JPH0799846B2 - Color electrostatic recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color electrostatic recording apparatus that obtains a color image by continuously recording images of different colors on the same recording medium.

2. Description of the Related Art A schematic configuration diagram of a conventional color electrostatic recording device is shown in FIG. In FIG. 5, 101 is electrostatic recording paper, 102, 105, 109, 11
3 is a multi-needle electrode recording head arranged along the path of the electrostatic recording paper, 104, 107, 111, 115 are developing portions to which developers of different colors are supplied, and 103, 106, 110, 114 are contact points between the electrostatic recording paper and the multi-needle electrode recording head. Presser roller for keeping, 108,112,
Reference numeral 116 is a mark detector, 117 is a conveying roller, and 118, 119 and 120 are translational drive units for translationally moving the multi-needle electrode recording heads 105, 109 and 113. FIG. 6 is a view of the color electrostatic recording apparatus of FIG. 5 seen from the lower side, 121 is a resist line drawn in the longitudinal direction of the electrostatic recording paper, and 122 is a registration mark provided at equal pitches.

The electrostatic recording paper 101 is transported by the transport roller 117 in the direction indicated by the arrow A. At this time, the first multi-needle electrode recording head 102
This forms a resist line 121 and a resist mark 122 on both sides outside the effective screen along the edge of the electrostatic recording paper 101, and an electrostatic latent image of a black image is formed in the effective screen, and a black developer is supplied. Development and fixing are performed by the original 104 being held. On the electrostatic recording paper 101 on which the black image is formed, the second recording head 105 forms an electrostatic latent image of the second color, for example, cyan. At this time, registration mark 122, registration line 1
21 is detected by the mark detectors 108a and 108b, and the deviation of the registration line 121 from a predetermined position (that is, the amount of meandering during conveyance) is calculated. A correction amount is determined for this calculated shift amount, the translation drive unit 118 is operated, and the multi-needle electrode recording head 105 is moved in the direction shown by the arrow x ₁ in FIG. The black image formed by 102 is aligned in the direction of arrow x ₁ . Further, the mark detectors 108a and 108b detect the registration mark 122, calculate the moving speed of the registration mark 122, and use a multi-needle type so that an electrostatic latent image with the same recording line density is always formed between the registration marks. The recording timing of the electrode recording head 105 is controlled. In this way, image superposition control is performed in the two directions indicated by arrows A and x ₁ in the figure.

The electrostatic recording paper 101 on which the cyan image has been superposed reaches the third multi-needle electrode recording head 109, and an electrostatic latent image for the magenta image is formed. In this case as well, as in the case of recording cyan, the registration line 121 and the registration mark 122 are detected by the mark detectors 112a and 112b, the translation drive unit 119 is operated, and the image superposition control is performed. Finally, the yellow image is recorded by detecting the registration mark 122 and the registration line 121 by the mark detectors 116a and 116b, and controlling the multi-needle electrode recording head 113 by the translation drive unit 120. In this way, an image in which four colors (black, cyan, magenta, and yellow) are superimposed can be obtained.

However, according to such a configuration, an image recorded by a plurality of multi-needle electrode recording heads is recorded in the lateral direction (relative to the moving direction) of the electrostatic recording paper regardless of the meandering of the electrostatic recording paper. In order to accurately superpose in the right angle direction), the multi-needle electrode recording heads for the second and subsequent colors must have a structure capable of translational movement, and must have a translational drive unit, which complicates the mechanism. Not only that, but it also causes a high cost. It was also difficult to make the recording unit compact.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a conveying unit that conveys a recording medium in one direction along a predetermined path, and a recording medium that is arranged along the predetermined path on the recording medium. A plurality of multi-needle electrode recording heads that sequentially form latent images corresponding to recorded images of the respective colors, and latent images formed on the recording medium by the multi-needle electrode recording heads are visualized in different colors. A plurality of developing devices, and a plurality of multi-needle electrode recording heads for the second and subsequent colors, registration marks provided on the upstream side in the recording medium transport direction and formed at substantially equal intervals along the edges of the recording medium, and the edges of the recording medium. Mark detecting means for detecting each of the resist lines formed along the line, and the recording based on the information obtained by detecting the resist marks by the mark detecting means when forming a latent image corresponding to each color recorded image. The recording timing control means for aligning the recording position of each color latent image in the transport direction of the medium, and the information obtained by the mark detecting means detecting the registration line when forming the latent image corresponding to each color recording image, Correction means for calculating a shift amount in a direction perpendicular to the conveyance direction of the recording medium, and for shifting the recording start position of the latent image on each multi-needle electrode recording head to the left or right according to the shift amount. The correction means is adapted to calculate the deviation amount of the registration line and control the recording start position of the image signal every time the mark detection means detects the registration mark.

Effect of the Invention According to the present invention, even if the recording medium meanders during conveyance, the mark detector detects the registration line to calculate the deviation amount from the predetermined position of the recording medium, and the multi-needle is used according to the deviation amount. Since the recording start electrodes of the electrode recording head can be displaced, it is possible to position the superimposed images without the need for a structure in which the multi-needle electrode recording head can be translated.

