JPH05197314A - Magnetic printer and magnetic latent image erasing and forming method - Google Patents

Abstract

PURPOSE:To provide a small and thin type magnetic printer whose construction elements are simplified by using a composite magnetic head unifying a magnetic head erasing a latent image and a head for latent image formation, are integrated. CONSTITUTION:The head 1 is a magnetic head provided with multi-channels having several tens to several hundreds of channels and it is also a composite magnetic head unifying a magnetic head to erase the magnetic latent image and a head for formation of the magnetic latent image. A magnetic drum 2 is rotated at a fixed speed, and the magnetic latent image is formed while the magnetic head 1 is scanned. The formed magnetic latent image is visualized by sticking developer 8, in other words magnetic toner, by the developing device 3. Next, the visualized image is transferred to recording paper 7 by a transfer roll 4. The transferred image is thermally fixed to the recording paper by a fixing device 5. Remaining toner on the magnetic drum 2 is removed by cleaner 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer used as an external output device such as a computer, and more particularly to a magnetic head used in a magnetic printer and a method for erasing and forming a magnetic latent image.

[0002]

2. Description of the Related Art Conventionally, a printing device, such as a magnetic printing device, used as an external output device for a computer or the like has a drum surface around a recording medium formed on a drum-shaped support as shown in FIG. A latent image erasing device for degaussing and a magnetic latent image forming device for recording a magnetic latent image on a drum by using a magnetic head, a developing device for visualizing a magnetic toner by attaching magnetic toner to the magnetic latent image, and a visualized image And a cleaning device for cleaning the residual toner remaining on the drum. Among them, the magnetic head used for forming the magnetic latent image may be a full line head in which heads are arranged in the width direction of the paper by the number of print dots obtained from the resolution, or a multi-channel head composed of a plurality of heads. In the case of a full line head, for example, if the resolution is 300 DPI, A4
To cover the recording width of the size paper in the width direction, 2500 heads are actually required. If these are arranged side by side to form a full line, it is not necessary to scan the head, and extremely high speed recording is possible. However, the full line head has a problem in that it is difficult to manufacture the head itself and the cost is huge. Therefore, in practice, a method of scanning and recording with a head of several tens to several hundreds of channels is adopted. The above magnetic head is a recording-only head used only for forming a magnetic latent image.

[0003]

However, in the conventional magnetic printing apparatus, in consideration of the continuous flow of the process, each component is arranged around the recording medium formed on the drum-shaped support. . Further, the recording medium is usually sized to cover the length of one page of paper. Therefore, there is a problem that the device becomes large. Further, in the conventional magnetic printing apparatus, since the magnetic latent image cannot be partially erased, there has been a problem that the magnetic latent image for one page has to be erased and recorded again to correct a slight character.

The present invention is intended to solve such a problem, and an object of the present invention is to provide a printing device used as an external output device for a computer or the like, particularly a magnetic printing device, in which the components are simplified and small in size and thin. To provide a magnetic printing device of the above.

[0005]

A magnetic printing apparatus of the present invention is a magnetic printing apparatus including a magnetic latent image forming apparatus, a developing apparatus, a transfer apparatus and a cleaning apparatus, which erases a magnetic latent image formed on a recording medium. A composite magnetic head in which a magnetic head for magnetic recording and a magnetic latent image forming head are integrated is used. In the magnetic latent image erasing and forming method in the magnetic printing apparatus of the present invention, the composite type magnetic head is scanned to simultaneously form the magnetic latent image while the magnetic latent image is erased in advance. It is characterized in that the magnetic latent image is erased by direct current or alternating current.

[0006]

EXAMPLES The present invention will be described in detail below based on examples. FIG. 1 is a diagram for explaining the configuration of the magnetic printing apparatus of the present invention. Here, 1 is a multi-channel magnetic head having several tens to several hundreds of channels, which is a composite magnetic head in which a magnetic head for erasing a magnetic latent image and a magnetic latent image forming head are integrated. This head will be described later. The process from magnetic latent image formation to fixing will be briefly described. First, the magnetic drum 2 is rotated at a constant speed, and the magnetic head 1 is scanned to form a magnetic latent image. The developing device 3 attaches a developer 8, specifically a magnetic toner, to the formed magnetic latent image to visualize it. Next, the visualized image is transferred by the transfer roller 4 to the recording paper 7 inserted from the right side of the drawing. The transferred image is thermally fixed on the recording paper by the fixing device 5. After that, the cleaner 6 removes the residual toner remaining on the magnetic drum. Known methods are used for developing, transferring and fixing.

