JP7004395B2 - heater - Google Patents

Description

The present invention relates to a heater.

Conventionally, heaters have been used for toner fixing in electronic devices such as copiers, facsimiles, and printers. For example, Patent Document 1 discloses an example of such a heater. Usually, the heater for fixing the toner includes a substrate and a heating element layer formed on the substrate. The heating element layer extends long in the width direction, which is perpendicular to the transport direction of the target medium to be heated (for example, sheet-shaped paper). The widthwise dimension of the heating element layer is set relative to the maximum width of the target medium used. When a narrow target medium is used for such a heater, the target medium does not come into contact with both side portions of the heating element layer. Therefore, both side portions of the heater tend to have a relatively high temperature, which may cause problems such as wasteful consumption of electric power.

Japanese Unexamined Patent Publication No. 2009-193844

The present invention has been conceived under the above circumstances. Therefore, it is an object of the present invention to provide a heater capable of suppressing an excessive temperature rise on both sides in the width direction when heating a target medium having a relatively narrow width.

The heater provided by the first aspect of the present invention is formed on a long substrate having a substrate main surface and a substrate back surface, a heat generation resistor layer formed on the substrate main surface, and the substrate main surface. An electrode layer in contact with the heat generation resistor layer is provided. The electrode layer has a first band-shaped portion and a second band-shaped portion extending in the longitudinal direction of the substrate and spaced apart from each other in the width direction of the substrate. The heat generation resistor layer has at least a first main heat generation part and a first sub heat generation part, and each of the first main heat generation part and the first sub heat generation part extends in the longitudinal direction. Moreover, it is provided between the first band-shaped portion and the second band-shaped portion in the width direction. The temperature coefficient of resistance of the first sub-heating unit is larger than the temperature coefficient of resistance of the first main heat-generating unit.

Preferably, at the reference temperature, the resistance value of the first main heat generating portion along the width direction is larger than the resistance value of the first sub heat generating portion along the width direction.

Preferably, at the reference temperature, the sheet resistance of the first main heat generating portion is larger than the sheet resistance of the first sub heat generating portion.

Preferably, the heat generation resistor layer further has a second sub heat generation part. In the width direction, the first main heat generating portion is arranged between the first sub heat generating portion and the second sub heat generating portion.

Preferably, the first sub-heating portion and the second strip-shaped portion have a first end portion and a second end portion that are separated from each other in the width direction, respectively. The first end portion of the first sub-heating portion is located on the first strip-shaped portion, and the first end portion of the second sub-heating portion is located on the second strip-shaped portion. There is.

Preferably, the second end portion of the first sub-heating portion and the second end portion of the second sub-heating portion are located on the first main heat generating portion.

Preferably, the heat generation resistor layer further has a second main heat generation part. In the width direction, the first sub-heating unit is arranged between the first main heat-generating unit and the second main heat-generating unit.

Preferably, the first main heat generating portion and the second main heat generating portion have a first end portion and a second end portion separated from each other in the width direction, respectively. The first end portion of the first main heat generating portion is located on the first band-shaped portion, and the first end portion of the second main heat generating portion is located on the second band-shaped portion. There is.

Preferably, the second end portion of the first main heat generating portion and the second end portion of the second main heat generating portion are located on the first sub heat generating portion.

Preferably, in the width direction, the first main heat generating portion and the first sub heat generating portion are partially in contact with each other.

Preferably, the first main heat generating portion has an end portion located on the first band-shaped portion.

Preferably, the first sub-heat generating portion has an end portion located on the second strip-shaped portion.

Preferably, the widthwise dimension of the first main heat generating portion is smaller than that of each of the first strip-shaped portion and the second strip-shaped portion.

Preferably, the widthwise dimension of the first sub-heating portion is smaller than that of each of the first strip-shaped portion and the second strip-shaped portion.

Preferably, the heat-generating resistor layer has a larger dimension in the width direction than each of the first band-shaped portion and the second strip-shaped portion.

Preferably, the electrode layer is formed directly on the main surface of the substrate.

Preferably, the heat generation resistor layer is directly formed on the main surface of the substrate.

Preferably, the exothermic resistor layer contains ruthenium oxide.

Preferably, the exothermic resistor layer contains copper oxide.

Preferably, the heater further comprises a protective layer that at least partially covers the heat generation resistor layer and the electrode layer.

Preferably, the protective layer is made of glass.

Preferably, the protective layer covers the entire heat generation resistor layer.

Preferably, the electrode layer has a first pad portion and a second pad portion that are separately connected to the first band-shaped portion and the second band-shaped portion. The first pad portion and the second pad portion are exposed from the protective layer.

Preferably, the first pad portion and the second pad portion sandwich the first band-shaped portion and the second band-shaped portion, and are separated from each other in the longitudinal direction.

Preferably, the first pad portion and the second pad portion are arranged on the same side of the first band-shaped portion and the second strip-shaped portion in the longitudinal direction.

Preferably, the heater further comprises a thermistor provided on the back surface of the substrate.

Preferably, the substrate is made of ceramic.

Preferably, the ceramic is alumina or aluminum nitride.

Preferably, the thickness of the substrate is 0.4 to 1.2 mm.

Preferably, the electrode layer contains Ag.

Preferably, the temperature coefficient of resistance of the first sub-heating unit is 3 times or more and 15 times or less of the temperature coefficient of resistance of the first main heat-generating unit.

Preferably, the dimensions of the first main heat generating portion and the first sub heat generating portion in the longitudinal direction are 290 mm to 310 mm.

According to the present invention, the heat generation resistor layer is composed of a main heat generation part and a sub heat generation part having different temperature coefficients of resistance from each other. Since the sub-heat generating portion has a large resistance temperature coefficient, the rate of increase in sheet resistance with respect to temperature rise is large. Therefore, when the temperature of the non-passing section through which the target medium does not pass becomes higher than the temperature in the passing section, the sheet resistance of the sub-heat generating portion becomes significantly larger in the non-passing section than in the passing section. As a result, the current supplied from the electrode layer to the heat generation resistor layer tends to flow intensively in the paper-passing section while avoiding the non-paper-passing section. As a result, the calorific value of the heat generation resistor layer in the non-paper section (particularly the calorific value in the main heat generating portion) can be suppressed, and excessive temperature rise in the non-paper section can be suppressed.

Other features and advantages of the invention will be more apparent by the detailed description given below with reference to the accompanying drawings.

It is sectional drawing of the main part which shows the printing apparatus which used the heater based on 1st Embodiment of this invention. It is a top view which shows the heater based on 1st Embodiment of this invention. It is a bottom view which shows the heater of FIG. It is an enlarged plan view of the main part which shows the heater of FIG. It is sectional drawing which follows the VV line of FIG. It is a graph which shows the relationship between the sheet resistance and the temperature of the heat generation resistor of the heater of FIG. It is sectional drawing which shows one process of the manufacturing method of the heater of FIG. It is sectional drawing which shows one process of the manufacturing method of the heater of FIG. It is sectional drawing which shows one process of the manufacturing method of the heater of FIG. It is a plan view and a temperature graph which shows the use example of the heater of FIG. It is a top view which shows the modification of the heater of FIG. It is an enlarged plan view of the main part which shows the heater based on 2nd Embodiment of this invention. It is sectional drawing which follows the XIII-XIII line of FIG. FIG. 3 is an enlarged plan view of a main part showing a heater based on the third embodiment of the present invention. It is sectional drawing which follows the XV-XV line of FIG. It is sectional drawing of the main part which shows the printing apparatus which used the heater based on 4th Embodiment of this invention. It is a top view which shows the heater based on 4th Embodiment of this invention. It is a bottom view which shows the heater of FIG. It is an enlarged plan view of the main part which shows the heater of FIG. 19 is a cross-sectional view taken along the line XX-XX of FIG. It is sectional drawing which follows the XXI-XXI line of FIG. It is sectional drawing which shows one process of the manufacturing method of the heater of FIG. It is sectional drawing which shows one process of the manufacturing method of the heater of FIG. It is sectional drawing which shows one process of the manufacturing method of the heater of FIG. It is sectional drawing which shows one process of the manufacturing method of the heater of FIG. It is a plan view and a temperature graph which shows the use example of the heater of FIG. It is a top view which shows the modification of the heater of FIG. FIG. 3 is an enlarged plan view of a main part showing a heater based on the fifth embodiment of the present invention. FIG. 8 is a cross-sectional view taken along the line XXIX-XXIX of FIG. 28. FIG. 3 is an enlarged plan view of a main part showing a heater based on the sixth embodiment of the present invention.

