JPS60225174A - Two-color electrophotographic copying method - Google Patents

Abstract

PURPOSE:To obtain a black-and-red two-color copy of superior picture quality by forming a red separated electrostatic latent image of an original on the 2nd N type photosensitive body and developing with positive black toner, superposing and transferring the black toner image on and to a red toner image which is fixed previously, and fixing the obtained black-and-red toner image. CONSTITUTION:The N type photosensitive drum 3 which is charged negatively by an electrostatic charger 12 is irradiated with a light image which is reflected by a half-mirror 24, reflected by mirrors 22 and 23, and passed through a red separation filter 36 to form a negatively charged red separated electrostatic latnet image thereupon. This electrostatic latent image is developed by the developing roller 7 of a developing device 5 which contains positive black toner to obtain the black toner image. When a form on which a red toner image is fixed previously reaches a transfer and separation charger 11, the black toner image is transferred onto the red toner image synchronously, passed through form conveyor belt 29 and 30, and fixed completely by fixing devices 31 and 32 to obtain the desired black-and-red two-color copy.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a two-color color 'FK photo first copying method, more specifically, the red part of the V3 original is red and the other parts u>S' The present invention relates to a two-color electrophotographic copying method capable of obtaining R-color copies.

2. Description of the Related Art A two-color electrophotographic copying method has already been proposed in which a specific color in a document is reproduced in a color other than all black. However, with the methods proposed so far, there are many technical problems that have not been solved, such as insufficient color density of each copy of the two-color power or color mixing, and it has not been commercialized in the end. The current situation is that this has not yet been achieved.

The biggest technical reason for these problems is 1. For example, when making a two-color copy of red and black, the contrast of one image of the electrostatic amount of the red part of the original (the electrostatic amount is a 7-position difference) is the black color. This is due to the fact that the contrast of the electrostatic m1 image is extremely poor compared to the contrast of the electrostatic m1 image in the area, and for this reason, the red electrostatic latent residue and the black electrostatic latent f image are all printed on the same photoreceptor drum of the Elko photographic printer. There is a Ks filling to be formed, and these electrostatic charges are 1 elephant? It was extremely difficult to maintain stability and obtain good color copies.

OBJECTS OF THE INVENTION The purpose of the present invention is to provide a complete two-color electrophotographic copying method that eliminates all the drawbacks of the conventional two-color electrophotographic copying method as described above and can perform red and black two-color copies with excellent image quality. 4)
That's true. Another object of the present invention is to separately provide a photoconductor for forming the red part of the original into a 1-ivory shape and a photoconductor for forming the non-red part of the document, and to SUMMARY OF THE INVENTION It is an object of the present invention to provide a two-color electrophotographic copying method capable of producing two-color copies of red and black with uniform image density without causing color mixture during subsequent transfer. The object of the present invention is to provide a two-color electrophotographic copying method capable of forming electrostatic latent images of red and non-red portions of an original E by one exposure.

Structure of the Invention The above object of the present invention is to convert a cyan color-separated electrostatic latent image of an original into P
A red-resolved electrostatic latent image of the original is formed on the 1N photoreceptor.
forming an electrostatic latent image on a P-type photoreceptor, and bringing these electrostatic latent images into superimposed contact to form an electrostatic latent image of the red portion of the original on the P-type photoreceptor;
This is developed with a red toner of negative polarity, transferred to paper, and prefixed.Meanwhile, a red resolved electrostatic latent image of the original is formed on a second N-type photoreceptor, and this is developed with a black toner of positive polarity. , a black toner image is superimposed and transferred onto the pre-fixed red toner image,
2, characterized in that the obtained red and black toner images are fixed.
Color is achieved by a color superimposed photocopying method.

The method of the present invention will be explained in more detail with reference to the drawings.

In Fig. 1, fllVi is a photoreceptor drum made of a P-type photoreceptor, and (2) is a photoreceptor drum made of an N-type photoreceptor, and these drums are in contact with each other and rotate in the direction of the arrow. . The -, I[l photoreceptor drum is for forming an electrostatic latent image of only the red portion of the original on the P-type photoreceptor. First half mirror C24) '117 and reflected by the half mirror (C) cyan color filter mill)
The light image that has completely passed through is P, which is positively charged by the charger (8).
The photoreceptor drum +11 is irradiated with light, and a positively charged cyan color separation electrostatic latent image is entirely formed thereon.

