JPS6120063A - Multicolor recording method - Google Patents

Abstract

PURPOSE:To record a polychromatic image with high resolution at a high speed by forming and developing latent images corresponding to respective colors on a photosensitive drum as a latent image formation medium repeatedly during one rotation of the photosensitive drum, and transferring toner images of many colors to a recording form by a transfer means at a time during the rotation. CONSTITUTION:The photosensitive drum 1 as the latent image formation medium has a photosensitive layer on its surface and rotate at a constant speed as shown by an arrow, and electrifier 21-23 supply uniformly a charge on the surface of the photosensitive layer. Exposure parts 31-33 form a latent image and irradiate the photosensitive layer on the photosensitive drum 1 with laser light corresponding to information such as characters to be recorded. One dot of laser light from those exposure parts 31-33 forms one picture element of information such as characters. Development parts 41-43 form the toner image of the latent image on the photosensitive layer by reversal development and one set of an electrifier exposure part, and development part forms a toner image of some color on the photosensitive layer. A transfer part 5 transfers the toner image formed on the photosensitive layer to the recording form 9 and is equipped wth a transfer corotron 51.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a multicolor recording method using an electrophotographic recording method, an electrostatic recording method, etc. The present invention relates to a method of performing high-resolution multicolor recording at high speed.

2. Description of the Related Art In recent years, with the diversification of information, there has been a demand for recording information in color, and electrophotographic recording and electrostatic recording are no exception, and various apparatuses and methods for multicolor recording have been proposed.

The electrophotographic recording method and the electrostatic recording method express and record information such as characters using a combination of a plurality of pixels.

That is, one character is represented by MXN donto matrices in which M pixels are arranged horizontally and N pixels are arranged vertically.

In the electrophotographic recording system, an exposure system using laser light is used as a latent image forming means, and one dot of this laser light corresponds to one pixel.

To record an image in color using such an electrophotographic recording method, in principle, a latent image corresponding to a first color is formed on a latent image medium such as a photosensitive tram, and then the latent image is transferred to a first color.
A toner image is obtained by developing with l-toner of color. This image forming process is sequentially repeated as many times as necessary to obtain a multicolor toner image, and is required to be capable of high resolution and high speed recording.

[Conventional technology]

The above-mentioned multicolor recording method, for example, using the electrophotographic recording method, is actually further divided into the following four methods.

That is, in the first method, one latent image forming means and a plurality of developing means with different toner colors are arranged around a photosensitive drum, which is a latent image forming medium, and during one rotation of the photosensitive drum, A toner image of one color is formed on a photosensitive drum 2, and the photosensitive drum is rotated multiple times to form a multicolored toner image, and then these multicolored l-toner images are transferred all at once to recording paper. It is something to do.

In the second method, one latent image forming means and a plurality of developing means with different toner colors are arranged around a photosensitive drum 1' serving as a latent image forming medium, and the photosensitive drum rotates once. During this process, a toner image of one color is formed on the rotating 1' ram, and the toner image is transferred to recording paper 1', and as the photosensitive drum rotates multiple times, l of different colors are sequentially formed on the recording paper. - A multicolor toner image is obtained on recording paper by transferring the toner image.

Furthermore, in the third method, +3 image forming means and developing means, which correspond to the number of colors used for recording, are arranged around a photosensitive drum, which is a latent image forming medium. A multicolor toner image is formed on the photosensitive drum, and during rotation of the photosensitive drum, the multicolor toner image is transferred onto recording paper.

Furthermore, in the fourth method, a plurality of latent image forming means and one stage of development are arranged around a photosensitive drum which is a latent image forming medium, and a plurality of dots corresponding to different colors are arranged to form one pixel. At the same time, during one rotation of the photosensitive drum, latent image formation and development corresponding to each color are repeated to form a multicolored toner image on the photosensitive drum, where one pixel is made up of a plurality of dots, and the multicolored toner image is formed on the photosensitive drum. The toner image is transferred all at once onto recording paper.

(Problems to be Solved by the Invention) However, in the first method and the second method, multicolor recording is performed on one sheet of recording paper by rotating the photosensitive drum multiple times. , it takes a long time to record and high-speed recording is difficult.

