JPH08162262A - Heating body and manufacture thereof - Google Patents

Abstract

PURPOSE: To prevent a heating body from cracking, enlarge the heating surface area satisfy withstand voltage standards with the minimum width of the heating body, and provide satisfactory fixing function by installing a plurality of resistors for heating on a heater substrate and forming an electrically insulating layer. CONSTITUTION: A first and a second resistor patterns 2a, 2b are formed in one face of a ceramic substrate 3 of alumina. etc., in parallel along the longitudinal direction of the substrate. One end parts of the patterns 2a, 2b are respectively connected with electricity supplying electrode patterns 1a, 1b through conductor patterns 4a. 4b. The other ends of the patterns 2a, 2 are connected with a conductor pattern 4c. The resistor formed parts of the substrate 3 are coated with a glass layer 6 as an electrically insulating layer. The patterns 2a, 2b are formed by, for example, printing a resistor paste prepared by mixing a metal e.g. Ag, Pd, etc., with a glass paste into thin stripe patterns with prescribed width and thickness by screen printing and sintering the patterns. The glass layer 6 is also formed by screen-printing a glass paste and then sintering the paste.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heater base material (substrate).
And a heating element of a type which has a resistor (a resistance heating element, an energization heating resistor) formed and equipped on the heater base material as a basic constituent body and energizes the resistor to generate heat, and a manufacturing method of the heating element. Regarding the method.

[0002]

2. Description of the Related Art Conventionally, for example, in an image forming apparatus such as an electrophotographic copying machine, a printer, a facsimile, etc., a heat-fixing developing agent (e.g., a heat-fixing agent) by an appropriate image forming process means such as electrophotography, electrostatic recording, magnetic recording, etc. Undefined corresponding to the intended image information that is formed and carried by the indirect (transfer) method or the direct method on the surface of the recording material (transfer material sheet, printing paper, electrofax sheet, electrostatic recording sheet, etc.) using toner As a heating device (image heating and fixing device) for heating and fixing the image of the developer image on the surface of the recording material, a heat roller type device is generally widely used.

This heating device of the heating roller type is a pressure contact nip between a heating roller (fixing roller) maintained at a predetermined heating temperature by heat generated by a built-in heat source such as a halogen heater and an elastic pressure roller pressed against the heating roller. A recording material as a material to be heated is introduced into a portion (fixing nip portion) and is nipped and conveyed to heat and fix the unfixed developer image on the surface of the recording material by the heat of the heating roller.

However, in the heating device as the image heating and fixing device of the heat roller system, the temperature of the heating roller must be constantly maintained at a high temperature so that an image can be output immediately at any time. It consumes a lot of energy, and heat is released into the machine even during standby, causing a problem of temperature rise inside the machine. In addition, a considerable waiting time (wait time) is required after the power is turned on until the heating roller heats up to a predetermined temperature suitable for heating the recording material as the material to be heated.

Recently, a film heating type heating device has been proposed and put into practical use (Japanese Patent Laid-Open No. 63-31318).
No. 2, JP-A-1-263679, JP-A-2-
No. 157878 / JP-A-4-44075-4408
No. 3, Japanese Patent Laid-Open No. 4-204980-204984).

This heating device has, as a heating body, an electrically insulating and heat resistant heater base material and a resistor formed and provided on the heater base material as a basic constituent body, and the resistor is energized to generate heat. Using a heating element of the type, a material to be heated is brought into close contact with the heating element via a heat-resistant film, and the heat of the heating element and the heat-resistant film are relatively moved to give the heat of the heating element to the material to be heated via the heat-resistant film. It is of a system and configuration, and can be utilized as a means for heat-fixing an unfixed developer image as a permanently fixed image on the surface of a recording material carrying the image.

In addition, for example, it is widely used as a device for heating a recording material carrying an image to improve surface properties such as gloss, a hypothetical adhesion processing device, and other means for heating a sheet-shaped heating material. Can be used.

[0008] In such a film heating type heating device, since a heating body having a low heat capacity or a thin heat-resistant film that quickly heats up can be used, the temperature of the heating body rises in a short time, and the heating is performed during standby. It is not necessary to heat the body by heating, and even if the recording material as the material to be heated is immediately passed, the heating body is sufficiently heated to a predetermined temperature before the recording material reaches the fixing portion. It is possible to save power and shorten the wait time (quick start property), and to lower the temperature rise inside the machine such as the image forming apparatus. is there.

FIG. 22 shows an enlarged cross-sectional model view of the essential part of an example of an image heating and fixing device as a film heating type heating device.

Reference numeral 5 denotes a ceramic heater as a heating element, which is a laterally elongated member having a length in a direction perpendicular to the drawing. 1
Reference numeral 0 denotes a heat-resistant / heat-insulating heater holder that holds the ceramic heater 5 on its lower surface. 11 is a heat resistant film (fixing film). Reference numeral 12 is an elastic pressure roller, and the heat resistant film 11 is sandwiched and pressed against the lower surface of the ceramic heater 5. N is a pressure contact nip portion (fixing nip portion) formed between the ceramic heater 5 and the elastic pressure roller 12 with the heat-resistant film 11 interposed therebetween.

The heat-resistant film 11 has a thickness of, for example, 40 μm.
It is an endless belt-shaped film or a cylindrical film of polyimide or the like having a thickness of about 100 μm or a long end film wound with a roll, and uses a film drive means (not shown) or an elastic pressure roller 12 as a drive member in the pressure contact nip portion N. While being kept in close contact with the lower surface of the ceramic heater 5, the lower surface of the ceramic heater 5 is rotated, rotated, or driven at a predetermined speed in the direction of the arrow while sliding on the lower surface of the ceramic heater.

When the ceramic heater 5 is energized to the resistor 2 which will be described later, the temperature of the ceramic heater 5 is rapidly raised by the heat generated by the resistor.

