JPH0282272A - image forming device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to an image forming apparatus such as an electrophotographic apparatus having an analog exposure function for slit exposure of an image and a digital exposure function using a laser beam, an LED array, etc. It is.

[Prior Art] Recently, due to advances in technology, electrophotographic apparatuses have become capable of monochrome copying and now have a two-color copying function. Along with this, it now has an image conversion function as an additional feature, and it has also become possible to specify any area of the document and selectively make monochrome copies inside and outside that area.

Currently, the most common method for specifying an area is by operating keys provided on the main body of the device or by providing a separate editor 80 as shown in FIG. 8 and inputting coordinates using a ben 81 to specify the area.

However, since input using keys or an editor is time-consuming, there is a need for an electrophotographic device that can directly specify an area on a document using a marker pen.

Currently, an electrophotographic device that performs area recognition using a marker pen includes a 2P prism 23 having a dichroic mirror surface 24, two line sensors 6°, and two line sensors 6°, as shown in FIG.
Depending on the combination of 61, there are a method of recognizing color information of a marker ben, a method of using a color line sensor, etc. That is, the reflected light from the original 1 illuminated by the original illumination system 2 is transmitted to the 2P prism 2 via the reflection mirror 3 and the imaging lens 4.
3, the image light traveling straight is read by the line sensor 6゛, the color mark information from the marker ben is recognized from the image information from the line sensor 6m, a designated area is set, and based on the setting, the line sensor The image information read in step 6" is processed, and, for example, only a specified area or other areas are copied.

[Problems to be Solved by the Invention] However, in the above conventional example, (1) the combination of a color line sensor or a plurality of monochrome line sensors 6°, 6" as shown in FIG. 7 and the prism 23 is expensive; , Difficult to assemble and adjust.

(2) If a copy image is to be formed only by digital exposure, high-definition digital reading means and digital exposure means will be required in order to improve copy quality, which will further increase the cost and make assembly and adjustment more difficult.

An object of the present invention is to form an image that is capable of forming an image only in an arbitrary area of a document with a simple configuration, that can change the image color of an arbitrary area, and that can obtain a high-quality image. The aim is to provide the equipment.

[Means for Solving the Problems] An element for achieving the object of the present invention is to scan a document placed on a document table and expose it to an image carrier to form a latent image on the image carrier. A first exposure means, a developing means for making the latent image visible, a second exposure means for exposing an arbitrary position across the width of the image carrier, and specifying image information of the document. a specific image reading means for reading with an imaging means through a separation means for separating only light in a wavelength range of , and area setting for driving and controlling the second exposure means based on specific image information from the imaging means of the specific image reading means. means, the area setting means determines a specific area in the document based on the image position of the specific wavelength light read by the imaging device;
The image forming apparatus is characterized in that the second exposure means is driven and controlled to erase the latent image corresponding to the specific area or other latent images before the development step by the developing means is started. .

[Function] The image forming apparatus configured as described above surrounds a desired area in a document using a pen or the like of a specific color that matches a specific wavelength of a specific image reading means, and then subjects this document to image analog exposure. A first exposure means is used to expose an image carrier to form a latent image, and at the same time a specific image reading means recognizes an area surrounded by a pen of a specific color and corresponds to an image inside or outside that area. By exposing the latent image on the image carrier with light by the second exposure means, the latent image within or outside the area is selectively erased, and only the desired image is developed.

[Example] The present invention will be described in detail below based on an example shown in the drawings.

FIG. 1 is a schematic diagram showing an embodiment of an image forming apparatus according to the present invention, which includes a digital image exposure system using a laser beam shown in FIG. 4, and an original on a fixed document table shown in FIG. It is equipped with an analog image exposure system operated by a moving illumination optical system, and is capable of multiple copying of two-color images.

In the figure, 1 is a document placed on the document table 13 of the apparatus main body 22, 2 is a document succession system consisting of an illumination lamp 2a for illuminating the document, a reflective shade 2b, a slit plate (not shown), etc., and 3a to 3f are Reflection mirror 4 of the analog image exposure system is an imaging lens,
The document illumination system 3 and the reflecting mirror 3a illuminate the document while moving in the direction of the arrow at a speed V, and the reflecting mirror 3b,
3c moves in the direction of the arrow at a speed S4v, and the reflected light from the document passes through the imaging lens 4 and forms an image on the photosensitive drum 15 via the reflection mirrors 3d and 3e.

