JPS6238481A - Image recording device - Google Patents

Abstract

PURPOSE:To simplify the constitution of a device and to reduce the cost and size of the device by heating a recording medium with a heating member in accordance with a recording image and removing toner from the heated part with a toner removing means. CONSTITUTION:When the recording medium 1 to which toner 9 is uniformly adhered reaches a heating head 14, toner adhesive force due to magnetic force is weakened on the heated part of a recording medium 1 and the original adhesive force is maintained on a non-heated part because the heating head 14 controls heating in accordance with a recording image. Since voltage having reverse polarity against the electric charge of a toner 9 is impressed on a toner removing device 15 by a power supply 16 and the toner 9 from which magnetizing force is removed is sucked and removed from the surface of the recording medium 1 to the toner removing device 15 by electrostatic force, only the toner 1 on the non-heated part is left on the surface of the recording medium 1 and the residual toner 9 is transferred to recording paper 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image recording apparatus, and more particularly to an image recording apparatus that forms an image by depositing toner on a recording medium in response to an image electric signal.

[Conventional technology]

Conventional image recording devices of this type include electrophotographic printers, which release a latent image on a photoreceptor using light and develop it with toner, and electrostatic printers, which release a latent image on a dielectric material using an electric droplet array and develop it with toner. Various recording devices have been proposed and put into practical use, including printers, magnetic printers that form a latent image with magnetism on a magnetic material and develop it with toner, and thermomagnetic printers that form a magnetic latent image with heat on a magnetic material (develop it with toner). It's coming.

[Problem that the invention seeks to solve]

Conventional thermomagnetic printer is $5D from S GFiST
Although it is disclosed in pages 250 to 253, it is not as simple as the electrophotographic method in terms of the types of component parts and the Pl: consideration process, and the present invention has no impact to replace it. It solves the complexity of the thermomagnetic method, and uses a new design process to reduce the number of components and simplify the image forming process, thereby making the device smaller, lower in cost, and more reliable.

[Means to resolve the gap]

The image recording apparatus of the present invention includes a heating member for recording, a recording medium having a magnetic layer on the surface, a toner applying means for applying magnetic toner to the surface of the recording medium, and a toner applying means for applying magnetic toner to the surface of the recording medium. The magnetic layer of the recording medium is uniformly magnetized to have a sharp rate of change in magnetization distribution at a pitch smaller than the recording resolution, and the toner applying means selectively removes the toner. , uniformly applying and adhering toner to the magnetized magnetic layer of the recording medium by magnetic force,
The heating member heats the recording medium in accordance with the recorded image, and the toner removing means removes toner from the heated portion of the recording medium, thereby obtaining a desired image.

〔Example〕

Figure 1 shows an embodiment of the image recording device of the present invention, with 1t
-t, a recording medium, in this example, a plastic film 2 which has been subjected to conductive treatment as shown in the cross-sectional view in Figure 2.
Two layers 11 coated with a magnetic layer 3 of C and Ol
It is already in the form of a seamless belt. The rollers 4, 5, 6.7 are inscribed in the recording medium 1 and drive the recording medium 1 at a constant speed. t, each roller 4, 5,
6.7 is electrically grounded, and the conductive layer of the recording medium 1 in contact with this is also grounded.

8 is a hopper containing 9 tons of magnetic toner, and inside is a toner application roller 1 made of a hollow cylinder made of non-magnetic and conductive material.
1 is immersed in toner 9, and a magnet 10 is placed inside it. 12 is a doctor blade for supplying a constant thickness of toner 9' onto the toner application roller 11; 13 is a power source for applying a constant DC voltage to the application roller 11; 14 is a heating head, which is shown here as an array of heat-generating resistive layers on a ceramic substrate and an electrographic array for supplying current to the heat-generating resistive layers, and is equivalent to a heating head used in a normal thermal recording device. It is something. Reference numeral 15 denotes a toner removing device for removing unnecessary toner 9, which is housed here by an electrical board to which a constant DC voltage is applied by a DC power source 16. Reference numeral 11 denotes a transfer device that uses corona discharge to transfer the toner image on the recording medium 1 to the recording paper 18. A fixing device 19 fixes the toner 01 on the recording paper 18 by heat or pressure.

The magnetic layer 3 of the recording medium 1 is magnetized in advance, and the state of magnetization is shown in Figure 3.
In an example in which the ffl material layer 3 is made into a main body layer 3fl, the direction of magnetization is reversed at a constant pitch P, but this pitch P is made smaller than the resolution of the recorded image.

That is, although the pitch is smaller than the pitch of the heating resistor array of the heating head 15, the leakage magnetic flux due to the magnetization of the magnetic layer 3 is as shown in the figure φ, and its rate of change is dφ/dX. The magnetic powder adheres to this surface because the absolute value of the rate of change of the leakage magnetic field, 1dφ/dX1+, is large. Figure 3 (b) is an example in which the magnetic layer 3 is perpendicularly @-shaped, and in this case too, the pitch P is smaller than the resolution of the recorded image.
The direction of magnetization is reversed. The reason for this is φ, dφ/
The situation of dX is similar to that of horizontal magnetization.