In particular, the second method is prone to color misregistration between toner images because the transfer is repeated multiple times to a single sheet of recording paper, and this requires high precision in positioning the recording paper.
This method has the drawback of requiring a highly accurate and expensive transfer mechanism.

On the other hand, in the third method, as many latent image forming means and developing means as the number of colors used for recording must be arranged along the rotational direction of the photoreceptor, there is a problem that the device configuration becomes large. .

Furthermore, in the fourth method, since one pixel is constructed using a plurality of color dots, there is a drawback that the resolution of the recorded image is reduced. In order to increase this resolution, the laser beam used as the latent image means must be made several times smaller than the conventional beam, which is accompanied by technical difficulties.

[Means for solving problems]

The present invention solves the above problems and provides high-resolution multicolor recording.
The purpose is to provide a multicolor recording method that can be performed at high speed, and the means is to develop a WI image formed on a latent image forming medium by means of adhering toner to perform multicolor recording. In a color recording method, a plurality of recording means including latent image formation and development are provided during the movement of the tS latent image forming medium during one recording period of the latent image forming medium, and a toner that develops a different color in each recording means is provided. on the latent image forming medium, the toner image consists of a toner image overlapping area made up of a plurality of superimposed toners, and a toner image non-overlapping area where the toner image is made up of a single toner. This is accomplished by the multicolor recording method according to the present invention, in which a multicolor toner image is formed and the multicolor tree image is transferred all at once onto a recording sheet.

[Effect]

That is, in the present invention, the latent image forming medium is formed by repeatedly forming and developing a latent image corresponding to each color on the photosensitive drum 1- which is the latent image forming medium during one rotation of the photosensitive drum. A multicolor toner image with a number of toner colors larger than the original number of toner colors is formed thereon, including a toner image overlapping area and a toner image non-overlapping area.

In addition, by transferring the multicolor toner image to the recording paper all at once by the transfer means during rotation, there is no color shift.
It becomes possible to rapidly record a high-resolution multicolor image in which one pixel is composed of color dots in which toner images of one color, two colors, three colors, etc. are superimposed.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an embodiment of a multicolor recording device that is applicable to the multicolor recording method according to the present invention, in which 1 is a photosensitive drum, 21 to 23 are chargers, 31 to 33 are exposure sections, 41～
43 is a developing section, 5 is a transfer section equipped with a transfer corotron 51, 6 is a static eliminating corotron, 7 is a brush cleaner, 8 is a static eliminating lamp, and 9 is a recording sheet.

A photosensitive drum 1 serving as a latent image forming medium has a photosensitive layer on its surface and rotates at a constant speed in the direction of the arrow. Charge m
+ to 23 are for uniformly supplying charges to the surface of the photosensitive layer. The exposure units 31 to 33 form latent images, and apply laser light to the photosensitive drum 1 according to information such as characters to be recorded.
The upper photosensitive layer is irradiated. The dots of laser light from each of the exposure sections 31 to 33 constitute one pixel of information such as characters.

The developing units 41 to 43 form l/toner images on the latent images formed on the photosensitive layer by reversal development.
For example, the developing section 41 forms a yellow toner image, the developing section 42 forms a magenta toner image, and the developing section 43 forms a cyan I toner image.

That is, a toner image of a certain color is formed on the photosensitive layer by these chargers, the exposing section, and the developing section.
It is attached.

The transfer unit 5 transfers the toner image formed on the photosensitive layer to a recording paper 9.
For this purpose, the transfer corotron 51
It is equipped with Further, the static eliminating corotron 6 electrostatically removes the residual toner that was not transferred in the transfer section 5 and the electric charge on the photosensitive layer, and the brush cleaner 7 removes the residual toner that was not transferred in the transfer section 5 from the surface of the photosensitive layer. The charge eliminating lamp 8 optically removes charges from the photosensitive layer.

The photosensitive drum 1 from which charges and residual toner have been removed by the above-described static elimination and toner removal mechanism is again subjected to a toner image forming process.