The heat-resistant film 11 in the pressure contact nip portion N and the elastic pressure roller are moved in a state where the heat-resistant film 11 is closely slid on the lower surface of the ceramic heater and the heating element 5 is heated to a predetermined temperature by energizing the resistor 2. A recording material P to be image-fixed as a material to be heated is introduced between the heating element 12 and the heat-resistant film 11, and the pressure contact nip portion N is nipped and conveyed.
The heat of the resistor 2 and the heat of the heater base material 3 heated by the heat of the resistor 2 are transferred to the recording material P via the heat resistant film 11.
And the unfixed visible image T on the recording material P is heated and fixed on the surface of the recording material P. The recording material P passing through the pressure nip portion N is separated from the surface of the heat resistant film 11 and conveyed.

FIG. 23 is a partially cutaway plan view of the ceramic heater 5 as a heating element on the heat resistant film contact sliding surface side.

The ceramic heater 5 is made of alumina (Al ₂ as a heater base material having electric insulation, heat resistance and low heat capacity).
O ₃ ), a horizontally long ceramic substrate 3, a resistor pattern 2 such as silver palladium (Ag / Pb) formed on one side of the ceramic substrate 3 in the form of a strip along the length of the substrate, and power feeding. Conductor patterns 4 and 4a (hereinafter referred to as conductor patterns) as paths, conductor patterns 1a and 1b (hereinafter referred to as power supply electrode patterns) as power supply electrodes, resistor pattern 2 and conductor patterns as power supply paths It is composed of an electrically insulating surface coating layer 6 such as a glass layer which covers four portions.

The conductor pattern 4 is formed in parallel with the resistor pattern 2 in a strip shape along the length of the ceramic substrate surface.

The two power supply electrode patterns 1a and 1b are provided side by side on the surface portion of the ceramic base material 2 on the one end side.

One end portion side of the resistor pattern 2 is electrically connected to one of the two power feeding electrode patterns 1a and 1b and the power feeding electrode pattern 1a through the conductor pattern 4a. Further, one end of the conductor pattern 4 is electrically connected to the other power feeding electrode pattern 1b. The other ends of the resistor pattern 2 and the conductor pattern 4 are electrically connected to each other.

The resistor pattern 2 and the conductor pattern 4 which are substantially parallel to each other are forward and backward of energization with respect to the length of the heating body between the two power supply electrode patterns 1a and 1b provided on one end side in the longitudinal direction of the ceramic base material 3. Is formed.

By supplying power from a power supply circuit (not shown) between the power supply electrode patterns 1a and 1b, the resistor pattern 2 generates heat over the entire length. The conductor patterns 4 and 4a have low resistance and do not generate heat. The ceramic heater 5 as a heating element quickly raises the temperature by the heat generated by the resistor pattern 2, and the temperature rise is detected by a temperature detecting element (not shown), and the detected temperature is fed back to a temperature control circuit (not shown). The energization of the resistor pattern 2 is controlled so that the temperature of the ceramic heater 5 is maintained at a predetermined temperature.

Like the heating element 5 in the above example, the heater base material 3
On the upper side, a resistor pattern 2 serving as an energization forward path and a conductor pattern 4 serving as an energization return path are provided in parallel with the resistor pattern 2 so that the two power supply electrode portions 1a and 1b are arranged on one longitudinal end portion side of the heater substrate 3. In the installed structure, the power supply connector for the heating body 5 can be provided only on the one longitudinal end side of the heating body 5, the wiring of the power supply wiring can be rationalized, and the wiring work can be facilitated. There is.

[0022]

However, in the case of the heating element 5 of this conventional example, In the width direction of the heating body (direction orthogonal to the longitudinal direction of the heating body), heat is generated between the energization forward path side portion in which the resistor pattern 2 that generates heat is present and the energization return path side portion in which the conductor pattern 4 that does not generate heat is present. There has been a problem that a difference in expansion coefficient occurs and the heating body is easily cracked.

.. Further, there is a problem that the width of the resistor pattern 2 is limited by the withstand voltage and a sufficient heating area cannot be obtained.

[0024]. Further, such a resistor pattern 2 of the heating element 5 has a ceramic base material 3 as a heater base material.
It is formed by printing and firing the resistor paste on top, but slight changes in the print width and thickness greatly affect the heat generation distribution.In order to obtain the desired distribution, the resistance of the pattern after firing Adjustments such as cutting the width while measuring the value were required, which resulted in production inconveniences such as poor yield and long completion time.

[0025]. Further, in such a heating device using the heating element 5, the accuracy of the mounting position of the heating element 5 becomes important, and the heating capacity is greatly changed with a slight error, which makes it difficult to handle.

.. Furthermore, in a heating device using such a heating element 5, the resistance distribution of the heating element may be affected. For example, when such a heating device is used for an image heating and fixing device of an electrophotographic printer, if uneven heating occurs due to the resistance distribution, the fixed image becomes glossy, and the heat-resistant film and the recording material have wrinkles. May occur, and in order to prevent it, the resistance distribution of the heating element must be controlled.

[0027] In such a heating element, as a heater substrate, one large-sized ceramic substrate capable of taking a plurality of heating elements is provided with a plurality of resistor patterns, conductor patterns, and coating layers corresponding to individual heating elements. After being formed, the large-sized ceramic substrate was divided into a plurality of individual heating elements to be manufactured. Therefore, when the width of each heating element is narrower, the number of heating elements that can be manufactured from one large-sized ceramic substrate of the same size at one time is large, and thus the cost and material taking are excellent.

However, the width of one heating element cannot be made as thin as possible, and the width is limited due to regulation of withstand voltage and accuracy limit of printing.

On the other hand, in the image heating and fixing device, it has been found that it is preferable to widen the width of the resistor as the heating element of the heating element in order to improve the fixing property. But,
Simply widening the width of the resistor is contrary to the cost and the narrowing of the width of the heating body, which is a requirement from material preparation.

Therefore, the present invention provides a heating element which solves the above problems (1) to (3) and a method for producing the heating element of this type.

That is, the present invention provides a heating element capable of preventing the heating element from cracking and having a large heating area, and a method for producing the heating element.

