JP3119226B2 - Multicolor recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a multicolor recording apparatus using an electrophotographic recording method or an electrostatic recording method, and more particularly, to developing after exposure from the back of a latent image forming medium. The present invention relates to an apparatus configuration for performing multi-color printing by performing the above operation. In recent years, with the diversification of information, colorization of recorded information is being demanded,
Electrophotographic recording, electrostatic recording, and the like are no exception, and various apparatuses and methods for multicolor recording have been proposed. [0002] In an electrophotographic recording system or an electrostatic recording system, information such as characters is represented and recorded by a combination of a plurality of pixels. That is, one character is represented by an M × N dot matrix in which M pixels are arranged in the horizontal direction and N pixels are arranged in the vertical direction. In the electrophotographic recording method, 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. In order to perform color recording of an image by such an electrophotographic recording method, in principle, after forming a latent image corresponding to a first color on a latent image forming medium such as a photosensitive drum, the latent image is first recorded. To obtain a toner image. Such an image forming step is sequentially repeated as many times as the number of colors required to obtain a multicolor toner image. FIG. 14 is a schematic configuration diagram showing a multicolor recording apparatus using an electrophotographic recording system according to the prior art. Latent image forming hands 21 to 23, a plurality of developing means 41 to 43 having different toner colors around the photosensitive drum 1 rotating at a constant speed in the direction of the arrow, and a toner image formed on the photosensitive layer. The recording paper
9, a transfer section 5 for transferring the toner to the transfer layer 9, a static elimination corotron 6 for electrostatically removing the residual toner not transferred in the transfer section 5 and the charge in the photosensitive layer, and a photosensitive layer surface for transferring the residual toner not transferred in the transfer section 5 to the photosensitive layer. And a charge removing lamp 8 for optically removing charges from the photosensitive layer. [0004] The above-described multi-color recording apparatus using, for example, an electrophotographic recording system is actually roughly classified into the following four systems. That is, in the first method, one latent image forming means and a plurality of developing means having different toner colors are provided around a photosensitive drum serving as a latent image forming medium, and the photosensitive drum is rotated once. A single color toner image is formed on a photosensitive drum, the photosensitive drum is rotated a plurality of times to form a multicolor toner image, and then the multicolor toner images are collectively transferred to recording paper. is there. In the second method, one latent image forming means and a plurality of developing means having different toner colors are arranged around a photosensitive drum serving as a latent image forming medium. While rotating, a toner image of one color is formed on a rotating drum, and the toner image is transferred onto a recording sheet. By rotating the photosensitive drum a plurality of times, toner images of different colors are sequentially transferred onto the recording sheet. To obtain a multicolor toner image on recording paper. Further, in the third method, latent image forming means and developing means of the number of colors used for recording are arranged around a photosensitive drum which is a latent image forming medium, and the photosensitive drum rotates during one rotation. A multicolor toner image is formed on the photosensitive drum, and the multicolor toner image is collectively transferred to recording paper during rotation. Further, in the fourth method, a plurality of latent image forming means and a developing means are arranged around a photosensitive drum as a latent image forming medium, and a plurality of dots corresponding to different colors are arranged to form one pixel. While the photosensitive drum makes one rotation, the latent image formation and development corresponding to each color are repeated to form a multicolor toner image in which one pixel is formed by a plurality of dots on the photosensitive drum, and the multicolor toner image is formed. The images are collectively transferred to recording paper. In each of the above-mentioned methods, a latent image forming means is arranged around a photosensitive drum as a latent image forming medium, and a toner image portion already formed on a photosensitive layer is formed. When a latent image is formed on the photosensitive layer immediately below by exposing to light, if a dye is used as a colorant for the color toner,
Light in a specific wavelength region is absorbed, but light in other wavelength regions is attenuated but transmitted. That is, for the yellow toner image layer,
Light with a wavelength longer than about 500 NM is transmitted. Further, light having a wavelength longer than about 600 NM passes through the magenta toner image layer. Further, light having a long wavelength of 600 NM or more is transmitted to the layer portion where the yellow and magenta toner images overlap, as in the case of the magenta toner image. For this reason, it is necessary to control the amount of exposure light at the same time as applying an HE-NE gas laser having an oscillation wavelength of 633 NM or a semiconductor laser having an oscillation wavelength of 740 to 780 NM as an exposure light source. Accordingly, the present invention solves the above-mentioned problems, and exposes a photosensitive layer immediately below a toner image portion which has already been formed irrespective of the type of dye contained in the toner, that is, regardless of the type of toner, to easily form a latent image. It is an object of the present invention to provide a multi-color recording apparatus which is enabled. [0010] To achieve the above object,
In the present invention, the formation of a latent image having a photosensitive layer on a substrate
Medium and exposure for forming a latent image on the latent image forming medium
Different from the latent image formed on the latent image forming medium.
