JPS5895362A - Color printer - Google Patents

Abstract

PURPOSE:To obtain a color image which scarcely causes a color shift, by constituting so that each separated color image developed on each recording body is matched as to its image position on a carrying body, and is transferred and superposed. CONSTITUTION:In case when the number of color separation of color print is 3, three recording bodies 2a, 2b and 2c are provided. As for a photosensitive body obtained by applying a photoconductive material onto a conductive drum, scanning is executed from scanners 3a, 3b and 3c of a laser, which have been modulated by a color-separated signal, respectively, and it is developed by an electrophotographing method. In accordance with a color tone recorded by developing devices 6a, 6b and 6c, the development is executed by a toner of cyan, magenta and yellow, respectively. Also, in accordance with each recording body, chargers 4a, 4b and 4c, cleaners 7a, 7b and 7c, and chargers 5a, 5b and 5c are provided, and each recording body 2a, 2b and 2c is provided so as to contact with a rotary drum 8, at a position separated in the circumferential direction of the drum 8 which is a carrying body of a large diameter provided in the center of the inside part of a housing 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color printer such as a color laser printer or a color copier.

Generally, in a copying machine, etc., it is a good practice to repeatedly develop color-separated electrostatic images using toners corresponding to each color, and then transfer and combine them onto a single sheet of paper to form a color image. Are known. Furthermore, there is a method in which a color image is formed by performing the phenomenon multiple times on one blanket, and then this color image is transferred to a flexible material (Japanese Patent Publication No.
No. 209) is also known.

However, in these configurations, exposure and development are repeated multiple times on one photosensitive drum, so the speed required to develop one sheet is slow9, and toners of different colors cannot be used on the same photosensitive drum. In order to carry out development, it is necessary to sufficiently collect the residual toner, but this has been difficult. There are also known examples of using a belt-shaped photoreceptor (Utility Model 5).
6-5149), but in this case as well, in addition to the same drawbacks as mentioned above, since the belt-shaped photoreceptor is directly transferred to a medium such as paper wound on a drum multiple times, lifting of the medium, expansion and contraction, etc. This method has the disadvantage that the influence of color cannot be removed, resulting in misalignment of the positions of each color image, which deteriorates the quality of the image.

The present invention eliminates the drawbacks of the conventional example and provides a color printer that can produce color images at high speed and with little color shift.

The gist of the present invention is to have a plurality of recording bodies provided so that images of the separated colors are displayed on the surface corresponding to each separated color, and a moving transfer surface with which each of the plurality of recording bodies sequentially contacts. A color printer is provided, comprising one image carrier, and configured such that the separated color images developed on each of the recording bodies are transferred and superimposed on the carrier in image alignment.

The present invention will be described below based on embodiments shown in the drawings.

In FIG. 1, 1 is a housing, and 2a, 2b, and 2c are recording bodies. In this embodiment, a case is shown in which the number of color separations for color printing is three, and therefore the number of recording bodies is three. The recording medium is a photosensitive drum in which a photoconductor is coated on a conductive drum, and an image is recorded by scanning with a laser modulated by color-separated signals. 3a, 3
Reference numerals b and 3c indicate scanners for performing laser scanning on each of the recording bodies, and directs light from a laser light source (not shown) onto the recording bodies. The image recorded on the recording medium by Rade scanning is developed by electrophotography. 6a, 6b
, 6c are developing devices, which in this embodiment are cyan and magenta depending on the respective recorded color tones.

The electrostatic latent image on the recording medium is developed with yellow toner. 4
a, 4b, 4a are chargers corresponding to each recording medium, 7a, 7
Denoted by b and 7c are cleaners for cleaning residual toner on each recording medium after the image is transferred to a carrier 8, which will be described later, and 5a, 5b and 5c are chargers, respectively.

Each of the recording bodies 2a, 2b, and 2c comes into contact with a large-diameter carrier 8 (rotating drum in this example) at positions spaced apart in the circumferential direction of the large-diameter carrier 8 disposed at the center inside the housing 1. It is arranged to do so.

The color separation images developed on the recording medium are aligned on the carrier 8 so that there is no color shift, and are sequentially superimposed and transferred at the points where the recording body and the carrier come into contact. Transfer can be performed, for example, by electrostatic transfer.

The images superimposed and transferred onto the carrier 8 from the three recording bodies 2a, 2b, and 2e become color images. IO is a transfer drum that winds the recording medium (for example, transfer paper) sent from the tray 11 by about 180 degrees in the illustrated example, and transfers the color image formed on the carrier 8 to the point where the carrier 8 and the transfer drum IO come into contact. Transfer and record onto a recording medium.

The transferred recording medium is sent to the outside via a fixing device 12 and a discharge roller 13. Note that 9 is a cleaner provided so as to be in contact with the carrier 8.

