JPH0673041B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus such as an electrophotographic copying machine or an electrostatic recording machine, and more particularly to an image forming apparatus having a function of printing an arbitrary image together with a document image.

Hereinafter, an electrophotographic copying machine will be described as an example. Manuscripts that the author does not want copied, as copiers become more prevalent
For example, there is a risk that the author's right, official documents, bills, etc. may be illegally copied or used.

Conventionally, as a measure against the above situation, a watermark is put on a piece of paper or the like that is copied when the copy is made, and it is possible to make it easier to determine that the watermark is not copied or, on the contrary, is a dark copy. Has been done. However, the manuscript becomes very expensive due to the limited paper quality, and it is necessary to prevent the paper from being used as a copy paper, so that it is currently difficult to obtain the manuscript.

An object of the present invention is to make it possible to write an identification image on a copy, and to prevent the identification image from being reproduced together with the original image of the original when the copy attached with the identification image is re-copied. The present invention provides a copying apparatus that

The present invention which achieves the above object is an image forming apparatus which exposes an original image on an electrophotographic photosensitive member to form an electrostatic latent image, and develops the electrostatic latent image to form a copied image. An original image is exposed on a photographic photosensitive member to form an electrostatic latent image, the electrostatic latent image is developed, and then the developed image is transferred to a transfer material to form a copy image as a first image on the transfer material. A second image forming unit and a second image forming unit on the transfer material on which the first image is formed, in which a second image different from the original image is formed with a color to which the photoconductor has sensitivity. An image forming unit, and the first
When a copy image is formed by using a transfer material having the first image and the second image as a document, the charge of the electrostatic latent image of the photoconductor corresponding to the second image is eliminated to copy only the first image. It forms an image.

An embodiment of the image forming apparatus of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment, in which 1 is a drum type photosensitive member as an image bearing member which is rotationally driven in the direction of an arrow, and a Se-Te vapor deposition film ( Te 10 wt%) 1b is provided in a thickness of about 40 μm. 2 to 7 are image forming process devices sequentially arranged around the photosensitive member 1 in the rotation direction, 2 is a corona charger, 3 is an optical image exposure station, 4 is a developing device, 5 is a transfer charger, 6 Is a cleaner, and 7 is a full exposure lamp for static elimination.

The photoconductor 1 rotates the corona charger 2 in the direction of the arrow.
Receives a uniform charge 8 of about +600 V, and in the optical image exposure station 3, the reflected image from the original 11 on the transparent original placing table 10 illuminated by the halogen lamp 9 is composed of the lens 12 and the mirror 13 and the optical system. Imaged through the slit 14,
An electrostatic latent image 15 corresponding to this image pattern is formed. Then, the electrostatic latent image is toner-developed by the developing device 4 to become the visible image 16 which is the first image.

The transfer material 17 is fed from the cassette 20 in synchronism with the rotation of the photoconductor 1 by a paper feed roller 18 and a timing roller pair 19, and is transferred between the photoconductor 1 and the transfer charger 5 as it advances. The visible image 16 on the photoconductor 1 is transferred onto the transfer material 17 by the charging action of the container. The transfer material 17 that has passed the transfer charger position is separated from the photoconductor 1 and is conveyed to the fixing roller 21. On the other hand, the photoconductor surface from which the transfer material is separated is cleaned by the cleaner 6
The residual toner image after transfer is removed by, and the residual charge is removed by the exposure by the whole-surface exposure lamp 7 to be cleaned and repeatedly used for image formation.

This example is a transfer material after completion of fixing after passing through the fixing roller 21.
An arbitrary identification image 22 (Fig. 2) is imprinted on 17
This imprinting means includes a central processing unit 23 (hereinafter referred to as CPU), keyboard 24, read / write memory 25, ink jet drive circuit 26, ink jet head 27, timer 28,
It is composed of a magnet 29 and a position detector composed of a Hall element 30.

The magnet 29 is attached to the photoconductor 1, and the Hall element 30 is attached on the side plate of the apparatus so as to face the movement trajectory of the magnet 29. Then, as described above, when the image formation on the photoconductor 1 and the transfer of the image onto the transfer material 17 proceed, the transfer material 17 separated from the photoconductor 1 passes under the ink jet head 27. Further, the magnet 29 crosses the front surface of the Hall element 30 and a position signal is output from the Hall element 30.

In the above configuration, an arbitrary identification image signal to be printed on the transfer material 17 is input to the CPU 23 via the keyboard 24. The CPU 23 reads an information signal corresponding to the input identification image signal from the read / write memory 25, and when receiving the position signal from the hall element 30, controls the ink jet drive circuit 26 in accordance with the read information signal. Start timer 28. The ink jet drive circuit 26 drives the ink jet head 27, and as shown in FIG. 2, outside the area E on the transfer material 17 where the original image is formed, the identification image 22 which is the second image based on the information signal. Imprint. Then, after a lapse of a predetermined time from the start of the identification image imprinting operation, the CPU 23 becomes inoperative upon receiving a stop signal from the timer 28, and stops the identification image imprinting operation.

The identification image can be arbitrarily changed by the identification image signal input by the keyboard 24. Therefore, by determining a specific identification image according to the distribution destination of the copy, the identification image is viewed and copied. It becomes clear that it is a product and the distribution destination is known, and it is easy to manage the copy.

