JPH021345A - Color electrostatic recording device - Google Patents

Abstract

PURPOSE:To improve the accuracy of overlapping of images together by providing temperature and humidity detection means in the neighborhood of a recording medium, calculating the contraction of the recording medium in a transport and a right angle direction, and extending/contracting a multi-pin electrode recording head in accordance with the calculated value. CONSTITUTION:A temperature/humidity detector 17 is installed near electrostatic recording paper 1, and atmospheric temperature/humidity for the recording paper 1 is measured prior to the recording by a multi-pin electrode recording head 5. Then the measured value is compared with reference temperature/humidity to calculate an extension and a contraction in the transport and its right angle directions of the recording paper 1. After this, the recording head 5 is extended and contracted by the heating section 18 of the multi-pin electrode recording head 5 in accordance with the calculated extension/contraction. Therefore, if the recording paper 1 extends or contracts due to a change in temperature and humidity at the time of recording, the recording head 5 extends and contracts according to the extension/contraction that generates, so that the images can be overlapped over the other with high accuracy under a simple structure.

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. Prior Art The schematic configuration diagrams of a conventional color electrostatic recording device are shown in FIGS. 6 and 7.
As shown in the figure. Reference numeral 51 denotes electrostatic recording paper, and 52.53 a winder and reel 7F-156 for unwinding and unwinding the electrostatic recording paper in order to reciprocate the electrostatic recording paper, which are arranged along the path of the electrostatic recording paper. A multi-needle electrode recording head, 64 a presser roller for maintaining contact between the electrostatic recording paper and the multi-needle electrode recording head, 56 a static elimination bar, 57.5B and 69.60 to which developers of different colors are supplied. Developing device 61 is a squeeze roller for collecting used developer, 62.63H% is a suppression roller and a drive roller for gripping and reciprocating the recording paper, and 64 is a drive source capable of forward and reverse rotation.

Next, the operation in this configuration will be explained.

The recording paper 51 is conveyed by a drive roller 62 in the direction indicated by the arrow. At this time, registration marks 66a and 65b are formed along the edge of the electrostatic recording paper 61 on both sides outside the effective screen by the multi-needle electrode recording head 66, and an electrostatic latent image of a black image is formed within the effective screen. After the image is visualized by electrostatic suction by the developing device 57 to which black developer is supplied, all of the used developer is collected by the squeezer 61 and fixed.

The electrostatic recording paper 51 on which a black image has been recorded is unwound by a winder 63, and after recording of the black image information is completed, the drive source 64 is reversed and the electrostatic recording paper 61 is rewound by the rewinder 52. After the rewinding is completed, the process moves to the electrostatic development process for a second color, for example, cyan. In electrostatic development for the second and subsequent colors, first, the registration marks 6sa, 65b are
i-mark detectors 66a, 66k) to calculate the deviation of the registration lines 65&, 66b from a predetermined position (that is, the meandering amount during conveyance). A correction amount is determined for the obtained deviation amount, and the multi-needle electrode recording head 65 is moved in the direction shown by the arrow X in FIG. 7, and the black image formed in the first electrostatic development is Perform alignment in the direction. Furthermore, the mark detector set,s
The registration marks 65a and 86b are detected with ob, the moving speed of the marks is calculated, and an electrostatic latent image with the same recording line density is always formed between the registration marks in the incoming direction.
The recording timing of the multi-needle electrode recording head 66 is controlled. In this way, image superimposition control is performed in the Z direction indicated by arrows A and X in the figure.

After the recording of the cyan image information is completed, the electrostatic recording paper 51 on which the cyan image is superimposed is rewound by the rewinder 52, and the third and fourth color images, such as magenta and yellow, are processed by the method described above. are superimposed. Thus 4 colors (black, cyan).

It is possible to obtain an image in which the colors (magenta and yellow) are superimposed.

Problems to be Solved by the Invention However, with this configuration, if the atmospheric humidity and temperature change after the first color electrostatic development and the electrostatic recording paper expands or contracts, the multi-needle electrode Because the minimum pitch of the recorded image, which corresponds to the minimum pitch of the electrodes of the recording head, expands and contracts, accurate overlay cannot be achieved even if the multi-needle electrode recording head is translated in translation for the second and subsequent colors, resulting in color misalignment. was there.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a detection means for detecting both temperature and humidity, which is provided in contact with or near the recording medium.
Based on the information obtained by this detection means, the total amount of expansion and contraction in the direction perpendicular to the direction of the conveyance force of the recording medium is calculated, and the multi-needle electrode recording head is expanded and contracted according to the calculated amount to perform the entire recording. .