Developing units for supplying toners of different colors, and the latent image formation
A recording paper that prints a toner image consisting of multiple color toners on a medium
A multi-color recording device including
Therefore, it is common that the latent image forming medium has a light transmitting property.
The exposure unit is disposed on the substrate side of the latent image forming medium.
Corresponding to the number of the developing units with respect to the exposed layer.
A control unit for controlling first and second selective exposures;
The control unit performs the first exposure in the second exposure.
Including the area developed with the color toner of the latent image part formed
Exposure control to perform selective exposure
Image containing a portion where the color toners overlap in pixel units
New multi-characteristics that are controlled to collectively transfer
A color recording device is employed. That is, in the present invention,
An optical unit is disposed on the substrate side of the latent image forming medium;
First and second layers corresponding to the number of the developing sections
A control unit for controlling the selective exposure, and this control
The part is formed by the latent exposure formed by the first exposure during the second exposure.
Selective, including areas developed with color toner in the image area
Exposure control is performed to perform exposure. And multiple color toner
Collectively transfers toner images including the part where pixels overlap in pixel units
Is controlled. Therefore, the present invention provides a color toner image
Exposure light source taking into account attenuation of exposure even when the thickness of the layer becomes thicker
It is not necessary to select
You. Therefore, the required exposure can be performed on the photosensitive layer just below the toner image.
It can be easily applied to form a latent image. In other words, multiple
Easily provides the required exposure even with a toner layer of
Can be achieved. That is, in the present invention, after the photosensitive layer is exposed through the rear surface of a latent image forming medium having a photosensitive layer on a substrate, toners of different colors are developed and transferred to recording paper. It is possible to do. Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram showing one embodiment of a multicolor recording apparatus according to the present invention, wherein 61 is a photosensitive drum, 21 to 23 are chargers, 31 to 33 are exposure units, 41 to 43 are development units, and 5 Is a transfer section provided with a transfer corotron 51, 6 is a charge removing corotron, 7 is a brush cleaner, 8 is a charge removing lamp, and 9 is a recording sheet. A photosensitive drum 61 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. The chargers 21 to 23 uniformly supply charges to the surface of the photosensitive layer. The exposure units 62 to 64 form a latent image, and are located inside the photosensitive drum, that is, on the back side of the photosensitive layer as shown in the figure, and apply laser light on the photosensitive drum 61 according to information such as characters to be recorded. Irradiate the photosensitive layer. A latent image corresponding to one pixel of information such as characters is formed by one dot of the laser light from each of the exposure units 62 to 64. The developing units 41 to 43 form a toner image by reversal development on the latent image thus formed on the photosensitive layer. For example, the developing unit 41 forms a yellow toner image and the developing unit 42 Forms a magenta toner image, and
