JPH02167569A - Color electrostatic recorder - Google Patents

Abstract

PURPOSE:To obtain a color picture free from color slippage by detecting the expansion/ contraction quantity of a recording medium, and permitting a temperature adjusting means to correct the expansion/contraction quantity of the recording medium based on the detected result. CONSTITUTION:Detecting signals from mark position detectors 16a and 16b are inputted to an expansion/contraction correcting part 19. In addition, a temperature adjuster 18 is constituted of a temperature adjusting circuit 23 and a temperature/humidity detector 24, and a correction commanding signal which controls the expansion/ contraction quantity of an electrostatic recording paper 1 is inputted to the adjuster 18. At this point, marks regularly formed along both edges of the electrostatic recording paper 1 are detected, a CCD sensor is provided in the vicinity of a multi-needle electrode recording head 5, and the positions of the marks are detected in order to detect the expansion/contraction quantity of the electrostatic recording paper 1 at the time of recording nth and (n-1)th-pictures. According to the detected result and ambient temperature and humidity at the time of recording the nth-picture, the temperature adjusting quantity of the temperature adjuster 18 is determined to adjust temperature. Therefore, the (n-1)th-picture and the nth-picture can be accurately aligned.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a color electrostatic recording apparatus that continuously records images of different colors in an overlapping manner on the same recording medium to obtain a color image.

2. Description of the Related Art A schematic diagram of a conventional color electrostatic recording apparatus is shown in FIG. 51 is electrostatic recording paper; 52 and 53 are winders for winding and unwinding the electrostatic recording paper to reciprocate; winder 55 is a winder for winding and unwinding the electrostatic recording paper 51; A needle electrode recording head, 54 a presser roller for maintaining constant contact between the electrostatic recording paper 51 and the multi-needle electrode recording head 55, 56 a static elimination bar, 57, 58°5
9. 60 is a developing device to which developers of different colors are supplied, 61
Reference numerals 62 and 63 indicate a squeeze roller for collecting used developer, a pressure roller and a drive roller for gripping the electrostatic recording paper and reciprocating it in directions A and B, and 64 a drive source capable of forward and reverse rotation.

Next, the operation in this configuration will be explained.

The electrostatic recording paper 51 is conveyed in the direction shown by arrow A by a drive roller 62. At this time, an electrostatic latent image of a black image is formed within the effective screen of the electrostatic recording paper 51 by the multi-needle electrode recording head 55, and the developing device 57 supplied with black image agent performs electrostatic suction and is visualized. After being imaged, squeeze 6
In step 1, the used developer is collected and fixed. The electrostatic recording paper 51 on which a black image has been recorded is wound up by a magenta roller 53. After recording the black image information, the driving source 64 is reversed and the electrostatic recording paper 51 is wound in the direction not shown by arrow B by the rewinder 52. 51, and after the rewinding is finished, the second, third, and fourth color images, such as cyan, magenta, and yellow, are superimposed in the same manner as the first color method described above. A color image in which cyan, magenta, and yellow are superimposed can be obtained.

Problems to be Solved by the Invention However, with this configuration, if the atmospheric temperature and humidity change and the electrostatic recording paper expands or contracts after electrostatic development of the nth color, the electrostatic Since the image formed on the recording paper 51 expands and contracts, it is not possible to accurately superimpose the images after the nth color, resulting in color misregistration.

Therefore, it is an object of the present invention to provide a non-Nonolar electrostatic recording device that does not cause color shift.

Means for Solving the Problems In order to achieve this object, the color electrostatic recording device of the present invention detects the position of marks regularly formed along at least one side edge of the recording medium. The apparatus includes an expansion/contraction amount detection means for detecting an expansion/contraction amount, and an expansion/contraction amount correction means for adjusting the expansion/contraction amount of the recording medium according to a signal from the expansion/contraction amount detection means.