9 is a laser light source consisting of a semiconductor laser element, lO is a collimator lens, 11 is a polygon mirror, 12 is an f-lens group including a toric surface, and o is set according to image information.
A four-bell laser scanner is configured in which light from a nloff laser light source is guided to a photosensitive drum 15 via a collimator lens 10, a polygon mirror 11, an f/θ lens group 12, and a reflecting mirror 3g.

Reference numeral 14 denotes a developing device unit that integrally combines a first developing device 14a having a red developer and a second developing device 14b having a black developer. On the other hand, the first developing device 14a or the second developing device 14b is selected to visualize a red or black image.

The developed image on the photosensitive drum 15 is transferred to the transfer paper P fed from the paper feed cartridge 22 by the transfer charger 16.
The transfer paper that has undergone the transfer process is separated from the photosensitive drum 15 via, for example, a separation claw (not shown), and then the developed image is fixed by a fixing device (not shown). The transfer paper P that has undergone the fixing process can be selectively conveyed to the transfer position via a paper refeeding path (not shown) or ejected to the paper ejection tray 21 in order to perform multiple copies. It will be held in In addition, the photosensitive drum 15
The transfer residual developer on the photosensitive drum 15 is removed by a cleaning device 17, the surface of the photosensitive drum 15 is illuminated by a static eliminating lamp 18 to eliminate static electricity, and the photosensitive drum 15 is uniformly charged by a charging device 19 and used for the next image formation.

On the other hand, a 4-pel digital reading system for reading the reflected light from the reflecting mirror 3c of the analog image exposure system is arranged in parallel near the imaging lens 4.

As shown in FIGS. 3(a) and 3(b), this digital reading system has a reading lens 5, a one-dimensional image sensor 6,
, and a bandpass filter 8, and the analog image light passes through the bandpass filter 8 and is imaged onto a one-dimensional image sensor 6 by a reading lens 5.

As shown by the spectral transmittance indicated by the broken line in FIG. 5(a), this bandpass filter 8 has a characteristic of passing only a specific wavelength range (in this embodiment, a wavelength range of around 600 mm corresponding to yellow). Also, the spectral sensitivity of the photosensitive drum 15 is not in this specific wavelength range, and an image of this specific color is not formed on the photosensitive drum 15.

In this embodiment, information from a one-dimensional image sensor 6 is inputted to a specified area setting device (not shown) consisting of a microcomputer, etc., and the drive control of a laser light source 9 is performed based on the output from the specified area setting device. As shown in Figure (a), it is possible to copy only the image within the "A" area of document 1, copy the image in area A and the image in area B other than that in different colors, or copy only the image in area B. The areas A and B are separated by colored marks as shown by diagonal lines C on the original 1.

The color of the mark used to set this designated area is a specific color (red in this embodiment) equal to the spectral transmittance of the bandpass filter 8, as shown by the solid line in FIG. 5(a). For example, a highlighter pen having a higher spectral reflectance (100%i or more) than the background color (white original) of No. 1 is used.

In order to distinguish the mark C read by the one-dimensional image sensor 6, the specified area setting device sets the mark C at a level higher than the maximum output level of the background color (white) of the document 1, as shown in FIG. 5(b). A level threshold value (slice level) lower than the maximum output level of a specific color of C is set in advance, and an area discriminating section that determines an image higher than this slice level as a mark C and a coordinate position of the mark C are determined. As shown in FIG. 6(b), it is composed of an area setting section that sets an area, and a laser driving section that drives the laser light source 9 according to the area set by the area setting section. Therefore, since the slice level is set to a high level, the one-dimensional line sensor 6 can mark C even if the required light amount of the illumination system 2 is small.
can be reliably recognized.

Here, the image forming process will be described using as an example a case where an area A is copied in red by the first developing device 14a and an area B is copied in black by the second developing device 14b.

