording trigger signal for each mark interval is converted into a continuous signal by the AND circuits 47a and 47b and the OR circuit 48 to start the LED head 23.
The first color image is recorded on the recording paper 33 while correcting an error in the sub-scanning direction for each mark 33a. Since the optical sensor 31 is provided at a distance substantially equal to the distance I between the transfer roller 25 and the LED head 23, an image is formed according to the amount of expansion and contraction of the recording paper 33 detected by the optical sensor 31. By simply controlling the recording line interval, the image to be transferred and the position of the expanded and contracted recording paper coincide with the position of the transfer roller 25, and the recording paper 33
An image matching the expansion and contraction of the image is transferred, and accurate positioning can be performed. Therefore, accurate positioning can be performed with a simple configuration without using a complicated delay circuit, memory, or the like. Similarly, for the images of the second to fourth colors, after the recording paper 33 is rewound for each of the images, the LED head 23 is driven by the recording trigger signal corresponding to the expansion and contraction of the recording paper 33 in the sub-scanning direction. Is started to perform color image recording in which four color images are superimposed. FIG. 6 shows the positional deviation of the mark 33b on the recording paper 33 in the main scanning direction.
FIG. 7 is a schematic configuration diagram of a line mark control mechanism for generating a signal indicating a recording start light emitting element of the ED head 23. FIG. 7 is a main signal waveform diagram. In FIG. 6, reference numeral 51 denotes a light source for illuminating the recording paper 33; 52, a lens array for condensing light reflected from the recording paper 33; 32, an optical sensor;
Is a control circuit. The optical sensor 32 detects the mark 3 on the recording paper 33.
A line image sensor having light receiving elements arranged at high density in a direction (main scanning direction) orthogonal to 3b. The control circuit 53 controls the recording paper 33 in response to a signal from each light receiving element of the line image sensor 32. The positional deviation in the main scanning direction due to the meandering is detected, and the recording start light emitting element of the LED head 23 is determined according to the positional deviation. In FIG. 7, a signal C is a trigger signal for the line image sensor 32 of the control circuit 53, a signal D,
E and F indicate output signals of the line image sensor 32. In the latter signal, when light is incident on the light receiving element of the line image sensor 32, that is, when the blank portion of the recording paper 33 is detected, the bit has the voltage output V ₀ , and on the other hand, when the light is not incident , That is, mark 3
It becomes 0V when 3b is detected. The signal D is a detection signal when the mark 33b is at the correct position, that is, when the recording paper 33 is not displaced in the main scanning direction, and the n-th light receiving element of the line image sensor 32 This shows a case where the left end of the mark 33b is detected and the next N light receiving elements detect the width of the mark 33b. On the other hand, a signal E indicates that the recording paper 33 has shifted to the right and the n'th light receiving element of the line image sensor 32 has detected the left end of the mark 33b. 23 is controlled so as to be shifted by a distance corresponding to the number of light emitting elements (n ² -n) for which image recording is started. Accordingly, a latent image is formed on the photosensitive drum 21 by moving a distance of (n'-n) in the main scanning direction, and even if the recording paper 33 meanders, the image is always located at a position equidistant from the mark 33b. Recording starts. When the amount of reflected light from the recording paper 33 decreases, the voltage level of the output signal F of the line image sensor 32 decreases, but the position of the light receiving element for detecting the mark 33b does not change. The mark 33b can be detected accurately. The control of the recording start light emitting element in the main scanning direction with respect to the LED head 23 is performed in accordance with the recording trigger signal in the sub-scanning direction, so that a two-dimensional color image in which four color images are accurately superimposed. Is obtained. In the above embodiment, the displacement in the main scanning direction is L
The correction was performed by controlling the recording start light emitting element of the ED head 23. Instead, as shown in FIG. 8, the LED head 23 was made movable in the main scanning direction by a stepping motor 54 or the like, and the main scanning detected by the optical sensor 32 was performed. The motor 54 may be driven by the control circuit 55 in accordance with the positional deviation in the direction, and the latent image forming position in the main scanning direction with respect to the photosensitive drum 21 may be corrected. As described above, according to the present invention, the first marks are formed at predetermined intervals in the transport direction and the second marks are formed at the same time.
An image holder that holds an image to be recorded on a recording medium in which at least one row of marks is formed extending in the transport direction or only the first marks are formed at predetermined intervals in the transport direction;
A recording station for forming a latent image on the image holding member,
A developing unit that variable visual image of the latent image the formation of a plurality of colors, and a transfer unit that transfers the visualized image on the recording medium, measuring means for measuring the first mark spacing And an error between the number of lines set between the previous marks and the number of lines of the actually recorded image is detected, and based on this error, the number of lines between two consecutive marks becomes a predetermined number of lines. First control means for setting the number of lines between the next marks, detecting means for detecting the second mark or the end of the recording medium and detecting a displacement in the direction perpendicular to the transport direction of the recording medium; Second control means for controlling the recording station to move and form a latent image in a direction orthogonal to the transport direction in accordance with the displacement, and the measuring means