Practical Examples A preferred embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 shows a schematic structure of a color electrostatic recording apparatus according to an embodiment of the present invention, and FIG. 2 is a view of the recording section as viewed from below. In FIGS. 1 and 2, reference numeral 1 is an electrostatic recording paper, and reference numerals 2, 3, 4 and 5 are multi-needle electrode recording heads arranged along a conveying path of the electrostatic recording paper. This multi-needle electrode recording head is not provided with a conventional translation mechanism. A mechanism for inclining the multi-needle electrode recording head with respect to the signal direction of the electrostatic recording paper may be provided to correct the twist of the electrostatic recording paper 1. 6,7,8,9 are developing parts to which developers of different colors are supplied respectively, and 10,11,12 are mark detections arranged in the vicinity of the multi-needle electrode recording heads 3, 4 for the second and subsequent colors. , 13, 14, 15, 16 are recording voltage signal generators for the multi-needle electrode recording heads, and 17, 18, 19 are recording bit correction units for the multi-needle electrode recording heads 3, 4 for the second and subsequent colors. Is. The recording bit correction units 17, 18, and 19 are the corresponding multi-needle electrode heads 3, 4, and
5 has a function of controlling the position of the recording start electrode, and its block diagram is shown in FIG. Details will be described later. 20, 21, 22, 23 are pressing rollers for keeping the electrostatic recording paper 1 and the multi-needle electrode recording heads 2, 3, 4, 5 in close contact with each other, and 24 is through each multi-needle electrode recording head of the electrostatic recording paper 1. It is a carrying roller that constitutes a carrying means for carrying.

The electrostatic recording paper 1 is carried by the carrying roller 24 in the direction shown by the arrow, and in the meantime, the multi-needle electrode recording heads 2, 3, 4, and the developing unit
Images of different colors are sequentially formed by 6,7,8,9, and finally a color image in which four colors (black, cyan, magenta, and yellow) are overlapped is formed.

Hereinafter, the alignment operation when superimposing the images of the respective colors will be described with reference to the mark detector 10 and the recording bit correction unit 17 shown in FIG.
Also, a detailed description will be given with reference to a block diagram of the recording voltage signal generator 14 and a waveform diagram of main signals in FIG.

At the same time that the electrostatic recording paper 1 is conveyed in the direction shown by the arrow in FIG. 2, the first multi-needle electrode recording head 2 causes an electrostatic latent image of a black image to be generated within the effective screen and to be removed from the outside of the effective screen. An electrostatic latent image of the resist lines 25 and the resist marks 26 at equal pitches is formed on a portion along the edge of the electrophotographic recording paper 1. This electrostatic latent image is developed and fixed by the developing unit 6 to which the black developer is supplied, and the black image and the resist line 25 and the resist mark 2 are formed.
6 is formed.

The electrostatic recording paper 1 on which the black image and the resist line 25 and the resist mark 26 are formed is then sent to the second-color multi-needle electrode recording head 3 to form an electrostatic latent image of a cyan image.
In forming the electrostatic latent image of the cyan image, the mark detector 10 detects the registration line 25 and the registration mark 26, and detects the meandering of the electrostatic recording paper 1, uneven feeding due to slip, and extension in the conveying direction. . As shown in FIG.
The mark detector uses CCD to detect the resist line 25 and the resist mark 26. 4A, 4B, and 4C show examples of output waveforms of the CCD circuit 27 when the resist line 25 is detected.

The output signal from the CCD circuit 27 is sent to the comparison circuit 28 and the counting circuit 30 of the recording bit correction unit 17 shown in FIG. Comparison circuit
In 28, the resist line 25 detection bit (indicated by n ₁ , n ₂ and n ₃ of each waveform in FIG. 4) in the CCD is compared with a predetermined value, and the resist line 25 is compared with the predetermined position to It is determined how much it is deviated from. The output from the comparison circuit 28 is then sent to the correction circuit 29. In the correction circuit 29,
Corresponding to the shift amount of the registration line 25, the shift amount of the image signal with respect to the recording period signal (Fig. 4d) (Fig. 4e, f,
The amount of g indicated by t ₁ , t ₂ , t ₃ ) is determined, and the timing circuit 31
Sent to. On the other hand, in the counting circuit 30, the detection signal of the registration mark 26 is extracted from the output waveform of the CCD circuit 27, the distance between the registration marks 26 is measured, and a predetermined number of lines is recorded at the time of detecting each registration mark 26, A recording trigger signal is sent to the timing circuit 31. In the timing circuit 31, in synchronization with the recording trigger signal sent from the counting circuit 30,
A recording period signal (Fig. 4d) is generated and sent to the recording control circuit 32 together with the recording signal (e, f, g in Fig. 4) obtained by shifting the image signal according to the shift amount from the correction circuit 29. . The recording control circuit 32 controls the recording driver circuit 33 to apply a recording voltage to the multi-needle electrode recording head 3. Thus, in the multi-needle electrode recording head 3 configured by arranging a large number of electrodes, recording is started from the electrode at a position corresponding to the shift amount of the image signal (for example, t _{1 in} FIG. 4e). Electronic recording paper 1
The image recording position in a direction perpendicular to the conveyance direction of is controlled according to the shift amount.