At 43, a cyan toner image is formed. That is, a toner image of a certain color is formed on the photosensitive layer by the set of the charger, the exposure unit, and the development unit. Three such units are provided along the rotation direction of the photosensitive drum 61. . The transfer section 5 is for transferring the toner image formed on the photosensitive layer to the recording paper 9 and includes a transfer corotron 51 for that purpose. The charge removing corotron 6 electrostatically removes the residual toner not transferred in the transfer section 5 and the charge of the photosensitive layer, and the brush cleaner 7 removes the residual toner not transferred in the transfer section 5 from the surface of the photosensitive layer. The static elimination lamp 8 is for optically removing the charge of the photosensitive layer. The photosensitive drum 61 from which the charge and the residual toner have been removed by the above-described charge elimination and toner elimination mechanism is again subjected to the toner image forming process. FIG. 2 is a partially enlarged sectional view of the photosensitive drum of FIG. A transparent substrate 65 is used as the substrate of the photosensitive drum, a transparent electrode 66 is provided on the upper surface, and a photosensitive drum 61 having a structure in which a photosensitive layer 67 made of Se, SeTe, or the like is further laminated is applied. The exposure of the photosensitive layer 67 is performed by exposing the transparent base material 65 and the transparent electrode 66 from the inside of the drum 61 by exposure means 62, 63, and 64. FIG. 3 is a block diagram showing control means for the exposure units 62 to 64, wherein 200 is a color decode circuit, 300 is an exposure position correction circuit, 201 to 203 are pattern memories, and 204
206 to 206 are scan control units, 207 to 209 are drive circuits, 220
222 to clock circuit, 213 to 215 laser diode, 216 to 218 photodetector, 311 to 313 rotating polygon mirror
(Polygon mirror). Thus, the color decode circuit 200 generates a dot pattern signal corresponding to the information to be recorded.
PD and color designation signal CD that designates the color to record the signal
Thus, the dot patterns are supplied to the pattern memories 201 to 203. 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 to 203. Therefore, in this embodiment, a total of eight colors including white can be designated. The clock control circuits 220 to 222 receive signals from the corresponding photodetectors 216 to 218 to
Create a print clock corresponding to a dot (1 pixel). When the dot patterns from the pattern memories 201 to 203 are "1", the driving circuits 207 to 209 are operated by the laser diodes 213 to 215.
And emit no light when the dot pattern is "0". The laser beams from the laser diodes 213 to 215 are deflected by rotating polygon mirrors 311 to 313 via an optical system, and are scanned on the photosensitive drum 1 in a predetermined scanning direction. At the start of the scanning, the laser beam is detected by the photodetectors 216 to 218. Next, the potential distribution diagrams of FIGS. 4 to 12 and FIG.
An embodiment of the multicolor recording method according to the present invention will be described with reference to a time chart of FIG. Assuming that the color of the image to be recorded is a mixed color of yellow, magenta, and cyan, a dot pattern of "1" is all recorded in the pattern memories 201 to 203. On the other hand, the photosensitive layer made of Se, SeTe or the like of the photosensitive drum 1 is initially charged to the potential VS1 by the charger 21 as shown in FIG. Next, a start signal shown in FIG. 13A is input to the clock control circuit 220 as the rotary polygon mirror 311 rotates. After a predetermined time T, the dot pattern "1" from the pattern memory 201 is driven as shown in FIG. 13C by the clock signal corresponding to the dot output from the clock control circuit 220 as shown in FIG. When input to the circuit 207, the laser diode 213 of the exposure unit 31 emits light, and exposure corresponding to yellow is performed to form a dot latent image DY whose potential has been attenuated to approximately 0 V as shown in FIG. Next, the dot latent image DY is subjected to reversal development by a yellow developing device 41 in the rotation direction of the photosensitive drum 1 so that the photosensitive drum 1 is rotated.
