JPS62235967A - Color image forming device - Google Patents

Abstract

PURPOSE:To simplify a device and to save power consumption by using a light source for image exposure as the uniform exposure of specific light in common. CONSTITUTION:An image exposing device 3 projects white light from an image exposing lamp to an original document O and makes the reflected light from the original document O incident upon the surface of a photosensitive body 1 electrostatically charged by an electrifier 2 as image exposure I. Consequently, a primary latent image obtained by color-decomposing the original document O is formed on the surface of the photosensitive body 1. Light projected from a lamp 4 is reflected by a dichroic mirror 7 and made incident upon the primary latent image surface of the photosensitive body 1 as blue light. An electrostatic latent image is formed by the exposure of the blue light. A developing device 9 develops the electrostatic latent image by using yellow toner. Then, light from the lamp 4 is reflected by a dichroic mirror 11 and green light is made incident upon the surface of the photosensitive body 1. A developing device 13 develops the formed electrostatic latent image by Magenta toner. Then, light from the lamp 4 is reflected by a dichroic mirror 15 and red light is made incident upon the surface of the photosensitive body 1. A developing device 17 develops the electrostatic latent image by cyanine toner.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a photoreceptor having an insulating surface layer and a distribution layer of color separation functional elements, which is charged and image-wise exposed to form a primary latent image.
Improvement of an apparatus for forming a color image on the insulating surface layer by repeatedly uniformly exposing a specific light to draw a color-separated electrostatic image from the primary latent image and developing the electrostatic image with a color toner of a specific light. Regarding.

[Background of the invention]

The present inventors previously completed various inventions regarding the color image forming apparatus as described above (Japanese Patent Application No. 59-1854).
No. 40, No. 59-187044, No. 60-22952
No. 4).

Conventional color image forming apparatuses require not only a light source for image exposure, but also multiple light sources for uniform exposure of specific light, or means for controlling their exposure amounts, making the apparatus large and complex. There was a problem that power consumption increased due to the light source.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned problem, and since the light of the light source for image exposure includes the entire spectrum of uniform exposure of a specific light, this invention can be used to create a light source for image exposure. This was achieved by focusing on the fact that it can be used commonly as a light source for uniform exposure of specific light.

That is, an object of the present invention is to provide a color image forming apparatus using a photoreceptor having a color separation function using a light source for imagewise exposure for uniform exposure of specific light.

[Structure of the invention]

In the present invention, after a photoreceptor having an insulating surface layer and a distribution layer of color separation functional elements is charged and imagewise exposed to form a primary latent image,
In the apparatus for forming a color image on the insulating surface layer by repeatedly performing uniform exposure with specific light to extract a color-separated electrostatic image from the primary latent image and developing the electrostatic image with a specific color toner, The color image forming apparatus is characterized in that a light source for image exposure is also used as a light source for uniform exposure of the specific light.

〔Example〕

The present invention will be explained below using illustrated examples.

FIG. 1 is a schematic configuration diagram showing an example of the image forming apparatus of the present invention;
FIG. 2 is a schematic partial cross-sectional view showing an example of the layer structure of the photoreceptor, and FIGS. 3 and 4 are partial plan views showing examples of the distribution shape of color separation functional elements in the color separation layer of the photoreceptor, respectively. FIG. 5 is an exposure operation timing chart, FIG. 6 is a potential change chart on the surface of the photoreceptor in the color image forming process, and FIG. 7 is a timing chart of the color image forming process.

The drum-shaped photoreceptor 1 in the image forming apparatus shown in FIG.
It has a layer structure as shown in FIG.

That is, a photoconductor layer 1b is provided on an electrosensitive substrate la, and a blue (B) color separation functional element is formed on the photoconductor layer 1b.

Color separation NI consisting of the distribution of green (G) and red (R) filters
This is a layer structure in which an insulating surface layer 1d having C is provided. The color separation layer IC is covered with a transparent protective layer 1e to prevent each filter from deteriorating due to ozone generated during image formation or the influence of the image exposure light source.

Regarding the distribution shape of the B, G, and R filters in color separation FJ1c, a mosaic distribution with l in the range of 10 to 200 μm as shown in Figures 3 and 4 is easy to form a distribution pattern. , is preferably used in terms of image resolution and color reproducibility.

