JPH01172859A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To improve picture quality without using a high-definition digital exposing means nor a read means and to recognize colors in a document by one image sensor by performing image formation by an analog exposing means and utilizing the digital exposing means for erasing light. CONSTITUTION:The read means 6 recognizes a specific color area in the document 1 which is separated by a color separating means 20 and has the peak of spectral reflectance in a specific wavelength range. Then when the image of the specific area in the document 1 is formed, the nonspecific color or black area of the electrostatic latent image of the document 1 which is formed by the analog exposing means A is erased by the exposure of the digital exposing means D according to the recognition signal. When the image of the nonspecific color area in the document 1 is formed, on the other hand, the parts other than the specific color or black area of the electrostatic latent image of the document 1 is formed by the erasure exposure of the digital exposing means. Consequently, an image of high picture quality is obtained without using any high-definition reading means nor digital exposing means, the reading means need not have high definition, and only one image sensor is required.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrophotographic apparatus having an analog exposure function for exposing an image of a document to slit exposure, and a digital exposure function using a laser beam LED array or the like.

(Prior Art) Conventionally, some electrophotographic apparatuses of this type are capable of monochrome copying and have a two-color copying function. That is, a specific color portion and other portions of a multicolor original are copied in different colors. Along with this, it has an image conversion function as an additional function, and it is now possible to specify a certain area in a document image and make a monochrome copy inside and outside the specified area, and a multicolor copy. As a method of specifying this image area, editor 1 as shown in Figure 8 is used.
There were coordinate input methods such as 00 and key operations.

However, key operations and input using the editor lOO are time-consuming, so the color information of the two-color original is separated and read by a reading device, and based on this reading information, an area is automatically specified and the two-color original is automatically created. There is a demand for a function that allows two-color copying. Methods for automatically reading such areas include using a color image sensor,
A plurality of monochrome solid-state image sensors 101 as shown in FIG.
．． 102 and a prism 103 having a micromirror surface 103a are combined to separate and read color information in an original image. Digital exposure is then performed using a laser scanner, an LED array, or the like to form an image corresponding to each color area that has been read.

(Problem to be Solved by the Invention) However, in the case of such conventional technology, it is convenient to read the color information in the document using the reading means and automatically set the image forming area, but the color image sensor and a plurality of monochrome solid-state image sensors 101 and 102 and a prism 10
Combining the three has the problem of high cost and difficult assembly and adjustment.

Furthermore, in order to set an image copying area in a document and perform image exposure for each area, it has conventionally been necessary to form an image by a digital exposure means based on a signal read by a reading means. Therefore, in order to improve image quality, high-definition digital reading means and digital exposure means are required, making the apparatus even more expensive and requiring high precision in assembly and adjustment, making it even more difficult.

The present invention has been made in order to solve the problems of the prior art described above, and its purpose is to form a high-definition image by using analog exposure means and using digital exposure means as erase light. An object of the present invention is to provide an electrophotographic apparatus that can improve image quality without using digital exposure means and reading means, and can recognize colors in a document with a single image sensor.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes an analog exposure unit that scans a document with a slit and exposes the document image onto an image carrier; In an electrophotographic apparatus, the electrophotographic apparatus includes a digital exposure unit that exposes an image with a light beam on the document, and a reading unit that reads image information on the document, wherein the reading unit includes one one-dimensional image sensor and a digital exposure device that detects image information of a specific wavelength in the document image. a color separation means for separating only the light of the region and guiding it to an image sensor, and a reading means recognizes a specific color region having a peak of spectral reflectance in a specific wavelength region separated by the color separation means in the document. Based on this recognition signal, when forming an image in a specific color area on the original, a non-specific color or black area of the electrostatic latent image of the original formed by the analog exposure means is erase-exposed by the digital exposure means, Image formation in a non-specific color area in a document is characterized in that non-specific color or black areas of the electrostatic latent image of the document formed by the analog exposure device are erase-exposed using a digital exposure device. Special (Function) Then, a multicolor original containing a specific color having a spectral reflectance peak in a specific wavelength range is read by the digital reading means, and a spectral reflectance peak is detected in the wavelength range on the multicolor original. At the same time as the analog exposure, in order to recognize non-specific color areas such as colors that do not have the same color or black parts, and form an image only in the specific color area that has a peak of spectral reflectance in the specific wavelength range on the multicolor original, Erasing the area with a digital exposure means and recording image information of the specific color portion of the multicolor original on the image carrier.Next, a peak of spectral reflectance is set in the specific wavelength range on the multicolor original. When forming an image of only the color or black area, the area other than the area is erased using a digital exposure means at the same time as the analog exposure, and a spectral reflectance of the specific wavelength range of the multicolor original is printed on the image carrier. Image information of a non-specific color area, which is a color without a peak or a black portion, is recorded.