With the minimum width of the heating element, the insulation withstand voltage standard is satisfied, and the fixing property is also satisfied in the case of the material heating and image heating fixing device, that is, the pressure regulation on the heating element width, the limit of the printing accuracy, and the fixing property. In view of the cost, the present invention proposes a method for manufacturing a heating element that can be made the narrowest.

The present invention proposes an optimum method for adjusting the resistance distribution resistance value in a heating element having a plurality of resistor patterns, and prevents an offset / fixing failure in an image heating and fixing device.

[0034]

The present invention is a heating body characterized by the following constitution and a method for producing the same.

(1) A heater base material, a plurality of resistors which are formed on the heater base material and generate heat when energized, and an electrically insulating layer which covers the resistor forming portion of the heater base material. A heating body characterized by having a basic structure.

(2) The heating element according to (1), wherein the heater base material is a ceramic base material.

(3) The heating element according to (1), which has a conductor portion for energizing a resistor on a heater substrate. (4) The electrically insulating coating layer is a glass layer (1) ) The heating element described in.

(5) The heating element according to (1), characterized in that there is a trimming portion in which the total resistance value of the resistors or the resistance distribution is adjusted, in the inner portions where the resistors face each other.

(6) The resistor located on the downstream side of the heating member in the conveying direction of the material to be heated has a trimming portion whose total resistance value or resistance distribution is adjusted. The heating element described.

(7) The heating element according to any one of (1) to (6), which is a heating element for an image heating and fixing device.

(8) After printing the resistor on the heater substrate,
The method for producing a heating element according to any one of (1) to (7), wherein the resistor is divided into a plurality of resistors by laser trimming or polishing.

(9) The method for manufacturing a heating element according to (8), wherein the plurality of resistors are divided into different widths by division by laser trimming or polishing.

(10) Trimming for adjusting the total resistance value or the resistance distribution of the resistors of the heating element having a plurality of resistors formed therein is performed by laser trimming or polishing inside the resistors facing each other. The method for manufacturing a heating element according to any one of (1) to (7), characterized in that

(11) Trimming for adjusting the total resistance value or resistance distribution of the resistors of the heating element provided with a plurality of resistors is provided on the downstream side in the transport direction of the material to be heated with respect to the heating element. The method for producing a heating element according to any one of (1) to (7), characterized in that the resistor is subjected to laser trimming or polishing.

[0045]

[Function] By forming a plurality of resistors that are formed on the heater base material and generate heat by energization, both forward and return paths of the energization path on the heater base material become resistors, and the resistors in both paths generate heat. Therefore, it is possible to eliminate or reduce the difference in the coefficient of thermal expansion between the energization forward path side portion and the energization return path side portion in the width direction of the heating element, and prevent the heating element from cracking due to strain due to the difference in the thermal expansion coefficient. It becomes possible to do.

The presence of the plurality of resistors makes it possible to increase the heating area or heating time. This makes it possible to improve the heating efficiency for the material to be heated.

After the resistors are printed on the heater substrate, the resistors are divided by laser trimming or polishing into a plurality of resistors, particularly by using a laser to divide the resistors. The gap between body patterns can be made very narrow. As a result, the distance between the resistors can be reduced by selecting a coating layer having a high withstand voltage. By narrowing the width of the heating element, there is a high possibility that many heating elements can be manufactured from the heater base material original sheet without wasting the original sheet.

By varying the width of the plurality of resistors to change the heat generation amount of each resistor, the heating efficiency is improved, or the material to be heated is separated at the end of heating. Is possible.

Trimming for adjusting the total resistance value or resistance distribution of the resistors of the heating element provided with a plurality of resistors is performed by laser trimming or polishing inside the resistors facing each other. Since the residue of the resistor scattered in step 3 is attached on the resistor pattern, there is no problem if the withstand voltage between the resistors is taken by the electrically insulating coating layer.

Trimming for adjusting the total resistance value or the resistance distribution of the resistors of the heating element having a plurality of resistors formed therein is applied to the resistors on the downstream side of the heating element in the conveying direction of the material to be heated. By performing laser trimming or polishing, in the image heating and fixing device, the fixing temperature and the occurrence of the offset are determined by the final temperature at which the recording material (paper) as the material to be heated reaches in the heating section. If the resistance distribution of the resistor is uniform, the paper temperature when leaving the heating unit becomes uniform over the entire width of the heating unit, and the fixing property and the state without offset can be realized. Furthermore, the way the toner melts is made uniform, and uneven gloss can be eliminated. Further, with this method, only the resistor on the downstream side needs to be adjusted by partial trimming, and the process can be completed in a short time, so that there is an advantage that productivity is increased.

[0051]

【Example】

<Embodiment 1> (FIGS. 1 to 3) FIG. 1 is a schematic cross-sectional view of a main part of a film heating type image heating and fixing device as a heating device using a heating body 5 (ceramic heater) according to the present invention. . Constituent members common to those of the above-described apparatus of FIGS. 22 and 23 are designated by the same reference numerals, and repetitive description will be omitted. FIG. 2 is a partially cutaway plan view of the heating element 5 on the sliding surface side of the heat resistant film. FIG.
Is an enlarged cross-sectional model view of the heating body 5.

This heating element 5 is provided on one surface side of a horizontally long ceramic base material 3 such as alumina (Al ₂ O ₃ ) as a heater base material having electric insulation, heat resistance and low heat capacity, along the length of the base material. First and second two-element resistor patterns 2 substantially parallel to each other
a and 2b are formed and provided. Two power supply electrode patterns 1a and 1b are provided side by side on one end side surface of the ceramic base material 3. One end side of the first resistor pattern 2a is electrically connected to one of the two power feeding electrode patterns 1a and 1b through the power feeding electrode pattern 1a through the conductor pattern 4a. Further, one end of the second resistor pattern 2b is electrically connected to the other power feeding electrode pattern 1b through the conductor pattern 4b. The other ends of the first and second resistor patterns 2a and 2b are electrically connected to each other by a conductor pattern 4c. The resistor forming portion of the ceramic substrate 3 is covered with a glass layer 6 (glass coat) as an electrically insulating layer.

