JPS62222281A - Fixing method - Google Patents

Abstract

PURPOSE:To improve energy efficiency and to reduce the size and weight of a device by heating a heating element of a thermal head in accordance with a prescribed signal and impressing the heat to an image surface to fix the image. CONSTITUTION:In a fixing part 2, the thermal head 3 to be heated by a prescribed signal is opposed to a guide memory 4 and heat is impressed to an image surface during the passage of a recording medium 1 between the head 3 and the member 4. The thermal head 3 is obtained by arraying many heating elements 3b on a line and signal electrodes 3c and common electrodes 3d are connected to respective heating elements 3b. If voltages are impressed to the electrodes 3c, 3d in accordance with signals from a control part, the heating elements 3b are individually heated. The guide member 4 for guiding the carried recording medium 1 is constituted of a metallic plate member and arranged so as to be opposed to the heating surface of the thermal head 3. Thus, heat is applied to the image surface of the recording medium 1 by uniformly heating the heating elements 3b arrayed like a line to solubly fix the toner image.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixing method used for image formation in copying machines, printers, etc.

<Prior Art> In an image forming apparatus such as a copying machine, as shown in FIG. The toner is developed in the developing section 7,
The toner image is transferred onto a recording paper 9 in a transfer section 8.

Since the I/S image transferred to the recording paper 9 is unfixed, it easily peels off. Therefore, in a general image forming apparatus, the first image is fixed in the fixing section 2 and then discharged from the apparatus.

As shown in FIG. 6(A), the conventional method for fixing the toner image is to apply heat to the recording paper surface by bringing it into contact with a heat roller 11 containing a built-in halogen heater 10, etc. A thermal fixing method in which the toner is fixed by heat, or a recording paper 9 is passed between a pair of rollers 12 pressed against each other to apply pressure as shown in FIG. 6(B),
There is a pressure fixing method in which toner is fixed by the pressure.

<Problems to be solved by the invention> However, among the above fixing methods, the heat fixing method requires the use of a heater with a capacity of several hundred watts, which is not economical in terms of power consumption. There are also problems such as the need to provide a protective circuit because of the risk of fire.

Furthermore, in the pressure fixing method, a large amount of torque is required to rotate the pair of pressure rollers, so the motor for conveying the recording paper must be made larger, and furthermore, the recording paper is attached to the pair of pressure rollers. There are problems such as the surface becoming glossy due to being pressed with the surface.

In any case, the energy efficiency of the structure for dissolving and fixing the toner was extremely poor.

The present invention aims to solve the above-mentioned conventional problems and provide a fixing method with good energy efficiency.

Means for Solving the Problems> Means of the present invention for solving the above-mentioned conventional problems is that in a fixing method for fixing an unfixed image formed on a recording medium, heat is generated in response to a predetermined signal. The heat generating surface of the heat generating throat, which has a heat generating element, is arranged to face the recording medium, and is moved relative to the recording medium to apply heat to the image surface of the recording medium.

<Operation> According to the above means, it is possible to fix the image by applying heat to the image plane by generating heat in the heating element of the throat.

Example Next, an embodiment of the present invention to which the above means is applied will be described.

FIG. 1 is an explanatory diagram of the structure of the fixing mechanism. In the figure, a recording medium 1 on which a toner image has been transferred is conveyed in the direction of arrow a by a conveying means (not shown) and passes through a fixing section 2.

The fixing section 2 is provided with a heat generating throat 3 and a guide member 4 facing each other in response to a predetermined signal, and applies heat to the image surface of the recording medium 1 while it passes between them.

Here, the configuration of the fixing section 2 will be explained. First, the thermal head 3 has a large number of heating elements 3 on a base 3a as shown in FIG.
b are arranged in a line, and a signal electrode 3C and a common i11 electrode 3d are connected to each of the heating elements 3b. Therefore, when a voltage is applied between the electrodes 3c and 3d in response to a signal from a control section (not shown), the heating elements 3b individually generate heat.

The guide member 4 guides the recording medium 1 being conveyed, is made of a metal plate member, and is disposed so as to face the heat generating surface of the thermal head 3.

Both ends of the thermal head 3 and the guide member 4 are fixed to the main body of the apparatus, and the heat generating surface of the thermal head 3 contacts the image forming surface of the recording medium 1 being conveyed, and the guide member 4 contacts the back surface of the recording medium 1. is installed to support it.

Therefore, when the recording medium 1 passes through the fixing section 2, heat is applied to the image surface of the recording medium 1 by uniformly generating heat from the heating elements 3b arranged in a row, and the toner image is dissolved and fixed. It is something.

In the above-mentioned embodiment, the heating throat 3 was fixed to the main body of the apparatus, but it may be swung as necessary.

Furthermore, the arrangement of the heat generating elements 3b in the heat nozzle 3 is not limited to the single row described above, but may be arranged in multiple rows as shown in FIG. 3 so that the cough heat generating elements 3b uniformly generate heat. . With this configuration, the conveyance speed of the recording medium 1 can be increased when the same amount of heat is applied, compared to the case where there is only one row.

For example, when n rows of heating elements 3b are provided, FIG. 4(A)
If we look at a point A in the image formed on the recording medium 1 as shown in FIG. 1B, the heating element 3b contacts the point A 0 times. Therefore, compared to the case where the heating elements 3b are arranged in a single line, even if the recording medium 1 is moved at n times the speed, the same amount of heat can be applied and reliable fixing can be performed.

Furthermore, the timing of heat application is such that, in addition to uniformly generating heat in the heat generating elements 3b as described above, for example, the conveyance speed and conveyance timing of the recording medium 1 are controlled, and the heat generating elements 3b are applied in response to the same pulse signal as the image recording signal. If 3b is configured to generate heat, heat is applied only to the image portion of the recording medium 1, so power consumption can be extremely reduced.

Furthermore, the guide member 4 is not limited to metal as described above as long as it has heat resistance.

Further, the shape is not limited to a plate shape, and may also be configured by, for example, a pressure roller or the like and rotated in accordance with the conveyance of the recording medium 1.

<Effects of the Invention> As described above, the present invention uses a thermal head to apply heat to an unfixed image to fix it, so it is possible to significantly improve energy efficiency compared to conventional fixing methods. Moreover, no warm-up time is required. Furthermore, the device can be made smaller and lighter, and furthermore, by heating with multiple rows of heating elements, the fixing time can be increased.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of a fixing mechanism according to an embodiment of the present invention, FIG. 2 is an explanatory plan view of a thermal head, FIG. 3 is an explanatory diagram of a thermal head provided with multiple rows of heating elements, and FIG. Diagram (A) (B)
FIG. 5 is an explanatory diagram of the image forming process, and FIG. 6 is an explanatory diagram of the conventional fixing method. 1 is a recording medium, 2 is a fixing section, 3 is a thermal head, 3a is a base, 3b is a heating element, 3C is a signal electrode, 3d is a common electrode,
4 is a guide plate.

Claims (2)

[Claims] (1) In a fixing method for fixing an unfixed image formed on a recording medium, the heating surface of a thermal head having a heating element that generates heat in response to a predetermined signal is faced to the recording medium, and , a fixing method characterized by applying heat to an image surface of a recording medium while moving the recording medium relatively. (2) The fixing method according to claim 1, wherein the heating elements are formed in a plurality of rows, and the heating elements uniformly generate heat to apply heat.