In the above operation, the three recording bodies 2a and 2b.

In order to superimpose and transfer images while sequentially positioning them on the carrier 8 from 2c, for example, each recording body 2a,
The starting timing of each of the recording bodies 2a, 2b, 2a is set according to the arrangement relationship of the recording bodies 2b, 2c and the rotating speed of the carrier 8, so that the positions of images transferred from each recording body are matched. Bye.

FIG. 2 shows an embodiment in which the present invention is applied to a copying machine.

The basic arrangement of three recording bodies and one carrier in this example is the same as in the previous example, so the configuration of this example will be explained below in connection with the operation of the apparatus. shall be taken as a thing.

Reference numeral 21 denotes a housing, in which a document 38 is placed on a transparent moving table 37;
The moving table is moved in the direction of the arrow by known means (not shown).

22a, 22b, and 22c are recording bodies, and each independent lens 23a is mounted on the recording body.

The original 36 is projected at 23b and 23c. Although explanations of the illumination method for projection and the method of synchronizing the recording medium and the moving table will be omitted, they may be carried out in the same manner as in known copying machines.

Different color filters are attached to the lenses 23a, 23b, and 23c so that the images on each recording medium are color-separated images. The image on the recording medium is developed by the developing devices 26a and 2.
After being developed in steps 6b and 26e, the images are aligned and sequentially transferred onto the carrier 28. In this embodiment, the carrier is constructed in the form of a belt and is arranged to be driven around pulleys 35, 36.

The color images that are superimposed and transferred from each recording medium onto the carrier while being aligned sequentially are placed on a recording medium (for example, transfer paper) that is stored in the tray 31 and sent out in synchronization with the image position on the carrier. The image is transferred by the corona charger 30 at the position of the pulley 36. After the transfer, the recording medium is conveyed on the conveyor belt 34, fixed under pressure by the fixing device 32, and discharged by the discharge roller 33.

In addition, in FIG. 2, 24a, 24b, 24c are 6
- Mirrors 25a, 25b, 25c are chargers 27a.

Cleaners 27b and 27c are provided separately corresponding to each recording medium. 29 is a cleaner provided corresponding to the carrier 28.

According to the above configuration, color separated images are recorded on the number of recording bodies corresponding to the plurality of color separations.

After development, it is stably held within the housing and has little expansion, contraction, or deformation.
After being aligned and transferred onto a single carrier, the resulting superimposed color image is transferred onto the recording medium in one go, so unlike conventional paper, it expands and contracts due to environmental changes such as tension, humidity, and temperature. Compared to a method in which multiple transfers are made to a recording medium that is unstable in holding and conveying, it is possible to obtain high-quality color images without color shift, and since multiple recording media are used, one One tatami size of color images of each separated color can be continuously produced on the carrier, and a printer with high recording speed can be obtained. Furthermore, since a monochromatic image is developed on a recording medium that is limited by photosensitive materials, toner can be collected and reused after cleaning, and an operation called phenomenon can be applied to carriers on which multiple color toners are superimposed. Since it is not necessary, there are fewer restrictions on the material, and there are also benefits such as being able to select a material with a high transfer rate and advantageously selecting mechanical strength conditions.

[Brief explanation of the drawing]

Figure 1 is a diagram showing an embodiment of the color printer of the present invention configured as a laser beam printer and the carrier is shaped like a drum. Figure 2 is a diagram showing an embodiment of the color printer of the present invention configured as a color copying machine and the carrier shaped like a belt. It is a figure showing an example of an apparatus. l... Housing, 2a, 2b, 2cm recording medium, 3a, 3b, 3cm scanner, 4a, 4b, 4c, 5a, 5b, 5cm... Charger, 6
a, 6b, 6cm developer, 7a, 7b, 7cm cleaner, 8...Carrier, 9...Cleaner, 10
...Transfer drum, 11...Tray, 12...
・Fuser, 13... Ejection roller, 21.
...Housing, 22a, 22b, 22c...Recording body, 23a, 23b
, 23cm/projection lens, 24m,
2 4 b, 2 4 c
・-・ Mira -, 25a, 25b, 25c
m・-charger, 26 a, 26 b, 26
c...Developer, 27a, 27b, 27cm--Cleaner, 28...Carrier, 29...Cleaner, 30...Corona charger for transfer, 31...Tray, 32...Fixer, 33
... Discharge roller, 34 ... Conveyance belt, 3
5.36...Zorley, 37...Manuscript stand. 38...Manuscript. 9-

Claims (1)

[Claims] A plurality of recording bodies are provided so that images of the separated colors are developed on the surface corresponding to each of the separated colors, and one image carrier has a movable transfer surface with which each of the plurality of recording bodies sequentially contacts. What is claimed is: 1. A color printer, characterized in that the separated color images produced on each recording medium are transferred and superimposed on a carrier in image alignment.