With the above-described configuration, the present invention detects the amount of expansion and contraction of the recording medium even if the recording medium expands and contracts due to changes in ambient temperature and humidity during recording of each color, and calculates the amount of expansion and contraction based on the detection result. By correcting the amount of expansion and contraction of the recording medium using the temperature adjusting means, it is possible to obtain a color image without color shift even if the recording medium is transported back and forth a plurality of times to form a color image.

Embodiments Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. 1 to 4.

FIG. 1 shows a schematic configuration of a color electrostatic recording apparatus according to an embodiment of the present invention. In FIG. 1, 1 is electrostatic recording paper, and 2 and 3 are magenta paper for winding up and unwinding the electrostatic recording paper for reciprocating motion.
5 is a multi-needle electrode recording head arranged along the path of the electrostatic recording paper 1, and 4 is a presser roller for maintaining contact between the electrostatic recording paper 1 and the multi-needle electrode recording head 5. , 6 is a static elimination bar; 7, 8, 9, and 10 are developing units each supplied with developer of a different color; 11 is a squeeze for collecting used developer; and 12.13 is a grip for electrostatic recording paper 1. A driving roller and a pressing roller 14 for causing reciprocating motion are a driving source capable of forward and reverse rotation. 15a and 15b are registration marks recorded in the first color on both sides of the electrostatic recording paper 1 and used for position correction for the second and subsequent colors;
6b is a mark position detector for detecting the registration marks 15a and 15b. Note that the mark position detector 16
a and 16b have a built-in CCD sensor (not shown), which illuminates the surface of the electrostatic recording paper 1 with illumination means such as a light emitting diode, and transmits the reflected light to a same-magnification optical system such as a SELFOC lens array. It is configured such that the light is incident on the CCD sensor.

Detection signals from the mark detectors 16a and 16b are input to an expansion/contraction corrector 19 as shown in FIG.

Reference numeral 8 denotes a temperature controller, which is composed of a temperature adjustment circuit 23 and a temperature/humidity detector 24, to which a correction command signal for controlling the amount of expansion and contraction of the electrostatic recording paper 1 is input.

The electrostatic recording paper 1 is conveyed in the direction shown by arrow A by a driving roller 12 and a pressing roller 13, and between them a multi-needle electrode recording spatula 1'' 5 and a developing device, for example, a developing device 7 to which a black developer is supplied. At this time, as the electrostatic recording paper 1 is conveyed, magenta-3
At the same time as winding, the rewinder 2 unwinds in synchronization with this. After all the black image information has been recorded, the drive source 14 is reversed and the electrostatic recording paper 1 is conveyed in the direction shown by arrow B by the drive roller and the pressure roller 13. At this time, contrary to recording, the rewinder 2 is used to wind the paper and at the same time the wine goo 3 is used to unwind it. After rewinding the electrostatic recording paper 1 to a predetermined position, recording is performed while being conveyed again in the direction shown by arrow A, and the operation of rewinding it in the direction shown by arrow B is performed for each color of cyan, magenta, and yellow in order. Color images are formed by superimposing each other, and the final color image is formed by superimposing four colors.

Hereinafter, the positioning operation when superimposing images of each color will be explained in detail with reference to FIGS. 2 to 4. Before the electrostatic recording paper 1 is conveyed in the direction shown by arrow A in FIG. 1 and recorded by the multi-needle electrode recording head 5, the electrostatic recording paper 1 at this time is
The amount of expansion and contraction is detected by mark position detectors 16a and 16b. That is, C at the time of the n-th image recording shown in FIG.
The reference dimension In between the registration marks 15a and 15b at the time of n-th image recording is detected from the output waveform of the CD sensor by the mark position detection circuit 17, and the output signal is sent to the expansion/contraction correction section 1.
9 is sent to the comparison circuit 2■. In the comparison circuit 21, the registration mark 15a at the nI-th image recording time is stored in the reference signal circuit 22 in advance.

A reference dimension In-1 between 15b and 15b is stored, and this is compared with the reference dimension In detected by the mark position detection circuit 17.
Atmospheric temperature and humidity are detected in step 4.