The first and second two resistor pattern 2a.
2b is formed, for example, by screen-printing a resistor paste in which a metal such as silver and palladium is mixed with a glass paste into a strip-shaped pattern having a predetermined width and thickness, and then firing at about 800 ° C.

The above conductor patterns 4a, 4b, 4c,
Each of the two feeding electrode patterns 1a and 1b is formed by screen-printing a conductor paste such as Ag and then firing.

The glass layer 6 is also formed by screen-printing a glass paste and firing it. The glass layer 6 as the coating layer may be a layer of heat-resistant resin such as fluororesin such as tetrafluoroethylene resin, or other electrically insulating / heat-resistant ceramic.

.. First and second two-element resistor pattern 2
a.2b ,. The conductor patterns 4b, 4c, 4d and the two feeding electrode patterns 1a, 1b ,. Each formation of the glass layer 6 may be carried out by printing and firing each of them in sequence, or after printing and, both print patterns are fired together, and then printing and firing of Alternatively, the procedure of printing .. and then firing the.

The first and second two resistor patterns 2a and 2b, which are substantially parallel to each other, are electrically connected to one end of the ceramic base material 3 in the longitudinal direction.
An energization forward path and a return path are formed between a and 1b with respect to the length of the heating body.

This heating element 5 is composed of the feeding electrode pattern 1a.
By supplying power from a power supply circuit (not shown) between 1b, both the first and second two resistor patterns 2a and 2b generate heat over the entire length, and the temperature rises. The temperature is detected by the temperature detecting element, the detected temperature is fed back to a temperature control circuit (not shown), and the energization is controlled so that the temperature of the heating element 5 is maintained at a predetermined temperature.

The turning point of the first and second resistor patterns 2a and 2b is a conductor pattern 4c, which has a low resistance to prevent heat generation here.

In this embodiment, both the first and second two-element resistor patterns 2a and 2b forming the forward and return paths of energization generate heat to the same extent and energize in the width direction of the heating element. It is possible to eliminate or reduce the difference in the coefficient of thermal expansion between the forward path side portion and the energization return path side portion, and it is possible to prevent the heating element 5 from cracking due to strain due to the difference in the thermal expansion coefficient.

The first and second plurality of resistors 2a are also provided.
The presence of 2b makes it possible to increase the heating area or heating time. This makes it possible to improve the heating efficiency for the material P to be heated. That is, when the material P to be heated moves in the width direction of the heating element 5, since the heating time is determined by the width of the resistor pattern, this embodiment is different from the heating elements of FIGS. The above heating body can obtain a higher heating effect. As described above, by using the heating element 5 of the present embodiment, a remarkable heating effect can be obtained as compared with the conventional case, the temperature can be lowered, and the problem of heat deterioration of the heater holder 10 can be solved.

<Embodiment 2> (FIGS. 4 to 12) FIG. 4 is a partially cutaway plan view of the heating element 5 of this embodiment on the sliding surface side of the heat-resistant film. FIG. 5 is an enlarged cross-sectional model view of the heating body 5.

The heating element 5 of the present embodiment is obtained by combining the first and second resistor element patterns 2a and 2b of the heating element of the first embodiment, and first of all, combining the first and second resistor element patterns 2a and 2b. A wide resistor pattern is formed by printing and firing on a ceramic substrate, and the wide resistor pattern is divided by laser trimming or polishing along the length at the center in the width direction to form a first resistor pattern. The second two resistor patterns 2a and 2b are formed. The other structure is the same as that of the heating body 5 of the first embodiment.

The heating element 5 of this example has the same performance as that of the heating element of the first embodiment, and the heating element width can be made smaller than that of the heating element of the first embodiment. In consideration of pressure regulation, limit of printing accuracy, fixability, and cost, the minimum width of the heating element satisfies the dielectric strength standard,
In the image heating and fixing device, the fixing property can also be satisfied.

FIGS. 6 to 12 explain the outline of a method for manufacturing a plurality of heating elements 5 according to this embodiment.

(A) In FIG. 6, reference numeral 14 designates a large-sized ceramic substrate (hereinafter referred to as an original plate) on which a plurality of heating elements 5 can be taken. The original plate 14 of this example has a thickness of 1 mm, for example.
-It is an alumina plate with a width of 70 mm and a length of 240 mm, and 11 heating elements 5 are taken. The original plate 14 is preliminarily equidistant (about 6.36 m) with a laser scribe or a mold so that it can be easily divided and separated into individual heating elements after the original.
A dividing groove or perforation 7 is provided in m).

Reference numeral 15 is a support base for holding the original plate 14. The original plate 14 is positioned and set on the support base 15 in a predetermined manner, and the state is stably held by pulling a vacuum from the back surface so that the positional deviation does not occur.

Reference numeral 16 is a screen for printing the resistor pattern, and 17 is a screen frame in which the screen is tensioned and held. Reference numeral 18 denotes a print pattern portion of the screen 16, which is provided at a predetermined surface position corresponding to each heating body portion of the original plate 14 for collecting 11 heating bodies.
It is a total of 11 parallel stripe patterns for printing a wide resistor pattern having a combined width of the first and second resistor patterns 2a and 2b. Only the printed pattern portion 18 of the screen 16 has a rough mesh, and only this portion 18 can transmit the resistor paste.

Numeral 19 is a squeezer for spreading the resistor paste on the screen 16 and adhering the resistor paste to the surface of the ceramic substrate with a constant thickness from the eyes of the print pattern portion 18 of the screen.

Reference numeral 20 is a dispenser, and a squeezing device 19
This is for supplying a certain amount of resistor paste before the moving direction of. The resistor paste is supplied to the dispenser 20 from a tank (not shown).

(B) Then, as shown in FIG. 7, the screen 16 is positioned and superposed on the support base 15 on which the original plate 14 is positioned and set, and after the resistor paste is supplied by the dispenser 20 before the squeezer 19. By moving the squeezer 19 in the direction of the arrow S, the original plate 1 containing 11 heating elements can be obtained.
A wide resistor pattern having a combined width of the first and second resistor patterns 2a and 2b is printed at a predetermined surface position corresponding to each of the individual heating body portions 4 and dried.