Hereinafter, preferred embodiments based on a plurality of aspects of the present invention will be specifically described with reference to the drawings. First, an embodiment based on the first aspect of the present invention will be described with reference to FIGS. 1 to 15.

FIG. 1 shows a printing apparatus 8 in which a heater based on the first embodiment of the present invention is used. The printing device 8 is, for example, an electronic copier, a facsimile, and a printer-dedicated machine, but is not limited thereto. The printing apparatus 8 includes a heater A1 and a platen roller 81.

The heater A1 faces the platen roller 81 and is used for thermally fixing the toner transferred to the target medium Dc to the target medium Dc. An example of the target medium Dc is sheet-shaped paper, but other recording media may be used.

As shown in FIGS. 1 to 5, the heater A1 includes a substrate 1, a heat generation resistor layer 2, an electrode layer 3, a protective layer 4, and a thermistor 5.

As shown in FIG. 2, the substrate 1 is elongated in the direction X. In the following description and drawings, the direction X is referred to as the longitudinal direction X, and the direction Y is referred to as the width direction (or the lateral direction) Y. Further, the direction Z (see FIGS. 1 and 5) orthogonal to both the direction X and the direction Y is referred to as a thickness direction Z. The width direction Y corresponds to the transport direction of the target medium Dc, and the longitudinal direction X corresponds to the width direction of the target medium Dc.

The substrate 1 is made of, for example, an insulating material. In this embodiment, the substrate 1 is made of ceramic. Examples of the ceramic include alumina or aluminum nitride.

The thickness of the substrate 1 is, for example, 0.4 to 1.2 mm. In another example, the thickness of the substrate 1 is, for example, 0.4 to 0.6 mm. When the substrate 1 is formed of a material having a low thermal conductivity (for example, alumina or aluminum nitride), the thickness of the substrate 1 is preferably thin.

The substrate 1 has a substrate main surface 11 and a substrate back surface 12. In this embodiment, the main surface 11 of the substrate and the back surface 12 of the substrate are both flat. The substrate main surface 11 and the substrate back surface 12 are separated from each other in the thickness direction Z and face each other on opposite sides. Both the main surface 11 of the substrate and the back surface 12 of the substrate have an elongated rectangular shape (see FIGS. 2 and 3).

The heat generation resistor layer 2 is formed on the main surface 11 of the substrate. The heat generation resistor layer 2 is a portion that generates heat when energized. The longitudinal dimension of the heat generation resistor layer 2 is, for example, 290 mm to 310 mm. This is a dimension when A3 size paper is assumed as the target medium Dc having the maximum width, but the present invention is not limited thereto. Further, the width dimension of the heat generation resistor layer 2 is constant over the longitudinal direction thereof. The heat generation resistor layer 2 has at least one main heat generation unit and at least one sub heat generation unit adjacent to each other. In the present embodiment, as described below, the heat generation resistor layer 2 has one main heat generation unit 21 and two sub heat generation units 22.

The main heat generating portion 21 has a band shape having a constant width extending in the longitudinal direction X. The main heat generating portion 21 is made of, for example, a material containing ruthenium oxide. The main heat generating portion 21 may contain copper oxide, for example, in order to adjust the temperature coefficient of resistance.

The two sub-heating portions 22 are strips having a constant width, each extending in the longitudinal direction X. In the present embodiment, the two sub-heating portions 22 have the same width dimension. The two sub-heating portions 22 are separated from each other in the width direction Y, and sandwich the main heating portion 21 between them. Each sub-heating unit 22 is made of, for example, a material containing ruthenium oxide, and may contain copper oxide, for example, for adjusting the temperature coefficient of resistance.

The thickness of the main heat generating portion 21 is, for example, 5 μm to 15 μm, and in the present embodiment, it is about 10 μm. The thickness of each sub-heating portion 22 is, for example, 5 μm to 15 μm, and in the present embodiment, it is about 10 μm. The widthwise dimension of the main heat generating portion 21 is, for example, 1.0 mm to 2.0 mm, and in the present embodiment, it is about 1.6 mm. The widthwise dimension (total dimension) of the two sub-heating portions 22 is, for example, 1.0 mm to 2.0 mm, and in the present embodiment, it is about 1.6 mm. Therefore, the widthwise dimension of the heat generation resistor layer 2 is, for example, 2.0 mm to 4. It is mm, and in this embodiment, it is about 3.2 mm.

The sub heat generating portion 22 is made of a material having a larger resistance temperature coefficient than the main heat generating portion 21. The temperature coefficient of resistance of the main heat generating portion 21 is, for example, 0 ppm / ° C. to 500 ppm / ° C., and in the present embodiment, it is about 250 ppm / ° C. On the other hand, the temperature coefficient of resistance of the sub-heating unit 22 is, for example, 2000 ppm / ° C. to 3000 ppm / ° C., and in the present embodiment, it is about 2500 ppm / ° C. Preferably, the temperature coefficient of resistance of the sub-heating unit 22 is 3 times or more and 15 times or less the temperature coefficient of resistance of the main heat-generating unit 21, and in the present embodiment, it is about 10 times.

The main heat generating portion 21 has a predetermined resistance value (“crossing resistance value”) measured along a path (path along the width direction Y) crossing the main heat generating portion. Similarly, each sub-heating unit 22 also has a predetermined resistance value (“cross-sectional resistance value”) measured along a path (path along the width direction Y) that traverses the sub-heating unit. In the present embodiment, for example, at the reference temperature, the cross-sectional resistance value of the main heat generating portion 21 is larger than the total cross-sectional resistance value of the two sub-heating portions 22. The widthwise dimension of the main heat generating portion 21 is substantially the same as the total widthwise dimension of the two sub heat generating portions 22. Therefore, the sheet resistance of the main heat generating portion 21 at the reference temperature is larger than the sheet resistance of the sub heat generating portion 22 at the reference temperature. The sheet resistance of the main heat generating portion 21 at the reference temperature is, for example, 1500 Ω / sq to 2500 Ω / sq, and in the present embodiment, it is about 2072 Ω / sq. On the other hand, the sheet resistance of the sub-heating unit 22 at the reference temperature is, for example, 500 Ω / sq to 800 Ω / sq, and in the present embodiment, it is about 691 Ω / sq.

FIG. 6 shows the relationship between the sheet resistance (R) and the temperature (T) of the main heat generating unit 21 and the sub heat generating unit 22. As shown in the figure, at the reference temperature T0 (for example, about 20 ° C.), the sheet resistance of the main heat generating portion 21 is larger than the sheet resistance of the sub heat generating portion 22. Further, even at the temperatures T1 and T2 that are expected to be reached during the operation of the heater, the sheet resistance of the main heating unit 21 is larger than the sheet resistance of the sub heating unit 22. On the other hand, the temperature coefficient of resistance of the sub heat generating portion 22 is relatively larger than that of the main heat generating portion 21. Therefore, the rate of increase in the sheet resistance of the sub-heating section 22 with the temperature rise is larger than the rate of increase in the sheet resistance of the main heating section 21.

As shown in FIG. 2, the electrode layer 3 has a pair of band-shaped portions 31, a pair of pad portions 32, and a pair of connecting portions 33. The electrode layer 3 constitutes a conduction path through which a current for causing heat generation of the heat generation resistor layer 2 to flow. The electrode layer 3 is made of, for example, a material containing Ag. The thickness of the electrode layer 3 is, for example, 5 μm to 15 μm, and in the present embodiment, it is about 10 μm.

Each of the pair of strips 31 extends long in the longitudinal direction X. The pair of strips 31 are separated in the width direction Y and are parallel to each other. The heat generation resistor layer 2 is arranged between the pair of strips 31 (see FIGS. 4 and 5).

The widthwise dimension of each strip 31 is, for example, 1.5 mm to 2.5 mm. In the present embodiment, the widthwise dimension of each band-shaped portion 31 is about 2.0 mm, which is larger than the respective dimensions of the main heat generating portion 21 and the sub heat generating portion 22. On the other hand, the heat generation resistor layer 2 as a whole has a larger dimension in the width direction than each band-shaped portion 31.