Further, when the copy is copied again as an original, if the above-mentioned identification image is copied, it will be overlapped with the identification image imprinted by the ink jet head 27, and the copy quality will be deteriorated.

Therefore, the ink color of the ink jet 27 for forming the identification image is selected according to the spectral sensitivity of the photoconductor 1. In other words, when the photoconductor has a color having sensitivity, the charged charge of the photoconductor portion that receives the reflected light from the identification image disappears and becomes the same as the bright portion of the document, and the identification image is not copied. For example, since the spectral sensitivity of the Se-Te photoconductor (containing 10 wt% Te) is as shown in Fig. 3, the dyes of the ink which have a reflection spectrum in this wavelength range are summarized as follows.
Balifast Yellow # 3104 (Orient Chemical) was chosen. An ink was prepared by diluting this dye "10" with ε-caprolactone "50" and sulfolane "40" as a liquid medium.

After an identification image is formed on a copy using this ink, the copy is used as a document for a document illumination light source, a halogen lamp,
When the re-copy was carried out using Se-Te (containing 100 wt% of Te) on the photoconductor, the above-mentioned identification image was not copied at all.

In this example, as described above, the ink is ejected from the ink jet head 27 and adhered to the transfer material 17, and the ink is soaked in the transfer material as it is to form an identification image. The results of the experiment are shown in the table below. Good results have been obtained by using a transfer material.

The ink jet was first proposed by the applicant of the present invention, for example.
In addition to the method of generating ink mist with thermal energy disclosed in Japanese Patent Publication No. 59936, a TeLetype method (US Pat.
29), Sweet method (U.S. Pat. Nos. 3,596,275, 3298030)
Ink jet methods such as the Herty method (US Pat. No. 3,416,153) and the Stemme method (US Pat. No. 3,747,120) can also be applied.

As the electrophotographic process, in addition to the process shown in FIG.
The so-called NP process disclosed in Japanese Examined Patent Publication Nos. 42-23910 and 43-24748 can also be applied.

FIG. 4 shows a second embodiment of the device of the present invention.
In the example in which the identification image which is the second image is imprinted on the transfer material by the ink jet head 27 on the system path on the way that 17 is carried in between the photoconductor 1 and the transfer charger 5. is there.

FIG. 5 shows a third embodiment of the apparatus of the present invention, which is an example in which the identification image is transferred onto the transfer material 17 by the semiconductor laser as the second image instead of the ink jet method. At the first rotation of the photoconductor 1, an original image is formed on the photoconductor by the same electrophotographic process as in FIG. 1, and
A transfer material 17 fed by a paper feed roller 18 and a timing roller 19 onto a transfer drum 32 that rotates in synchronization with the photoconductor 1.
Is wound and supported, and the original image formed on the photoconductor is transferred onto the transfer material by a known transfer means. Next, at the second rotation of the photoconductor 1, the developing device 4 is moved away from the photoconductor, and instead the developing device 33 is moved closer. The CPU 23 controls the semiconductor laser drive circuit 34 by the information signal read from the read / write memory 25, and this semiconductor laser drive circuit drives the semiconductor laser generator 35, and the identification image on the photoconductor 1 is generated by the generated semiconductor laser. To form a latent image of. This latent image is developed with the toner of the developing device 33 to form a visible image, and then the visible image is transferred onto the transfer material on which the original image is formed.

After the transfer material 17 is fixed, the transfer material 17 is separated from the transfer drum 32 and is fed toward the discharge port by a pair of paper feed rollers 36. The toner of the developing device 33 has a color different from that of the toner of the developing device 4 and has a sensitivity to the photosensitive member 1.

The present invention relates to a first image forming means for forming an image from a document by an electrophotographic process using an image carrier, and a second image forming means for forming an arbitrary identification image in a color to which the image carrier has sensitivity. Since the image forming apparatus is provided with, the identification image can be imprinted on the copy of the original image, and the copy can be clearly recognized by the identification image. Further, since the identification image can be arbitrarily changed, it is easy to manage the copy by copying the identification image specified according to the distribution destination of the copy to the copy. Further, by making the color of the identification image a color at which the image carrier has sensitivity, the identification image is not copied to the copy when the copy is re-copied as an original in the electrophotographic process. Therefore, by imprinting the identification image on the copy, it is possible to obtain the same high-quality copy as when the copy is made directly from the original.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the apparatus of the present invention, FIG. 2 is a front view of a copy produced by the apparatus of the present invention, and FIG. 3 is a characteristic diagram of wavelength vs. relative sensitivity of an image carrier, FIG. 4 is a schematic diagram showing a second embodiment of the device of the present invention, and FIG. 5 is a schematic configuration diagram showing a third embodiment of the device of the present invention. 1 is a photoconductor, 27 is an ink jet head, and 35 is a semiconductor laser generator.

Claims (1)

[Claims] 1. An image forming apparatus for exposing a document image on an electrophotographic photosensitive member to form an electrostatic latent image and developing the electrostatic latent image to form a copied image. To form an electrostatic latent image,
After developing this electrostatic latent image, transfer the developed image to a transfer material,
First image forming means for forming a copy image as a first image on a transfer material, and a color for which the photoconductor has sensitivity to the transfer material on which the first image is formed. A second image forming means for forming another arbitrary second image, and when a copy image is formed by using a transfer material having the first and second images as an original, a second image is formed on the second image. An image forming apparatus, which forms a copy image of only the first image by eliminating the charge of the electrostatic latent image of the corresponding photoconductor.