FIG. 8 is a plan model view of the original plate 14 after the printing. FIG. 12A is an enlarged cross-sectional model view of a part thereof. 2A is a wide resistor pattern having a combined width of the first and second resistor patterns 2a and 2b, which are formed by printing at predetermined surface positions corresponding to the individual heating body portions of the original plate 14.

(C) Next, although not shown in the figure, the conductor patterns 4a and 4b are formed on the printed original plate 14 at predetermined surface positions respectively corresponding to the individual heating elements of the original plate 14.・ 4c and two feeding electrode patterns 1a ・ 1
The screens for printing b are overlapped, and those patterns 4a, 4b, 4c,
Print 1a and 1b. FIG. 9 is a plan view of the original plate 14 after the printing.

(D) As in (b) and (c) above,
The resistor pattern 2A, the conductor pattern 4a, and the conductor pattern 4a are provided at predetermined surface positions respectively corresponding to the individual heating body portions of the original plate 14.
The original plate 14 on which 4b and 4c and two power supply electrode patterns 1a and 1b are printed is fired at a predetermined temperature and time.

(E) Next, the wide resistor patterns 2A corresponding to the individual heating elements of the original plate 14 after firing are divided by laser trimming or polishing along the length at the center thereof. First
And the second two resistor patterns 2a and 2b.

FIG. 10 is a schematic plan view of the original plate 14 after the division trimming process. FIG. 12B is an enlarged cross-sectional model view of a part thereof. Reference numeral 2c is a division trimming line.

(F) Next, with respect to the original plate 14 after the division trimming process, although not shown in the drawing, the original plate 14
A screen for printing and covering the glass layer 6 as an electrically insulating layer is laid on a predetermined surface position corresponding to each individual heating element part of, and the glass layer pattern 6 is printed using a glass paste, Then, firing treatment is performed at a predetermined temperature and time.

FIG. 11 shows the printing of this glass layer pattern 6.
FIG. 4 is a partially cutaway plan view of the original plate 14 after firing. FIG.
2 (c) is an enlarged cross-sectional model view of a part thereof.

(G) Next, the original plate 14 is divided along the dividing grooves or the perforations 7 into individual heating elements, and separated to complete a total of 11 heating elements 5.

In the series of manufacturing steps described above, a wide resistor pattern 2A is printed and fired, and this is divided and trimmed into two first and second resistor patterns 2a and 2b by laser trimming or polishing. After that, the conductor patterns 4a, 4b, 4c and the two feeding electrode patterns 1
a ・ 1b is printed / fired or conductor pattern 4a ・
4b and 4c, two feeding electrode patterns 1a and 1b, and the glass layer pattern 6 may be printed and fired.

Next, the width dimension of the heating element 5 will be described. The heating element 5 of FIG. 3 of the first embodiment and the heating element 5 of the present embodiment.
In the heating element 5 of: W1 and W2 are the first and second resistor pattern 2a.
Width dimension of b-A is the distance between the first and second resistor patterns 2a and 2b-B is the length of the first and second resistor patterns 2a and 2b of the glass layer 6. The width dimension of the portion covering the ceramic base material surface outside the outer edge portion along the line C is the width dimension of the ceramic base material allowance between the edge portion along the length of the glass layer 6 and the ceramic base material dividing groove 7. Is. The margin C is provided to prevent the glass of the glass layer 6 from entering the ceramic base dividing groove 7.
That is, when the glass of the glass layer 6 enters the ceramic base material dividing groove 7, the cracking becomes unstable when the ceramic base material 14 is divided and separated, and a defect is likely to occur, which is for preventing this.

Therefore, the width of the heating element 5 is determined as follows: heating element width = A + 2B + 2C + W1 + W2.

From the viewpoint of safety, UL1950, CSA95
0, IEC950, etc., determine the distance between AC lines and the distance between AC and ground. Since the distance A between the resistor patterns 2a and 2b is between the different poles of the primary AC, the withstand voltage of 1 KV may be obtained by the sampling test.

In each of the above dimensions, B should be 1.6 mm at the minimum for 100V and 2.0 mm at 200V.

C needs to be about 0.3 mm.

As in the heating element 5 (FIG. 3) of the first embodiment, when the first and second two resistor patterns 2a and 2b are formed by printing from the beginning, respectively,
As a result of experience, it is necessary to allow 0.2 mm or more for each print smear in the width direction of each of the resistor patterns 2a and 2b.
Further, in order to maintain the withstand voltage of the glass layer 6, the width of the glass must be at least 0.1 mm, and it is necessary to ensure the distance between the resistor patterns 2a and 2b and the withstand voltage with the printing accuracy as shown in FIG. The distance A above is 0.5m.
m was needed.

Therefore, from the fixing, the width dimensions W1 and W2 of the first and second resistor patterns 2a and 2b are both 1.
When 2 mm is required, the heating element width of the heating element 5 of Example 1 is at least A + 2B + 2C + W1 + W2 = 0.5 mm + 2 × 1.6 mm + 2 × 0.3 mm + 1.2 mm +
1.2 mm = 6.7 mm is required.

In the case of this heating element, the width is 70 mm.
10 heating bodies are manufactured from the ceramic base plate 14 of, and the unnecessary plate discarding margin is 3 mm.

On the other hand, like the heating element 5 of this embodiment, first, a wide resistor pattern 2A having a combined width of the first and second resistor patterns 2a and 2b is printed on a ceramic substrate.
This wide resistor pattern 2A is formed by firing and forming.
Is divided into the first and second resistor patterns 2a and 2b by laser trimming 2c or polishing, the first and second divided resistor patterns 2a and 2b are divided by using a laser. The gap between the resistor patterns 2a and 2b can be made very narrow. As a result, if the glass layer 6 having a high withstand voltage is selected, the distance A between the first and second resistor patterns 2a and 2b can be reduced to 0.1 mm.

Therefore, the width of the heating element is 6.36 mm (≈70)
mm 11), and as a result, 11 heating bodies can be manufactured from the ceramic base material 14 having a width of 70 mm, and there is a high possibility that many heating bodies can be manufactured at one time without waste of the ceramic base material. Become.