The contact between the image carrier and the transfer unit from the recording station.
The point of contact between the image carrier and the transfer unit approximately the same distance as the point
Is disposed away from, and, since the first mark and the second mark is recorded in the same time the recording medium and the image recording of the first color, position by stretching and slippage of the conveyance direction of the recording medium Misregistration and color misregistration are corrected by keeping the number of lines between the first marks constant, and positional misregistration and color misregistration due to meandering of the recording medium move image recording on the recording medium in a direction perpendicular to the transport direction. Therefore, regardless of expansion and contraction of the recording medium, slippage and meandering in the transport direction, a plurality of images of different colors can be aligned and superimposedly recorded on the recording medium with high accuracy,
Further, it is possible to realize an inexpensive color electrophotographic recording apparatus in which color shift does not occur. As described above, according to the present invention, the mark
There the image holding body that holds an image to be recorded on the recording medium formed at predetermined intervals in the conveying direction, and a recording station for forming a latent image on the image holding member, a latent image said formed of a plurality of colors Developing means for visualizing the image, a transfer unit for transferring the visualized image to the recording medium, measuring means for measuring the mark interval, and the number of lines set between previous marks The first control detects an error with the number of lines of the image recorded in the memory and sets the number of lines between the next marks based on the error so that the number of lines between two consecutive marks becomes a predetermined number of lines. Means and a mark of the first color.
Second control means for recording on the recording medium at the time of image recording , wherein the measuring means comprises an image carrier having substantially the same distance as the distance from the recording station to a contact point between the image carrier and the transfer section. It is located away from the contact between the transfer section
Since, displacement or color shift caused by expansion and contraction or slip of the conveyance direction of the recording medium, since it is corrected by a constant number of lines between the marks, regardless of the expansion and the conveying direction of the sliding of the recording medium, the recording medium A plurality of images of different colors can be superimposed and recorded with high accuracy on the top, and an inexpensive color electrophotographic recording apparatus without color shift can be realized. Further, since at least the first mark is recorded on the recording medium simultaneously with the recording of the image of the first color, a color image can be obtained by four recording operations, one less than the ordinary recording operation. The recording time can be shortened accordingly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram showing one embodiment of a color electrophotographic recording apparatus according to the present invention. FIG. 2 is a main part showing one embodiment of a color electrophotographic recording apparatus according to the present invention. FIG. 3 is an explanatory view of a main part showing an embodiment of a color electrophotographic recording apparatus according to the present invention. FIG. 4 is a registration control circuit diagram for correcting in a sub-scanning direction. FIG. 6 is a schematic configuration diagram of a line mark control mechanism for correcting in the main scanning direction. FIG. 7 is a main signal waveform diagram. FIG. 8 is a schematic configuration diagram showing a modification of the line mark control mechanism in FIG. 9 Schematic configuration diagram showing a conventional color electrophotographic recording apparatus. FIG. 10 is an explanatory view of the apparatus in FIG. Supply roller 30 winding Rollers 31 and 32 optical sensors 33 recording sheets _{33a, 33a 1, 33a 2,} 33a 3, 33a 4 registration marks 33b line mark 34a recorded image 34b latent 42 flip-flops 43a, 43b count circuit 44a, 44b dividing circuit 45a, 45b Correction circuit 46 Trigger count circuit 47a, 47b AND circuit 48 OR circuit 53, 55 Control circuit 54 Stepping motor

Continuation of front page (72) Inventor Kazuhiro Shimamura 2-3-8, Shimomeguro, Meguro-ku, Tokyo Matsushita Electric Transmission Co., Ltd. (56) References JP-A-61-14656 (JP, A) JP-A-59-59 105660 (JP, A) JP-A-60-113264 (JP, A) JP-B-55-6225 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 13/01 G03G 15 / 01-15/01 117 G03G 15/00 303 G03G 21/00 370-540

Claims (1)

(57) [Claims] An image holding member for holding an image to be recorded on a recording medium having marks formed at predetermined intervals in the transport direction; a recording station for forming a latent image on the image holding member; in a developing unit that visible image, a transfer unit that transfers the visualized image on the recording medium, wherein
Measuring means for measuring the mark interval, detecting an error between the number of lines set between the previous marks and the number of lines of the actually recorded image, and determining the number of lines between two consecutive marks based on this error. First control means for setting the number of lines between the next marks so as to have a predetermined number of lines ;
A second color to be recorded on the recording medium when recording the image of the first color;
Control means, and the measuring means is disposed at a position apart from the contact point between the image carrier and the transfer unit by substantially the same distance as the distance from the recording station to the contact point between the image carrier and the transfer unit. color electrophotographic recording apparatus characterized by there.