The reference signal circuit 22 stores correlation data between the rate of change in expansion and contraction of the electrostatic recording paper 1 and the temperature and humidity as shown in FIG. Determine the temperature correction amount from the amount.

For example, if the atmospheric temperature of the n-th image recording paper is 25°C, the atmospheric humidity is 50% RH1, and the expansion/contraction change rate of the electrostatic recording paper 1 is 0.05% with respect to the reference value, then the expansion/contraction of the electrostatic recording paper 1 is It is determined that the ambient temperature must be set to 20'C in order to prevent the formation of a large amount of gas.

The output from the comparator circuit 21 is then sent to a temperature control circuit 23.The temperature control circuit 23 is for varying the ambient temperature near the multi-needle electrode head 5, and the temperature control circuit 23 is for controlling the temperature of the electrostatic recording paper 1, for example. It consists of a heat roller with a rod-shaped heater 18A built in inside a kite roller provided perpendicularly along the conveyance direction.

The temperature regulator 18 operates based on a signal from the temperature regulating circuit 23, varies the temperature of the electrostatic recording paper 1, and maintains the ambient temperature at 20°C.

Marks regularly formed along both edges of the electrostatic recording paper 1 are detected as shown in (2) below. A CCD sensor is installed near the multi-needle electrode recording head 5 to detect the position of this mark and detect the amount of expansion and contraction of the electrostatic recording paper 1 during the n-th and (n-1) times of image recording. By determining the temperature correction amount of the temperature controller 18 from the ambient temperature and humidity at the time of recording and adjusting the temperature, it is possible to accurately align the (n-1)th image and the n-th image.

Effects of the Invention As is clear from the above description, the present invention provides the above-mentioned method in which detection means for detecting marks regularly formed along at least one side edge of a recording medium is provided near the multi-needle electrode recording head. Since it is equipped with a correction means that detects the mark position, detects the conveyance direction of the recording medium and the amount of expansion and contraction of the recording medium in the direction perpendicular to the conveyance direction, and adjusts the temperature according to the amount, it is possible to avoid overlapping. Even if the recording medium expands and contracts due to changes in temperature and humidity during recording, the temperature can be adjusted to the same value using a temperature controller according to the amount of expansion and contraction, making it easy to overlay images with high precision. Can be combined, simple structure,
It has advantages such as being able to be realized at low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a Noller electrostatic recording device according to an embodiment of the present invention, FIG. FIG. 4 is a block diagram of the main parts of the apparatus, FIG. 4 is a correlation diagram between wetness/humidity and elongation of electrostatic recording paper, and FIG. 5 is a schematic diagram of a conventional color electrostatic recording apparatus. 1...Electrostatic recording paper, 2...Wine goo, 3...Rewine goo, 4...Press roller, 5...Multi-needle electrode Recording head, 6...
・・Static elimination bar, 7, 8, 9゜10...Developer,
11...Squeeze, 12...Drive roller, 13...Press roller, 14...
Drive source, 15a, 15b-registration mark,
16a, 16b... mark detector, 17...
... Mark position detection circuit, 18 ... Temperature controller, 19 ... Expansion/contraction correction section, 24 ... Temperature/humidity detector.

Claims (2)

[Claims] (1) A conveyance means that reciprocates a recording medium along a certain path, a single recording head that forms an electrostatic latent image on the recording medium on the conveyance path, and a single recording head that forms an electrostatic latent image on the recording medium. In a color electrostatic recording device equipped with a liquid developing device capable of developing with a plurality of color developers, the amount of expansion and contraction of a mark medium regularly formed along at least one side edge of the recording medium is detected, and the temperature is measured. expansion/contraction amount detection means for detecting the position of the color electrostatic recording apparatus and detecting the amount of expansion/contraction of the recording medium, the expansion/contraction amount correction means being provided with an expansion/contraction amount correction means by the adjustment means; a color electrostatic recording device comprising: expansion/contraction amount correction means for expanding/contracting the recording medium; (2) The color electrostatic recording device according to claim 1, wherein the expansion/contraction amount correction means has a temperature adjustment section.