JP3044098B2 - Temperature detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an electrophotographic apparatus,
The present invention relates to a temperature detecting device that detects the temperature of a roller of a heat fixing device in a non-contact manner.

[0002]

2. Description of the Related Art Conventionally, a non-contact type temperature detecting device is disclosed in Japanese Patent Application Laid-Open No. 58-83880. The structure was such that the temperature detecting element was fixed with an adhesive or the like.

[0003]

However, in the above conventional example, the heat insulating wire for supporting the element becomes thicker in order to keep the distance from the surface of the fixing roller to the element constant, and the lead wire becomes thicker from the viewpoint of strength. However, heat from the element was easily taken away, and the temperature of the roller surface could not be detected with high sensitivity. Further, as described in JP-A-55-96970, in order to prevent offset in the fixing roller,
The edge distance between the surface of the fixing roller and the element / lead wire required in the case where a voltage is applied between the fixing roller and the pressure roller, which is required by safety standards, could not be obtained.

SUMMARY OF THE INVENTION The present invention solves the above problems, maintains the distance between the surface of the fixing roller and the temperature detecting element constant without deteriorating the sensitivity of the temperature detecting element, and maintains the distance between the fixing roller surface and the element and the element.
It is an object of the present invention to provide a temperature detecting device that can take an edge surface distance between a lead wire.

[0005]

According to the present invention, an object of the present invention is to provide a substrate having a through hole and a lead wire on the surface thereof, and a substrate mounted on the surface of the substrate and around the through hole. A temperature detecting device comprising: a temperature detecting element connected to the lead wire; and an insulating tape attached to at least a back surface of the substrate so as to entirely cover the through hole, wherein the insulating tape is attached. This is attained by arranging the attached back surface so as to face the fixing roller surface, and the lead wires are arranged parallel to the axial direction of the fixing roller.

[0006]

According to the present invention, the temperature detecting element is mounted on the substrate, and the distance from the surface of the fixing roller to the temperature detecting element is kept constant. Further, the substrate has a through-hole, so that the response of the temperature detecting element to heat is good. Further, the substrate has a lead wire connected to the temperature detecting element on the front surface, the back surface of the substrate and the surface of the fixing roller face each other, and the lead wire is parallel to the axial direction of the fixing roller. The distance between the temperature detecting element and the lead wire with respect to the surface of the fixing roller is substantially equal. Therefore, the temperature detection element and the lead wire are heated to substantially the same temperature, so that the lead wire does not lose heat. Further, since the through hole is entirely covered with an insulating tape on the back surface, the fixing roller surface and the element
Ensure the edge distance from the lead wire.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment and a second embodiment of the present invention will be described with reference to the drawings.

<First Embodiment> A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a configuration diagram of the present embodiment. The temperature detecting element 1 that detects a temperature change as its resistance value change has a copper foil pattern width of 0.15 m.
It is mounted on a 0.1 mm thick polyimide substrate 3 having m lead wires 2. The substrate 3 has four rectangular holes in the center, and a vertical substrate portion 4 and a horizontal substrate portion 5.
Are at right angles. The position of the detection element is set at the center of a cross formed by the horizontal substrate portion 5 and the vertical substrate portion 4. The lead wire 2 is connected to a circuit outside the device from the solder pad 6 at the end of the substrate 3. Then, as shown in FIG. 2, the insulating tape 7 (SCOTCH single-sided tape # 375) is attached so that the four holes formed in the substrate 3 are covered with the back surface of the substrate 3. Further, as shown in FIG. 3, the horizontal substrate portion 5 and the lead wire 2 are made parallel to the axis of the fixing roller 8, and the distance from the surface of the fixing roller 8 is 0.5 ± 0.2 m.
It is held at the position of m. Further, the substrate 3 is disposed so that the front surface of the fixing roller 8 and the back surface of the substrate 3 face each other as shown in FIG. Next, FIG. 4 shows a circuit diagram of the present embodiment. By connecting the resistor 9 and the temperature detecting element 1 in series, the resistance change due to the temperature of the element is converted into a voltage change,
The surface temperature of the fixing roller 8 is detected by inputting it to the A / D conversion port 11 of FIG.

