JPH02167571A - 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 correction commanding signal is inputted to a humidity adjuster 18 which controls the expansion/contraction quantity of an electrostatic recording paper 1. The humidity adjuster 18 is constituted of a humidity adjusting circuit 23 and a temperature/humidity detector 24. Thus, the mark position detectors 16a and 16b which detect marks regularly formed along both edges of the electrostatic recording paper 1 are provided in the vicinity of a multi-needle electrode recording head 5, and the positions of the marks are detected and the expansion/contraction quantity of the electrostatic recording paper 1 at the time of recording nth and (n-1)th-pictures is detected. According to the detected result and ambient temperature and humidity at the time of recording the nth-picture, the humidity adjusting amount of the humidity adjuster 18 is determined to adjust humidity. Therefore, after recording the (n-1)th-picture, even if temperature and humidity conditions are changed, a picture can be accurately aligned at the time of recording the nth picture.

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 for reciprocating motion; Electrode recording head, 54 is a presser roller for maintaining constant contact between the electrostatic recording paper 51 and the multi-needle electrode recording head 55, 56 is a static elimination bar, 57, 58°5
9. 60 is a developing device to which developers of different colors are supplied, 61
62 and 63 are a press roller and a drive roller for gripping and reciprocating the electrostatic recording paper, and 64 is 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, the multi-needle electrode recording head 55 (
As a result, an electrostatic latent image of a black image is formed within the effective screen of the electrostatic recording paper 51, and after being visualized by electrostatic attraction by the developing device 57 supplied with black image agent, the image is visualized by the squeeze 61. The used developer is collected and fixed. The electrostatic recording paper 51 on which the black image has been recorded is wound up by the magenta paper 53. After recording the black image information, the drive source 64 is reversed and the electrostatic recording paper 51 is moved in the direction shown by arrow B by the rewinder 52. ], and after rewinding, the second color,
Images of third and fourth colors, for example, cyan, magenta, and yellow, are superimposed in the same manner as the method for the first color described above to obtain a color image in which four colors (black, cyan, magenta, and yellow) are superimposed. Can be done.

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 static Since the image formed on the electrographic paper expands and contracts, the images cannot be accurately superimposed after the nth color, resulting in color shift.

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

Means for Solving the Problems In order to achieve this object, the present invention provides an expansion/contraction method that detects the position of marks regularly formed along at least one side edge of the recording medium to detect the amount of expansion/contraction of the recording medium. and an expansion/contraction amount correcting means for expanding or contracting the recording medium by changing the humidity near the recording medium based on 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 a change 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 humidity adjusting means, it is possible to obtain a color image without color shift even if the recording medium is moved back and forth a plurality of times to form a color image.

EXAMPLE A preferred embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

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 an electrostatic recording paper, 2 and 3 are magenta and magenta for winding and unwinding the electrostatic recording paper for reciprocating motion, and 5 is a passage for the electrostatic recording paper 1. 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, and 7, 8, 9.10 are multi-needle electrode recording heads arranged along the line. Developing devices each supplied with a developer of a different color; 11 an asqueeze for collecting used developer; 12 and 13 a pressure roller and a drive roller for gripping and reciprocating the electrostatic recording paper; 14; is a driving source capable of forward and reverse rotation.

Registration marks 15a and 15b are formed on both edges of the electrostatic recording paper 1 and are regularly repeated at a predetermined pitch.

Mark position detectors 16a and 16b for detecting registration marks 15a and 15b are disposed near the front side of the multi-needle electrode recording head 5 in the electrostatic recording paper conveyance direction. Although the mark detector positions 16a and 16b are not shown, the CC
It has a built-in D sensor, and is configured so that the surface of the electrostatic recording paper l is illuminated with illumination means such as a light emitting diode, and the reflected light is made incident on the CCD sensor using a 1x optical system such as a SELFOC lens array. has been done.

The detection signals from the mark position detectors 16a and 16b are the fourth
As shown in the figure, the correction command signal is input to the expansion/contraction correction section 19, and the correction command signal is input to the humidity controller 18 which controls the amount of expansion/contraction of the electrostatic recording paper 1. This humidity controller 18 is composed of a humidity adjustment circuit 23 and a temperature/humidity detector 24.