Operation The present invention has the above-described structure, so that even if the recording medium expands or contracts due to a change in the ambient temperature and humidity during recording of each color, the temperature sensor provided in contact with or in the vicinity of the recording medium will
A humidity detector detects the temperature and humidity after the change, compares the internal temperature and humidity with information on the expansion and contraction of the recording medium, and applies thermal energy to the multi-needle electrode recording head according to the comparison amount. Since the pitch between the applied electrodes can be expanded and contracted uniformly, it is possible to align the superimposed images for each color.

EXAMPLE Hereinafter, a preferred embodiment of the present invention will be described with reference to all of FIGS. 1 to 5.

FIG. 1 shows a schematic configuration of a color electrostatic recording apparatus according to an embodiment of the present invention, and FIG. 2 shows details (2) of the recording section thereof. In FIGS. 1 and 2, 1 is an electrostatic recording paper, 2 and 3 are winders and winders for unwinding and unwinding the electrostatic recording paper in order to make the electrostatic recording paper fully reciprocate, and 5 is an electrostatic recording paper. This is a multi-needle electrode recording head arranged along one path, and this multi-needle electrode recording head is not provided with a translation mechanism like the conventional one. 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, 9.10 is a developer to which developers of different colors are supplied, respectively. 11 is a squeeze roller for collecting used developer; 12 and 13 are a suppression roller and a drive roller for gripping the entire electrostatic recording paper and causing it to reciprocate; and 14 is a drive source capable of forward and reverse rotation. 152L, 1
Reference numeral 5b indicates a registration mark recorded in the first color and used for position correction for the second and subsequent colors, and 1e)L and 1eb mark detectors for detecting the registration mark. 17 is provided in contact with or near the electrostatic recording paper.

Temperature/humidity detector for detecting the atmospheric temperature/humidity of the electrostatic recording paper immediately before recording with the multi-needle electrode recording head, 18
is a heating section for expanding and contracting the multi-needle electrode recording head.

The electrostatic recording paper 1 is conveyed in the direction indicated by the arrow by a driving roller 12 and a pressing roller 13, and between them is conveyed by a multi-needle electrode recording head 6 and a developing device, for example, a developing device 7 to which a black developer is supplied. Any black [i! ii image information is recorded. At this time, as the electrostatic recording paper 1 is transported, the winder 3 winds it up, and at the same time, the rewinder 2 unwinds it. 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 12 and the pressure roller 13VC.

At this time, contrary to the recording, the rewinder 2 winds up the paper and the winder 3 unwinds it at the same time.

After rewinding the electrostatic recording paper 1 to a predetermined position, recording is performed while being conveyed again in the direction indicated by the arrow B, and the operation of rewinding the electrostatic recording paper 1 in the direction indicated by the arrow B is performed for each color of cyan, magenta, and yellow in order. Color images are formed by superimposing them, and finally a color image is formed by superimposing four colors.

Hereinafter, the positioning operation when all images of each color are aligned will be explained in detail with reference to FIGS. 3(2) to 51.

Before the electrostatic recording paper 1 is conveyed in the direction indicated by the arrow in FIG. 1 and recorded by the multi-needle electrode recording head 5Vc, a temperature/humidity detector 17Vc is placed in contact with or near the electrostatic recording paper 1.
The atmospheric temperature and humidity of the electrostatic recording paper 1 at the time of levering are detected. The temperature/humidity detector 17 includes a full-width temperature/humidity sensor.
The output signal from the humidity detection circuit 2o is sent to the comparison circuit 21 of the expansion/contraction correction section 19. The comparison circuit 21 compares the temperature/humidity output signal from the temperature/humidity detection circuit 20 with the temperature/humidity output signal from the reference signal circuit 22 to determine the amount of expansion/contraction of the electrostatic recording paper 1. The reference signal circuit 22 contains correlation data of temperature/humidity and head applied energy as shown in FIG.
The comparator circuit 21 determines that the energy applied to the multi-needle electrode recording head 6 at this time is about 15°C at the head heating temperature.
Judgment will be made.

The output from the comparison circuit 21 is then sent to the recording head heating circuit 23. Recording head heating circuit 23
1 is for expanding and contracting the multi-needle electrode recording head 6, and is configured by, for example, a coil heater or a ceramic heater, which is arranged on the side wall or inside of the full multi-needle electrode recording head 5. Since the multi-needle electrode recording head 5 is generally formed by fixedly molding linear electrodes arranged at equal pitches using a resin material, it can be said to be a kind of composite material made of a metal material and a resin material.

When thermal energy is applied to this composite material, both the metal linear electrode and the resin molded part expand thermally, but the coefficient of thermal expansion of the resin material is much higher than that of the metal material. Because of their large size, the thermal expansion of the linear electrodes is minute within the thermal energy load range necessary for expansion and contraction of the multi-needle electrode recording head 6, and changes in the recording dot diameter hardly pose a problem. Further, since thermal expansion and contraction have a property of acting uniformly on the material, the pitch between the linear electrodes can be varied to be equal.