A preferred method for forming the photoreceptor 1 as described above is to form a color separation layer IC having a distribution pattern as shown in FIGS. This method uses an insulating adhesive or adhesive to adhere onto the photoconductor layer lb. However, the present invention is not limited to this, and even if the insulating surface layer 1d having a color separation layer IC made of resin, dye, or pigment is formed by direct printing, photoresist, vapor deposition, etc. on the photoconductor layer lb, or the color The film having the decomposable layer IC may be provided on the photoconductor layer lb by mechanical fixing means instead of by adhesive. The distribution shape of the color separation functional elements is not limited to the examples shown in Figures 3 and 4, and the numbers of B, G, and R filters are not all equal. The number of G filters may be increased somewhat compared to the number of filters.

The charger 2 performs corona discharge on the surface of the photoreceptor 1 rotating in the direction of the arrow to uniformly charge the surface. This corona discharge is a positive discharge when the photoconductor layer 1b of the photoreceptor 1 is made of an n-type semiconductor such as cadmium sulfide, and a negative discharge when it is made of a p-type semiconductor such as selenium.

In the image exposure bag 23, the image exposure lamp 4 irradiates the original 0 with white light, and the charger 2 uses the reflected light from the original O as image exposure I.
The light is incident on the surface of the photoreceptor 1 which is charged by. The incidence of this image exposure (2) is performed by keeping the slit shutter 5 open while the image exposure lamp 4 scans and exposes the surface of the document O. This can be done by reciprocating the system or document table, or by passing the document 0 over the platen.In addition, in the case of a fixed optical system, the optical system is equipped with a light converging element array (trade name CellHock). ) can also be used.As the image exposure lamp 4, a halogen lamp, a fluorescent lamp having a panchromatic emission spectrum, B, G, R
A light source that combines fluorescent lamps with different spectra is used.

The charger 6 of the image exposure device 3 performs direct current or alternating current corona discharge of substantially opposite polarity to the corona discharge of the charger 2, at least while the image exposure light (1) is incident on the surface of the photoreceptor 1.

In the illustrated example, the charger 6 performs corona discharge at the incident position of the image exposure I, but this may also be performed immediately after the incident position.

As a result, a primary latent image is formed on the photoreceptor 1 by color-separating the original document 0, which does not function as an electrostatic image to be developed with toner.

The light from the image exposure lamp 4 is reflected by the microink mirror 7 onto the primary latent image forming surface of the photoreceptor 1, and uniformly enters the light as blue light. The incidence of this blue light is performed by opening the shutter 8 which also serves as a slit while at least the surface of the photoreceptor 1 on which the image exposure portion of the original is incident passes through the incident position of the blue light. As described above, it is preferable that the shutter 8 is of a type in which it opens only when the primary latent image forming surface passes through, in order to avoid contamination of the uniform exposure system by scattered toner, but it may be of a type in which it is opened only during the image forming process.

By uniformly exposing the blue light, the primary latent image is transferred to the photoreceptor 1.
A potential pattern, that is, an electrostatic image is generated on the surface of the B filter portion. Note that the amount of light for uniform exposure to maintain color balance is adjusted by adjusting the opening width of the slit. The surface of the shutter is coated black so as not to reflect light from the light source.

The developing device 9 develops the electrostatic image described above using yellow toner. As a result, a yellow toner image consisting of yellow toner adhering to the surface of the B filter portion of the photoreceptor 1 is formed. The developing device 9 includes a developing bag R, which will be described later.
Similarly, in Nos. 13 and 17, a layer of a -component or two-component developer is formed on the developing sleeve to a thickness that does not contact the surface of the photoreceptor 1, and toner is removed from the developer layer by using an alternating current bias as the development bias. A developing device that performs so-called contact development in which the toner is caused to fly and adhere to the photoreceptor 1 is preferably used. However, it is not limited to this.

The charger 10 is used to prevent color mixing due to the fact that even if the potential of the electrostatic image is lowered due to the adhesion of toner charged to the opposite polarity, the potential will remain at the potential at which the toner will adhere when development is performed again next time. , a photoreceptor 1 on which a yellow toner image is formed
A discharge similar to that of the charger 6 is applied to the 0 surface to smooth the surface potential to a potential at which toner does not adhere.