In the apparatus of the present embodiment as described above, the heat received by the temperature detecting element 1 from the fixing roller 8 is easily transmitted through the lead wire 2 having high thermal conductivity, but as described above, the heat is applied to the fixing roller 6 axis. When the lead wire 2 is drawn out in parallel, the distance between the lead wire 2 and the surface of the fixing roller 8 becomes equal to that of the temperature detecting element 1 and is heated to substantially the same temperature. Further, since the lead wire 2 is a pattern on the substrate, the width can be reduced to 0.15 mm and the heat capacity thereof can be reduced, so that the amount of heat that escapes can be suppressed in the same manner as described above. Further, the supporting vertical substrate portion 4
Is provided, the distortion of the horizontal substrate portion 5 due to heat can be reduced, and the distance between the temperature detecting element 1 and the surface of the fixing roller 6 can be accurately maintained. In addition, a hole is formed in the substrate 3 and the hole is prevented by the insulating tape 7.
Even when a voltage is applied between the fixing roller 8 and the pressure roller in order to prevent an offset in the fixing roller 8 as described in JP-A-5-96970, the circuit on the surface of the fixing roller 8 and the circuit on the primary side are used. It is possible to secure a safety standard edge surface distance between a certain temperature detecting element 1 or a lead wire 2 and to improve heat transfer by the above-mentioned holes to improve the responsiveness of the temperature detecting element 1. it can.

<Second Embodiment> FIG. 5 is a block diagram of the present embodiment. This is a case where the temperature detecting element 1 of the first embodiment is mounted on the back surface of the substrate 3, that is, on the side of the fixing roller.
Join with. Thereby, the gap between the temperature detecting element 1 and the insulating tape 7 can be filled, the peeling of the insulating tape 7 can be prevented, and the heat from the fixing roller 8 can be captured with high sensitivity.

[0011]

As described above, according to the present invention,
A temperature detecting element is attached to the surface of the substrate having the through hole and the lead wire, the through hole is entirely covered with an insulating tape on the back surface of the substrate, and the back surface faces the fixing roller surface, and the lead wire Is disposed so as to be parallel to the axial direction of the fixing roller, so that it has the strength to keep the distance between the roller surface and the element constant, suppresses the amount of heat escaping from the element, and enables highly accurate temperature detection. In addition, the edge distance in the safety standard between the roller surface to which the voltage is applied and the element or the lead wire as the primary circuit can be set.

[Brief description of the drawings]

FIG. 1 is a plan view showing a schematic configuration of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the apparatus in FIG. 1;

FIG. 3 is a diagram illustrating a positional relationship between the apparatus of FIG. 1 and a fixing roller.

FIG. 4 is a circuit diagram of the device in FIG. 1;

FIG. 5 is a front view showing a schematic configuration of an apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Temperature detection element 2 Lead wire 3 Substrate 7 Insulating tape 8 Fixing roller

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tatsuto Tachibana 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Izumi Narita 3-2-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Kazuhiko Okazawa Canon Inc. 3- 30-2 Shimomaruko, Ota-ku, Tokyo (56) References JP-A-2-114135 (JP, A) JP-A-59-44633 (JP) JP-A-58-83880 (JP, A) JP-A-2-146338 (JP, U) JP-A-3-115829 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB G01J 5/00-5/02 G03G 15/20 109

Claims (2)

(57) [Claims] 1. A substrate having a through hole and a lead wire wired on the surface, a temperature detecting element attached to the surface of the substrate around the through hole and connected to the lead wire,
A temperature detecting device having an insulating tape attached so as to entirely cover the through hole on at least a back surface of the substrate, wherein the back surface on which the insulating tape is attached faces a fixing roller surface. A temperature detecting device, wherein the lead wire is disposed so as to be parallel to the axial direction of the fixing roller. 2. A temperature detector attached to a surface of the substrate.
The temperature attached to the back of the substrate instead of the output element
It has a detecting element, the insulating tape and between the temperature detecting element is a temperature sensing device according to claim 1, characterized in that are joined with a high thermal conductivity adhesive.