For example, suppose that the electrostatic recording paper 1 is in its most contracted state when the atmosphere near the electrostatic recording paper 1 has a temperature of 5°C and a humidity of 35°RH, and the head applied energy is set to 0°C. At this time, the minimum dots recorded on the multi-needle electrode recording pad 6 and the electrostatic recording paper 1 are 7'1. The result will be as shown in 5-(a) and 24-(a) in Figure 5.The temperature or humidity will change at the next arbitrary recording opportunity. Humidity 60%R
If it becomes H, the minimum dot record mentioned above will be extended to 24.
−Φ). Since the elongation of the electrostatic recording paper 1 at this time is about 0.5%, the head applied energy required to elongate the multi-needle electrode recording head 6 by an amount corresponding to this is about 10%.
When temperature is applied using a coil heater or ceramic heater, the resin molded part of the multi-needle electrode recording head 6 expands and the 5-
As shown in (b), overlapping recording consistent with 24-(bl can be made. Also, if the temperature or humidity changes further,
For example, temperature 30℃, humidity IW50%RH1 or temperature 5℃,
If the humidity becomes 75 degrees RH, the minimum dot record mentioned above will be further extended to 24-(c), but in this case, the multi-needle electrode recording head 6 will be thermally expanded in the same way to 5-(
By doing as in C), all overlapping recording can be performed.

Temperature/humidity detection unit 1 that detects temperature and humidity as described above
7 is provided in contact with or near the electrostatic recording paper 1, and this detection section 1
By comparing and determining the signal obtained in step 7 with the reference signal in the comparing section, the amount of expansion and contraction in the direction perpendicular to the conveying force direction of the electrostatic recording paper 1 is calculated, and the recording head heating circuit 23 is adjusted according to the amount. By applying thermal energy to expand and contract the multi-needle electrode recording head 5 to perform recording, positioning can be performed with accuracy with respect to the image before the temperature and humidity change.

Effects of the InventionAs is clear from the above description, the present invention provides a temperature/humidity detection means for detecting temperature and humidity near the multi-needle electrode recording head, and uses the information obtained by this detection means to perform recording. Since it is equipped with a correction means that calculates the amount of expansion and contraction in the direction perpendicular to the conveyance direction of the medium and expands and contracts the gutter according to the calculated amount, recording with any multi-needle electrode recording head is possible. Even if the recording medium expands or contracts due to changes in temperature or humidity, the multi-needle electrode recording head can be expanded or contracted in accordance with the amount of expansion or contraction, thereby easily overlapping the positions of images with high precision. is possible,
Moreover, since no mechanism such as a moving part is required, the structure is simple and can be realized at 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 schematic perspective view of the vicinity of the recording section of the color electrostatic recording device [1], and FIG. 3 is a temperature/humidity detection block diagram of the unit, signal correction unit, and heating voltage signal generation unit, fourth
The figure shows the correlation between temperature/humidity and head impression daily energy, Figure 5 shows the minimum tod recording recorded on any electrostatic recording paper and the state of the multi-needle electrode recording head at that time, and Figure 6 shows the state diagram of the multi-needle recording head. A schematic configuration diagram of a conventional color electrostatic recording device, FIG. 7 is a diagram of the conventional color electrostatic recording device viewed from below. 1... Electrostatic recording paper, 2... Winder, 3... Rewinder-14... Presser roller, 5... Multi-needle electrode Recording head, 6...
・・Static elimination bar, 7, 8, 9° 10・・・・Developer, 1
1... Squeeze, 12... Drive roller, 13... Press roller, 14... Drive source, 15 a, 15 b. V cyst mark, 16a. 16b... Mark detector, 17... Temperature/humidity detector, 18... Heating section, 19
・・・・・・Expansion correction section. Name of agent: Patent attorney Toshio Nakaichio wa Chikara・1 person f
Figure 32 Figure 3 Figure (“c) Shallow area

Claims (2)

[Claims] (1) A conveyance means for conveying a recording medium, and a plurality of multi-needle needles arranged along a conveyance path of the recording medium so as to sequentially record images of different colors on the recording medium conveyed by the conveyance means. A recording device consisting of an electrode recording head and a developing device, a detection device that is provided in contact with or near the recording medium and detects temperature and humidity, and information obtained by the detection device, A color electrostatic recording device comprising a correction means for calculating an amount of expansion and contraction in a right angle direction and expanding and contracting a multi-needle electrode recording head according to the calculated amount. (2) Claims that include a correction means that calculates the amount of expansion and contraction of the recording medium in the conveyance direction based on the information obtained by the detection means, and changes the recording cycle of the image signal of the recording head according to the calculated amount. 2. The color electrostatic recording device according to item 1.