At the same time, the half mirror (251 kA passing mirror (21) reflects the light image that has passed through the red filter (39) and is irradiated onto the N-type photoreceptor drum +21, which is negatively charged by the charger (9). Forms a charged red-resolved electrostatic latent image.

P photosensitive drum (1) and N type photosensitive drum (2)
are rotating in contact with each other, and the cyan color-separated electrostatic latent image and the red-separated electrostatic latent image formed on each drum overlap, and the cyan color-separated electrostatic latent image on the P sensitizer drum (1) causes Unnecessary portions of the red-resolved electrostatic latent image are electrically neutralized and erased, and a positively charged electrostatic latent image of the red portion of the original is obtained on the P-type photoreceptor drum. This electrostatic latent image is developed by the developing roller (6) trap of the developing device (4) containing the negative polarity red toner bag, and the resulting red toner image is transferred to the R- The image is transferred onto a sheet of paper sent from the part tray (toward), and is preliminarily fixed in a pre-fixing device C37) on a paper conveying belt. On the other hand, the light reflected by the half mirror C (22), reflected by (c) and completely passed through the red color separation filter (g) is the N-type photoreceptor drum (3) which is negatively charged by the charger (1). ) to form a negatively charged red-resolved electrostatic latent image on it.This electrostatic latent image is a phenomenon of the developing device (5) in which the black toner of the positive electrodes t and h is collected. It is developed by roller (7) K, and a black toner image is obtained.When the paper on which the red toner image has been pre-carried first reaches the transfer/separation charger Ql), the black toner image becomes red toner. synchronously transferred onto the image,
The paper is conveyed via route @ (to) to the fixing device (31, 32) K.
The desired red/black two-color copy can be obtained with more complete fixation. The positively charged electrostatic latent image formed on the P photosensitive drum (1) is developed with negatively polarized red toner and transferred to paper, while the electrostatic latent image formed on the N type photosensitive drum (3) is A black toner image obtained by developing a negatively charged electrostatic latent image with a positively charged black toner When transferring the black toner image onto a red toner image on gold paper, the black toner image is positively charged, so the transfer and
The transfer electric field of the separation charger 01) has the same negative polarity as the red toner image.

Therefore, the red toner image on the paper must be prefixed by the prefixer C371 to completely prevent the red toner image from being disturbed by the transfer electric field of the charger αB due to scattering of a portion of the red toner.

The principle of the present invention will be explained with reference to FIG. Figure 2 (1)
indicates a state in which the P-type photoreceptor (A) is positively and uniformly charged. Next, this photoreceptor (A)K is used for the original shown in FIG. 2 (7) (here, W: white, R: red, a: green, B: blue).

Cyan color separation, M: magenta, Y: yellow, and BL: black are shown in Figure 2. Figure 2 (I') shows a uniformly negatively charged N-type photoreceptor (shown in Bl'), which was subjected to red separation image exposure of the original, and the image shown in Figure 2 (n') K was obtained. A red-resolved electrostatic latent image with a potential pattern is obtained.Next, the cyan-resolved electrostatic latent image on the photoreceptor (N) is superimposed on the red-resolved electrostatic latent image on the photoreceptor (Bl). The images are brought into contact and electrically neutralized to form a red-resolved electrostatic latent image on the photoreceptor (At) as shown in Figure 2 (to).The surface potential of this red-resolved electrostatic latent image is Photoreceptor (contains about 60% of the potential of the cyan color separation electrostatic latent image formed on Al, and when developed with negative polarity red toner, a red image with sufficient density can be obtained (second
Figure (5)). On the other hand, as shown in Fig. 2 (I"), an N-type photoconductor (C) which was uniformly charged under negative pressure was subjected to red separation image exposure of the K original, and the potential shown in Fig. 2 (ff') K was carried out. The red-resolved electrostatic latent image formed by Nomiturn gold is developed with gold black toner to obtain a black toner image (Figure 2 (*')).The red toner image on the photoreceptor is transferred onto paper. The black toner image on the photoconductor (C1) is transferred and fixed in a superimposed manner onto the photoreceptor (C1), and a desired two-color red/black color copy (second k
l(V)) is obtained.