Place the original 1 marked with mark C as shown in Figure 6(a) on the original platen.
3 and press the copy button (not shown), the scanning of the document illumination system 2 and the like starts, and the areas A, A, and A are placed on the photosensitive drum 1.
A latent image B is formed. On the other hand, at the same time as the latent image light is applied to the photosensitive drum 1, the specified area setting device identifies the mark C from the image read by the one-dimensional sensor 6 of the digital reading system and determines its coordinate position, and the latent image on the photosensitive drum 15 is In the middle, the laser light source 9 is driven so as to expose only the B area, and the latent image in the B area is erased.

Therefore, since the latent image in area B formed on the photosensitive drum 1 is immediately erased, only 9 of the latent images in area A exist at the development position, and the red developer in the driving state is accommodated. The latent image in area A is developed in red by the first developing device 14a, and is transferred and fixed onto the transfer paper P. Here, if you only need to copy the image in area A,
The transfer element P of the fixing device will be ejected to the paper ejection tray 21 as it is, but since the image of area B has been selected to be copied in black onto this transfer paper P, it will be transported to the paper re-feeding path. be done. Then, the document 1 is illuminated and scanned again by the document illumination system 2, and latent images of the images in the area A and the area B are formed on the photosensitive drum 15.

Simultaneously with the formation of the latent image, the designated area setting device recognizes areas A and H as in the previous scan, and this time exposes a latent image corresponding to the image of area A formed on the photosensitive drum 15. The laser light source 9 is driven as follows. Therefore, the latent image in area A is erased, and only the latent image in area B is developed by the second developing device 14b containing the black developer in the driving state, and this black developed image is reproduced from the paper refeeding path to the transfer position. The fed image of area A is transferred to transfer paper P in red. Then, on this transfer paper P, the black developed image in area B is fixed by the fixing device, and the transfer paper P with the image in area A in red and the image in area B in black is ejected to the paper ejection tray 21.

Note that in the above embodiment, the image of area A is red and the image of area B is black, but the reverse is also possible;
Alternatively, it is also possible to selectively copy only B.

[Effects of the Invention] (1) Since image formation is performed by the analog first exposure means, a high-quality original image in a desired area can be obtained.

(2) Since the second exposure means is used as an eraser for erasing the latent image, it does not need to be highly precise and can be made at low cost.

(3) Similar to (2), the specific image reading means does not need to be of high definition, and since only one imaging device such as a one-dimensional image sensor is sufficient, the cost is low.

(4) Reading of a specific image Since original exposure and eraser exposure are performed in parallel, almost no memory is required for reading a specific image, resulting in low cost.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the overall configuration of an embodiment of an image forming apparatus according to the present invention, Fig. 2 is a diagram showing its analog image exposure system, and Figs. 3 (a) and (b) are its digital reading system. FIG. 4 is a diagram showing the digital image exposure system, FIG.
) is a diagram explaining the slice level setting for the output of a one-dimensional image sensor, Figure 6(a) is a diagram showing an example of displaying a specified area on a document, and Figure 6(b) is a diagram showing the area setting state. 7 is a diagram showing a conventional image forming apparatus, and FIG. 8 is a diagram showing a conventional image forming apparatus.
The figure is a perspective view of a conventional editor. 1... Original 2... Original illumination system 38-3
g...Reflection mirror 4.5...Lens 6...One-dimensional image sensor 8...Band pass filter 9...Laser light source 10...Collimator lens 11...Polygon mirror 12...・f・θ lens l
4...Developer unit 15...Photosensitive drum 16...Transfer charger 17...Cleaner 18...Pre-exposure device 19...Primary charger and 4 other people d) (b) Oke tomoe

Claims (1)

[Claims] 1. A first exposure device that scans an original placed on a document table and exposes an image carrier to form a latent image on the image carrier; a developing device that visualizes the latent image; a second exposure means capable of exposing any position across the width of the carrier;
a specific image reading means for reading image information of the document with an imaging means via a separation means that separates only light in a specific wavelength range; and a second exposure based on the specific image information from the imaging means of the specific image reading means. and area setting means for driving and controlling the means, the area setting means determines a specific area on the document based on the image position of the specific wavelength light read by the imaging means, and the developing process by the developing means is started. An image forming apparatus characterized in that the second exposure means is driven and controlled to erase the latent image corresponding to the specific area or other latent images before the image forming apparatus.