Returning to Figure 1, the recording medium 1 thus magnetized is driven in the direction of arrow A by rollers 4.5 and 6.7. On the other hand, the toner 9 in the fuser 8 is attracted to the toner application roller 11 by the action of the magnet 10, and as the toner application roller 11 rotates in the direction of arrow B, the toner 9 is conveyed and a uniform layer of toner is formed by the doctor blade 12. This toner 9 obtains a charge by applying a DC voltage from a bias voltage [13]. When one layer of toner on the toner application roller 11 contacts the recording medium 1, the toner 9
Since it is a magnetic substance with an electric charge, it is uniformly adhered to the recording medium 1 by magnetizing force and electrostatic force. Regarding the magnetizing force, since the rate of change dφ/dX of the magnetic field shown in FIG. 3 is not constant, uneven adhesion of the toner 9 occurs, but this can be ignored because the magnetization pitch P is smaller than the recording resolution.

When the recording medium 1 with the toner 9 uniformly adhered to its surface reaches the heating head 14, the heating head 14 controls the heat generation of its heat generating section in accordance with the recorded image, so that the heating section of the recording medium 1 The adhesion force due to the magnetization force of the toner 9 is weakened, and the original adhesion force is maintained in the non-heated portion. The reason for this is that in this embodiment, the Curie temperature of the magnetic layer 3 on the recording medium 1 is 761 m, and the Curie temperature of the magnetic toner 9 is T6! *If the temperature applied by the heating head 14 is TH, then Ta1>TH>Ta2, so the toner 9 in the heating section on the recording medium 1 has a Curie temperature and is therefore non-magnetic. be.

The toner removing device 15 has an electric charge applied to the toner 90 by an electric current 16 and a reverse voltage, and removes the toner 9 that has lost its magnetizing power from the recording medium 1 by an electrostatic force.
The toner 9 is removed from the recording medium 1 by suction to the recording medium 1. Therefore, only the toner 9 in the non-heated portion remains on the recording medium 1. 17 is a transfer device that transfers this residual toner 9 onto the recording paper 18. .

Here, a corona transfer device used in ordinary electrophotography is used, and the toner particles transferred onto the recording paper 18 are
The fixing device 19 fixes the image by pressure or heat and outputs the image.A small amount of toner that was not transferred to the recording paper 18 remains on the recording medium 1 after the transfer device 17, but a cleaning device removes this. I feel anxious. This is because once the toner application roller 11 is reached, the toner 9 is uniformly deposited again.Also, since the magnetic layer 3 is not heated above its Curie temperature To1, its magnetization is maintained. No equipment is required. These are necessary in the conventional device, and are simplified accordingly, allowing the device to be reduced in cost and size.

The present invention is not limited to the above, and various modifications as described below are possible.

The material of the magnetic layer of the recording medium is CyO.

There's no reason why it has to be.

As for the heating head, it is possible to use the heat generated by irradiating it with laser light, or to apply current-carrying thermal technology1.
What is the application of energizing thermal? The heating head is composed of a TT plate array, and a energizing heat generating layer is placed on the recording medium, and heat is generated by electricity from the head. is omitted, improving responsiveness (improving printing speed).

Depending on the applied temperature, Tc, (as a TIE, a recording medium magnetization device is provided after the transfer device. In this case, a magnetization device is required, but the Curie temperature Tc* of the toner can be ignored. Also, the toner imparts an electric charge It is also possible to attach the toner to the recording medium using only magnetic force, demagnetize the recording medium by heating, and remove the toner using, for example, magnetic force (the toner removing device is a permanent magnet).About the toner removing device There are two methods: making it into a roller shape and removing the toner attached to the surface with a rubber blade, using magnetic force as mentioned above in addition to electrostatic force, blowing it off with air, sucking it with a blower, and reusing the removed toner. etc. are also possible.

Regarding the transfer device, a method using magnetic force is also possible.

〔Effect of the invention〕

As described above, according to the present invention, the structure is simplified, the cost is reduced, and the device is made smaller.Since a cleaner is not required, no external force is applied to the recording medium, so durability is improved. The surface of the recording medium is a magnetic layer, which has advantages such as improved durability compared to electrophotographic photoreceptor layers, and the ability to ignore the special characteristics of photoreceptors such as dark decay and carrier mobility. .

[Brief explanation of the drawing]

Figure 1 is a sectional view showing an embodiment of the image recording apparatus of the present invention, Figures 2 and 3 are detailed views of the recording medium shown in Figure 11, respectively. l@ Recording medium 8 fists... Toner supply hopper 14...
・Heating head 15...Fist toner removal device 17・φ・Transfer device 19...Fixing device Above

Claims (1)

[Claims] A recording heating member, a recording medium having a magnetic layer on its surface, a toner applying means for applying magnetic toner to the surface of the recording medium, and a toner removing means for selectively removing the toner applied to the surface of the recording medium. The magnetic layer of the recording medium is uniformly magnetized and has a sharp rate of change in magnetization distribution at a pitch smaller than the recording resolution, and the toner application means magnetizes the recording medium. The toner is uniformly coated and adhered to the magnetic layer by magnetic force, the heating member heats the recording medium in accordance with the recorded image, and the toner removing means removes the toner from the heated portion of the recording medium. An image recording device characterized in that a desired image is obtained by removing.