The pair of pad portions 32 are portions for ensuring continuity with the printing apparatus 8. The pair of pad portions 32 are provided at positions separated from the heat generation resistor layer 2 and the pair of band-shaped portions 31 in the longitudinal direction X. In the present embodiment, the pair of pad portions 32 are arranged apart from each other in the longitudinal direction X with the heat generation resistor layer 2 and the pair of band-shaped portions 31 interposed therebetween.

Each of the pair of connecting portions 33 connects a strip-shaped portion 31 and a corresponding pad portion 32. In the present embodiment, each connecting portion 33 has a strip shape extending in the longitudinal direction X.

As shown in FIG. 5, each sub-heating portion 22 has an outer end portion and an inner end portion separated from each other in the width direction Y, and the outer end portion is located on a corresponding strip-shaped portion 31. The inner end portion is located on the main heat generating portion 21.

In the present embodiment, the heat generation resistor layer 2 and the electrode layer 3 are directly formed on the main surface 11 of the substrate. Instead of such a configuration, by providing an insulating layer made of glass or the like on the main surface 11 of the substrate, the insulating layer is interposed between the main surface 11 of the substrate and the heat generation resistor layer 2 and the electrode layer 3. You may.

The protective layer 4 covers the entire heat generation resistor layer 2. Further, the protective layer 4 covers the electrode layer 3 except for the pair of pad portions 32 (and the vicinity thereof) (see FIG. 2). That is, the protective layer 4 partially covers the electrode layer 3. The protective layer 4 is made of, for example, glass, and its thickness is, for example, 40 μm to 100 μm. In the present embodiment, the thickness of the protective layer 4 is about 60 μm. As shown in FIG. 5, the dimension of the protective layer 4 in the width direction Y is smaller than the dimension of the substrate 1. In the present embodiment, the protective layer 4 has a pair of edge edges (right edge and left edge in FIG. 5) that are separated from each other in the width direction Y. Similarly, the substrate 1 has a pair of edge edges (right edge and left edge in FIG. 5) that are spaced apart from each other in the width direction Y. In the width direction Y, the right end edge of the protective layer 4 is separated from the right end edge of the substrate 1 inward (that is, closer to the main heat generating portion 21). Further, the left end edge of the protective layer 4 is separated from the left end edge of the substrate 1 inward (that is, closer to the main heat generating portion 21).

The thermistor 5 is a sensor that detects the temperature of the heater A1 during operation. In this embodiment, the thermistor 5 is provided on the back surface 12 of the substrate. The amount of electric power applied to the heater A1 is controlled according to the detection result of the thermistor 5.

Next, an example of a method for manufacturing the heater A1 will be described with reference to FIGS. 7 to 9.

First, as shown in FIG. 7, the substrate 1 is prepared, and the conductive paste is printed on the main surface 11 of the substrate. This conductive paste contains, for example, Ag. By firing the printed conductive paste, the electrode layer 3 including the pair of strips 31 is obtained.

Next, as shown in FIG. 8, the main heat generating portion 21 is formed on the main surface 11 of the substrate. The formation of the main heat generating portion 21 is performed, for example, as follows. The substrate main surface 11 has a region sandwiched between a pair of strips 31 in the width direction Y. A conductive paste containing, for example, ruthenium oxide is printed in this area. At this time, the conductive paste is printed so as to be separated from the pair of strips 31. Next, the printed conductive paste is fired to obtain the main heat generating portion 21.

Next, as shown in FIG. 9, two sub-heating portions 22 are formed on the main surface 11 of the substrate. The formation of the sub-heating portion 22 is performed, for example, as follows. The substrate main surface 11 has two regions sandwiched between the main heat generating portion 21 and each band-shaped portion 31. A conductive paste containing, for example, ruthenium oxide and copper oxide is printed on these areas. At this time, each region is printed so that the conductive paste is in contact with both the band-shaped portion 31 and the main heat generating portion 21. In the present embodiment, the applied conductive paste covers the inner end of each strip 31 and both ends of the main heat generating portion 21. Then, by firing this conductive paste, two sub-heating portions 22 are obtained. The firing for forming the heat generation resistor layer 2 and the electrode layer 3 may be performed separately or collectively. After the formation of the sub-heating portion 22, the heater A1 is obtained through the formation of the protective layer 4 and the mounting of the thermistor 5.

Next, the operation of the heater A1 will be described.

FIG. 10 shows an example of using the heater A1. The heater A1 in a plan view is shown on the upper side of the figure, and the target medium Dc is shown by an imaginary line. The target medium Dc is conveyed in the direction of the arrow while sliding on the heater A1 by the platen roller 81 (FIG. 1). In this usage example, it is assumed that the size of the target medium Dc is smaller than that of the heater A1. Specifically, for example, the heater A1 has a size that can correspond to an A3 size target medium, whereas the target medium Dc has an A4 size. As shown in the figure, in the longitudinal direction of the heater A1, the section through which the target medium Dc passes is referred to as a paper passing section S1, and the section outside the target medium Dc is referred to as a non-passing section S2.

In the non-energized state, the heat generation resistor layer 2 does not generate heat, and its temperature is, for example, the reference temperature T0. When the transfer of the target medium Dc is started and the energization of the heat generation resistor layer 2 is started, the heat generation resistor layer 2 generates heat. In the paper passing section S1, the heat of the heat generation resistor layer 2 is transferred to the target medium Dc. On the other hand, in the non-paper-passing section S2, the heat of the heat generation resistor layer 2 is not transferred to the target medium Dc. Therefore, the temperature of the heater A1 in the non-paper passing section S2 is relatively higher than the temperature in the paper passing section S1.

It is assumed that the temperature in the paper passing section S1 reaches the temperature T1 under certain conditions. If, unlike the present embodiment, the entire heat generation resistor layer 2 is composed of the main heat generation unit 21, the temperature in the non-passing paper section S2 becomes excessively high and reaches the temperature T3. On the other hand, in the present embodiment, the heat generation resistor layer 2 is composed of one main heat generation unit 21 and two sub heat generation units 22. Since the sub-heat generation unit 22 has a large resistance temperature coefficient, the higher the temperature, the higher the sheet resistance. Therefore, the higher the temperature of the non-passing section S2, the more the sub-heating section in the non-passing section S2 than the sheet resistance of the sub-heating section 22 (hereinafter, “passing section 201”) in the passing section S1. The sheet resistance of 22 (hereinafter, “non-passing paper portion 202”) becomes large. Therefore, the current flowing from the electrode layer 3 to the heat generation resistor layer 2 avoids the non-passing section 202 and concentrates on the passing section 201. As a result, the calorific value of the heat generation resistor layer 2 (particularly the main heat generating portion 21) in the non-passing paper section S2 is suppressed, and the temperature in the non-passing paper section S2 becomes T2, which is lower than T3. As described above, according to the present embodiment, it is possible to prevent the temperature in the non-paper passing section S2 from becoming excessively high with respect to the temperature in the paper passing section S1.

In general, it is difficult to increase both the temperature coefficient of resistance and the sheet resistance in one heat generating member. For example, a member having a large resistance temperature coefficient tends to have a small sheet resistance. In this embodiment, the main heat generating section 21 having a relatively large sheet resistance and the sub heating section 22 having a relatively large temperature coefficient of resistance are used. The following technical effects are achieved by the configuration in which two types of heat generating portions having different resistance characteristics are combined in this way. That is, when the heater A1 is used, the sheet resistance of the sub heat generating portion 22 in the non-passing paper section S2 becomes relatively large. As a result, as described above, the current tends to flow through the paper-passing portion 201, avoiding the non-paper-passing portion 202. In this way, the non-paper passing section 202 functions as a barrier for controlling the flow of the supplied current. On the other hand, the main heat generating portion 21 having a low temperature dependence of the resistance value (high sheet resistance) can secure the heat generation amount required for fixing the toner and the like.