FIG. 2 is a block diagram showing the control circuits of the exposure units 31 to 33, in which 200 is a color decoding circuit, 300 is an exposure position correction circuit, 201 to 203 are pattern memories, 2
04 to 206 are scan control units, 207 to 209 are drive circuits, 220 to 222 are clock circuits, 213 to 215
is a laser diode, 216 to 218 are photodetectors, 31
) to 313 are rotating polygon mirrors (polygon mirrors).

Thus, the color decoding circuit 200 supplies dot patterns to the batanine memories 201 to 203 using a dot pattern signal Pd corresponding to information to be recorded and a color designation signal Cd designating the color of the signal to be recorded.

For example, when the color designation signal Cd is yellow, a dot pattern of 1° is supplied to the pattern memory 201, and a dot pattern of 0° is supplied to the pattern memories 202-203. Therefore, in this embodiment, a total of eight colors can be specified.

Further, the clock control circuits 220 to 222 generate a print clock corresponding to one dosodo (one pixel) in response to signal input from the corresponding photodetectors 216 to 218. Pattern memory Dot pattern from 201 to 203 is '1
When the dot pattern is 0, the drive circuits 207 to 209 cause the laser diodes 213 to 215 to emit light, and do not cause the laser diodes 213 to 215 to emit light when the dot pattern is 0.

The laser beams from the laser diodes 213 to 215 are deflected by rotating polygon mirrors 31) to 313 via an optical system, and scanned on the photosensitive drum 1 in a predetermined scanning direction. At the start of this scan, the laser beam is transmitted to the photodetectors 216 to 21.
8.

Next, an embodiment of the multicolor recording method according to the present invention will be described with reference to the potential distribution diagrams shown in FIGS. 3 to 1) and the time chart shown in FIG.

If the color of the image to be recorded is a mixed color of yellow, magenta, and cyan, dot patterns of 1° are all stored in the pattern memories 201 to 203.

On the other hand, the photosensitive layer of the photosensitive drum l is charged with a potential Vsl by the charger 21 as shown in FIG.
Perform initial charging.

Next, as the rotating polygon mirror 31) rotates, a start signal shown in FIG. 12 1a) is input to the clock control circuit 220. After a predetermined time, the dot pattern "1" from the pattern memory 201 is changed as shown in FIG. 12(b) by the clock signal corresponding to the dot output from the clock control circuit 220 as shown in FIG. 12(b). Drive circuit 20
7, the laser diode 213 of the exposure section 31 emits light, exposure corresponding to yellow is performed, and the potential is attenuated to approximately Ov as shown in FIG.
Form DY.

Next, the dot latent IDY is subjected to reversal development by the yellow developing device 41 located in the rotational direction of the photosensitive drum 1 to form a toner image TV corresponding to the yellow dot on the photosensitive drum 1 as shown in FIG. Form.

After that, the charger 22 changes the total surface potential of the photosensitive layer to
As shown in FIG. 6, recharging is performed to a potential νs2 higher than the initial charging potential Vsl. At this time, the portion where the toner image TV corresponding to the yellow dot is formed has a potential close to the recharging potential Vs2 due to the increase in the potential of the photosensitive layer immediately below.

Next, the photosensitive layer is exposed to light corresponding to magenta by light emission from the laser diode 214 of the exposure section 32 in response to the signal input shown in FIG. 12 (dl), and the potential is attenuated to approximately Oν as shown in FIG. A dot latent image DH is formed in which the potential of the toner image TV portion corresponding to the yellow dots already formed is attenuated.

The exposure at this time is delayed and controlled by the n-light position correction circuit 300 at the time when the toner IJjlTV corresponding to the already formed yellow dot reaches the exposure section 32.

Next, the dot latent image DH is subjected to reversal development by a magenta developing device 42 located in the rotational direction of the photosensitive drum 1, and a toner image TM corresponding to the magenta dots is formed on the photosensitive drum 1''2 as shown in FIG. A toner image is formed in which a toner image TM corresponding to a magenta dot is superimposed on a toner image TV corresponding to a yellow dot.

