JP3207478B2 - Heating body manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a heater used as a heater for a toner fixing section in a copying machine.

[0002]

2. Description of the Related Art Conventionally, a heating element used as a heater for a toner fixing section in a copying machine is disclosed in, for example, JP-A-2-65086 and JP-A-2-129883. On the upper surface of the rectangular insulating substrate, a band-shaped electric resistance film is formed so as to extend in a straight line along the longitudinal direction of the insulating substrate, and energization terminal portions for both ends of the electric resistance film are formed, The electric resistance film is configured to generate heat by the application of current from the current-carrying terminals at both ends.

Conventionally, a band-shaped electric resistance film in a heating element of this type is formed by applying a material paste constituting the electric resistance film on the upper surface of an insulating substrate in a band shape by screen printing and then firing. I am trying to do it.

[0004]

The amount of heat generated in the electric resistance film of the heating element is determined by its resistance value, and the resistance value is determined by the cross-sectional area (that is, width and thickness) of the electric resistance film. ), And the length of the electric resistance film, and the specific resistance of the electric resistance film, the heating value of the electric resistance of the heating element is set to the same value for each of the plurality of heating elements. In the above, the cross-sectional area and length dimensions and specific resistance,
It is necessary to make the same for each of the plurality of heating elements.

However, conventionally, the electric resistance film in the heating element is formed by applying a material paste by screen printing and then sintering the material paste as described above. Since the shape and dimensions of each heating element become irregular,
The resistance value of the electric resistance film cannot be set to the same value for each of the plurality of heating elements. In other words, a large variation occurs in the resistance value of the electric resistance film of each heating element, that is, the amount of generated heat. Become.

Moreover, the variation in the calorific value of each of the heating elements further increases due to the variation in the specific resistance of the electric resistance film due to the variation of each of the plurality of heating elements. Since the out-of-range rate increases, there is a problem that the yield rate is low when manufacturing a heating element having a resistance value falling within a predetermined standard range.

[0007] Among the heating elements manufactured by the above method, for the heating element whose resistance value in the electric resistance film is lower than a predetermined standard, a part of the electric resistance film in the heating element is cut out by a laser or the like. If the resistance is adjusted so that the resistance value falls within the predetermined standard range by performing trimming, the yield rate can be improved. Since the width is reduced due to trimming for value adjustment and the heat generation amount in the portion becomes locally larger than the heat generation amount in other portions, the heat generation amount along the longitudinal direction of the electric resistance film is reduced. Another problem is that the temperature distribution becomes uneven.

[0008] An object of the present invention is to provide a manufacturing method capable of solving these problems.

[0009]

In order to achieve this technical object, the present invention provides a method for forming a linear paste on a top surface of an insulating substrate by screen printing a material paste constituting an electric resistance film.
An electric resistance film is formed by firing after coating so that the effective length portion of the electric resistance film
The surface in minutes has a width approximately the same as the effective length dimension
The dimension of the polishing sheet is set so that the axis is the length of the electric resistance film.
And the axial length dimension is at least said effective
Press with a presser roller approximately the same as the length
In this state, the polishing sheet is perpendicular to the longitudinal direction of the electric resistance film.
It polished I'm to be moved feed in the direction of the corner. "It was to be.

[0010]

As described above, when the surface of the effective length portion of the electric resistance film formed in the shape of a straight strip is polished, the thickness of the electric resistance film becomes thin, so that the resistance value of the electric resistance film becomes large. Therefore, the resistance value of the electric resistance film is added to the effective length of the electric resistance film .
The surface can be adjusted so as to fall within a predetermined specification range by polishing the surface.

When a heating element is used as a heater for a toner fixing section in a copying machine, the surface of an effective length portion of the electric resistance film of the heating element is coated with a sheet as an object to be heated. And the axis is
Reduce the length dimension of the anti-membrane in the longitudinal direction and the axial direction
Is also pressed by the feed roller which is almost the same as the effective length
And in this pressed state, the paper
It is configured to feed and move at right angles to the longitudinal direction of the membrane.
You.

Therefore, the effective length portion of the electric resistance film
Polishing on the surface in minutes, the effective length on this surface
Abrasive sheet with approximately the same width dimension as
Reduce the length of the electrical resistance film in the longitudinal direction and the axial direction.
At least to the press roller which is almost the same as the effective length
And press the polishing sheet in this state.
By performing the feeding movement in a direction perpendicular to the longitudinal direction of the film, the effective length portion of the electric resistance film is formed.
The effective length portion of the electric resistance film is formed such that a trace of a line due to polishing is formed in the moving direction of the paper on the surface of the electric resistance film.
The surface in the minute can be polished to the condition when the paper is actually pressed and fed .

