JPS62134665A - Image recorder - Google Patents

Abstract

PURPOSE:To automatize the detection and setting of an area to be erased of an image by controlling the lighting of an exposure means based on the detection signal of a color having a wavelength for a maximum sensitivity or a sensitivity in the vicinity of it of a latent image carrier to which a photodetector detects from the picture information. CONSTITUTION:A pair of marking members 9-1 and 9-2 are stuck to the diagonal corner parts of an original image erasing area 9 on an original 3. Yellow detection parts and white non-detection parts are formed in stripes on members 9-1 and 9-2. Coordinate information of the area 8 from the photodetector 10 is inputted to an stored in a DC controller 15. When the part of a photosensitive drum 1 corresponding to the area 8 reaches the projected position of an LED array 16 in the copying process, the array 16 is controlled to light by the controller 15, and the electric charge of the area 8 is erased. Thus, a latent image is not formed through the area 8 is projected with the exposure light of the original 3 thereafter, and the part other then the area 8 is developed by a developing device 22.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an image recording apparatus that erases and records an arbitrary area in a document image.

[Background of the invention]

In general, in an image recording device such as an electrophotographic copying machine, forming a copy image by selectively erasing a desired area in the original image is performed by charging an area on the photoreceptor drum corresponding to the area to be erased in the original image. It is usual to erase the original image by irradiating it with light from a lamp or the like before exposing the original image.

If the charge is erased in this way, even if the original image is exposed afterwards, no electrostatic latent image will be carried on the desired area on the photoreceptor. Further, charge erasure in a desired area can also be performed by exposing the original image.

Incidentally, the erasing area in the original image has conventionally been set by the following method. First, a document is placed face up on a document table, and a separately prepared transparent sheet with grid-shaped auxiliary lines drawn thereon is placed over the document. Identification numbers are attached to the base end of the auxiliary edge of this transparent sheet in both the vertical and horizontal directions, and the operator memorizes the number of the rectangular area to be erased, and copies the erased rectangular area to the main body of the 4-child photocopying machine. Input before operation. In the main body of the copying machine, an LED array is provided along the axial direction of the photoreceptor drum, facing the outer peripheral surface of the photoreceptor drum, and the lighting area and lighting timing are determined by an LED lighting control circuit into which the number of the rectangular area is input. controlled. Next, place the original face down on the original table and press the copy button to start exposing the original image. Accordingly, the photoreceptor drum rotates, and when the photoreceptor drum reaches the set erasing rectangular area, the LED array lights up at a constant width for a predetermined period of time, erasing the charge in the rectangular area on the photoreceptor drum.

However, the nine-inch photographic copying machine employing this method has a problem in that the procedure for setting the charge erasing area before the copying process is complicated.

[Purpose of the invention]

The present invention has been made in order to solve these conventional problems, and is an image recording system in which the erasing area can be set simply by irB by automatically detecting the area of the document to be erased. The purpose is to provide a device.

[Summary of the invention]

The photoconductive layer formed on the surface of the photoreceptor drum has maximum sensitivity to a specific wavelength; for example, in the case of an OPC photoreceptor, it has maximum sensitivity around 550 nm, as shown by the solid line in Figure 6. Therefore, for example, a color (yellow) having a spectral sensitivity near the maximum sensitivity of the photoreceptor drum, as shown by the dotted line ■, is perceived by the photoreceptor drum almost in the same way as a white original with a spectral sensitivity shown by the solid line ◎.

The present invention utilizes the sensitivity characteristics of such a photoreceptor drum,
For example, a yellow marking material is pasted on the corner of the area to be erased on the original, and its position is detected by a photodetector element with characteristics in the blue wavelength sensitivity region, which is the complementary color of yellow, as shown by ■ in Figure 6. During exposure of the original, the area to be erased on the original is automatically detected without forming the marking member as an image, and the LE is automatically scanned based on the obtained detection information.
The surface of the photosensitive drum corresponding to the erased area is exposed to light by an exposure means such as D, and the electric charge thereon is erased.

[Embodiments of the invention]

The present invention will be described in detail below based on embodiments shown in the drawings.

FIG. 1 is a schematic diagram showing an embodiment of a copying machine according to the present invention, in which 1 is an OPC photosensitive drum, 2 is an original platen, 3 is an original document,
4 is an original illumination rung, 5 is a first mirror, 6 is a second mirror, and 7 is a third mirror, and the lamp and mirror constitute an exposure scanning system.

When you press the copy button (not shown), lamp 4 lights up and the first
The document 3 is scanned while moving together with the mirror 5 in the direction of the arrow A at a speed v1, and at the same time, the second mirror 6 and the third mirror 7 move in the direction of the arrow A at a speed of 12V while following the first mirror 5. do. This exposure scan of a document using the exposure scanning system is repeated twice when partial erasure copying of the document image is selected, and at the time of the first exposure scan, the rotation of the photosensitive drum 1 is stopped, and the second exposure scan is performed. Photoreceptor drum 1 during scanning
is set to rotate.

On the other hand, on the original 3, a pair of marking members 9-1 and 9-2 are affixed to opposing corners K of a rectangular original image erasing area 8 as shown in FIG. The members 9-1 and 9-2 are formed of square sheets as shown in FIG. 3, and have a yellow detecting part 9a and a white non-detecting part 9b formed in a striped pattern with equal pitches. , a weak adhesive 9 is attached to the back side, so that it can be easily removed from the document at any time.In this example, a yellow detection part 9a is placed on a 5W square white sheet.
Three pieces are formed in one pitch.