Thereafter, the entire surface potential of the photosensitive layer on the photosensitive drum 1 is recharged by the charger 23 to a potential Vs3 higher than the potential Vs2, as shown in FIG.

At this time, a toner image TV corresponding to the already formed yellow dot and a toner image T corresponding to the yellow dot
The potential of the portion where the toner image TM corresponding to the magenta dot is superimposed on V also rises to a potential close to the recharging potential Vs3 due to the potential of the photosensitive layer immediately below.

Subsequently, exposure corresponding to cyan is performed on the photosensitive layer by emitting light from the laser diode 215 of the exposure section 33 in response to the signal input shown in FIG. 12 (el), which is delayed and controlled by the exposure position correction circuit 300, A dot latent image DC whose potential is attenuated to approximately Ov, a toner image TV portion corresponding to the already formed yellow dot, a toner image TFI portion corresponding to the magenta dot, and a toner image corresponding to the yellow dot ↑ A dot latent image DC is formed in which the potential of the portion where the toner image TM corresponding to the magenta dot is superimposed on Y is attenuated.

Next, the dot latent image DC is reversely developed by a cyan developing device 43 located in the rotational direction of the photosensitive drum 1, and a toner image TC and a toner image corresponding to the cyan dots are formed on the photosensitive drum 1 as shown in FIG. A toner image in which a toner image TC corresponding to a cyan dot is superimposed on a toner image 7M corresponding to a magenta dot, a toner image TM corresponding to a magenta dot and a cyan dot on a toner image TV corresponding to a yellow dot. A toner image is formed in which toner images TC corresponding to TC are superimposed.

In this manner, while the photosensitive drum 1 rotates for a month, yellow, magenta, cyan, red due to a mixture of yellow and magenta, edges due to a mixture of yellow and cyan, and blue due to a mixture of magenta and cyan are formed on the photosensitive layer of the photosensitive drum 1. , black consisting of a mixture of yellow, magenta and cyan 7
Color dots] A toner image is obtained, and during its rotation, this toner image is electrostatically transferred all at once to the recording paper 9 in the transfer section 5, and is fixed in a fixing section (not shown) to make a permanent multicolor recording. Ru.

Therefore, compared to conventional methods, there is no color shift, and each pixel is composed of one color dot or dots of multiple colors, resulting in high resolution and high-speed multicolor recording. It can be carried out.

In addition, in the developing section 42 and 43 described in "1", the photosensitive drum 1
Develop toner images corresponding to dots of other colors without destroying the toner image TV corresponding to yellow dots or the toner image TM corresponding to magenta dots already formed on the photosensitive layer of need to be formed.

For this reason, the particle size of the carrier of the developer used in the developing section 42, 43 is set to 5 to 100 ttta, which is about the same as that of the toner.
A toner image is formed on the latent image of the photosensitive drum 1'' in the form of a flying i-toner by using a soft developing method, or by applying an alternating current bias with a frequency of about K1)z between the two. It is desirable to use a non-contact development method that allows

In addition, the reason why the surface potential of the photosensitive layer is raised each time the recharging performed after the initial charging is to obtain sufficient latent image strength even in the toner image area that has already been formed. The bias is also set proportionally higher.

Furthermore, in the above embodiment, when a toner image portion that has already been formed on the photosensitive layer is exposed to light to form a latent image on the photosensitive layer directly below it, if a dye is used as a coloring agent for the color toner, it is possible to Light is absorbed, but light in other wavelength ranges is attenuated but transmitted.

That is, for the yellow toner image layer, approximately 500n
Light with a wavelength longer than s is transmitted. Furthermore, light having a wavelength longer than approximately 600 nm is transmitted through the magenta toner image layer. Furthermore, since light with a long wavelength of 60On+o or more is transmitted through the layer portion where the yellow and magenta toner images overlap, as in the case of the magenta toner image,
As a light source for exposure, 1le- with an oscillation wavelength of 633n-
Ne gas laser or oscillation wavelength of 740 to 780 nm
By applying a semiconductor laser, it is possible to pass through the various color toner image layers and provide sufficient exposure to the photosensitive layer to form a latent image.

