JPH0310315B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copying machine that performs copying using a magnetic latent image.

Various types of copying machines have been developed to date. Among these, electronic copying machines that use electrostatic photography have the feature of being able to create copied images on plain paper, and have become widely popular. However, such electronic copying machines usually use a photosensitive drum and a high-voltage power supply, making it difficult to reduce the cost and size of the apparatus. Furthermore, since the latent image is formed optically, it has been difficult to incorporate it into an image processing system using digital signals.

In view of these circumstances, an object of the present invention is to provide a copying machine that can electrically form a latent image without using a high-voltage power source and can also create a copy image on plain paper. do.

In the present invention, a magnetic belt is used as a recording medium,
A thermal pulse is generated by a thermal head while a magnetic field is applied to this, and a magnetic latent image corresponding to this thermal pulse is formed. This magnetic latent image is developed with magnetic toner and transferred onto paper to form a copy image.

The present invention will be explained in detail with reference to Examples below.

FIG. 1 shows a multipurpose copying machine capable of performing various types of image processing. Inside this copying machine, an endless magnetic belt (magnetic recording medium) 1 with a width of about 28 cm is connected to four rollers 2 to 4.
It spans 5. The first and second of these
The belt portion 1A stretched between the rollers 2 and 3 is horizontal, and a first bias magnetic field device 6 and a heat ray radiation device 7 are placed approximately in the center of the belt so as to sandwich it therebetween. . These devices 5 and 6 constitute a first latent image forming means. Further, on the right side of the heat ray radiation device 7 in the figure, a magnetic latent image reading head 8 and a thermal head 9 are arranged in order, and a second bias magnetic field device is located at a position facing the thermal head 9 with the belt portion 1A in between. 11 are arranged. Thermal head 9 and 2
The bias magnetic field device 11 constitutes a second latent image forming means. The magnetic latent image on the magnetic belt 1 moving around the outer circumference of the second roller 3 is developed by a developing device 12, and the developed image is transferred to a transfer roller 13 disposed opposite to the third roller 4. Paper 1
4 is now transcribed. A cleaning device 15 is arranged near the fourth roller 5, and the magnetic belt 1 after cleaning is transferred to the initial magnetization setting device 1.
It is initialized by 6. A supply tray 18 is arranged on the right side of the device to which paper 14 is fed by a feed roller 17, and a discharge tray 19 is arranged at the bottom of the device to eject the paper 14 after copying.
is provided.

The operation of this copying machine will be specifically explained next. The first bias magnetic field device 6 is a device having a magnetic field generating surface 6A slightly larger than the maximum size of the original.
It can be opened and closed in the direction of the arrow with one end as the center of rotation. The operator opens the first bias magnetic field device 6 and places the original 21 (FIG. 2A) on a platen (not shown) disposed on and in close proximity to the belt portion 1A. At this time, the side on which the image information 22 to be processed is written is placed at the bottom. Thereafter, the first bias magnetic field device 6 is returned to the closed state and information processing operation is started. At the same time, the magnetic belt 1 starts to be conveyed in the direction of the arrow (clockwise), and the heat ray radiation device 7
performs flash exposure using a built-in infrared generator (Figure 2B).

By the way, as shown in FIG. 3, the magnetic belt 1 is
A magnetic layer 24 mainly composed of chromium dioxide particles is formed with a uniform thickness on a base layer 23 made of Mylar or polyester film, and like the relatively transparent magnetic layer 24, these layers are made of a transparent support. The base layer 23 is transparent as a whole. The belt portion 1A immediately below the first bias magnetic field device 6 is magnetized in the opposite direction to the applied bias magnetic field, and a magnetic gradient exists in its entire region. When the heat ray radiation device 7 performs flash exposure from the base layer 23 side of the magnetic belt, the heat rays emitted thereby are exposed to the magnetic belt 1.
and reaches the reading surface (lower surface) of the document 21.
The heat rays that reach the reading surface are absorbed by the colored image area and generate heat. In addition, most of the background (white) portion is reflected and transmitted through or reflected by the magnetic belt 1. Therefore, on the magnetic belt 1,
A thermal pattern is generated depending on the density of the image. The magnetic layer 24 of the magnetic belt 1 loses its magnetized state at a portion heated above the Curie point or compensation point temperature. The portion where this magnetized state has disappeared is magnetized in the same direction as the bias magnetic field when the exposure is completed and the temperature thereof falls below the Curie point or compensation point temperature. That is, the magnetization direction is reversed in an image portion colored to a predetermined density or higher compared to other portions. FIG. 2C shows a magnetic latent image on the magnetic belt 1 formed by a recorded image portion 25 whose magnetization direction has been reversed and a background portion 26 whose magnetization direction has not been reversed.

The magnetic latent image thus formed passes directly above the magnetic latent image reading head 8 as the magnetic belt 1 moves. The magnetic latent image reading head 8 is a magnetic latent image sensor array in which a large number of magneto-electric transducers are arranged in a direction perpendicular to the moving direction of the magnetic belt 1 (width direction). Image information on the document 21 can be read by sequentially and repeatedly outputting the electrical signals appearing in these elements from one end of the head to the other end. After the read image information is binarized, it can be sent to another device such as a computer or facsimile. Of course, if such image processing is not performed, the magnetic latent image reading head 8
There is no need to make it work.