Further, the heat generation resistor layer 2 of the present embodiment has a configuration in which one main heat generation unit 21 is sandwiched by two sub heat generation units 22 in the width direction Y. Therefore, in the non-passing section S2, the main heat generating section 21 is electrically closed by the two non-passing sections 202. This is suitable for suppressing the temperature rise in the non-passing paper section S2. Further, preferably, the thermal conductivity of the sub-heating portion 22 is set lower than the thermal conductivity of the band-shaped portion 31 of the electrode layer 3. This makes it possible to prevent the heat generated in the main heat generating portion 21 from escaping to the band-shaped portion 31 via the sub heat generating portion 22, particularly in the paper passing section S1.

Preferably, the temperature coefficient of resistance of the sub-heating unit 22 is set to about 3 to 15 times the temperature coefficient of resistance of the main heat-generating unit 21. As a result, the effect of suppressing the temperature rise in the non-paper-passing section S2 described above is more reliably achieved.

11 to 15 show a modification of the first embodiment and other embodiments. In these figures, the same or similar elements as those in the first embodiment are designated by the same reference numerals.

FIG. 11 shows a modified example of the heater A1 described above. In the illustrated heater A1', the pair of pad portions 32 are arranged on the same side in the longitudinal direction X with respect to the pair of strip-shaped portions 31. Even in such a configuration, it is possible to suppress the temperature rise in the non-passing paper section S2. As can be understood from this modification, the arrangement of the pair of pad portions 32 can be appropriately changed. For example, a pair of pad portions 32 may be provided on the back surface 12 of the substrate. The variations relating to the pair of pad portions 32 are also applicable to the embodiments described below.

12 and 13 show a heater according to the second embodiment of the present invention. The heater A2 of the present embodiment has a different structure of the heat generation resistor layer 2 from the heater A1 of the first embodiment described above. Specifically, the heat generation resistor layer 2 of the heater A2 has two main heat generation units 21 and one sub heat generation unit 22. In the present embodiment, the widthwise dimension of the sub heat generating portion 22 is about twice the widthwise dimension of each main heat generating portion 21, and is smaller than the widthwise dimension of each strip-shaped portion 31. On the other hand, the widthwise dimension of the entire heat generation resistor layer 2 is larger than the widthwise dimension of each band-shaped portion 31. The present invention is not limited to this.

In the present embodiment, one sub-heating unit 22 is sandwiched by two main heat-generating units 21 in the width direction Y. Each main heat generating portion 21 has an outer end portion in the width direction Y, and the outer end portion is located on a corresponding strip-shaped portion 31. On the other hand, the inner end portion of each main heat generating portion 21 in the width direction Y is located on the sub heat generating portion 22.

Also in the heater A2, the sheet resistance of the non-passing section 202 in the non-passing section S2 is larger than the sheet resistance of the passing section 201 in the non-passing section S1 (FIG. 10). Therefore, the current from the electrode layer 3 tends to concentrate and flow in the paper passing section S1, and excessive temperature rise in the non-paper passing section S2 can be suppressed.

14 and 15 show a heater according to a third embodiment of the present invention. The illustrated heater A3 differs from the heaters A1 and A2 described above in the configuration of the heat generation resistor layer 2. The heat generation resistor layer 2 of the heater A3 has only one main heat generation unit 21 and only one sub heat generation unit 22. In the present embodiment, the widthwise dimension of the main heat generating portion 21 is substantially the same as the widthwise dimension of the sub heat generating portion 22. Further, the width direction dimension of the main heat generation portion 21 (that is, the width direction dimension of the sub heat generation portion 22) is smaller than the width direction dimension of each band-shaped portion 31. On the other hand, the widthwise dimension of the entire heat generation resistor layer 2 is larger than the widthwise dimension of each band-shaped portion 31. The present invention is not limited to this.

In the heater A3, one sub-heating portion 22 and one main heating portion 21 are arranged adjacent to each other between the pair of strip-shaped portions 31 in the width direction Y. That is, the main heat generating portion 21 and the sub heat generating portion 22 are partially in contact with each other. Further, in the width direction Y (see FIG. 15), the outer end portion (right end portion) of the main heat generating portion 21 is located on the corresponding strip-shaped portion 31 (right strip-shaped portion). Similarly, in the width direction Y, the outer end portion (left end portion) of the sub-heating portion 22 is located on the other strip-shaped portion 31 (left strip-shaped portion). In the illustrated configuration, the inner end portion (right end portion) of the sub-heating portion 22 is located on the main heating portion 21. Instead of this, the inner end portion (left end portion) of the main heat generating portion 21 may be located on the sub heat generating portion 22.

Also in the heater A3, the sheet resistance of the non-passing section 202 in the non-passing section S2 is larger than the sheet resistance of the passing section 201 in the non-passing section S1. Therefore, the current from the electrode layer 3 tends to concentrate and flow in the paper passing section S1, and excessive temperature rise in the non-paper passing section S2 can be suppressed.

Next, an embodiment based on the second aspect of the present invention will be described with reference to FIGS. 16 to 30.

FIG. 16 shows a printing apparatus using a heater based on the fourth embodiment of the present invention. The printing device 8 is, for example, an electronic copier, a facsimile, and a printer-dedicated machine, but is not limited thereto. The printing apparatus 8 includes a heater A4 and a platen roller 81.

The heater A4 faces the platen roller 81 and is used for thermally fixing the toner transferred to the target medium Dc to the target medium Dc. An example of the target medium Dc is sheet-shaped paper, but other recording media may be used.

As shown in FIGS. 16 to 21, the heater A4 includes a substrate 1, a heat generation resistor layer 2, an electrode layer 3, a protective layer 4, and a thermistor 5.

The substrate 1 is elongated in the direction X. Similar to the first to third embodiments described above, in the following description and drawings, the direction X is referred to as the longitudinal direction X, the direction Y is referred to as the width direction (or the lateral direction) Y, and the direction Z is referred to as the thickness direction Z. .. The width direction Y corresponds to the transport direction of the target medium Dc, and the longitudinal direction X corresponds to the width direction of the target medium Dc.

The substrate 1 is made of an insulating material. In this embodiment, the substrate 1 is made of ceramic. Examples of the ceramic include alumina or aluminum nitride.

The thickness of the substrate 1 is, for example, 0.4 to 1.2 mm. In another example, the thickness of the substrate 1 is, for example, 0.4 to 0.6 mm. When the substrate 1 is formed of a material having a low thermal conductivity (for example, alumina or aluminum nitride), the thickness of the substrate 1 is preferably thin.

The substrate 1 has a substrate main surface 11 and a substrate back surface 12. In this embodiment, the main surface 11 of the substrate and the back surface 12 of the substrate are both flat. The substrate main surface 11 and the substrate back surface 12 are separated from each other in the thickness direction Z and face each other on opposite sides. Both the main surface 11 of the substrate and the back surface 12 of the substrate have an elongated rectangular shape.

The heat generation resistor layer 2 is formed on the main surface 11 of the substrate. The heat generation resistor layer 2 is a portion that generates heat when energized. The X dimension in the longitudinal direction of the heat generation resistor layer 2 is, for example, 290 mm to 310 mm. This is a dimension when A3 size paper is assumed as the target medium Dc having the maximum width, but the present invention is not limited thereto. The heat generation resistor layer 2 of the present embodiment has a strip shape extending long in the longitudinal direction X.

The heat generation resistor layer 2 is made of, for example, a material containing ruthenium oxide. Further, the heat generation resistor layer 2 may contain copper oxide, for example, in order to adjust the temperature coefficient of resistance.

The widthwise dimension of the heat generation resistor layer 2 is, for example, 1 mm to 5 mm, and in the present embodiment, it is about 3 mm. The thickness of the heat generation resistor layer 2 is, for example, 5 μm to 15 μm, and in the present embodiment, it is about 10 μm.

The temperature coefficient of resistance of the heat generation resistor layer 2 is, for example, 1500 ppm / ° C. to 5000 ppm / ° C., and in the present embodiment, it is about 2000 ppm / ° C. The sheet resistance of the heat generation resistor layer 2 at the reference temperature is, for example, 10 Ω / sq to 2000 Ω / sq, and in the present embodiment, it is about 500 Ω / sq.