In contrast to this, FIG. 2 is a diagram for explaining the configuration of a conventional magnetic printing apparatus. The same components as those in FIG. 1 are designated by the same reference numerals as those in FIG. Before the magnetic head 9 dedicated to recording forms a magnetic latent image, the degausser 10 is used to degauss the magnetic latent image. The process from development to fixing is the same as in the present invention. The degausser usually uses a permanent magnet or electromagnet having a size that covers the width of the recording paper. The degausser is placed adjacent to the magnetic head and requires a mechanism for holding it and a mechanism for moving it up and down with respect to the medium. Furthermore, since the conventional degausser cannot partially erase the magnetic latent image, even if a slight correction is made, the magnetic latent image for one page must be erased and recorded again.

FIG. 3 is a schematic perspective view showing an embodiment of a composite type magnetic head used in the magnetic printing apparatus of the present invention. Actually, the magnetic head has multi-channels of several tens to several hundreds of channels, but here, for convenience of explanation, the case of one channel is shown. One is for erasing and the other is for forming a latent image with the spacer 14 in between. When the erasing coil 13 is wound around the erasing core 11 and a predetermined current is passed through, a magnetic flux leaks from the erasing gap 12. The leakage magnetic flux erases the magnetic latent image recorded on the recording medium. Erase gap 1
2 is a gap wider than the recording gap 17 of the recording head, and the track width is also wide so that erasing can be sufficiently performed. On the other hand, the structure of the recording head is the same as the conventional one. An erasing head and a recording head are integrated to form a composite magnetic head. The composite type magnetic head in which erasing and recording are integrated is already used in a magnetic storage device such as a floppy disk device, and the manufacturing method is known. A method of erasing and forming a magnetic latent image using this head will be described with reference to FIG. This figure shows a state where the drum-shaped recording medium 30 and the composite type magnetic head are sliding. The large arrow in FIG. 5 indicates the scanning direction of the head. The medium is demagnetized by the leakage magnetic flux generated from the erase gap 26. As shown in the figure, a new magnetic latent image 31 is formed by the recording head arranged behind while erasing the previously recorded latent image in advance while scanning the head. The width of the preceding erasure is made wider than the width of recording the magnetic latent image to reduce the influence from the adjacent latent image. By using such a method for erasing a magnetic latent image, the magnetic latent image can be partially erased, and even slight correction of characters can be performed at high speed.

Next, regarding the erasing method, the DC method or the AC method is used in the present invention. FIG. 6 is a diagram for explaining the erasing of the magnetic latent image in the magnetic printing apparatus of the present invention, which is the case of erasing by the DC method. (A) is a figure which shows the time change of an erasing magnetic field, (b) is a figure explaining the magnetic characteristic of a recording medium with a change of an erasing magnetic field on a hysteresis loop. The direct current method is a method in which a strong direct current magnetic field Hs is applied to the recording medium as shown in (a) to saturate the medium in one direction, and is also called a direct current saturation degaussing method.
Considering on the hysteresis loop of (b), when a DC magnetic field Hs that is sufficiently larger than the coercive force of the recording medium is applied, the magnetization of the medium is brought to Bs in the figure, that is, the saturation region.
Then, when the erasing operation ends and the erasing magnetic field is removed, the magnetization of the medium becomes the residual magnetization Br. The state in which Br is magnetized is the demagnetized state by the DC method. In contrast to this, FIG. 7 shows the case of erasing by the AC method. 6A and 6B show the contents corresponding to FIGS. 6A and 6B, respectively. In the AC method, a magnetic field, which has a frequency much higher than that of the recording signal and is temporally attenuated, is applied to the recording medium by the erasing head as shown in (a). Then, the magnetization of the medium is once brought into the saturation region on the hysteresis loop as shown in (b), and then gradually attenuates and follows the minor loop toward the central zero point, and finally settles at this zero point. Therefore, this zero point is the demagnetized state by the AC method. In addition to the above, the AC method also includes a method of moving the erasing head away from the medium itself while applying a magnetic field having a high frequency and which is not attenuated in time to the medium.

