JPH07235369A - Non-induction type heater sheet - Google Patents

Abstract

PURPOSE:To provide a heater sheet of non-induction type which best suits the heating of a sensor etc., and with which no effective magnetic field to cause noises is induced externally when a heating current is fed. CONSTITUTION:A heater sheet 4 for heating is used upon being wound on or put in tight attachment to an object to be heated such as a sensor. An element sheet 1 is prepared by shaping a heat resistant resin so that its flexibility is kept, and the heater sheet 4 is structured so that a wire-form heat emitting element 2 is laid on the sheet 1 or between two such sheets while the wire is bent in such a way that the forward path and return path are equal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention heats a detecting element which constitutes a sensor and a portion such as an amplifier which is coupled to the detecting element so that the sensitivity of the sensor which outputs a weak signal is not influenced by the ambient temperature. The present invention relates to a heating heater used when maintaining a constant temperature.

[0002]

2. Description of the Related Art A radiation sensor comprising a radiation detecting element such as a NaI scintillator and a photomultiplier tube for detecting and amplifying light emitted from the NaI scintillator, or PbS.
An infrared sensor including an infrared detection element and a weak current amplification circuit has a large sensitivity variation with temperature. Therefore, in order to suppress the fluctuation of the sensor sensitivity due to the change of the ambient temperature, the sensor portion is heated to a temperature slightly exceeding the upper limit of the change range of the ambient temperature and kept constant.

Conventionally, to raise the temperature of a heated object such as a sensor,
As illustrated in FIG. 4, a method is used in which a linear electric heating element 2 is wound around a heating target 5 and heated, and an electric current is applied to the wound electric heating element 2. When it is necessary to prevent noise from invading the detection element or the amplifier due to the electromagnetic induction effect that occurs when the heating target 5 is surrounded by the magnetic material 6 having a high magnetic permeability, an electric heat is generated outside the magnetic material 6. Measures are taken to prevent or reduce the invasion of magnetic flux into the heated body 5 by winding the body 2.

[0004]

In the conventional heating and heating method in which a linear electric heating element is wound around a heated body, a magnetic material having a high magnetic permeability is provided between the heated body and the electric heating body. Even with the interposition, it is extremely difficult to suppress the penetration of the magnetic flux into the object to be heated to a sufficiently low level below the noise level. INDUSTRIAL APPLICABILITY The present invention does not generate a magnetic flux itself when a heating current is applied, and even if it is used in close contact with a heated object for heating and heating the heated object, noise of the sensor, which is the heated object, is generated. An object is to provide a heating heater sheet such as a sensor that does not rise.

[0005]

[Means for Solving the Problems] In order to solve the above problems,
In the present invention, a heater sheet for heating, which is used in close contact with the object to be heated, is formed on the sheet formed by molding the heat resistant resin so as to maintain flexibility, or in the middle of the two sheets, A linear electric heating element is arranged in a bent shape so that the path length of the return traffic is equal.

[0006]

When the heating current is applied to the linear electric heating elements arranged in a bent shape so that the path lengths of the return traffic are equal, the directions of the currents flowing through the adjacent electric heating elements are opposite to each other, The directions of the magnetic fields induced by the currents are also opposite to each other and cancel each other out. In addition, since the heat-resistant resin that holds the electric heating element is molded so as to maintain flexibility, it is possible to wind this heater sheet around the object to be heated or place it closely along the shape of the object to be heated. it can.

[0007]

1 is a diagram showing the schematic construction of an embodiment of a non-induction type heater sheet 4 according to the present invention. In FIG. 1, 1 is a sheet made of a heat-resistant resin such as polyimide, and 2 is a linear electric heating element arranged in a bent shape on the sheet 1 so that the path lengths of forward and return are equal. And
Reference numeral 3 is a lead wire for guiding a heating current to the electric heating element 2.

When a heating current is applied from the lead wire 3 of the electric heating element 2 arranged as described above, the electric currents flowing through the linear electric heating elements 2 adjacent to each other are directed to each other and are induced by the electric current. The directions of the magnetic fields generated are also opposite to each other and cancel each other out, so that no effective magnetic field appears outside the heater sheet 4. FIG. 2 shows another embodiment of the present invention in which two groups of linear electric heating elements 2 arranged in a bent shape so as to have the same path length of traffic are arranged symmetrically on the heat-resistant sheet 1 and connected. It is a figure which shows the arrangement pattern of the electric heating element 2, and when the heating elements are arranged in this way, a current path is formed by the electric heating element 2 in which the directions of the currents are opposite to each other in both vertical and horizontal directions. Therefore, the cancellation of magnetic fields becomes more complete.

[0009]

As described above, in the heater sheet of the present invention, even if a heating current is applied, the magnetic field that acts effectively does not appear outside the heater sheet. Even if this heater sheet is closely arranged by winding or the like around the heating body and a heating current is input, the magnetic field that effectively acts does not appear outside the heater sheet, so that the heated body is not susceptible to disturbance. Even in such a case, it is possible to obtain the effect that noise due to the electromagnetic induction effect is not induced in the detection element or the amplifier of the sensor unit.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a non-induction type heater seat according to the present invention.

FIG. 2 is a configuration diagram of another embodiment of the non-induction type heater seat according to the present invention.

[Fig. 3] Winding state diagram of non-induction type heater seat

FIG. 4 is a configuration diagram of a heater by winding a conventional electric heating element.

[Explanation of symbols]

 1 Heat resistant resin sheet 2 Electric heating element 3 Lead wire 4 Heater sheet 5 Heated object 6 Magnetic material

Claims (1)

[Claims] 1. A bent electric heating element is provided on a sheet formed by molding a heat-resistant resin so as to maintain flexibility, or in the middle of two sheets, so that the path lengths of traffic are equal. A non-induction type heater seat characterized by the above.