As shown in FIG. 6, a toner image TY corresponding to a yellow dot is formed. Thereafter, the charger 22 recharges the entire surface potential of the photosensitive layer to a potential VS2 higher than the initial charging potential VS1, as shown in FIG. At this time, the portion where the toner image TY corresponding to the yellow dot is formed has a potential close to the recharge potential VS2 due to the rise in the potential of the photosensitive layer immediately below. Next, exposure corresponding to magenta is performed on the photosensitive layer by the light emission of the laser diode 214 of the exposure section 32 in response to a signal input shown in FIG. 13D, and the potential is substantially 0 V as shown in FIG. The latent image DM in which the electric potential of the toner image TY portion is selectively attenuated is formed on the dot latent image DM which has been attenuated and the area where the yellow dot has already been developed. The exposure at this time is delayed and controlled by the exposure position correction circuit 300 during the time when the toner image TY corresponding to the already formed yellow dot reaches the exposure unit 32. Next, the dot latent image DM is subjected to reversal development by a magenta developing device 42 in the rotation direction of the photosensitive drum 1, and a toner image corresponding to the magenta dot is formed on the photosensitive drum 1 as shown in FIG. A toner image is formed by superimposing the TM and the toner image TM corresponding to the magenta dot vertically on the toner image TY corresponding to the yellow dot. Then, the entire surface potential of the photosensitive layer on the photosensitive drum 1 is charged by a charger.
With 23, recharging is performed to a potential VS3 higher than the potential VS2 as shown in FIG. At this time, the potential of the portion where the toner image TM corresponding to the magenta dot is vertically superimposed on the toner image TY corresponding to the already formed yellow dot and the toner image TY corresponding to the yellow dot is also immediately below the photosensitive layer. Rises to a potential close to the recharge potential VS3. Subsequently, an exposure position correcting circuit 30 is provided on the photosensitive layer.
The exposure corresponding to cyan is performed by the light emission of the laser diode 215 of the exposure unit 33 by the signal input shown in FIG. 13 (E) which is delay-controlled by 0, and the dot potential is attenuated to approximately 0 V as shown in FIG. Image DC and toner image TY part selectively over the area where yellow dots have already been developed, and toner image TM part selectively over the area where magenta dots have already been developed. A latent image DC in which the potential of the toner image TM portion is selectively attenuated is formed on the developed region in which the toner corresponding to the magenta dots is superimposed on the toner image TY. Next, the dot latent image DC is subjected to reversal development by a cyan developing device 43 in the rotation direction of the photosensitive drum 1 to form a toner image TC and a magenta image corresponding to the cyan dot on the photosensitive drum 1 as shown in FIG. A toner image TC corresponding to a cyan dot is superimposed on a toner image TM corresponding to a dot, a toner image TM corresponding to a magenta dot on a toner image TY corresponding to a yellow dot, and a cyan dot Is formed so that the toner image TC corresponding to. As described above, while the photosensitive drum 1 makes one rotation, yellow, magenta, cyan, red by mixing yellow and magenta, green by mixing yellow and cyan, and magenta and cyan on the photosensitive layer of the photosensitive drum 1. A dot toner image of seven colors consisting of blue, yellow, magenta, and cyan by mixing is obtained, and the toner image is collectively electrostatically transferred to the recording paper 9 in the transfer unit 5 during the rotation. The image is fixed by a fixing unit (not shown) to perform permanent multicolor recording. Therefore, according to the present invention, since the exposure can be performed from the back side of the latent image forming medium, even if the layer of the color toner image becomes thick, the exposure wavelength has a long wavelength of 600 nm or more in consideration of attenuation of the exposure amount. There is no need to select a light source for use, and the control of the amount of exposure light is simplified. Therefore, the photosensitive layer 67 immediately below the toner image portion