Next, the scanning positioning of the composite magnetic head including the erasing head will be described with reference to FIG. FIG. 4 is a schematic perspective view showing an embodiment of the carriage mechanism portion of the magnetic printing apparatus of the present invention. The carriage 18 on which the composite magnetic head 19 described with reference to FIGS. 1 and 3 is mounted is supported by a slide bearing 21 and reciprocates on a guide shaft 20. At that time, the rotation of the motor 23 is transmitted to the carriage through the timing belt 22. A DC motor is mainly used as the motor, and the rotary encoder 24 is directly connected to the motor shaft. The encoder output is fed back to the motor control circuit to perform closed-loop control and position the carriage. Although the above description has been made with respect to the sub-scanning direction which is the main axis direction of the drum, in reality, the positioning is performed in accordance with the main scanning direction of the rotating direction of the drum.

In the above embodiment, the composite type magnetic head used in the magnetic printing apparatus has been described as a bulk type, but it may be a thin film type head. In addition to the above-described embodiment, the carriage mechanism may be driven by directly driving the carriage using a stepping motor or a linear motor.
Further, a wire rope or a feed screw may be used for transmitting power in the carriage mechanism. Further, in the above embodiment, the case of the recording medium formed on the drum-shaped support has been described, but the recording medium may be formed on the film-shaped or plate-shaped support.

[0012]

As described above, according to the present invention, a composite type magnetic head in which a magnetic head for erasing a magnetic latent image formed on a recording medium and a magnetic latent image forming head are integrated is used. Since the conventional magnetic latent image erasing device can be omitted, a compact and thin magnetic printing device can be constructed. Further, according to the present invention, since the magnetic latent image can be formed simultaneously while scanning the composite type magnetic head to erase the magnetic latent image in advance, it is possible to partially erase the magnetic latent image, thereby making it possible to slightly erase characters. Can be corrected at high speed. Furthermore, the carriage drive mechanism can be configured with the same system as before without adding any complicated parts.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration of a magnetic printing apparatus of the present invention.

FIG. 2 is a diagram illustrating a configuration of a conventional magnetic printing device.

FIG. 3 is a schematic perspective view showing an embodiment of a composite magnetic head used in the magnetic printing apparatus of the present invention.

FIG. 4 is a schematic perspective view showing an embodiment of a carriage mechanism section of the magnetic printing apparatus of the present invention.

FIG. 5 is a diagram illustrating a method of erasing and forming a magnetic latent image in the magnetic printing apparatus of the present invention.

FIG. 6A is a diagram illustrating an erasing magnetic field when a magnetic latent image is erased by a direct current method in the magnetic printing apparatus of the present invention. FIG. 6B is a diagram illustrating magnetic characteristics of a recording medium when a magnetic latent image is erased by a direct current method.

FIG. 7A is a diagram illustrating an erasing magnetic field when a magnetic latent image is erased by an AC method in the magnetic printing apparatus of the present invention. FIG. 6B is a diagram illustrating magnetic characteristics of a recording medium when a magnetic latent image is erased by an AC method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Composite type magnetic head 2 Magnetic drum 3 Developing device 4 Transfer roller 5 Fixing device 6 Cleaner 7 Recording paper 8 Developer 9 Magnetic head 10 Degausser 11 Erasing core 12 Erasing gap 13 Erasing coil 14 Spacer 15 Recording core 16 Recording Coil 17 recording gap 18 carriage 19 composite magnetic head 20 guide shaft 21 sliding bearing 22 timing belt 23 motor 24 rotary encoder 25 erasing core 26 erasing gap 27 recording core 28 recording gap 29 spacer 30 recording medium 31 magnetic latent image

Claims (3)

[Claims] 1. A magnetic head for erasing a magnetic latent image formed on a recording medium and a magnetic latent image forming head in a magnetic printing device comprising a magnetic latent image forming device, a developing device, a transfer device and a cleaning device. A magnetic printing apparatus characterized by using a composite type magnetic head in which the above are integrated. 2. A magnetic latent image erasing and forming method in a magnetic printing apparatus, wherein the composite type magnetic head is scanned to simultaneously erase the magnetic latent image while simultaneously forming the magnetic latent image. 3. The magnetic latent image erasing and forming method in a magnetic printing apparatus according to claim 2, wherein the erasing of the magnetic latent image by the composite type magnetic head is performed in a direct current or an alternating current manner.