Only the green light from the image exposure lamp 4 is reflected by the gicroic mirror 11 onto the surface of the photoreceptor 1, which has been smoothed to a potential to which toner does not adhere, and the green light is uniformly incident on the surface of the photoreceptor 1.

The green light is incident at least while the surface of the photoreceptor 1, on which the image exposure ① of the original is incident, passes through the green light incident position.
This is done by opening the slit shutter 12.

Similarly to the shutter 8 described above, this may also be opened during the image forming process. A potential pattern is generated on the surface of the G filter portion of the photoreceptor 1 from the primary latent image by uniform exposure to green light.

The developing device I3 develops this potential pattern using magenta toner. As a result, a magenta toner image consisting of magenta toner adhered to the surface of the G filter portion of the photoreceptor 1 is formed.

Like the charger 10, the charger 14 smoothes the surface potential of the photoreceptor 1 on which the magenta toner image is formed.

Only the red light from the image exposure lamp 4 is reflected by the dichroic mirror 15 onto the surface of the photoreceptor 1 whose potential has been smoothed, so that the red light is uniformly incident. The incidence of this red light is also performed through the opening of the shutter 16 similar to the shutters 8 and 12. As a result, R of the photoreceptor 1 is changed from the primary latent image.
A potential pattern is created on the surface of the filter section. In addition, when two mirrors are used in the dedicated optical path of one specific light as in the illustrated example, the mirror closest to the shack 16 is not used as a dichroic mirror, but is used as a total reflection mirror.
It goes without saying that the far mirror may be a dichroic mirror.

A developing device 17 develops the electrostatic image formed by uniform exposure to red light with cyan toner.

As a result, a cyan toner image consisting of cyan toner adhered to the surface of the R filter portion of the photoreceptor 1 is formed.

As a result of the above, yellow, magenta,
A color image consisting of a cyan toner image is formed without color shift. An AC or DC corona discharger having a DC component and B, G, R of the photoreceptor 1 such as white light or infrared light.
The transfer pretreatment device 18 includes an exposure lamp that irradiates light that passes through a filter and makes the photoconductor layer 1b conductive.
The formed toner image is easily transferred onto the transfer material P fed by a paper feeding device (not shown), the transfer device 19 transfers the toner image onto the transfer material P, and the separator 20 transfers the toner image to the transfer material P. The transfer material P onto which the image has been transferred is separated from the photoreceptor 1. The separated transfer material P is sent to a fixing device (not shown), the toner image is fixed thereon, and the transfer material P is discharged outside the machine.

A pre-cleaning static eliminator 21 having the same configuration as the transfer pre-processing device 18 removes static electricity from the surface of the photoreceptor 1 to which a toner image has been transferred to facilitate the removal of toner remaining on the surface. The residual toner is removed from the surface of the photoreceptor 1 by means of a method such as the following. As a result, the photoreceptor 1
The surface returns to the state where the next image formation is performed again.

FIG. 5 shows an example of the timing of lighting of the image exposure lamp 4 and uniform exposure while the copy button is turned on and the copying process is performed. In this example, the image exposure lamp 4 is turned on in synchronization with document scanning after a certain period of time after the copy button is turned on, and turned off in synchronization with the closing of the shutter 16. The slit shutter 5 is opened immediately after the image exposure lamp 4 is turned on, and is closed by a signal when the image exposure lamp 4 finishes scanning exposure of the original size detected in advance by preliminary scanning. , and a shutter for uniform exposure of specific light 8°12
．． 16 by the timing corresponding to the distance between the incident position of the image exposure ■ and the incident position of the specific light, respectively, and the shutter 5
The opening time is the same as the opening time. In this way, by controlling the opening time of the shutters 5 and 8°12.16, it is possible to record a clear color image on the transfer material P without creating a black frame or the like. In this example,
Not only the corona discharge of the charger 2 but also the corona discharge of the charger 6 is performed only in the image forming section. That is, in order to reduce the deterioration of the photoreceptor 1, the discharge duration time of the chargers 2 and 6 and the operating time of other devices around the photoreceptor 1 are adjusted depending on the length of the photoreceptor l on which the image exposure I of the document 0 is incident. control the timing to match the surface of the surface. However, the present invention is not limited to this, and the charger 2 and the like may be turned on from the time when the copy button is turned on until the end of the copy button.