<Embodiment 3> (FIGS. 13 to 15) In Embodiment 2 described above, the resistor pattern 2 having a wide width is formed.
Although A is divided into two substantially equal widths to form the first and second resistor patterns 2a and 2b, they may be divided non-uniformly.

For example, as shown in FIG. 13A, if the width W1 of the first resistor pattern 2a on the upstream side in the heat-resistant film moving direction is made narrower than the width W2 of the second resistor pattern 2b on the downstream side. The temperature on the upstream side rises and the temperature on the ceramic substrate portion on the upstream side of the resistor rises, and heat is transferred to the heat-resistant film 11 also from this portion, so the fixability is improved.

On the contrary, as shown in FIG. 13B, when the width W2 of the second resistor pattern 2b on the downstream side is narrowed by the width W1 of the first resistor pattern 2a on the upstream side, heating on the upstream side is performed. The image trailing phenomenon, which occurs when the moisture in the paper as the recording material P due to abrupt heating becomes vapor and the toner is blown off backward, can be prevented.

As described above, it is possible to divide the resistor pattern 2A formed wide according to the purpose into arbitrary widths.

Further, as shown in FIG. 14, the wide resistor pattern 2A is divided into curved lines to form the first and second resistor patterns 2a and 2b. The total heating amount of the end portions is the same, and the highest temperature portion moves from the center to the end portion as the heat-resistant film 11 and the recording material P pass through the pressure contact nip portion N nip. As a result, the thermal expansion of the paper as the recording material P gradually occurs toward the end, and wrinkles are less likely to occur because a large thermal expansion does not occur at one time. Also, since steam is generated gradually from the center to the end,
Good for tailing.

FIG. 15 shows a wide resistor pattern 2 formed.
A is divided diagonally and the first and second resistor patterns 2a.
In this case, the same effect as that of FIG. 14 can be obtained.

<Embodiment 4> (FIGS. 16 and 17) It is difficult to obtain the required resistance value only by printing the resistors 2a and 2b or by dividing the wide resistor 2A. , Because the distribution of resistance cannot be accurately measured. As a result, defective fixing due to a partial lack of heat and offset due to excessive heat are likely to occur.

In this embodiment, the resistance value and distribution are adjusted to predetermined values by trimming the resistors.

In this case, trimming the outside of the resistor reduces the effective heating width W1 + W2 + A.
In order to ensure the dielectric strength of the glass layer 6 because the residue of the resistance after trimming cannot be completely removed by cleaning, the width B of the glass must be taken against the limit scattered by trimming. Therefore, the width of the heating element must be increased.

In this embodiment, trimming is performed by using two resistors 2.
It is performed inside a and 2b. As a result, since the residue of the resistor scattered by trimming is attached to the resistor pattern, there is no problem as long as the withstand voltage between the resistors 2a and 2b is secured by the glass layer 6.

In FIG. 16, the wide resistor pattern 2A is divided and trimmed 2c by a laser to form the first and second resistor patterns 2a and 2a as in the second embodiment, and the partial trimming 2d is performed. It shows how to adjust the partial resistance.

(A) shows the wide resistor pattern 2A as the first pattern.
And the state before the trimming is performed on the second resistor patterns 2a and 2a.

(B) shows the wide resistor pattern 2A as the first pattern.
And the second resistor pattern 2a, divided into two trimmings 2a
The state of c is shown.

(C) and (d) show that the resistors are partially trimmed 2d while reciprocating with a short length with respect to the divided resistor pattern 2b in order to adjust the partial resistance. .

FIG. 17 shows the movement (trajectory) of the trimming laser.

(A) shows the first state in which the resistance distribution is adjusted by the partial trimming 2d while reciprocating from one side after the division trimming 2c.

(B) is a state of partial trimming 2d. When the partial trimming 2d with a width of 10 mm to 25 mm where the difference in resistance distribution is not noticeable is finished, the laser moves next as shown by the broken line to adjust the adjacent partial resistance. It is shown to do.

(C) shows that this division trimming 2d is repeated over the entire length of the resistor pattern 2a.
When the partial resistance is a predetermined value in the middle part, trimming may not be performed.

Finally, in (d), the resistance patterns 2a and 2b are used.
By re-trimming 2e of the residue in the divided trimming 2c between the two over the entire length of the resistor pattern (total length of the divided trimming 2c), it is evaporated to ensure the insulation between the resistor patterns 2a and 2b. ing. This step (d) may be omitted if unnecessary.

In the case where the first and second resistors 2a and 2b are originally formed by printing as in the heating element 5 of the first embodiment, only the steps (c) and (d) are required. good.

<Embodiment 5> (FIGS. 18 and 19) When there are two resistor patterns 2a and 2b, there is a problem of which resistor pattern the resistance should be adjusted. It is preferable to partially trim the second resistor pattern 2b located on the downstream side of the nip N of the fixing device. The reason for this is that the fixing temperature and the occurrence of offset are determined by the final temperature at which the paper as the recording material reaches in the nip portion N, and for that reason, the second resistor pattern 2 on the downstream side is required.
This is because if the resistance distribution of b is uniform, the paper temperature when exiting the nip portion N will be uniform over the entire width of the nip portion, and the fixing property and the state without offset can be realized. Furthermore, the way the toner melts is made uniform, and uneven gloss can be eliminated.

FIG. 18 shows the temperature change of the paper as a recording material passing through the nip portion N over time. The resistance distribution of the second resistor pattern 2b on the downstream side is made uniform. A line B shows a portion where the resistance distribution of the resistor pattern 2a on the upstream side is high, a line C shows a standard portion, and a line D shows a portion where the resistance is low.

From this result, it can be seen that the temperature of the paper is smoothed by the second resistor pattern 2b on the downstream side.

On the other hand, in FIG. 19, the resistance distribution of the first resistor pattern 2a on the upstream side is trimmed so as to be uniform. A line E shows a portion where the resistance distribution of the second resistor pattern 2b on the downstream side is high, a line F shows a standard portion, and a line G shows a portion where the resistance is low.