Reference numeral 10 denotes a photodetector composed of a filter 11, a reduction lens 12, and a photodetector element 13 such as a CCD, and the filter 11 has the characteristics shown by the solid line D in FIG. During the first exposure scan of the original, the third mirror 7
The image information is incident on a photodetector element 13 via a filter 11 and a reduction lens 12, and is digitized by a converter 14. And marking member 9-1,
9-2, the signal shown in Figure 4 is A.
/D converter 14. Since the filter 11 has a background color that is complementary to the yellow printed on the detection parts 9a of the marking members 9-1 and 9-2,
The exposure light from the detection section 9a is cut through the filter 11, and during this time a signal of level "L#" is output from the A/D converter 14.In this embodiment, the marking member has a striped pattern. is yellow 11iIi in the original image.
If there is an image part, this will be detected and an incorrect image erasing area will be set, so this pattern can be distinguished. The A/D converter 14 only detects an arm turn that is the same as the pattern of the marking member being marked.
A signal is sent from the DC controller 15 to the DC controller 15.

The document 3 is placed face down on the cooling bucket table 2, and the marking member 9-1 is detected first, and then the marking member 9-2 is detected. The marking member 9-1 and the marking member 9-2 are not located on the same straight line in the scanning direction of the linear photophages (hereinafter referred to as the main scanning direction), but are directly aligned with the nuclear main scanning direction. Since they are provided apart from each other in the burning direction (hereinafter referred to as the sub-scanning direction), the images are formed at different positions on the photodetecting element 12, and the top of the image erasing area in the sub-scanning direction is determined.

On the other hand, from the start of the -th exposure scan (to) to the time of detection of the marking member 9-1 (tl) and the marking member 9
The coordinates of the image erasing area in the main scanning direction are determined by the time until the detection time (t,) of -2.

The coordinate information of the image erasing area from the photodetector 10 described above is input to the DC controller 15, and as shown in FIG.
), the coordinates where the marking member 9-1 is pasted are (xt
, yt) The coordinates where the marking member 9-2 is pasted are (xz
,y,), and the image erasure area that the user is trying to specify based on the coordinates of these two points is (Xyu, y,).
Yl).

It is set and memorized as an area surrounded by four points: (x,,y,)t (x,,y,), (x,,y,).

Reference numeral 16 denotes an LED play that is disposed facing the outer circumferential surface of the photoreceptor drum 1 along the axial direction of the photoreceptor drum 1 between a primary charger to be described later and an exposure image forming position; 15. LED that should be lit during copying operation
The lighting timing is controlled.

Reference numeral 17 denotes a lens system that forms an image from the exposure scanning system onto the photoreceptor drum 1. The light is guided to the Kiko image forming area position I on the photosensitive drum 1 and is imaged. The photoreceptor drum 1 rotates at a circumferential speed v1 at the same time as the first thermal light scanning of the line light set meal system ends, that is, the automatic routine process of the erase area ends, and is first uniformly charged by the primary charger 21. Negative charging is performed, and then the image exposure light from the document 3 accompanying the second exposure scan is applied to the lens system 1.
7, fourth mirror 18, fifth mirror 19, sixth mirror 20
A latent image is formed through the irradiation.

On the other hand, during the second line light run, that is, during the temporary copying process, when the part of the photosensitive drum 1 corresponding to the image erasing area reaches the irradiation position of the LED array 16, the DC controller 15
The LED array 15 is controlled to light up in a pre-designated area, and the charge in that area is erased. Therefore, even if this charge erasing area is subsequently irradiated with document exposure light at the exposure position, no latent image is formed, and the developing device 2
In the next development step No. 2, development is performed except for this charge erasing area. Then, the obtained toner image is transferred to a transfer sheet (not shown) in a transfer step, and furthermore, in a fixing step, the toner image is fixed on the transfer sheet, forming a rectangular shape surrounded by marking members 9-1 and 9-2. The image of the document 3 is copied except for the erased area 8.

[Effects of embodiments of the invention]

As described above, according to this embodiment, it is possible to automatically set the erasing area while the original is placed face down on the original table. You can obtain a copy of the original image.

Note that in this embodiment, the marking member was directly pasted on the original, but by placing a transparent sheet over the original and pasting the marking member on top of the transparent sheet, it is possible to specify an area without staining the original.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to automatically detect and set an area to be erased in an image of a document or the like.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of an embodiment of the present invention, Fig. 2 is a plan view showing the marking member attached to a document, Fig. 3 is an enlarged view of the marking member, and Fig. 4 is A/D conversion. FIG. 5 is a diagram showing the coordinates of the set erase area, and FIG. 6 is a diagram showing the spectral sensitivities of the oPC sensitive element, the marking member, and the photodetecting element.

Claims (1)

[Claims] an image erasure area setting means for setting an image erasure area according to image information; and an exposure means for exposing a latent image carrier based on information from the image erasure area setting means; a photodetector that is sensitive to light having a complementary color relationship with the maximum sensitivity of the latent image carrier or a wavelength in the vicinity; and a maximum sensitivity of the latent image carrier that the photodetector detects from the image information. An image recording apparatus comprising: a control circuit that controls lighting of the exposure means based on a detection signal of a color having a wavelength at or near the sensitivity.