The magnetic latent image that has passed above the magnetic latent image reading head 8 then passes between the thermal head 9 and the second bias magnetic field device 11. If necessary, image processing is performed at this timing. An example of image processing is adding an image. Additional image information includes company mark, date and time of copying,
There are numbers etc. that represent the pages of the manuscript. Such additional information is provided as an image signal from a character pattern generator within the copying machine or an external device such as a computer. The additional information is magnetically recorded on the magnetic belt 1 as an additional image portion 28 (FIG. 2D) with the direction of magnetization reversed. If the image information read by the magnetic latent image reading head 8 is processed and then applied to the thermal head 9, it becomes possible to thicken the image or form a double image.

Belt section 1 passing over thermal head 9
A is then developed by the developing device 12. A magnetic toner 29 is contained in the developing device 12 and is attracted onto the recorded image portion 25 and the additional image portion 28 . In this way, a toner image 31 (FIG. 2) is formed on the magnetic belt 1. By reversing the polarity within the developing device 12, it is also possible to form an inverted toner image.

When the magnetic belt 1 moves further and the area on which the toner image is formed reaches the vicinity of the third roller 4, the feed roller 16 is driven and only one sheet of paper 14 stacked in the supply tray 17 is sent out. At the timing when the leading edge of the fed paper 14 passes between the third roller 4 and the copy roll 13, the leading edge portion of the toner image is overlapped with the paper 14. The copying roll 13 magnetically copies the toner image onto the paper 14, and pressurizes and fixes the copied toner image. After fixing, the paper 14 (see FIG. 2) is discharged onto the discharge tray 19. Of course, it is also possible to provide a thermal fixing device between the copy roll 13 and the discharge tray 19 to thermally fix the toner image.

Now, by copying a toner image, the magnetic belt 1
An afterimage of magnetic toner 29 remains on the top. The magnetic belt 1 is cleaned by a cleaning device 15,
Magnetic toner 29 is collected. To collect the magnetic toner 29, well-known methods such as using a cleaning brush or scraping it off with a blade can be used.

After cleaning, the magnetic belt 1 is initialized by the initial magnetization setting device 16 to prepare for the next copying or reading of image information. However, when obtaining a plurality of copies from the same original or when reading additional image information 28 at the same time, the initial magnetization setting device 16 is not operated until these operations are completed. In this case, as the magnetic belt 1 rotates, continuous copying and image information reading by the reading head 8 are performed. If the magnetic belt 1 on which the magnetic latent image is formed is stored as it is, image information can be stored. Also, do not place the document on the platen and place it on the thermal head 9.
When a magnetic latent image is formed using only the magnetic belt 1, it can be independently copied or read, and it can also be stored on the magnetic belt 1 in the same way. This accumulated image information will not be destroyed even if the power to the copying machine is cut off, and moreover, it can be visualized immediately when necessary.

As described above, the present invention does not require a charging process for forming a latent image, unlike an electrostatic copying machine. Therefore, problems such as destruction of thin charging wires and non-uniform charging due to dirt on the thin wires are eliminated, and it is possible to improve the reliability of the copying machine and stabilize the image quality. In addition, in the present invention, a magnetic recording medium in which a relatively transparent magnetic material is formed on a transparent support is used, and flash exposure is performed from the transparent support side of the magnetic recording medium, and the magnetic material is placed on the magnetic layer surface side. Because it illuminates the surface of the document that should be
Compared to the technology described in the issue, there is no need to convert the manuscript to film. Furthermore, compared to the technique described in JP-A No. 53-114170, the present invention has the effect of improving heat generation efficiency because exposure can be performed from the side of the original.

[Brief explanation of the drawing]

The drawings are for explaining one embodiment of the present invention; FIG. 1 is a schematic diagram of a copying machine, and FIGS. 2A to 2F are for explaining each process for copying.
Figure A is a plan view of the original, B is a perspective view of the vicinity of the platen, Figures H to H are plan views showing part of the magnetic belt, F is a plan view of the paper 14 on which copying has been performed,
FIG. 3 is a sectional view showing the structure of the magnetic belt. 1...Magnetic belt, 2-5...Roller, 6...
first bias magnetic field device, 7... heat ray radiation device,
8...Magnetic latent image reading head, 9...Thermal head, 11...Second bias magnetic field device, 12...
Developing device, 13...Transfer roller, 14...Paper, 2
1... Original document, 23... Base layer, 24... Magnetic layer.

Claims (1)

[Scope of Claims] 1. A conveying means for moving a magnetic recording medium having a relatively transparent magnetic layer formed on a transparent support along a predetermined path; Flash exposure is performed from the transparent support side of the recording medium, and the document surface to be placed on the magnetic layer side is irradiated to convert the image information of the document into a thermal pattern, and a magnetic latent image is formed on the magnetic recording medium using a bias magnetic field. a first latent image forming means for forming a magnetic latent image on a magnetic recording medium using a bias magnetic field; A copying machine comprising: a second latent image forming means for forming a magnetic latent image; a developing means for developing the magnetic latent image; and a transfer means for transferring the developed image onto a sheet of paper.