Therefore, according to the present invention, of the plurality of heating elements, the heating element whose resistance value in the electric resistance film is lower than a predetermined standard impedes the temperature distribution in the electric resistance film in the longitudinal direction. Without performing, since the resistance value of the electric resistance film in the heating element can be adjusted to fall within a predetermined specification range, when manufacturing a heating element having a resistance value falling within a predetermined specification range. Yield rate can be greatly improved, manufacturing costs can be reduced, and the effective length of the electrical resistance film
If the surface of the part is moved by pressing the paper, which is the object to be heated, with a roller , the paper may be damaged.
Optimal condition, so that you can reduce the number of
It has the effect that can be .

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes an insulating substrate formed in a rectangular shape from a heat-resistant insulating material such as ceramic, and a slit-shaped opening window 2a is formed on the upper surface of the insulating substrate 1 as shown in FIG. Are stacked, and then Ag is inserted into the cutout window 2a of the screen plate 2.
By performing screen printing to remove the screen plate 2 after filling with the Pd paste, the Ag-Pd paste is applied in a straight strip shape, and then placed in a heating furnace and fired, whereby the insulating substrate is removed. As shown in FIG. 3, a band-shaped electric resistance film 3 is formed on the upper surface of the substrate 1.

Next, an Ag paste is applied to the upper surface of both ends of the insulating substrate 1 and then baked in a heating furnace, as shown in FIG.
Are formed at both ends of the terminal.

Then, by applying a predetermined current between the current-carrying terminals 4 and 5, the resistance value of the electric resistance film 3 is measured by a resistance measuring instrument 6 as shown in FIG. .

If the resistance value of the electric resistance film 3 is determined to be lower than a predetermined standard range by the measurement of the resistance value, as shown in FIGS. In a state where the resistance value of the film 3 is measured by the resistance measuring device 6, the width dimension of the portion of the effective length L of the surface which is taken out from the pay-out roll 7 and then sequentially taken up by the take-up roll 8. S (this width dimension S
It is the abrasive sheet 9 of the effective equivalent to the length L), the axis
Is the longitudinal direction of the electric resistance film 3 and the length in the axial direction
Times when the dimension is at least substantially equal to the effective length dimension L
The roller is pressed by the rubber pressing roller 10 which rolls.
In the direction perpendicular to the longitudinal direction of the electric resistance film 3,
By moving the feed in degrees, of the electrically resistive film 3
The surface in the portion of the effective length L is polished.

Then, the portion of the effective length L of the electric resistance film 3 is reduced in thickness along the length direction of the portion of the effective length L by the polishing, so that the effective length L is reduced. Since the resistance value of the electric resistance film 3 increases, when the resistance value falls within a predetermined standard range, the polishing is stopped by raising the pressing roller 10.

Accordingly, among the plurality of heating elements manufactured, if the resistance value of the electric resistance film is lower than a predetermined standard, the distribution of the temperature in the longitudinal direction of the electric resistance film is hindered. Since the resistance value of the electric resistance film in the heating element can be adjusted so as to fall within a predetermined specification range, the yield when manufacturing a heating element having a resistance value falling within the predetermined specification range can be obtained. The rate can be greatly improved.

It is needless to say that, at the time of the polishing, the pressing roller 10 may be reciprocated in a direction perpendicular to the longitudinal direction of the electric resistance film 3.

[Brief description of the drawings]

FIG. 1 is a perspective view of an insulating substrate.

FIG. 2 is a perspective view showing a state in which a screen plate is overlaid on an upper surface of the insulating substrate.

FIG. 3 is a perspective view showing a state in which an electric resistance film is formed in a band shape on the upper surface of the insulating substrate.

FIG. 4 is a perspective view showing a state where current-carrying terminals are formed at both ends of the electric resistance film.

FIG. 5 is a perspective view showing a state where the surface of the electric resistance film is being polished.

FIG. 6 is an enlarged sectional view taken along line VI-VI of FIG. 5;

FIG. 7 is an enlarged sectional view taken along line VII-VII of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating substrate 2 Screen board 2a Opening window 3 Electric resistance film 4,5 Current-carrying terminal part 6 Resistance measuring instrument 9 Polishing sheet 10 Holding roller

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H05B 3/10 B41J 2/32 B41J 2/335 H05B 3/00 335 H05B 3/16 G03G 15/20

Claims (1)

(57) [Claims] 1. A material paste for forming an electric resistance film is formed on a top surface of an insulating substrate by screen printing so as to extend in a linear band shape.
The electrically resistive film formed by baking After urchin Nurigi, then you the effective length portion of the electrically resistive film
To the same width as the effective length.
Polished sheet, the axis line in the longitudinal direction of the electric resistance film
And the axial length dimension is at least the effective length dimension.
Press with a holding roller that is almost the same as the method, and in this state,
Orient the polishing sheet at right angles to the longitudinal direction of the electric resistance film.
Method for manufacturing a heating element, which comprises grinding I by the moving feeding countercurrent.