(Example) The present invention will be explained below based on the illustrated example. In FIGS. 1 to 6 showing an electrophotographic apparatus according to a first embodiment of the present invention, reference numeral 1 denotes a document on which an image to be read is written, and is illuminated by an illumination lamp 2. As shown in FIG. A photoreceptor drum IT is rotatably supported approximately at the center of the apparatus main body 17, and around the photoreceptor drum 11, chargers 16. Although the developing device 12, the transfer charger 13, the cleaning device 14, the static eliminating lamp 15, etc. are arranged, in this embodiment, the developing device 12 has two colors, red and black.

FIG. 2 shows an analog exposure means (A), which is configured to guide reflected light from an original document 1 onto the photosensitive drum 11 through a reflecting mirror 3 and a lens 4.

FIGS. 3 and 4 show a 4-bell digital reading means, and FIG. 3 shows a digital reading lens 5, a monochrome one-dimensional image sensor 6, and a filter 20 as a color separation means that transmits only a specific wavelength range. As shown, they are arranged next to the lens 4. In this embodiment, a red filter is used as the filter 20. A contact image sensor may be used as the digital reading means.

FIG. 5 shows digital exposure means, including a laser light source 8.
An fθ lens group 10 including a collimator lens 9, a polygon mirror 7, and a toric surface. This is a laser scanner composed of a mirror 3. However, since it is used as an eraser, it does not need to be high-definition, and should have 4 pels. Although not shown in FIG. 1, the electrophotographic apparatus of the present invention has a multiple copy function.

Here, color recognition by digital reading means will be explained with reference to FIG. This figure shows red filter 2.
Multiply the white background of the one-dimensional image sensor 6 by 10
It shows the image sensor output of black, red, and blue when the value is 0%.

As shown in the equivalent figure, by quantizing at a certain slice level, colors that do not have a spectral transmittance peak in the red region, such as blue and black, and colors that have a spectral transmittance peak in the red region, such as red and white, It can be separated into

When performing normal copying, the original l is illuminated by the halogen lamp 2, and the reflected light is reflected from the mirror 3.
, is guided through the lens 4 to the photosensitive drum 11 which has been charged in advance by the charging charger 16, and an electrostatic latent image corresponding to the original document l is formed thereon. This electrostatic latent image is developed by supplying developer from the developing device 12. The developing device 12 is composed of two color developing devices, for example, red and black, and one of them can be arbitrarily selected. Then, in the transfer charger 13, the photosensitive drum 1 is transferred to the paper P from the paper feeding force sensor 18 and is transferred to the photosensitive drum 1 by a separation mechanism (not shown).
After being peeled off from 1, the paper is discharged onto a paper discharge tray 19 via a fixing device (not shown). - The developer remaining on the photosensitive drum 11 is removed by the cleaning device 14, and the surface of the photosensitive drum 11 is neutralized by the static eliminating lamp 15, and the copying process is completed.

Next, a case will be described in which a document containing color information such as red, blue, black, white, etc. is automatically made a two-color copy, for example, a two-color copy of red and black. Original l by halogen lamp 2
The reflected light is imaged onto a one-dimensional image sensor 6 via a red filter 20 and a lens 5. According to the principle shown in FIG. 6, color defect areas, such as black and blue areas, which do not have a peak of spectral reflectance in the red area on the document surface are identified. At the same time as this digital reading, a copying operation similar to the normal copying operation described above is performed, but in this case,
A laser scanner shown in FIG. 5 selectively exposes the photosensitive drum 11 corresponding to the digitally read area portion. Therefore, only the red portion of the document is copied in color, for example, in red, by the developer 12.

