JPH08295206A - Mirror with heater - Google Patents

Abstract

PURPOSE: To improve safety by interrupting a current when generated additional heat, by grounding a thermal fuse in the vicinity of a power feed point of an electrode. CONSTITUTION: A pair of electrodes 3a, 3b are provided in a reverse surface of a heating resistor 2, and a contact point of a lead wire 5 with the electrodes 3a, 3b, serving as power feed points A1, A2, is positioned in almost the center part of each electrode 3a, 3b. A thermal fuse 7 is arranged between the power feed point A2 and a thermostat 6, to place a mounting position of the thermal fuse in the vicinity of the power feed point A2. Generally when deteriorated the electrodes 3a, 3b, a current much flows between the power feed points A1, A2, and it is difficult to warm a part, with the thermostat 6 provided, distant from the power feed points A1, A2 consequently when left as it is to a temperature till off-operating the thermostat 6, a part between the power feed points A1, A2 is heated to a high temperature. Accordingly, even when not off operated the thermostat 6, the thermal fuse 7 is fused to be cut at a certain temperature, so that an accident can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention removes anti-fogging ability suitable for bathroom mirrors, vehicle door mirrors, etc., or water droplets, raindrops, dew, frost and ice attached to the surface of a mirror. A mirror with a heater having a capability.

[0002]

2. Description of the Related Art When a vehicle travels during rain or snow in a cold region, water drops adhere to the rear-view mirrors or icy, and the rear view becomes insufficient and driving safety is impaired. For the purpose of preventing the above, various mirrors have been proposed in which water drops, ice, etc. attached to the mirror are removed by heating the mirror surface.

For example, in Japanese Utility Model Application Laid-Open No. 61-192963, a heating resistor is formed on the entire rear surface of the glass of the rearview mirror, and the rear surface of the rearview glass is made uniform by energizing with electrodes provided at both ends. A rearview mirror with a heater that warms with a temperature distribution is disclosed.

[0004]

However, the above-mentioned mirror with a heater has a structure in which current is applied to the entire surface of the mirror to heat the mirror by electrodes provided at both ends of the heating resistor. When it deteriorates during use, the electrode resistance value increases, and the current flows in a concentrated manner between the feeding points, so that the current flow in the portion away from the feeding point decreases. In such a case, there is a problem that only a portion near the feeding point is heated and a portion away from the feeding point is hard to be heated, and as a result, the neighborhood of the feeding point is overheated.

Further, in the above-mentioned mirror with a heater, in order to keep the mirror surface at about 50 to 65 ° C. by heating the heating resistor with electricity, a temperature control mechanism such as a temperature control circuit using a thermostat or thermistor is usually provided. , The current is conducted, cut off, and adjusted, but if these temperature control mechanisms fail, or if the mirror breaks and heat is not transmitted to the heat sensing part of the temperature control mechanism, heating continues to be overheated. It may be heated. If you leave it overheated, it will cause burns if it comes into contact with the human body, deformation of parts around the mirror,
It also causes a disaster such as burning. The present invention
The present invention provides a mirror with a heater, which has improved safety by installing a temperature fuse near the feeding point to shut off the flow of current even when the performance deteriorates or is overheated for some reason.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a heating resistor is provided on a mirror substrate, and the heating resistor is provided to the heating resistor by electrodes provided at both ends of the mirror substrate. A mirror with a heater for heating a mirror substrate by heating by energization, wherein a temperature fuse is installed in the vicinity of a feeding point of the electrode.

[0007]

Embodiments of the present invention will be described with reference to the accompanying drawings. 1 is a schematic rear perspective view of a heater-equipped mirror used in a vehicle door mirror that is Embodiment 1 of the present invention.
Is a schematic view of a vertical section thereof. Reference numeral 1 is a mirror substrate, which is made of a transparent material such as glass. On the back surface of the mirror substrate 1, a heating resistor 2 which is also a reflective film is formed. The heating resistor 2 is composed of a single layer of a resistor material such as chromium, nickel, nichrome, titanium or a plurality of layers thereof, and is formed by a sputtering method or a vacuum deposition method. Furthermore, on the back surface of the heating resistor 2,
A pair of opposing electrodes 3a and 3b for energizing the heating resistor 2 are provided.