The electrode layer 3 has a first band-shaped portion 301, a second strip-shaped portion 302, a plurality of first branch-shaped portions 311 and a plurality of second branch-shaped portions 312, a pair of pad portions 32, and a pair of connecting portions 33. There is. The electrode layer 3 constitutes a conduction path for passing a current for causing the heat generation resistor layer 2 to generate heat. The electrode layer 3 is made of, for example, a material containing Ag. The thickness of the electrode layer 3 is, for example, 5 μm to 15 μm, and in the present embodiment, it is about 10 μm.

Each of the first strip-shaped portion 301 and the second strip-shaped portion 302 extends long in the longitudinal direction X. The first strip-shaped portion 301 and the second strip-shaped portion 302 are arranged in parallel with each other so as to be separated from each other in the width direction Y. A heat generation resistor layer 2 is arranged between the first band-shaped portion 301 and the second band-shaped portion 302. The distance between the first band-shaped portion 301 and the heat generation resistor layer 2 in the width direction Y is, for example, about 0.5 mm, which is smaller than the width direction dimension of the heat generation resistor layer 2. Further, the distance between the second band-shaped portion 302 and the heat generation resistor layer 2 in the width direction Y is, for example, about 0.5 mm, which is smaller than the width direction dimension of the heat generation resistor layer 2.

The widthwise dimension of the first band-shaped portion 301 is, for example, 1.5 mm to 2.5 mm, and in the present embodiment, it is about 2.0 mm. The widthwise dimension of the second band-shaped portion 302 is, for example, 1.5 mm to 2.5 mm, and in the present embodiment, it is about 2.0 mm. Therefore, the heat generation resistor layer 2 has a larger dimension in the width direction than the first band-shaped portion 301 and the second band-shaped portion 302.

The plurality of first branch-shaped portions 311 are spaced apart from each other along the longitudinal direction X, and each extends from the first strip-shaped portion 301 toward the second strip-shaped portion 302. In this embodiment, each first branch-shaped portion 311 is parallel to the width direction Y. Further, as shown in FIG. 19, each first branch-shaped portion 311 protrudes beyond the heat generation resistance layer 2 and protrudes toward the second strip-shaped portion 302 in the width direction Y. That is, each first branch-shaped portion 311 has a tip that does not overlap with the heat generation resistor layer 2 in the thickness direction Z. This tip is located between the heat generation resistor layer 2 and the second band-shaped portion 302 in the thickness direction Z view.

The plurality of second branch-shaped portions 312 are spaced apart from each other along the longitudinal direction X, and each extends from the second strip-shaped portion 302 toward the first strip-shaped portion 301. In this embodiment, each second branch portion 312 is parallel to the width direction Y. Further, as shown in FIG. 19, each second branch-shaped portion 312 protrudes beyond the heat generation resistance layer 2 and protrudes toward the first strip-shaped portion 301 in the width direction Y. That is, each second branch-shaped portion 312 has a tip that does not overlap with the heat generation resistor layer 2 in the thickness direction Z. This tip is located between the heat generation resistor layer 2 and the first band-shaped portion 301 in the thickness direction Z view.

The plurality of first branch-like portions 311 and the plurality of second branch-like portions 312 are alternately arranged in the longitudinal direction X so as not to overlap each other. That is, in the longitudinal direction X, the first branch-shaped portion 311 and the second branch-shaped portion 312 are arranged so as to be adjacent to each other and separated from each other.

In the present embodiment, the heat generation resistor layer 2 is formed so as to intersect the plurality of first branch-shaped portions 311 and the plurality of second branch-shaped portions 312 along the longitudinal direction X. The heat generation resistor layer 2 has a plurality of heat generation portions 20, and each heat generation portion 20 is a portion sandwiched between the adjacent first branch-shaped portion 311 and the second branch-shaped portion 312. The plurality of heat generating portions 20 are arranged in a row in the longitudinal direction X. When energized via the electrode layer 3, the plurality of heat generating portions 20 are electrically connected in parallel.

The distance between the adjacent first branch-shaped portion 311 and the second branch-shaped portion 312 in the longitudinal direction X (“heat-generating portion specified distance”) is, for example, 3 mm to 10 mm. In the present embodiment, the heat generation portion specified distance is about 5 mm, which is larger than the width direction dimension of the heat generation resistor layer 2. Therefore, in the present embodiment, each heat generating portion 20 has a rectangular shape extending in the longitudinal direction X.

The pair of pad portions 32 are portions for ensuring continuity with the printing apparatus 8. The pair of pad portions 32 are provided at positions separated from the heat generation resistor layer 2, the first strip-shaped portion 301, and the second strip-shaped portion 302 in the longitudinal direction X. In the present embodiment, the pair of pad portions 32 are arranged apart from each other in the longitudinal direction X with the heat generation resistor layer 2, the first strip-shaped portion 301, and the second strip-shaped portion 302 interposed therebetween.

The pair of connecting portions 33 connect one of the first strip-shaped portion 301 and the second strip-shaped portion 302, and one pad portion 32 corresponding thereto, respectively. In the present embodiment, each connecting portion 33 has a strip shape extending in the longitudinal direction X.

As shown in FIGS. 20 and 21, in the present embodiment, the heat generation resistor layer 2 as a whole is directly formed on the main surface 11 of the substrate. Further, a portion of the electrode layer 3 that overlaps the heat generation resistor layer 2 in a plan view (Z view in the thickness direction) is located on the heat generation resistor layer 2. On the other hand, the portion of the electrode layer 3 that does not overlap with the heat generation resistor layer 2 in a plan view is directly formed on the substrate main surface 11. Instead of such a configuration, by providing an insulating layer made of glass or the like on the main surface 11 of the substrate, the insulating layer is interposed between the main surface 11 of the substrate and the heat generation resistor layer 2 and the electrode layer 3. You may.

The protective layer 4 covers the entire heat generation resistor layer 2. Further, the protective layer 4 covers the electrode layer 3 except for the pair of pad portions 32 (and its vicinity) (see FIG. 17). That is, the protective layer 4 partially covers the electrode layer 3. The protective layer 4 is made of, for example, glass, and its thickness is, for example, 40 μm to 100 μm. In the present embodiment, the thickness of the protective layer 4 is about 60 μm. As shown in FIG. 21, the dimension of the protective layer 4 in the width direction Y is smaller than the dimension of the substrate 1. In the present embodiment, the protective layer 4 has a pair of edge edges (right edge and left edge in FIG. 21) that are separated from each other in the width direction Y. Similarly, the substrate 1 has a pair of edge edges (right edge and left edge in FIG. 21) that are spaced apart from each other in the width direction Y. In the width direction Y, the right end edge of the protective layer 4 is separated from the right end edge of the substrate 1 inward (that is, closer to the heat generation resistor layer 2). Further, the left end edge of the protective layer 4 is separated from the left end edge of the substrate 1 inward (that is, closer to the heat generation resistor layer 2).

The thermistor 5 is a sensor that detects the temperature of the heater A4 during operation. In this embodiment, the thermistor 5 is provided on the back surface 12 of the substrate. The amount of electric power given to the heater A4 is controlled according to the detection result of the thermistor 5.

Next, an example of a method for manufacturing the heater A4 will be described with reference to FIGS. 22 to 25.

First, as shown in FIGS. 22 and 23, the substrate 1 is prepared, and the conductive paste is printed on the main surface 11 of the substrate in a strip shape extending in the longitudinal direction X. This conductive paste contains, for example, ruthenium oxide. The heat generation resistor layer 2 is obtained by firing the printed conductive paste.

Then, as shown in FIGS. 24 and 25, a conductive paste containing, for example, Ag is printed to form the electrode layer 3. At this time, the shape in the plan view is the above-mentioned first band-shaped portion 301, second strip-shaped portion 302, a plurality of first branch-shaped portions 311 and a plurality of second branch-shaped portions 312, a pair of pad portions 32, and a pair of contacts. Printing is performed so as to correspond to the unit 33. The electrode layer 3 is obtained by firing the printed conductive paste.

The firing for forming the heat generation resistor layer 2 and the electrode layer 3 may be performed separately or collectively. After firing, the heater A4 is obtained through the formation of the protective layer 4 and the mounting of the thermistor 5.

Next, the operation of the heater A4 will be described.