As described above, by detecting the deviation amount of the registration line 25 from the predetermined position and recording the cyan image while shifting the image signal according to the deviation amount, the cyan image developed and fixed by the developing unit 7 is recorded. With this, the alignment can be performed with high accuracy.

Further, in the same manner as when recording a cyan image, the mark detecting unit 11 detects the registration line 25 and the registration mark 26 while the third-color multi-needle electrode recording head 4 and the developing unit 8 overlap the magenta image. To record. By the last mark detector 12, the registration line 25 and the registration mark 26
While detecting the, a yellow image is recorded by the fourth-color multi-needle electrode recording head 5 and the developing unit 9.

Through the above steps, a color image in which four colors are mixed can be obtained.

In the above embodiment, the first multi-needle electrode recording head 2 is used.
The resist line 25 and the resist mark 26 are recorded by using the above, but instead of this, electrostatic recording paper on which the resist line and the resist mark are recorded in advance is used to detect the mark in the vicinity of the first-color multi-needle electrode recording head 2. A mark detector may be provided to detect the registration line position and the multi-needle electrode recording head 2 may record an image at a predetermined position relative to the position.

EFFECTS OF THE INVENTION As is clear from the above description, according to the present invention, a transporting unit that transports a recording medium in one direction along a predetermined path, and a recording medium of each color sequentially arranged along the predetermined path. A plurality of multi-needle electrode recording heads that form latent images corresponding to recorded images, and a plurality of developing devices that visualize the latent images formed on the recording medium by the multi-needle electrode recording heads in different colors. A plurality of multi-needle electrode recording heads for the second and subsequent colors, which are provided on the upstream side in the recording medium conveyance direction and are formed along the edges of the recording medium at substantially equal intervals along the edges of the recording medium. Mark detecting means for detecting each of the registered resist lines, and how to convey the recording medium based on information obtained by detecting the resist marks by the mark detecting means when forming a latent image corresponding to each color recorded image. Recording timing control means for aligning the recording positions of the latent images of the respective colors, and information obtained by the mark detecting means detecting the resist line when forming the latent images corresponding to the recording images of the respective colors. Correction means for calculating a shift amount in a direction perpendicular to the transport direction and for shifting the recording start position of the latent image on each multi-needle electrode recording head to the left or right according to the shift amount. The multi-needle electrode recording is performed every time the registration mark is detected (sequentially) by calculating the deviation amount of the registration line and controlling the recording start position of the image signal every time the mark detection unit detects the registration mark. Since the recording start position of the latent image on the head is controlled, it is possible to perform extremely accurate image superposition processing and obtain a clear color image. The ability. Further, since the multi-needle electrode recording head is not moved, no mechanism of the movable portion is required, the structure is simple, and the above effect can be obtained at low cost.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a color electrostatic recording apparatus according to an embodiment of the present invention, FIG. 2 is a view of a recording section of the color electrostatic recording apparatus as seen from below, and FIG. 3 is a mark detector. , A block diagram of a recording bit correction unit and a recording voltage signal generation unit, FIG. 4 is a main signal waveform diagram in the block diagram of FIG. 3, FIG. 5 is a schematic configuration diagram of a conventional color electrostatic recording apparatus, FIG. FIG. 3 is a bottom view of a conventional color electrostatic recording device. 1 ... Electrostatic recording paper, 2,3,4,5 ... Multi-needle electrode recording head,
6,7,8,9 …… Developing part, 10,11,12 …… Mark detector, 13,1
4,15,16 …… Recording voltage signal generator, 17,18,19 …… Record bit correction unit, 24 …… Conveying roller, 25 …… Register line, 26 …… Register mark.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-59-226559 (JP, A) JP-A-57-67369 (JP, A) JP-A-56-122276 (JP, A) JP-A 61- 272759 (JP, A)

Claims (1)

[Claims] 1. A transporting means for transporting a recording medium in one direction along a predetermined path, and a plurality of means arranged along the predetermined path for sequentially forming a latent image corresponding to a recorded image of each color on the recording medium. Multi-needle electrode recording head, a plurality of developing devices for visualizing latent images formed on the recording medium by the multi-needle electrode recording head into different colors, and multi-needle electrode recording for the second and subsequent colors. Mark detection means provided on the upstream side of each head in the recording medium conveyance direction and detecting a resist mark formed at substantially equal intervals along the edge of the recording medium and a resist line formed along the edge of the recording medium. When the latent image corresponding to each color recorded image is formed, the recording position of each color latent image in the transport direction of the recording medium is adjusted based on the information obtained by the mark detection means detecting the registration mark. The amount of deviation in the direction perpendicular to the conveyance direction of the recording medium is calculated from the recording timing control means and information obtained by the mark detection means detecting the registration line when forming a latent image corresponding to each color recording image. And a correction unit that shifts the recording start position of the latent image on each multi-needle electrode recording head to the left or right according to the amount of deviation, and the correction unit detects the registration mark by the mark detection unit. A color electrostatic recording apparatus, wherein the registration line shift amount is calculated and the image signal recording start position is controlled for each time.