Can easily be given the required exposure to form a latent image. In the developing units 42 and 43, the toner image TY corresponding to the yellow dots already formed on the photosensitive layer of the photosensitive drum 1 or the toner image TM corresponding to the magenta dots is destroyed. Instead, it is necessary to develop and form a toner image corresponding to dots of other colors thereon. For this reason, the soft developing method in which the particle size of the carrier of the developer used in the developing units 42 and 43 is 5 to 100 μM, which is about the same as that of the toner, or an AC bias having a frequency between them of about 1 KHZ is applied thereon. It is desirable to use a non-contact development method in which a toner image is formed on the latent image on the photosensitive drum 1 by applying the toner so that the toner flies. The reason why the surface potential of the photosensitive layer is set to a high potential every time recharging is performed after the initial charging is to obtain a sufficient latent image intensity even in the toner image portion that has already been formed. Is also set proportionally higher. As the exposure means 62, 63 and 64 shown in the figure, a configuration in which a semiconductor laser is combined with an optical system and a rotating polygon mirror, or a small exposure apparatus comprising an LED array, a liquid crystal shutter array, etc. can be used. . According to the multicolor recording apparatus of the present invention, since exposure can be performed from the back of the latent image forming medium, it is not necessary to select a light source having a special wavelength as a light source of the exposure unit. In addition, it is easy to control the amount of exposure, and it is not necessary to consider the transparency of the color toner. Therefore, the present invention is extremely advantageous when applied to multicolor recording such as this type of electrophotographic recording system or electrostatic recording system.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram showing one embodiment of a multicolor recording apparatus according to the present invention; FIG. 2 is an enlarged cross-sectional view of the photosensitive drum of FIG. 1; FIG. 4 is a block diagram showing a control circuit; FIG. 4 is a potential distribution diagram showing a change in the potential of the photosensitive layer in each recording process; FIG. 5 is a potential distribution diagram showing a change in the potential of the photosensitive layer in each recording process; FIG. 7 is a potential distribution diagram showing a change in the potential of the photosensitive layer in each recording process; FIG. 7 is a potential distribution diagram showing a change in the potential of the photosensitive layer in each recording process; FIG. 9 is a potential distribution diagram showing a change in the potential of the photosensitive layer in each recording process. FIG. 10 is a potential distribution diagram showing a change in the potential of the photosensitive layer in each recording process. An electric potential indicating a change in electric potential of the photosensitive layer in each recording step. FIG. 12 is a cloth diagram, FIG. 12 is a potential distribution diagram showing a change in potential of a photosensitive layer in each recording process, FIG. 13 is a time chart showing signal waveforms of the circuit in FIG. 3, and FIG. 1 is a schematic configuration diagram showing a multicolor recording apparatus according to a system. [Description of Signs] 1, 61 Photosensitive Drums 21, 22, 23 Exposure Units 41, 42, 43 Developing Unit 5 Transfer Unit 200 Color Decoding Circuit 300 Exposure Position Correction Circuits 201, 202, 203 Pattern Memory 204, 205, 206 Scan Control Units 207, 208, 209 Drive circuits 220, 221, 222 Clock circuits 213, 214, 215 Laser diodes 216, 217, 218 Photodetectors 311, 312, 313 Rotating polygon mirrors 62, 63, 64 Exposure means 65 Transparent substrate 66 Transparent electrode 67 Photosensitive layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-181066 (JP, A) JP-A-53-91743 (JP, A) JP-A-58-43470 (JP, A) 60658 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 13/01 G03G 15/01-15/01 117 G03G 15/04-15/04 120 B41J 2/44 G03G 15 / 05

Claims (1)

(57) [Claims] A latent image forming medium having a photosensitive layer on a substrate, an exposure section for forming a latent image on the latent image forming medium, and a latent image formed on the latent image forming medium. A multicolor recording apparatus comprising: a plurality of developing units for supplying toners of different colors; and a transfer unit for collectively transferring toner images composed of a plurality of color toners on the latent image forming medium to recording paper. The substrate of the latent image forming medium has a light transmitting property, the exposure unit is disposed on the side of the substrate of the latent image forming medium, and
A first and a second number corresponding to the number of the developing units with respect to the exposed layer.
And a control unit for controlling the second selective exposure.
The part is formed by the latent exposure formed by the first exposure during the second exposure.
Selective, including areas developed with color toner in the image area
Exposure control is performed to perform exposure, and multiple color toners are
Collectively transfers toner images including the part where pixels overlap in pixel units
A multi-color recording apparatus characterized in that the control is performed so that