FIGS. 13 and 14 show another embodiment of the present invention. In this embodiment, the photosensitive layer immediately below the already formed toner image portion is easily exposed to light to form a latent image. For this purpose, a transparent base material 65 is used as the base material of the photosensitive drum, as shown in the partially enlarged cross-sectional view of FIG. A photosensitive drum 61 having the following configuration is applied.

For exposure of the photosensitive layer 67, the drum 6
The exposure means 62, 63, and 64 transmit the transparent substrate 65 and the transparent electrode 66 from the inside of the transparent substrate 65 and the transparent electrode 66.

According to the method described in 1, even if the color toner image layer becomes thick, there is no need to select an exposure light source with a long wavelength of 60 Onun or more in consideration of attenuation of the exposure amount, and the exposure light amount can be reduced. It also becomes easier to control. Therefore, it becomes possible to easily apply the required exposure to the photosensitive layer 67 immediately below the I/color image portion.

The illustrated exposure means 62, 63, and 64 may be a combination of a semiconductor laser, an optical system, and a rotating polygon mirror, or may be a small exposure device comprising an LεD array, a liquid crystal shank array, or the like.

〔Effect of the invention〕

As is clear from the above description, according to the multicolor recording method according to the present invention, one pixel is formed on the latent image forming medium during one rotation of the latent image forming medium as a monolayer color toner image. A mixed color toner image is formed by stacking a plurality of different color toner images, and is electrostatically transferred all at once to the recording paper during rotation, so there is no color shift and there is no color shift due to more colors than the number of toner colors. It becomes possible to perform high-resolution multicolor recording at high speed.

Therefore, it is extremely advantageous for use in multicolor recording such as this type of electrophotographic recording method or electrostatic recording method.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram showing an embodiment of a multicolor recording device applicable to the multicolor recording method according to the present invention, Fig. 2 is a block diagram showing a control circuit of the exposure section, and Figs. 3 to 1). The figure is a potential distribution diagram showing changes in the potential of the photosensitive layer in each recording process to explain one embodiment of the multicolor recording method of the present invention. Figure 12 is a signal waveform from the main part of the circuit in Figure 2. FIG. 13 is a schematic diagram of an apparatus configuration for explaining another embodiment of the multicolor recording method according to the present invention; FIG. 14 is a partially enlarged sectional view of the apparatus configuration of FIG. 13. In the figure, 1.61 is a photosensitive drum, 21 to 23 are chargers, 3
1 to 33 are exposure sections, 41 to 43 are development sections, 5 is a transfer section,
200 is a color decoding circuit, 300 is an exposure position correction circuit, 201 to 203 are pattern memories, 204 to 206
is a scan control unit, 207 to 209 are drive circuits, 220
-222 are clock circuits, 213-215 are laser diodes, 216-218 are photodetectors, 31)-313 are rotating polygon mirrors, 62, 63, and 64 are n-point means, 65 is a transparent base material, and 66 is transparent Electrodes and 67 indicate photosensitive layers, respectively. Fig. 3 Fig. 4r: IJ No. 51!1 Fig. 6 Fig. 9 Fig. 10 uL+ Fig. 1) Fig. 7 Y No. 8m! C Figure 12(e)

Claims (3)

[Claims] (1) In a multicolor recording method in which a latent image formed on a latent image forming medium is developed by a means for adhering toner to perform multicolor recording, the latent image is formed during one recording cycle of the latent image forming medium. A plurality of recording means including latent image formation and development are provided during the movement of the medium, and each recording means is arranged so as to supply toner of a different color, and a toner image is formed on the latent image forming medium. Forming a multicolor toner image consisting of a toner image superimposed region made of a plurality of superimposed toners and a toner image non-superimposed region made of a single toner, and combining the multicolor toner images at once. A multicolor recording method characterized by transferring onto recording paper. (2) The multicolor recording method according to claim (1), characterized in that the charging potential of the latent image forming medium is controlled to a higher potential each time latent image formation is repeated. (3) Claim No. 1, characterized in that the developing means is performed by a soft developing method or a non-contact developing method.
The multicolor recording method described in item 1).