As can be seen from these results, the temperature of the paper coming out of the nip portion N was uneven in each part, resulting in defective fixing and offset.

With this method, if the resistor pattern is 2
Even if it is a book, only the second resistor pattern 2b on the downstream side needs to be adjusted by partial trimming, and the process can be completed in a short time, so that there is an advantage that productivity is increased. <Embodiment 6> (FIG. 20) Although the heating element 5 of the above-described Embodiments 1 to 5 has two resistor patterns, three or more resistor patterns can be provided.

FIG. 20 shows an example thereof. In this example, in order to prevent or reduce the temperature rise in the non-sheet passing portion of the heating element, the resistor pattern is set to the main resistor pattern 2 ₁ as shown in the figure.
And the first, second and third branch resistor patterns 2 ₂ , 2 ₃ and 2 ₄ which are branched from predetermined positions in the middle of the main resistor pattern 2 ₁ , respectively. . Each of the resistor patterns 2 _{1 to} 2 ₄ is divided by laser trimming into a plurality of lines as in the second embodiment. 2c is the division trimming line. O is a one-sided sheet feeding base line.

When a voltage is applied between the power supply electrodes a and b, the main resistor pattern 2 ₁ generates heat with a predetermined heat generation amount over the entire length k to heat the recording material P of A3 size. .

When a voltage is applied between the power supply electrodes a and b and c, the main resistor pattern 2 ₁ has a predetermined heat generation in the length j to the branch point of the first branch resistor pattern 2 _2. The recording material P of B4 size can be heated by generating heat in an amount.
The heat generation amount of the non-sheet passing portion (k-j) is reduced by the parallel conduction of the main resistor pattern 2 ₁ and the first branch resistor pattern 2 ₂ in this portion, and the heat generating amount is reduced. Temperature rise is suppressed.

When a voltage is applied between the power supply electrodes a and b and d, the main resistor pattern 2 ₁ generates a predetermined amount of heat in the length i of the second branch resistor pattern 2 _{3 up to} the branch point. The recording material P of A4 size can be heated by generating heat according to the amount.
The heat generation amount of the non-sheet passing portion (ki) is reduced by the parallel energization of the main resistor pattern 2 ₁ and the second branch resistor pattern 2 ₃ of this portion, and the heat generating amount is reduced. Temperature rise is suppressed.

When a voltage is applied between the power supply electrodes a and b and e, the main resistor pattern 2 ₁ has a predetermined heat generation in the length h to the branch point of the third branch resistor pattern 2 _4. The recording material P of B5 size can be heated by generating heat in an amount.
The heat generation amount of the non-sheet passing portion (kh) is reduced by the parallel energization of the main resistor pattern 2 ₁ and the third branch resistor pattern 2 ₄ in this portion, and the heat generating amount is reduced. Temperature rise is suppressed.

<Embodiment 7> (FIG. 21) FIG. 21 shows a schematic structure of an example of an image forming apparatus in which a film heating type heating device using a heating body according to the present invention is incorporated as an image heating and fixing device 8. There is. The image forming apparatus of this embodiment is a reciprocating platen type, a rotary drum type, a transfer type, and a process cartridge attaching / detaching type electrophotographic copying apparatus.

Reference numeral 100 denotes an apparatus casing, 101 denotes a reciprocating type document placing table made of a transparent plate member such as a glass plate disposed on the upper surface plate 102 of the apparatus casing, and the apparatus casing upper surface plate 102.
The upper part is driven to reciprocate to the right a and the left a'in the drawing at a predetermined speed.

Reference numeral G denotes an original, which is placed on the upper surface of the original placing table 101 with the image surface side to be copied facing downward in accordance with a predetermined placing reference, and the original pressure plate 103 is placed on the original placing plate 103 and pressed down. Set.

Reference numeral 104 denotes a slit opening serving as a document illuminating section which is opened on the surface of the upper surface plate 102 of the machine casing with a direction perpendicular to the reciprocating direction of the document placing table 101 (direction perpendicular to the paper surface) as a longitudinal direction.

The downward image surface of the document G placed and set on the document placing table 101 sequentially passes through the position of the slit opening 104 from the right side to the left side in the reciprocating process of the document placing table 101 to the right a. In the course of the passage, the light L of the lamp 105 is received through the slit opening 104 and the transparent original placing table 101 to be illuminated and scanned, and the original surface reflected light of the illumination scanning light is reflected by the image element array 106 by the photosensitive drum 107. The image is exposed on the surface.

The photosensitive drum 107 is coated with a photosensitive layer such as a zinc oxide photosensitive layer or an organic semiconductor photosensitive layer, and is rotated in the clockwise direction indicated by the arrow b at a predetermined peripheral speed around the central support shaft 108. During the rotation process, the charging device 109 receives a uniform charging process of positive polarity or non-polarity, and the uniformly charged surface is subjected to the image formation exposure (slit exposure) of the original image, so that the surface of the photosensitive drum 107 is formed. An electrostatic latent image corresponding to the image-exposed original image is sequentially formed.

This electrostatic latent image is sequentially visualized by the developing device 110 with toner made of resin or the like that is softened and melted by heating, and the toner image as the visualized image is provided with a transfer discharger 111 as a transfer portion. It moves to the part.

Reference numeral S denotes a cassette in which transfer material sheets P as recording materials are stacked and housed, and the sheets in the cassette are fed and fed one by one by the rotation of the feeding roller 112,
Next, when the leading edge of the toner image forming portion on the drum 107 reaches the transfer discharger 111 portion by the registration roller 113, the leading edge of the transfer material sheet P is also transferred.
And the photosensitive drum 107 are just moved to a position between the photosensitive drum 107 and the photosensitive drum 107.

The toner images on the photosensitive drum 107 side are sequentially transferred by the transfer discharger 111 onto the surface of the fed sheet.