Next, a multiple copying mechanism (not shown in FIG. 1) performs a normal copying operation in the same manner as described above. In this case as well, digital reading and digital exposure are performed in parallel, and the exposure to light corresponding to the area other than the area described above is carried out in parallel. body drum 11
The top is selectively exposed by the laser scanner. Therefore, a color portion, such as a blue portion and a black portion, which does not have a peak of spectral reflectance in the red region of the document, is subjected to a color copy, such as a black copy, by the developing device. Thus, the document containing the red and black information is automatically copied in two colors, red and black. Note that the color to be copied is not limited to red or black, and the color of the filter 20 is not limited to red.

FIG. 7 shows a second embodiment of the present invention, and the same components as in the first embodiment are designated by the same reference numerals.In this second embodiment, the digital exposure means is different. It is arranged in parallel with the lens 14 of the analog exposure means A, and shares a part of the mirror 3. In this way, the number of mirrors can be reduced, the number of parts can be reduced, and it is advantageous in terms of space. The other configurations and operations are the same as those in the first embodiment, so their explanations will be omitted.

In each of the above embodiments, a laser scanner was used as the digital exposure means, but it is not limited to lasers, and it is of course possible to use various methods such as an LED array or a liquid crystal shutter method. be.

(Effects of the Invention) The present invention has the above-described structure and operation, and the digital exposure means is used for erase exposure, and the analog exposure means is used to image-expose images in any area inside or outside the area of a specific color part in the original image. Since the image is formed using the above-mentioned method, a high-quality image can be obtained without using a high-definition reading means or a digital exposure means as in the past.

Therefore, it is no longer necessary for the digital exposure means to have high definition, and costs can be reduced. Further, the reading means does not need to be of high definition, and only one image sensor is required, so that it is possible to further reduce costs.

[Brief explanation of the drawing]

1 to 6 show an electrophotographic apparatus according to a first embodiment of the present invention, FIG. 1 is a side view showing a schematic structure, and FIG. 2 is a schematic structure of the analog exposure means of FIG. 1. 3 is a plan view schematically showing the arrangement of the digital reading means in FIG. 1, FIG. 4 is a side view showing the arrangement of the digital reading means in FIG. 1, and FIG. FIG. 6 is a side view showing the arrangement of the digital exposure means shown in FIG. 8 is a side view and a plan view showing a schematic configuration of an exposure optical system of an electrophotographic apparatus according to the second embodiment, FIG. 8 is a perspective view showing a conventional digitizer, and FIG. 9 is a diagram showing the arrangement of a conventional digital reading means. FIG. Explanation of symbols l...Manuscript 2...Halogen lamp 3.
...Mirror 4...Lens 5...Digital reading lens 6...Image sensor (reading means) 8...Laser light source 11...Photosensitive drum 12
...Developer 13...Transfer unit 16...
・Charger 17...Device body 20...Filter (color separation means) A...Analog exposure means D...Digital exposure means Fig. 3 Fig. 4 Fig. 5\

Claims (4)

[Claims] (1) Analog exposure means that scans a document with a slit to expose the document image onto an image carrier, digital exposure device that exposes the image carrier with a light beam, and converts image information on the document into digital information. In the electrophotographic apparatus, the digital reading means includes one one-dimensional image sensor and color separation means that separates light in a specific wavelength range in the original image and guides it to the image sensor. , the reading means recognizes a non-specific color or a black region that does not have a peak of spectral reflectance in the specific wavelength range separated by the color separation means in the document, and based on this recognition signal, the In forming an image in a color region, a non-specific color or black region of an electrostatic latent image on a document formed by an analog exposure means is erase-exposed by a digital exposure means, and in forming an image in a non-specific color region in the document, An electrophotographic apparatus is characterized in that an electrostatic latent image of a document formed by an analog exposure means is subjected to erase exposure of a non-specific color or non-black area using a digital exposure means. (2) The electrophotographic apparatus according to claim 1, wherein reading of the original by the digital reading means, the analog exposure, and the digital exposure are performed in parallel. (3) Claim 2, wherein the image carrier is provided with means for developing the image in multiple colors, and the color is selectable when copying the image information of the multicolor original onto the image carrier. The electrophotographic device described. (4) It has means for multiple copying onto an image carrier, and when copying image information of the multicolor original onto the image carrier multiple times, a spectral reflectance is applied to the specific wavelength range on the multicolor original. 4. The electrophotographic apparatus according to claim 3, wherein the electrophotographic apparatus is configured to copy different colors for a specific color portion having a peak and a color or black portion having no spectral reflectance peak in the specific wavelength range.