The electrostatic recording paper 1 is conveyed by a driving roller and a pressing roller 13 in the direction shown by arrow A, and in the meantime, a multi-needle electrode recording head 5 and a developing device, for example, a developing device 7 supplied with black developer, are used to optionally develop the electrostatic recording paper 1. black image information is recorded. At this time, as the electrostatic recording paper 1 is transported, the magenta paper 3 winds it up, and at the same time, the rewinder 2 unwinds it 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 the recording operation, the rewinder 2 winds up the paper and at the same time the winder 3 unwinds it. After rewinding the electrostatic recording paper 1 to a predetermined position, the recording paper 1 is again conveyed in the direction shown by arrow A for recording, and then rewound in the direction shown by arrow B for each color of cyan, magenta, and yellow. Images of different colors are superimposed to form a color image, 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. 3 and 4. Before the electrostatic recording paper 1 is conveyed in the direction shown by arrow A in FIG. 16b. That is, the mark position detection circuit 17 detects the reference dimension In between the registration marks 15a and 15b during the n-th image recording from the output waveform of the CCD sensor during the n-th image recording shown in FIG. 3(A). , the output signal is sent to the comparison circuit 21 of the expansion/contraction correction section 19.

The comparison circuit 21 compares the registration marks 15a, 15 at the time of the n-1th image recording stored in advance in the reference signal circuit 22.
A reference dimension In-1 between b is stored, and this is compared with the reference dimension In detected by the mark position detection circuit 17. At the same time, the temperature and humidity detector 24 provided in the humidity controller Detects humidity and ambient temperature. 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.
1. The humidity correction amount is determined from the ambient temperature and humidity and the amount of expansion and contraction of the electrostatic recording paper l. For example, if the ambient temperature at the time of n-th image recording is 25°C, the atmospheric humidity is 50% RH1, and the rate of change in expansion/contraction of electrostatic recording paper 1 is 0.05% with respect to the reference value, then electrostatic recording paper 1 will expand/contract. It is determined that the atmospheric humidity must be set to 45% RH in order to prevent this from occurring.

The output from comparison circuit 21 is then sent to humidity adjustment circuit 23. The humidity adjustment circuit 21 is for varying the atmospheric humidity near the multi-needle electrode head 5, and is connected to the humidity controller 18.
For example, an ultrasonic humidifier is arranged on both sides of and near recording on electrostatic recording paper. The humidity controller 18 operates based on a signal from the humidity adjustment circuit 21 to vary the amount of humidity.

A mark position detector 16a, 1 detects marks regularly formed along both edges of the electrostatic recording paper 1 as shown in 2 below.
6b is provided near the multi-needle electrode recording head 5, and the position of this mark is detected to detect the amount of expansion and contraction of the electrostatic recording paper 1 during the nth and (n-1)th image recording. By determining the correct amount of humidity force 11 of the humidity controller 18 from the atmospheric temperature and humidity at the time of recording and adjusting the humidity, even if the temperature and humidity conditions change after the n,-1st image recording, the nth image recording Images can be aligned accurately.

Effects of the Invention As is clear from the explanation in Section 2, the present invention provides a CCD sensor that detects marks regularly formed along at least one side edge of a recording medium in the vicinity of a multi-needle electrode recording head. , which is equipped with a correction means that detects the position of the mark, detects the conveyance direction of the recording medium and the amount of expansion and contraction of the recording medium in a direction perpendicular to the conveyance direction, and adjusts the humidity according to the detected amount. Even if the recording medium expands or contracts due to changes in temperature and humidity during overlapping recording, the humidity controller adjusts the humidity according to the amount of expansion and contraction to bring the amount of expansion and contraction to the same value. It has the advantage of being able to superimpose images with high precision, and realizing high-quality color images with a simple structure and low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a color electrostatic recording device according to an embodiment of the present invention, FIG. 2 is a perspective view of the main parts of the device, and FIG. 3 explains a recording medium mark position detection method in the device. Explanatory diagram, Fig. 4 is a block diagram of the temperature/humidity detection section, signal correction section, and humidity adjustment voltage signal generation section, Fig. 5 is a correlation diagram between temperature/humidity and elongation of electrostatic recording paper, and Fig. 6 is a block diagram of the temperature/humidity detection section, signal correction section, and humidity adjustment voltage signal generation section. 1 is a schematic configuration diagram of a conventional color electrostatic recording device. ■... Electrostatic recording paper, 2... Winder, 3... Rewinder-54... Presser 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 ... Humidity controller, 19 ... Expansion/contraction correction section, 24 ... Temperature/humidity detector.

Claims (1)

[Claims] A conveyance means for reciprocating a recording medium along a fixed path, a single recording head for forming an electrostatic latent image on the recording medium on the conveyance path, and a plurality of color electrostatic latent images for forming an electrostatic latent image on the recording medium on the conveyance path. In a color electrostatic recording device equipped with a liquid developing device capable of developing with a developer, mark positions regularly formed along at least one side edge of the recording medium are detected to determine the amount of expansion and contraction of the recording medium. A color electrostatic recording apparatus comprising: an expansion/contraction amount detection means for detecting an expansion/contraction amount; and an expansion/contraction amount correction means for expanding/contracting the recording medium by changing humidity near the recording medium based on a signal from the expansion/contraction amount detection means.