An example of implementing the present invention will be described below. In Figure 1, m is P8+! The photoreceptor is a photoreceptor drum used to form a red-resolved electrostatic latent image of the original.
A) It is made by fully doping l'tsgKAs, I, etc. +2) lf, N type photoreceptor 03).

This is a photoreceptor drum for completely forming a cyan-resolved electrostatic latent image which has opposite polarity and a complementary color relationship to the red-resolved electrostatic latent image on the P-type line light body fAJ, and this photoreceptor (B) is a PVK- TN
It is made of F-based organic photoconductive N-type photoreceptor. (3) is a photoreceptor drum made of an N-type photoreceptor (C1) for obtaining an all-black image except for the red portion of the original. A positive red-resolved electrostatic latent image formed on the photoreceptor drum fil. The negative red electrostatic latent image formed on the photoreceptor (2) is transferred from the developing device (4) containing negative polarity red toner, and the developing device (5) containing positive polarity black toner ( ), and the red toner *' obtained from photosensitive drum 9 (1) is transferred to the paper sent from tray c (infrared F using radiant heat τ)! Fixing device C3 consisting of a heater
7+ causes the prefix (Hit constant λ centering 1).The red toner image and residual charge on the paper disappear due to the heat during this prefixing.

Transfer of the subsequent black toner image is advantageously <j. The paper carrying this pre-fixed red toner GHr reaches the photoreceptor drum (3), and the black toner image on the photoreceptor drum (3), which is rotating at the same time as the paper moves, appears on the paper. The red toner 7 is pre-fixed and transferred in a superimposed manner onto the R image, and then the pressure roller C31) and the heating roller C (7+
A fixing device consisting of (the desired red and black 2
A color copy is obtained. Photoreceptor (N.

(Bl A/Yohi (QrL panchromatic type, photoreceptor (N l'kh'& in case of light, cyan color filter A38A (via Kodak company network, photoreceptor fBl;
The base νC for deep exposure uses a red branch filter 25 (manufactured by Kodak) and 1% of the original source of the photoreceptor tC+.
In the case of monthly 1 or photoconductor tBl and interpolation filter,
4625/ and c respectively. The edge of the exposure frame is formed once every t of these exposures, so that a color-separated electrostatic latent image corresponding to each photoreceptor trim is formed at the same time. That is, as shown in FIG.
The emitted light is reflected from the mirror (19, 20) K and passes through the lens system (one pole) - the mirror C! 4), some of the light passes through the half-mirror f24)ffi and reaches the next half-mirror.
It is reflected by the no-f mirror (c) and the cyan color filter Ω
A cyan color separation electrostatic column 51. The other part of the light passes through the No.F Mirror C powder and forms a red-resolved electrostatic latent image on the CN-type photosensitive drum (2) through a red filter C351. on the other hand.

Half mirror - +2 (1 light reflected by + is reflected by mirror (22
, 23), a red-resolved electrostatic latent image is entirely formed on the N-type photoreceptor drum (1+) through a reflective red filter 4'6.

The optical path length from the lens system (8) to the surface of each photoreceptor drum is the same, and the electrostatic latent image on photoreceptor drum 1 and the electrostatic latent image on photoreceptor drum (2) are When both drums rotate in contact, they form exactly the same shape as the husband.
When the paper on which the color toner image (7) has been transferred to the P-type photoconductor drum (11-2) reaches the N-type photoconductor drum 8 (3) after being prefixed by the pre-fixing unit c3 force, the paper is The pre-fixed red toner image on the photosensitive drum (3) is overlapped with the black toner (drops 19') on the photosensitive drum (3).

Therefore, a desired tIL image is simultaneously formed on each photosensitive drum, and the red image and transfer and the black image are developed and superimposedly transferred while the paper continues to be conveyed. A copying process can be carried out in which one copy is obtained per revolution of the drum.

