JPS62223768A - Color image forming device - Google Patents

Abstract

PURPOSE:To rapidly record a multicolor image of high quality on the same recording body by forming an image having the largest image forming area by an electrophotographic recording part and forming other image by a heat transfer recording part. CONSTITUTION:In the heat transfer recording part 1, a recording signal voltage is applied from a recording signal generating circuit to a heat sensitive head 7 and required color ink is transferred to recording paper 3. Heads 7 in the recording part 1 are arranged by the number corresponding to the number of required colors and an image having a comparatively small image forming area is successively recorded on the same recording body with a prescribed color. Then, the paper 3 is carried to the electrophotographic recording part 2 and an image having the largest image forming area is recorded and fixed by a fixing machine 6. Thus, a multicolor image of high quality can be recorded at a high speed by properly using the heat transfer recording capable of easily coloring images by a small-sized device and the electrophotographic recording characterized by high speed and high quality in accordance with the size of an image forming area.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to an apparatus for forming a multicolor image consisting of a plurality of different colors on the same recording medium, and particularly relates to an apparatus for forming a multicolor image consisting of a plurality of different colors on the same recording medium. The present invention relates to a color image forming apparatus that forms multicolor images using a thermal transfer recording section and an electrophotographic recording section.

(Prior Art) The following two electrophotographic apparatuses that perform color recording are already known.

In other words, there are two types of devices: one that repeats charging, exposure, and development for each color and sequentially transfers it to a recording medium to form a color image, and the other that forms a multicolor toner image on a photoreceptor and transfers it to the recording medium all at once. It has been known.

In the former device, the transfer process is complicated, requiring a mesh-like transfer drum and a complicated paper conveyance mechanism. This has the disadvantage that the device becomes large and expensive.

In the latter device, there are problems such as the toner image previously attached to the photosensitive belt being disturbed or peeled off and mixed into the developing device when developing the second and subsequent colors, and problems such as the formation of latent images for the second and subsequent colors. Many problems remain, such as the need for recharging to equalize the surface potential of the photoreceptor before transferring, and this recharging imparts an electric charge to the toner, causing transfer defects.

On the other hand, thermal transfer recording devices have a relatively simple recording process, making it easy to downsize and colorize the device, and are superior to electrophotographic devices in terms of ease of maintenance. It had inherent drawbacks such as inferior image quality and slow recording speed compared to photographic devices.

(Problems to be Solved by the Invention) As described above, the conventional color measuring and forming apparatus has a problem in that it is not possible to record at high speed and produce 1q high-quality multicolor images.

The present invention has been made in view of the above-mentioned drawbacks of the conventional apparatus, and an object of the present invention is to provide a color image forming apparatus that can record at high speed and easily obtain high-quality multicolor images.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention forms a multicolor image consisting of 0 colors (n is an integer of 2 or more) on the same recording medium. The color image forming apparatus is provided with a thermal transfer recording section that forms images of the first color to the (n-1)th color, and an electrophotographic recording section that forms the image of the nth color.

(Function) Therefore, the thermal transfer recording unit forms images from the first color to the (n-1)th color, which has a smaller amount of recording, and
By forming colors using an electrophotographic recording section, it is possible to record at high speed and obtain a high quality multicolor image.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic sectional view showing one embodiment of the present invention.

This color image forming apparatus includes a thermal transfer recording section 1, an electrophotographic recording section 2, a paper cassette 4 and a feed roller 5 for supplying recording paper 3 to each recording section, and fixing the recording paper 3 on which a toner image has been transferred. It is composed of a fixed @ machine 6.

Roughly speaking, the thermal transfer recording unit 1 includes a thermal head 7 to which a recording signal voltage is applied from a recording signal generation circuit (not shown), a replaceable blue ink sheet 8, and a platen 9 that presses the recording paper 3 against the thermal head 7. It is composed of.