FIG. 6 shows the change in surface potential of the photoconductor 1 during the color image forming process when the photoconductor N1b of the photoconductor 1 is made of a p-type semiconductor such as a 5e-Te photoconductor.
. For primary charging from tl to tl, the surface of photoreceptor 1 is charged by charger 2.
The dark decay from time t1 to t2 is the change due to charge injection and dissipation of the injected charge until the primary charged surface reaches the charger 6, and the change from time t2 to t. Curves ■ and VD in secondary charging and image exposure
is the change in the parts corresponding to the bright and dark parts of the image exposure I while passing through the charger 6, and the uniform exposure from time t to t4 is the bright part potential due to the uniform exposure of blue light. vL and dark potential V. The development from time t4 to t is a change due to yellow toner adhesion by the developing device 9, and the recharging from time t to t is a change due to smoothing by the charger 10, time t6. The uniform exposure from t7 to t7 is a change due to uniform exposure to green light, the development from time t7 to t is a change due to adhesion of magenta toner by the developing device 12, and time t8. Recharging is a smoothing change by the charger 14, from time t to tl. The uniform exposure up to this point shows a change caused by uniform exposure to red light, and the development from time t1° to tll shows a change caused by the adhesion of cyan toner by the developing device 17. Here, the bright area potential VL is the original 0.
It shows the potential not only of the part where the bright part of the image exposure ■ is incident, but also of the part of the white part of the document table or platen cover where the image exposure I is incident, and maintains the potential at which toner does not adhere at least after time t3. There is almost no change. therefore,
By setting the opening timing of the shutter 8, 12, and 16 to a timing at which uniform exposure is incident on an area narrower by about O to Low on the outer periphery than the formed primary latent image forming area, a black frame etc. is generated on the transfer material P. Things disappear. In addition,
Since the potential of the part where the gradation part between the bright part and the dark part of the image exposure (2) is incident is a potential intermediate between the bright part potential vL and the dark part potential VD, an image with gradation can be obtained.

Although the color image forming apparatus shown in FIG. 1 uses a dichroic mirror for uniform exposure of specific light, it is possible to use a total reflection mirror and a transmission filter (for example, a glass filter or an interference filter) instead. Needless to say,
Color liquid crystals can also be used. Of course, only the shutter can be replaced with a liquid crystal. Further, although a color image is formed within one rotation of the photoreceptor 1, a three-color image may be formed within three rotations. In that case, a dichroic mirror such as a rotary switching type may be provided at the position of the dichroic mirror 7, and other dichroic mirrors may be omitted.

The color image forming apparatus of the present invention is not limited to one that forms color images using yellow, magenta, and cyan toners, but also applies to those that form color images using red, green, and blue toners, as well as those that form color images using red, green, and blue toners. The image forming apparatus may also include a device and form a color image with a four-color configuration, or may include only two developing devices.

The color image forming apparatus of the present invention can not only form a monochrome image made of one color toner, but also produce the monochrome image with the same image density and resolution as in an electrophotographic copying machine using a photoreceptor without a color separation layer. It can also be formed with.

The present invention provides an image forming apparatus that repeats charging for smoothing, full-surface exposure with specific light, and development after secondary charging, secondary charging, and image exposure, as described in Japanese Patent Application No. 60-229524. It can also be applied to In addition, a configuration in which the photoreceptor is provided with a filter on the side opposite to the side receiving corona discharge from a charger or the like and receives image exposure and uniform exposure from the filter side (Japanese Patent Application No. 59-199547) and other configurations (Patent Application Showa 5
9-198166, 198167゜201084)
It can also be applied to In addition, the photoconductive layer of the photoreceptor is not a single layer, but has a functionally separated structure consisting of a charge generation layer and a charge transfer layer (Japanese Patent Application No. 60-229524, No. 60-245).
No. 178), or one in which the photoreceptor has a color separation function in the photoconductive layer (Japanese Patent Application No. 59-201085, No. 60)
-245177) may be used.

