JPS6097587A - Thermosensitive panel heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a heat-sensitive sheet heating element used in electric carpets and the like.

(Background technology) Conventionally, in electric carpets, etc., for example, negative temperature -
A heating line is placed on one side of the thermosensitive resin film that determines the impedance characteristics, and a temperature detection electrode is provided on the same side as the heating line, and multiple auxiliary conductive plates are placed on the other side of the thermosensitive resin film. However, temperature control is performed by applying a signal voltage of a predetermined frequency between the heat generating line and the temperature detection electrode and controlling the energization to the heat generating line according to the impedance change of the thermosensitive resin film accompanying the temperature change.

That is, FIG. 4 shows this type of conventional heat-sensitive sheet heating element A'.
and its temperature control circuit, in which 1 is a thermosensitive resin film, 2 is a heating line, 3 is a temperature detection electrode arranged in parallel on the outgoing and returning paths of the heating line 2, 4 is an auxiliary conductive plate, 2a
, 2b, 3a, and 3b are each a lead wire connection part, 7 is a commercial power supply, 8 is a comparison circuit, B is a switching circuit, C is a constant voltage DC power supply, T is an I/lance, R1 is a detection resistor, and Dl is a Diode, C1 is capacitor, S is relay R which will be explained later.
Normally open contact of y, diode for beam absorption of Dl, Q
indicates a transistor, and R2 indicates a resistor.

In this B-degree control operation, the impedance of the thermosensitive resin film 1 decreases due to the temperature upper limit of the heat generating line 2, and the current flowing through the heat generating line 2 to the detection resistor R1 via the temperature detection electrode 3 increases, that is, the detection resistor R1 The voltage Vo across capacitor C1 increases.

This output voltage Vo is input to the comparator circuit 8 and compared with the standard voltage value, and when the output voltage Vo exceeds this reference voltage, the comparator circuit 8 switches the switching state, which had been kept in the on state within the safe temperature range, until then. The transistor Q constituting the latter part of the circuit B is inverted to the on state, and the driving of the excitation coil of the relay Ry connected in series to this transistor Q is stopped, and the normally open contact S is returned to the previously on state. The power supply path of the heating line 2 is cut off by inverting from the on state to the on state.

However, according to this, when using an electric carpet or the like, the lead wire connection portion 2a as shown in FIG.

If a conductive pin P or the like is inserted near 3a and 3b, 1. :
Otherwise, if conductive foreign matter gets mixed in, the heat generating line 2 and temperature detection electrode 3 will be ignored through the auxiliary conductive plate 4, and the lead wire connection parts 2a and 3a will also be in a state of ignorance, which is not the case in the original case. Then, as the impedance of the thermosensitive resin film 1 decreases due to temperature rise, the detection resistance R+
Although the voltage should increase, not much current flows through the detection resistor R+, and a sufficient voltage does not appear across it, making it impossible to accurately control the temperature, which is dangerous. .

(Object of the Invention) The present invention has been proposed in order to solve the above-mentioned drawbacks, and its purpose is to provide a conductive bottle, etc. for use in the case of electricity. An object of the present invention is to provide a safe heat-sensitive sheet heating element that can maintain and perform normal 8 degree control even if the photothermal line and temperature detection electrode are accidentally pierced.

(Disclosure of Zadeaki) The present invention will be described below with reference to the drawings. Figures 1 to 3
The figure shows a heat-sensitive sheet heating element A according to the present invention, and FIG. 1 shows a cross-sectional view. In the same figure, 1 in a3 indicates a thermosensitive resin film that has a negative temperature-impedance characteristic, that is, the impedance decreases as the temperature rises, and is made of, for example, nylon resin with a thickness of about 40 to 80 μm. . On one side of this thermosensitive resin film 1, a heat generating line 2 made of metal foil such as aluminum foil with a thickness of about 10 to 30 μm and a temperature detection electrode 3 are provided.
Furthermore, on the other side of the thermosensitive resin film 1, an auxiliary conductive plate 4 having a relatively small area and made of metal foil such as aluminum foil with a thickness of approximately 10 to 30 μm is arranged to form an exclusion portion 1a, which will be described later. Except for the heating line 2 through the thermosensitive resin film 1.
A large number of temperature detection electrodes 3 are arranged so as to face each other on both sides of the temperature detection electrodes 3 adjacent to the heating line 2. Further, insulating films 5.6 are attached to the surfaces of the heat generating line 2 and the flooding detection voltage tl 3, and to the surface of the auxiliary conductive plate 4, respectively.