Effects of the Invention According to the present invention, an original color separation image of cyan light, which is a complementary color of red light, is formed on the P-type photoreceptor drum-F at the same time. ? A latent image is formed on the first N-type photoreceptor drum, and after superimposing both electrostatic images, it is developed with red toner, transferred to paper, pre-fixed, and red-colored toner 1 is formed.
Meanwhile, at the same time, the red color decomposition electrostatic latent (intaglio formation) of the original was made on the second N-type photoreceptor drum, and the black toner was applied to the original.
4: Make black toner e1, do you have a spare? 7 toss tl,
fc red t (1 toner image is combined with the toner image, transferred, and fixed to obtain a two-color copy of red and black, so the red part has sufficient color density by the - times of operation, and the surroundings of the black part are There is no red ghost on the image, and there is no color mixing between red toner and black toner, making it possible to obtain clear two-color copies of red and black.The red toner image on the first N-type photoreceptor drum is pre-fixed. During pre-fixing, the red toner image is well preserved on the paper and the charge on the red toner and the paper is removed, and the black toner image is superimposed on the red toner image. The transfer is performed flawlessly, resulting in high-quality red and black two-color copies.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the equipment qJ for carrying out the method of the present invention;
Figure 2 fi1. +III, (In), OVL (V) -t
VI), (1'). (n/)-(1', (II'') and (III'') are diagrams for explaining the present invention in detail. Reference numbers in the figure: l, 2.3...photosensitive drum, 4 ,5...
・fA imager-8, 9, 1, 2... Band 14i, instrument-1,
0,11...Transfer/separation band is squared, 13,14.1
5...Static elimination lamp-16, 17...Cleaning plate 9.18---L/7 series-19, 20, 21,
22゜23...Mirror, 24.25...Half mirror-126...Haratsudai glass, 27...Fukiko Unzu,
28°z9. :>o...paper conveyance belt, 31...
Pressure roller, 32...NoNro, l-Rocy, 33
...R-part tray, 311, 35.3G...color filter. Figure 1-I: 1st procedure amendment document August 1980 and (1 1981 Umochi Permission No. 81061 2 Name of the invention 2-color color 1. Child copy 1'j substitute copy method 3 Person making the amendment l1lI'l and IV11 〒υ [,''i:ca Masterpiece (549)-1 Sat U Lonox stock d17 or Leap Hill internal mail (Ri-kii-',, lj box η49 month glory ffFli affairs Tokoro'l (revised, (581) 9601 (Il, 12)),
)+l15911:July 111-1(Shipping II:lli
:11I59(1"7, 'l51t 6 The number of inventions increases due to positive 0 1) O'JJ+ttll;?l+7th jt6 line question, r(
1') Correct J to r(1-a)J. 0 Same 7th line 5th line, ``(■' month is corrected as ``(n-a) J. 0 Same 7th line 6th line from the bottom, r(1'') J becomes r(1-b)
Correct it with J. 0 Same page 7th line, 4th line from the bottom, change "(■'U" to r(It-b
Correct it with l. 0 Same page 7th line, 1st line from the bottom, r(one) as r('I-b)
Correct it with J. 2) 0 Specification, page 12, line 6 from the bottom, r(one) is replaced by r(
1-a)'' ~ 0 Same page 12th line, 5th line from the bottom, r(It')J is corrected to r(II
6 ) Correct the division number in Figure 2 of the drawings as if it were not provided in the attached sheet.

Claims (1)

[Claims] A cyan color separation electrostatic latent image of the original is formed on the 2P type photoreceptor, and at the same time, a red separation electrostatic latent image of the original is formed on the No. 1N type photoreceptor, and these electrostatic layers are brought into superimposed contact. The electrostatic charge of the red part of the original is formed on a full P-type photoconductor, and this is developed with red toner of 1-1 polarity, transferred to paper, and prefixed. It is formed on a 1.2N type photoconductor of 1.2N type after disassembly. A two-color color TF photocopying method characterized by fully overlapping transfer and fixing of one image of red and k toner.