Finally, specific examples of the present invention will be shown.

Example 1 A 60 μm thick 5e-Te photoconductor layer sensitive to long wavelengths was laminated on a 20 μm thick Ni substrate,
A photoreceptor with a color separation function, which is formed by adhering a 25-μm-thick film having color separation filters in the array pattern shown in FIG. 3, is used in the image forming apparatus shown in FIG. 1 to form images. Ta. The layer structure of the photoreceptor is as shown in FIG.

This image forming device is U-Bix3 manufactured by Konishiroku Photo Industry (11).
This is a modified version of the 300MR. During image formation, the linear velocity of the photoreceptor is set to 92+u/sec due to sensitivity and other considerations.

FIG. 7 shows a time chart for copying an A4 size (297 x 210 ++n) original in its original size. The time to charge and irradiate A4 size is 210÷92÷2
．． 3 (seconds). However, in order to prevent black frames from forming during image formation, the irradiation time of uniform exposure light is 2.25 (
seconds).

The irradiation time is adjusted by the opening time of the shutter 8.12.16. Recharger 10.14 and developer bag R9, 13,
The ON time of No. 17 is set to be slightly longer than 2.3 seconds. Further, when forming an image, the following must be satisfied: charging width by charger 2≦charging width by charger 6; charging width by chargers 2 and 6≧image exposure width.

The image exposure width is determined by the 0N-O of the shutter 5 which also serves as a slit, since the lamp 4 lights up after a certain period of time after the copy button is turned on.
Adjust with FF. In order to prevent the light from the lamp 4 from reflecting there and encroaching on the optical path for uniform exposure, the portion of the shutter 5 on the lamp 4 side is coated in black so as to absorb the light. With this image forming device, there is no color shift.
It was possible to obtain a copy original with good color reproducibility.

〔Effect of the invention〕

Since the color image forming apparatus of the present invention uses the light source for image exposure as the light source for uniform exposure of specific light, there is no need for multiple light sources for uniform exposure, simplifying the apparatus and reducing power consumption. This has the advantageous effects of being able to save money, reduce costs, downsize the device, and form color images without color shift.

Furthermore, if the color image forming apparatus of the present invention is a copying machine capable of variable magnification, it is necessary to adjust the light amount of image exposure or uniform exposure when changing the magnification. The amount of light for multiple exposures can also be adjusted, and the effect that conventional adjustments were made separately can now be made with just one adjustment.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an example of the image forming apparatus of the present invention;
FIG. 2 is a schematic partial cross-sectional view showing an example of the layer structure of the photoreceptor, and FIGS. 3 and 4 are partial plan views showing examples of the distribution shape of color separation functional elements in the color separation layer of the photoreceptor, respectively. FIG. 5 is an exposure operation timing chart, FIG. 6 is a potential change chart on the surface of the photoreceptor in the color image forming process, and FIG. 7 is a timing chart of the color image forming process. 1... Photoreceptor, 1a... Conductive substrate,
1b...Photoconductor layer, IC...Color separation layer, 1d
... Insulating surface layer, 2, 6.10.14... Charger, 3... Image exposure device, 4... Image exposure lamp, 5
...A shutter that doubles as a slit? , 11.15... Dichroic mirror, 8, 1
2.16. ...Slit-duty shutter, 9, 13.1
7...Developing device. Patent applicant: Konishiroku Photo Industry Co., Ltd. Figure f Figure 2 Figure 3 Figure 4 Figure 5 Figure 7 N

Claims (2)

[Claims] (1) After a photoreceptor having an insulating surface layer and a distribution layer of color separation functional elements is charged and imagewise exposed to form a primary latent image, a specific beam of light is used to draw out a color separation electrostatic image from the primary latent image. In the apparatus for forming a color image on the insulating surface layer by repeatedly performing uniform exposure and development of the electrostatic image with a specific color toner, the light source for the imagewise exposure is shared as the light source for the uniform exposure to the specific light. A color image forming apparatus characterized by: (2) The color image forming apparatus according to claim 1, wherein light from a light source for image exposure is used for uniform exposure of the specific light through a dichroic mirror and a shutter.