Here, the arrangement pattern of the heating line 2 and the like must satisfy the following conditions. That is, as is clear from FIG. 2, first, the heat generating line 2 has the lead wire connection parts 2a, 21+ provided at the ends of the thermosensitive photothermal body A as both ends thereof, and its forward and backward routes are connected to the thermosensitive resin film 1. They are arranged substantially parallel to each other over the entire surface. Further, the temperature detection electrode 3 has a lead wire connection portion 3a.

3b as both ends, they are arranged in parallel along and inside the heat generating line 2 so as to cover almost the entire surface of the thermosensitive resin film 1. Furthermore, each auxiliary conductive plate 4 faces only the outgoing path or only the incoming path of the heating line 2 and the temperature detection electrode 3,
The width dimension of the heat generating line 2 and the shape of the auxiliary conductive plate 4σ2 are determined so that the facing surfaces (^) of the outward and return paths of the heat generating line 2 facing the individual auxiliary conductive plates 4, excluding the excluded portion 1a, are approximately equal. It is desirable that the

The exclusion part 1a is formed on the back surface of the thermosensitive resin film 1 so as to cover the end of the heat generating line 2 and the end of the temperature detection electrode 3 near the lead wire connection parts 2a and 3a.
This excluded portion 1a is not provided with the auxiliary conductive plate 4 facing the heating line 2 and temperature detection electrode 3 on the front surface.

Note that the configuration and temperature control operation of the temperature control circuit in the present invention are the same as those shown in FIG. 4 showing the conventional example, so the explanation will be omitted, but the structure of the heat-sensitive sheet heating element A is roughly as shown in FIG. 3. become. In this FIG. 3, the range of the exclusion part 1a is defined by the heating line 2 and the temperature detection electrode 3 by means of a conductive bottle P, etc.
The voltage across the detection resistor R3 is set to be higher than the voltage across the detection resistor R+ at the set maximum temperature when the two are short-circuited through the auxiliary conductive plate 4. Since the impedance is more than two orders of magnitude higher than the resistance of the heat generating line 2 and the temperature detection electrode 3, the detection resistance R
If the size of 1 is made small, a narrow range of exclusion part 1a is actually sufficient. In reality, it is almost detected by the ratio of the resistance value from the short circuit part by pin P to the lead wire connection part 2a, the resistance value from the short circuit part to the lead wire connection part 3a, and the value of the detection resistor R1. Since the magnitude of the voltage across the resistor R8 is determined, the range of the exclusion section 1a is the detection resistor R at the time of short circuit.
1 is determined so that the voltage across the detection resistor R+ is at least larger than the voltage across the detection resistor R+ at the highest set temperature.

Furthermore, even if the temperature detection electrode 3 and the part of the heating line 2 near the other lead wire connection part 2b are not known, the lead wire connection part 2b side is close to 100V and the lead wire connection part 2
Since the resistance of the path leading to a is also large, a sufficient current flows through the detection resistor R+ and an OFF level voltage is generated across the detection resistor R+, so that there is no problem or danger in operation.

(Effects of the Invention) As described above, according to the present invention, since the excluded portion in which the auxiliary conductive plate is not disposed on the back surface of the thermosensitive resin film is provided within a predetermined range, the auxiliary conductive plate is not disposed within the range of the excluded portion. There is no short circuit between the heating line and the temperature detection electrode, and even if a short circuit occurs through the auxiliary V# conductive plate in a range other than this, the temperature control circuit can be operated reliably by the voltage across the detection resistor. This has the effect of enabling highly precise temperature control.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention,
Figure 1 is a sectional view, Figure 2 is a partially cutaway plan view, and Figure 3 is a cross-sectional view.
The figure is a temperature control circuit diagram, and FIG. 4 is a temperature control circuit diagram showing a conventional example.

Claims (1)

[Claims] The outgoing and returning paths of the heat-generating line are arranged almost parallel to each other over almost the entire surface of the heat-sensitive resin film, and temperature detection is provided on the surface of the heat-sensitive resin film to detect a change in impedance of the heat-sensitive resin film relative to the heat-generating line. In a heat-sensitive planar heating element in which electrodes are arranged substantially parallel to each other along the entire length of the heat-generating line, the heat-sensitive resin film is provided on the back surface of the heat-sensitive resin film except for an exclusion portion formed on the back surface of the heat-sensitive resin film. A plurality of auxiliary conductive plates made of metal parts facing only the outgoing path or only the incoming path of the heating line and temperature detection electrode are distributed and arranged,
When the heating line and temperature detection electrode included in a range other than the exclusion part are ignored, the exclusion part is a temperature control part connected in parallel to the series circuit of the short-circuited heating line and temperature detection electrode. A heat-sensitive sheet heating element characterized in that a voltage across the detection resistor is set within a range that is greater than an operating voltage of a temperature control circuit that operates to cut off electricity to the heating line.