The electrophotographic recording unit 2 also includes a photoreceptor drum 10 on which an electrostatic latent image is formed, a charging charger 11 that uniformly charges the photoreceptor drum 10, and a charger 11 that forms an electrostatic latent image on the photoreceptor drum 10. The exposure section 12 and the electrostatic latent image are supplied with
- A developing section 13 that forms a lunar image, a transfer charger 14 that transfers this toner image onto the recording paper 3, a cleaner part 15 that removes residual toner on the photoreceptor drum 9, and a part that neutralizes the photoreceptor drum 10. It is composed of a static eliminator 16.

Next, the operation of this color image forming apparatus will be explained.

First, the recording paper 3 is sent from the paper cassette 4 toward the thermal transfer recording section 1 by the feed roller 5, and in the thermal transfer recording section 1, a recording signal voltage is sent from the recording signal generation circuit to the thermal head 7, and blue ink is applied to the recording paper 3. transcribed.

Next, the recording paper 3 is conveyed at a constant speed to the electrophotographic recording section 2 at the same time as the blue image is printed.

On the other hand, in the electrophotographic recording section 2, the photosensitive drum 10 is uniformly charged by the charging charger 11, and is irradiated with light by the exposure section 12, so that an electrostatic latent image is formed on the surface.

As this exposure method, a method using a modulated laser beam, a method in which a liquid crystal shutter array is opened and closed by a signal voltage to expose it in a pattern, a method in which a light emitting diode array is blinked by a signal voltage, etc. can be used.

The electrostatic latent image thus formed is visualized with black toner in the developing section 13 and transferred onto the recording paper 3 by the transfer charger 14.

This transferred black image is fixed by a fixing device 6,
Formation of a blue and black two-color image is completed.

Generally, office documents handled in offices do not need to be full-color images, but only have lines, underlines, or areas to be emphasized that are marked with blue or red ridges.
In most cases, it is sufficient to simply perform a

Recording of relatively simple patterns such as ruled lines requires 16 to 2
Even a thermal transfer recording method of about 4 dots per dot is practically acceptable.

Furthermore, for complex patterns such as letters, the low resolution of the thermal transfer method can be compensated for by increasing the size of the letters. Increasing the font size also makes the font more emphasized, and is not a particularly big problem.

As described above, this embodiment is effective for printing a black image mainly with ruled lines or only a portion to be emphasized in blue, red, or the like.

Furthermore, there is no need for any complicated paper conveyance technology, transfer drum, or color mixing prevention technology required in conventional color image forming apparatuses.

In this embodiment, the thermal transfer recording section is only blue, but it is also possible to replace this ink sheet with another ink sheet, and a plurality of similar recording heads can be arranged along the paper conveyance path. By doing so, it is also possible to roughly increase the number of colors without impairing the recording speed.

In addition to this embodiment, the electrophotographic recording section may employ an electrostatic recording method in which a dielectric drum is used and an electrostatic latent image is formed on the drum by an electrostatic recording head.

[Effects of the Invention] As explained above, according to the present invention, the image of the color with the largest image forming area among the 0-color images is formed by the electrophotographic recording section, and the image with the smaller image forming area is formed by the thermal transfer recording section. Therefore, it is possible to obtain almost the same recording speed as the electrophotographic method without deteriorating image quality.

[Brief explanation of drawings]

The drawing is a sectional view schematically showing an embodiment of the present invention.

Claims (5)

[Claims] (1) In a color image forming apparatus that forms multicolor images of n colors (n is an integer of 2 or more) on the same recording medium, a thermal transfer recording section that forms images of the first color to the n-1th color. and an electrophotographic recording section for forming an n-th color image. (2) The color image forming apparatus according to claim 1, wherein the electrophotographic recording section forms a black image. (3) The electrophotographic recording unit forms an electrostatic latent image on the photoreceptor using a modulated laser beam.
The color image forming apparatus described in 1. (4) The color image forming apparatus according to claim 1, wherein the electrophotographic recording section forms an electrostatic latent image by irradiating a photoreceptor with a light beam modulated by opening and closing a liquid crystal shutter. (5) The color image forming apparatus according to claim 1, wherein the electrophotographic recording section forms an electrostatic latent image on the photoreceptor by blinking a light emitting diode.