FIG. 26 shows an example of using the heater A4. The heater A4 in a plan view is shown on the upper side of the figure, and the target medium Dc is shown by an imaginary line. The target medium Dc is conveyed in the direction of the arrow while sliding on the heater A4 by the platen roller 81 (FIG. 16). In this usage example, it is assumed that the size of the target medium Dc is smaller than that of the heater A4. Specifically, for example, the heater A4 has a size that can correspond to an A3 size target medium, whereas the target medium Dc has an A4 size. As shown in the figure, in the longitudinal direction of the heater A4, the section through which the target medium Dc passes is referred to as a paper passing section S1, and the section outside the target medium Dc is referred to as a non-passing section S2.

In the non-energized state, the plurality of heat generating portions 20 of the heat generating resistor layer 2 do not generate heat, and the temperature of each heat generating portion 20 is, for example, the reference temperature T0. When the transfer of the target medium Dc is started and the energization is started, the plurality of heat generating portions 20 generate heat. In the paper passing section S1, the heat of the heat generating portion 20 is transferred to the target medium Dc. On the other hand, in the non-passing section S2, the heat of the heat generating portion 20 is not transferred to the target medium Dc. Therefore, the temperature of the heater A4 in the non-paper passing section S2 is relatively higher than the temperature in the paper passing section S1.

It is assumed that, unlike the present embodiment, the heater A4 is a single heat generating member extending in the longitudinal direction X, and is energized only through both ends thereof in the longitudinal direction. In this case, it is assumed that the temperature in the paper passing section S1 reaches the temperature T1 under certain conditions. Then, in the heat generating member, the temperature in the non-passing section S2 becomes excessively high and reaches the temperature T3. On the other hand, according to the present embodiment, the heat generation resistor layer 2 has a configuration having a plurality of heat generation portions 20 defined by a plurality of branch-shaped portions. Further, the heat generation resistor layer 2 (and thus each heat generation unit 20) has a resistance temperature coefficient set in the range of 1500 ppm / ° C. to 5000 ppm / ° C. (for example, about 2000 ppm / ° C.). Therefore, as the temperature of the non-passing section S2 becomes higher than the temperature T1, the non-passing section S2 is more than the sheet resistance of the plurality of heat generating portions 20 (hereinafter, “passing section 201”) in the passing section S1. The sheet resistance of the plurality of heat generating portions 20 (hereinafter, “non-passing section 202”) in the above is increased. As a result, the current flowing from the electrode layer 3 to the heat generation resistor layer 2 avoids the non-passing section 202 and concentrates on the passing section 201. As a result, the calorific value in the non-passing section 202 is suppressed, and the temperature in the non-passing section S2 becomes T2, which is lower than T3. As described above, according to the present embodiment, it is possible to prevent the temperature in the non-paper passing section S2 from becoming excessively high with respect to the temperature in the paper passing section S1.

In the present embodiment, the current flowing through each heat generating portion 20 mainly flows along the longitudinal direction X. Therefore, it is possible to increase the resistance value of the heat generating portion 20 as the distance between the adjacent first branch-shaped portion 311 and the second branch-shaped portion 312 increases, and a sufficient calorific value can be obtained. Further, the smaller the width direction dimension of the heat generating portion 20, the higher the resistance value of the heat generating portion 20 can be. As described above, the more the heat generation resistor layer 2 is formed in the shape of an extremely thin band, the larger the heat generation can be obtained. Further, since heat is intensively generated in the thin heat generation resistor layer 2, heat can be efficiently transferred to the target medium Dc pressed by the platen roller 81 having a circular cross section.

In the present embodiment, the pair of pad portions 32 are arranged separately in the longitudinal direction X. Therefore, the conduction path from the pair of pad portions 32 via each heat generating portion 20 has a uniform length for the plurality of heat generating portions 20. This is preferable for suppressing the variation in the calorific value in the longitudinal direction X.

In the present embodiment, the tips of the first branch-shaped portion 311 and the second branch-shaped portion 312 protrude from the heat generation resistor layer 2. As a result, in the width direction Y, the first branch-shaped portion 311 and the second branch-shaped portion 312 completely cross the heat generation resistor layer 2. This is preferable in order to secure a uniform amount of heat generated for each heat generating unit 20. In addition, unlike the present embodiment, the tip of the first branch-shaped portion 311 and the second branch-shaped portion 312 may be configured to coincide with the edge of the heat generation resistor layer 2.

27 to 30 show modifications and other embodiments of the present invention. In these figures, the same or similar elements as those in the above-described fourth embodiment are designated by the same reference numerals.

FIG. 27 shows a modified example of the heater A4. In the illustrated heater A4', the pair of pad portions 32 are arranged on the same side of the heat generation resistor layer 2 in the longitudinal direction X. Even in such a modified example, it is possible to suppress the temperature rise in the non-passing paper section S2. As can be understood from this modification, the arrangement of the pair of pad portions 32 can be appropriately changed. For example, a pair of pad portions 32 may be provided on the back surface 12 of the substrate. As described above, the variation of the pair of pad portions 32 can be appropriately adopted in the embodiments described below.

28 and 29 show a heater according to a fifth embodiment of the present invention. The heater A5 of the present embodiment is different from the heater A4 described above in the configurations of the heat generation resistor layer 2 and the electrode layer 3.

In the heater A5, the entire electrode layer 3 is directly formed on the main surface 11 of the substrate. Therefore, a part of the resistor layer 2 (a portion overlapping the plurality of first branch-like portions 311 and the plurality of second branch-like portions 312 in a plan view) is formed on the upper side of each branch-like portion 311 and 312. There is. On the other hand, in the heat generation resistor layer 2, the portion that does not overlap with the branched portions 311 and 312 is directly formed on the main surface 11 of the substrate (see FIG. 29).

Also in the heater A5, the sheet resistance of the non-passing section 202 (FIG. 26) is larger than the sheet resistance of the passing section 201. Therefore, the current from the electrode layer 3 tends to concentrate and flow in the paper passing section S1. Therefore, it is possible to suppress an excessive temperature rise in the non-passing paper section S2.

FIG. 30 shows a heater according to the sixth embodiment of the present invention. The heater A6 of the present embodiment is different from the above-mentioned heaters A4 and A5 in the configuration of the plurality of first branch-shaped portions 311 and the plurality of second branch-shaped portions 312.

In the heater A6, each first branch-shaped portion 311 and each second branch-shaped portion 312 are inclined with respect to the width direction Y. The plurality of first branch-like portions 311 are parallel to each other, and the plurality of second branch-like portions 312 are parallel to each other. Further, the plurality of first branch-like portions 311 and the plurality of second branch-like portions 312 are parallel to each other.

The inclination angle of the first branch-shaped portion 311 with respect to the width direction Y is set as follows. On both sides of each first branch-shaped portion 311 are two heat generating portions 20 adjacent to each other. The inclination angle of the first branch-shaped portion 311 is set so that a part of these two heat generating portions 20 overlap each other in the width direction Y view. In such a case, as shown in FIG. 30, of the two straight lines L1 and L2 extending in the width direction Y, the straight line L1 is located on the left side of the straight line L2. Here, in the figure, the straight line L1 passes through the intersection of the right side edge of each first branch-shaped portion 311 and the upper edge of the heat generation resistor layer 2 (the edge close to the first band-shaped portion 301), and is in the width direction Y. It is a straight line that extends. On the other hand, the straight line L2 is a straight line extending in the width direction Y through the intersection of the left side edge of the first branch-shaped portion 311 and the lower edge of the heat generation resistor layer 2 (the edge close to the second strip-shaped portion 302). be. Such an inclined form of the first branch-shaped portion 311 is the same for each second branch-shaped portion 312.

Also in the heater A6, the sheet resistance of the non-passing section 202 (FIG. 26) is larger than the sheet resistance of the passing section 201. Therefore, the current from the electrode layer 3 tends to concentrate and flow in the paper passing section S1. Therefore, it is possible to suppress an excessive temperature rise in the non-passing paper section S2.

Further, in the heater A6, as described above, the plurality of first branch-shaped portions 311 and the plurality of second branch-shaped portions 312 are inclined with respect to the width direction Y. Therefore, when being conveyed along the width direction Y, a part of the target medium Dc faces only the first branch-shaped portion 311 or the second branch-shaped portion 312 (that is, does not face the heat generating portion 20 at all). ) Does not occur. That is, it is possible to suppress a problem that the portion to be heated in the target medium Dc is not heated at all.