The sheet to which the toner image has been transferred at the transfer portion is sequentially separated from the surface of the photosensitive drum 107 by separation means (not shown), and is guided to the fixing device 8 by the conveying device 114 to form the unfixed toner image carried thereon. The image is heated and fixed, and is discharged as an image-formed product (copy) onto the discharge tray 117 outside the apparatus through the discharge roller 116.

The surface of the photosensitive drum 107 after the image transfer is subjected to removal of adhered contaminants such as transfer residual toner by the cleaning device 118, and is repeatedly used for image formation.

The PC is a process cartridge which is attached / detached to / from the cartridge attaching / detaching portion 120 in the apparatus main body 100.
In the case of the present example, the apparatus main body 10 including the four process devices of the photosensitive drum 107 as an image bearing member, the charging device 109, the developing device 110, and the cleaning device 118 together.
It is detachable and replaceable with respect to 0.

[0134]

As described above, according to the heating body of the present invention, the heater base material and the resistor formed and provided on the heater base material are used as basic components, and the resistor is energized. With respect to the heating element of the type that generates heat, cracking of the heating element can be prevented and a large heating area can be secured.

Further, according to the method for manufacturing a heating element of the present invention,
Satisfies the dielectric strength standard with a minimum width of the heating element, and material fixing, and also the fixing property in the image heating and fixing device, that is, the pressure regulation regarding the heating element width, the limit of printing accuracy,
The width can be minimized in view of fixing property and cost, and a larger number of prints can be simultaneously manufactured by printing while maintaining the dielectric strength.

Further, the resistance value and the resistance distribution of the resistor pattern of the heating element can be adjusted optimally and easily without affecting the withstand voltage and the width of the heating element. As a result, it is possible to prevent offset and defective fixing.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a main part of a film heating type image heating and fixing device as a heating device using a heating body according to the present invention.

[FIG. 2] A partially cutaway plan view of the heating element on the sliding surface side of the heat-resistant film.

[Fig. 3] Enlarged cross-sectional model view of this heating element

FIG. 4 is a partially cutaway plan view of a heat-resistant film-contacting sliding surface side of the heating element of Example 2.

[Figure 5] Enlarged cross-sectional model view of this heating element

FIG. 6 is a perspective view of a means for printing a resistor pattern on a heater base plate.

[Fig. 7] Illustration of printing procedure

FIG. 8 is a schematic plan view of a heater base plate after printing a resistor pattern.

FIG. 9 is a schematic plan view of a heater base plate after a conductor pattern is formed on it.

FIG. 10 is a plan view of a heater base material plate after the resistor pattern is divided and trimmed.

FIG. 11 is a partially cutaway plan view of a heater base plate after a glass layer is further formed.

12 (a), (b), and (c) are manufacturing process diagrams.

13 (a) and 13 (b) are partially cutaway plan view model diagrams of the heating body of Example 3, respectively.

FIG. 14 is a partially cutaway plan view model of a heating element having another configuration.

FIG. 15 is a partially cutaway plan view model of a heating element of still another configuration.

16 (a), (b), (c), and (d) show Example 4.
Explanation drawing of dividing and partial trimming of resistor pattern of heating element

17 (a), (b), (c), and (d) are explanatory views of the movement trajectory of the trimming laser.

FIG. 18 is a graph showing the temperature change of the paper as a recording material passing through the nip portion of the heating body of Example 5 over time.

FIG. 19 is a graph showing a temperature change of another heating member, which is a recording material passing through the nip portion, over time.

FIG. 20 is a partially cutaway plan view model of the heating body of Example 6.

FIG. 21 is a schematic configuration diagram of an example of an image forming apparatus in which a film heating type heating device using a heating body according to the present invention is incorporated as an image heating fixing device.

FIG. 22 is an enlarged cross-sectional model view of a main part of an example of an image heating and fixing device as a film heating type heating device.

FIG. 23 is a partially cutaway plan view of a ceramic heater as a heating element on a sliding surface of a heat-resistant film.

[Explanation of symbols]

 5 Heater 1a ・ 1b Power supply electrode (conductor pattern) 2a ・ 2b First and second resistor pattern 3 Heater base material (ceramic base material) 4a ・ 4b ・ 4c Conductor pattern 6 Electric insulating coating layer ( Glass layer) 7 Dividing groove or perforation line 10 Heater holder 11 Heat resistant (fixing) film N Pressure contact (fixing) nip P Heated material (recorded material)

Claims (11)

[Claims] 1. A heater base, a plurality of resistors formed on the heater base and generating heat when energized, and an electrically insulating layer covering a resistor forming portion of the heater base. A heating body characterized by being a constituent. 2. The heating element according to claim 1, wherein the heater base material is a ceramic base material. 3. The heating body according to claim 1, further comprising a conductor portion for energizing the resistor on the heater base material. 4. The heating element according to claim 1, wherein the electrically insulating coating layer is a glass layer. 5. The heating element according to claim 1, wherein a trimming portion in which the total resistance value of the resistors or the resistance distribution is adjusted is provided inside the resistors facing each other. 6. The resistor on the downstream side of the heating body in the conveying direction of the material to be heated has a trimming portion whose total resistance value or resistance distribution is adjusted. Heating body. 7. The heating element according to claim 1, which is a heating element for an image heating and fixing device. 8. The heater according to claim 1, wherein after the resistor is printed on the heater substrate, the resistor is divided into a plurality of resistors by laser trimming or polishing. The method for manufacturing a heating element according to. 9. The method for manufacturing a heating element according to claim 8, wherein the plurality of resistors are divided into different widths by division by laser trimming or polishing. 10. Trimming for adjusting a total resistance value or a resistance distribution of the resistors of a heating element having a plurality of resistors formed therein is performed by laser trimming or polishing inside the resistors facing each other. The method for manufacturing a heating element according to any one of claims 1 to 7, which is characterized in that. 11. A resistor located on the downstream side in the transport direction of the material to be heated with respect to the heating body, and trimming for adjusting the total resistance value or the resistance distribution of the resistors of the heating body having a plurality of resistors formed therein. The method for manufacturing a heating element according to any one of claims 1 to 7, wherein the heating is performed on the body by laser trimming or polishing.