This electrode can be formed by various methods. For example, copper or silver paste is used to form a thin layer of copper or silver, solder is further applied thereon, or a thin layer of nickel is formed by nickel plating.
Further, the rear surface of the mirror is coated with an insulating material 4 such as resin for electrical insulation.

Reference numeral 5 is a lead wire for connecting the electrodes 3a, 3b, the thermostat 6, the temperature fuse 7, and a power feeding circuit (not shown). Lead wire 5 and electrodes 3a, 3
The contact points with b are the feeding points A1 and A2, and the electrodes 3a,
It is located approximately in the center of 3b. This feeding point A1, A2
Is a solder on the electrode. The thermal fuse 7 should be arranged between the feeding point A2 and the thermostat 6 for temperature control, and its mounting position should be near the feeding point A2.

The mounting position of the temperature fuse 7 is set near the feeding point A2 because a large amount of current flows between the feeding points A1 and A2 when the electrodes 3a and 3b are deteriorated.
Since the part where the thermostat 6 is apart from 2 does not easily warm up, if the temperature is kept at the temperature at which the thermostat 6 is turned off, the temperature between the feeding points A1 and A2 becomes overheated and becomes extremely high. Therefore, the temperature fuse 7 is blown at a certain temperature (the temperature at which the thermal fuse 7 is blown) even if the thermostat 6 is not turned off, so that an accident or a fire is prevented.

Embodiment 2 is shown in FIG. The second embodiment is the same as the first embodiment except that the thermal fuse 7 is attached in the vicinity of the feeding point A1 in the first embodiment, and the operation effect is also the same.

A third embodiment is shown in FIG. In the third embodiment, the mounting position of the thermal fuse 7 in the first embodiment is the feeding point A.
The second embodiment is similar to the first embodiment except that it is in the vicinity of 2 and on the line connecting the feeding point A1 and the feeding point A2. This example has a higher effect of preventing overheating than the first example.

FIG. 5 shows a fourth embodiment. In the fourth embodiment, the mounting position of the thermal fuse 7 in the second embodiment is set to the feeding point A.
The second embodiment is similar to the second embodiment except that it is in the vicinity of 1 and is on the line connecting the feeding point A1 and the feeding point A2. This example has a higher effect of preventing overheating than the second example.

A fifth embodiment is shown in FIG. In the fifth embodiment, the feeding points A1 and A2 are provided at diagonal ends of the electrodes 3a and 3b, the mounting position of the thermal fuse 7 is near the feeding point A2, and the feeding points A1 and A2 are It was made on the line connecting the two. This embodiment has a high effect of preventing overheating, as in the third and fourth embodiments.

[0015]

The heater-equipped mirror according to the present invention can prevent overheating of the mirror by attaching a temperature fuse in the vicinity of the feeding point even when the performance deteriorates due to long-term use or some abnormality occurs. , It has improved safety by preventing accidents and disasters.

[Brief description of drawings]

FIG. 1 is a schematic rear perspective view of a first embodiment of the present invention.

FIG. 2 is a schematic vertical sectional view of FIG.

FIG. 3 is a schematic rear perspective view of the second embodiment of the present invention.

FIG. 4 is a schematic rear perspective view of the third embodiment of the present invention.

FIG. 5 is a schematic rear perspective view of the fourth embodiment of the present invention.

FIG. 6 is a schematic rear perspective view of a fifth embodiment of the present invention.

[Explanation of symbols]

 1 Mirror Substrate 2 Heating Resistor 3a Electrode 3b Electrode 4 Insulation Material 5 Lead Wire 6 Thermostat 7 Thermal Fuse A1 Feed Point A2 Feed Point

Claims (1)

[Claims] 1. A heater-equipped mirror in which a heating resistor is provided on a mirror substrate, and the electrodes provided at both ends of the mirror substrate energize and heat the heating resistor to heat the mirror substrate. A mirror with a heater, which is equipped with a thermal fuse in the vicinity.