The inclination angles of the plurality of first branch-shaped portions 311 may be different from each other. Similarly, the tilt angles of the plurality of second branch portions 312 may be different from each other. Further, the inclination angles of the plurality of first branch-shaped portions 311 and the inclination angles of the plurality of second branch-like portions 312 may be different from each other.

The heater according to the present invention is not limited to the above-described embodiment. The specific configuration of each part of the heater according to the present invention can be freely changed in design.

The configurations and variations thereof of the embodiments based on the second aspect of the present invention are listed below as appendices.

[Appendix 1]
A long board with a main board surface and a back surface of the board,
The heat generation resistor layer formed on the main surface of the substrate and
A heater provided with an electrode layer formed on the main surface of the substrate and in contact with the heat generation resistor layer.
The electrode layer has a first strip-shaped portion and a second strip-shaped portion extending in the longitudinal direction of the substrate and spaced apart from each other in the width direction of the substrate, and the first strip-shaped portion to the second strip-shaped portion. It has a plurality of first branch-shaped portions extending toward the direction, and a plurality of second branch-shaped portions extending from the second band-shaped portion toward the first band-shaped portion.
The plurality of first branch-like portions and the plurality of second branch-like portions are alternately arranged in the longitudinal direction.
The heat-generating resistor layer has a plurality of heat-generating portions, and each heat-generating portion is in contact with a first branch-shaped portion and a second branch-shaped portion adjacent to each other.
[Appendix 2]
The heater according to Appendix 1, wherein the heat generation resistor layer extends long in the longitudinal direction as a whole and has a strip shape intersecting the plurality of first branch-like portions and the plurality of second branch-like portions.
[Appendix 3]
The heater according to Appendix 2, wherein the tip of each first branch-shaped portion protrudes from the heat generation resistor layer toward the second strip-shaped portion.
[Appendix 4]
The heater according to Appendix 3, wherein the tip of each second branch portion projects from the heat generation resistor layer toward the first band-shaped portion.
[Appendix 5]
The heater according to any one of Supplementary note 2 to 4, wherein the plurality of first branch-shaped portions are parallel to the width direction.
[Appendix 6]
The heater according to Appendix 5, wherein the plurality of second branch portions are parallel to the width direction.
[Appendix 7]
The heater according to any one of Supplementary note 2 to 4, wherein the plurality of first branch-shaped portions are inclined with respect to the width direction.
[Appendix 8]
The heater according to Appendix 7, wherein the plurality of second branch-shaped portions are inclined with respect to the width direction.
[Appendix 9]
The heater according to Appendix 8, wherein a part of two heat generating portions adjacent to each other with the first branch-shaped portion thereof overlap each other in the width direction view.
[Appendix 10]
The heater according to Appendix 9, wherein a part of two heat generating portions adjacent to each other with the second branch-shaped portion thereof overlap each other in the width direction view.
[Appendix 11]
The description in any of Supplementary note 2 to 10, wherein the distance between the first branch and the second branch adjacent to each other in the longitudinal direction is larger than the dimension in the width direction of the heat generation resistor layer. heater.
[Appendix 12]
The heater according to Supplementary note 2 to 11, wherein the distance between the first band-shaped portion and the heat generation resistor layer in the width direction is smaller than the dimension of the heat generation resistance layer in the width direction.
[Appendix 13]
The heater according to Appendix 12, wherein the distance between the second band-shaped portion and the heat generation resistor layer in the width direction is smaller than the dimension of the heat generation resistance layer in the width direction.
[Appendix 14]
The heater according to any one of Supplementary note 2 to 13, wherein the dimension of the first band-shaped portion in the width direction is smaller than the dimension of the heat generation resistor layer in the width direction.
[Appendix 15]
The heater according to Appendix 14, wherein the dimension of the second band-shaped portion in the width direction is smaller than the dimension of the heat generation resistor layer in the width direction.
[Appendix 16]
The heater according to any one of Supplementary note 2 to 15, wherein each first branch-shaped portion and at least a part of each second branch-shaped portion are formed on the heat generation resistor layer.
[Appendix 17]
The heater according to Appendix 16, wherein the heat generation resistor layer is directly formed on the main surface of the substrate.
[Appendix 18]
The heater according to Appendix 17, wherein the portion of the electrode layer that does not overlap with the heat generation resistor layer is directly formed on the main surface of the substrate.
[Appendix 19]
The heater according to any one of Supplementary note 1 to 18, wherein the heat generation resistor layer contains ruthenium oxide.
[Appendix 20]
The heater according to Appendix 19, wherein the heat generation resistor layer contains copper oxide.
[Appendix 21]
The heater according to any one of Supplementary note 1 to 20, further comprising a protective layer covering at least a part of each of the heat generation resistor layer and the electrode layer.
[Appendix 22]
The heater according to Appendix 21, wherein the protective layer is made of glass.
[Appendix 23]
The heater according to Supplementary Note 21 or 22, wherein the protective layer covers the entire heat generation resistor layer.
[Appendix 24]
The electrode layer has a pair of pad portions that are separately connected to the first strip-shaped portion and the second strip-shaped portion.
The heater according to any one of Supplementary note 21 to 23, wherein the pair of pads are exposed from the protective layer.
[Appendix 25]
The heater according to Appendix 24, wherein the pair of pad portions are separated from each other in the longitudinal direction with the first strip-shaped portion and the second strip-shaped portion interposed therebetween.
[Appendix 26]
The heater according to Appendix 24, wherein the pair of pad portions are arranged on the same side of the first band-shaped portion and the second strip-shaped portion in the longitudinal direction.
[Appendix 27]
The heater according to any one of Supplementary note 1 to 26, further comprising a thermistor provided on the back surface of the substrate.
[Appendix 28]
The heater according to any one of Supplementary note 1 to 27, wherein the substrate is made of ceramic.
[Appendix 29]
The heater according to Appendix 28, wherein the ceramic is alumina or aluminum nitride.
[Appendix 30]
The heater according to Appendix 28 or 29, wherein the thickness of the substrate is 0.4 to 1.2 mm.
[Appendix 31]
The heater according to any one of Supplementary note 1 to 29, wherein the electrode layer contains Ag.
[Appendix 32]
The heater according to any one of Supplementary note 1 to 31, wherein the temperature coefficient of resistance of the heat generation resistor layer is 1500 ppm / ° C. to 5000 ppm / ° C.
[Appendix 33]
The heater according to Appendix 32, wherein the sheet resistance of the heat generation resistor layer at a reference temperature is 10 Ω / sq to 2000 Ω / sq.
[Appendix 34]
The heater according to any one of Supplementary note 1 to 33, wherein the heat generation resistor layer has a longitudinal dimension of 290 mm to 310 mm.

According to the configuration according to the above appendix, for example, as shown in FIG. 19, each of the electrode layers 3 extends in the longitudinal direction X of the substrate 1 and is spaced apart from each other in the width direction of the substrate 1. And a second band-shaped portion 302, a plurality of first branch-shaped portions 311 extending from the first strip-shaped portion 301 toward the second strip-shaped portion 302, and a plurality of plurality of extending from the second strip-shaped portion 302 toward the first strip-shaped portion 301. It has a second branch-shaped portion 312 and. The plurality of first branch-shaped portions 311 and the plurality of second branch-shaped portions 312 are alternately arranged in the longitudinal direction X, and the heat generation resistor layer 2 has a plurality of heat generation parts 20 and each of them. The heat generating portion 20 is in contact with the first branch-shaped portion 311 and the second branch-shaped portion 312 adjacent to each other. By adopting such a configuration, it is possible to provide a heater capable of suppressing an excessive temperature rise on both sides in the width direction when heating a target medium having a relatively narrow width.

A1 to A3 Heater 1 Board 11 Board main surface 12 Board back surface 2 Heat generation resistor layer 21 Main heat generation part 22 Sub heat generation part 201 Paper-passing part 202 Non-paper-passing part 3 Electrode layer 31 Band-shaped part 32 Pad part 33 Communication part 4 Protective layer 5 Thermistor 8 Printing device 81 Platen roller Dc Target medium X Longitudinal direction Y Width direction (short side direction)
Z Thickness direction S1 Paper-passing section S2 Non-paper-passing section

A4 to A6 Heater 1 Board 11 Board main surface 12 Board back surface 2 Heat generation resistor layer 20 Heat generation part 201 Paper-passing part 202 Non-paper-passing part 3 Electrode layer 301 1st band-shaped part 302 2nd band-shaped part 311 1st branch-shaped part 312 2nd branch 32 Pad 33 Communication 4 Protective layer 5 Thermistor 8 Printing device 81 Platen roller Dc Target medium X Longitudinal direction Y Width direction (short direction)
Z Thickness direction S1 Paper-passing section S2 Non-paper-passing section

Claims (29)

A long substrate having a main substrate surface and a back surface of the substrate,
The heat generation resistor layer formed on the main surface of the substrate and
A heater provided with an electrode layer formed on the main surface of the substrate and in contact with the heat generation resistor layer.
The electrode layer has a first strip-shaped portion and a second strip-shaped portion extending in the longitudinal direction of the substrate and spaced apart from each other in the width direction of the substrate.
The heat generation resistor layer has at least a first main heat generation part and a first sub heat generation part, and each of the first main heat generation part and the first sub heat generation part extends in the longitudinal direction. Moreover, in the width direction, it is provided between the first band-shaped portion and the second band-shaped portion.
The temperature coefficient of resistance of the first sub-heating unit is larger than the temperature coefficient of resistance of the first main heat-generating unit.
The heat generation resistor layer further has a second sub heat generation part, and has a second sub heat generation part.
In the width direction, the first main heat generating portion is arranged between the first sub heat generating portion and the second sub heat generating portion.
Further comprising a protective layer that at least partially covers the heat generation resistor layer and the electrode layer.
The thickness of the protective layer is larger than the thickness of the main heat generating portion, the heater. The heater according to claim 1, wherein at the reference temperature, the resistance value of the first main heat generating portion along the width direction is larger than the resistance value of the first sub heat generating portion along the width direction. The heater according to claim 2, wherein the sheet resistance of the first main heat generating portion is larger than the sheet resistance of the first sub heating portion at the reference temperature. The first sub-heating portion and the second strip-shaped portion have a first end portion and a second end portion that are separated from each other in the width direction, respectively.
The first end portion of the first sub-heating portion is located on the first band-shaped portion, and the first end portion of the second sub-heating portion is located on the second band-shaped portion. The heater according to any one of claims 1 to 3. The heater according to claim 4, wherein the second end portion of the first sub-heating portion and the second end portion of the second sub-heating portion are located on the first main heat generating portion. A long substrate having a main substrate surface and a back surface of the substrate,
The heat generation resistor layer formed on the main surface of the substrate and
A heater provided with an electrode layer formed on the main surface of the substrate and in contact with the heat generation resistor layer.
The electrode layer has a first strip-shaped portion and a second strip-shaped portion extending in the longitudinal direction of the substrate and spaced apart from each other in the width direction of the substrate.
The heat generation resistor layer has at least a first main heat generation part and a first sub heat generation part, and each of the first main heat generation part and the first sub heat generation part extends in the longitudinal direction. Moreover, in the width direction, it is provided between the first band-shaped portion and the second band-shaped portion.
The temperature coefficient of resistance of the first sub-heating unit is larger than the temperature coefficient of resistance of the first main heat-generating unit.
The heat generation resistor layer further has a second main heat generation part, and has a second main heat generation part.
In the width direction, the first sub-heating unit is a heater arranged between the first main heat-generating unit and the second main heat-generating unit. The first main heat generating portion and the second main heat generating portion have a first end portion and a second end portion separated from each other in the width direction, respectively.
The first end portion of the first main heat generating portion is located on the first band-shaped portion, and the first end portion of the second main heat generating portion is located on the second band-shaped portion. The heater according to claim 6. The heater according to claim 7, wherein the second end portion of the first main heat generating portion and the second end portion of the second main heat generating portion are located on the first sub heat generating portion. A long substrate having a main substrate surface and a back surface of the substrate,
The heat generation resistor layer formed on the main surface of the substrate and
A heater provided with an electrode layer formed on the main surface of the substrate and in contact with the heat generation resistor layer.
The electrode layer has a first strip-shaped portion and a second strip-shaped portion extending in the longitudinal direction of the substrate and spaced apart from each other in the width direction of the substrate.
The heat generation resistor layer has at least a first main heat generation part and a first sub heat generation part, and each of the first main heat generation part and the first sub heat generation part extends in the longitudinal direction. Moreover, in the width direction, it is provided between the first band-shaped portion and the second band-shaped portion.
The temperature coefficient of resistance of the first sub-heating unit is larger than the temperature coefficient of resistance of the first main heat-generating unit.
In the width direction, the first main heat generating portion and the first sub heat generating portion are partially in contact with each other.
Further comprising a protective layer that at least partially covers the heat generation resistor layer and the electrode layer.
The thickness of the protective layer is larger than the thickness of the main heat generating portion, the heater. The heater according to claim 9, wherein the first main heat generating portion has an end portion located on the first band-shaped portion. The heater according to claim 10, wherein the first sub-heating portion has an end portion located on the second band-shaped portion. A long substrate having a main substrate surface and a back surface of the substrate,
The heat generation resistor layer formed on the main surface of the substrate and
A heater provided with an electrode layer formed on the main surface of the substrate and in contact with the heat generation resistor layer.
The electrode layer has a first strip-shaped portion and a second strip-shaped portion extending in the longitudinal direction of the substrate and spaced apart from each other in the width direction of the substrate.
The heat generation resistor layer has at least a first main heat generation part and a first sub heat generation part, and each of the first main heat generation part and the first sub heat generation part extends in the longitudinal direction. Moreover, in the width direction, it is provided between the first band-shaped portion and the second band-shaped portion.
The temperature coefficient of resistance of the first sub-heating unit is larger than the temperature coefficient of resistance of the first main heat-generating unit.
The widthwise dimension of the first main heat generating portion is smaller than that of each of the first strip-shaped portion and the second strip-shaped portion.
Further comprising a protective layer that at least partially covers the heat generation resistor layer and the electrode layer.
The thickness of the protective layer is larger than the thickness of the main heat generating portion, the heater. The heater according to claim 12, wherein the first sub-heating portion has a dimension in the width direction smaller than that of each of the first strip-shaped portion and the second strip-shaped portion. The heater according to claim 13, wherein the heat generation resistor layer has a dimension in the width direction larger than that of each of the first band-shaped portion and the second band-shaped portion. The heater according to any one of claims 1 to 14, wherein the heat generation resistor layer is directly formed on the main surface of the substrate. The heater according to any one of claims 1 to 15, wherein the heat generation resistor layer contains ruthenium oxide. The heater according to claim 16, wherein the heat generation resistor layer contains copper oxide. The heater according to any one of claims 1 to 5 and 9 to 14 , wherein the protective layer is made of glass. The heater according to claim 18, wherein the protective layer covers the entire heat generation resistor layer. The electrode layer has a first pad portion and a second pad portion that are separately connected to the first band-shaped portion and the second band-shaped portion.
19. The heater according to claim 19, wherein the first pad portion and the second pad portion are exposed from the protective layer. The heater according to claim 20, wherein the first pad portion and the second pad portion sandwich the first band-shaped portion and the second band-shaped portion and are separated from each other in the longitudinal direction. The heater according to claim 20, wherein the first pad portion and the second pad portion are arranged on the same side of the first band-shaped portion and the second band-shaped portion in the longitudinal direction. The heater according to any one of claims 1 to 22, further comprising a thermistor provided on the back surface of the substrate. The heater according to any one of claims 1 to 23, wherein the substrate is made of ceramic. The heater according to claim 24, wherein the ceramic is alumina or aluminum nitride. The heater according to claim 24 or 25, wherein the thickness of the substrate is 0.4 to 1.2 mm. The heater according to any one of claims 1 to 26, wherein the electrode layer contains Ag. The heater according to any one of claims 1 to 27, wherein the temperature coefficient of resistance of the first sub-heating unit is 3 times or more and 15 times or less the temperature coefficient of resistance of the first main heat-generating unit. The heater according to any one of claims 1 to 28, wherein the dimensions of the first main heating unit and the first sub-heating unit in the longitudinal direction are 290 mm to 310 mm.

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