JP2916964B2 - Reflector made of thermoplastic resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflector made of a thermoplastic resin for lighting equipment, and more particularly, to a reflector made of a thermoplastic resin for light emitting equipment used in a lighting posture other than vertical.

[0002] Reflectors for various floodlights, such as headlamps used in transportation systems such as automobiles, railways, ships, etc., are mainly used for sheet metal processing of metal, molded articles of glass or thermosetting resin. Those on which a reflective film is deposited are widely used. These materials have stable properties,
There are drawbacks such as poor workability, heavy weight, and high cost. For example, the use of a reflector made of these materials in an automobile or the like violates the demand for weight reduction and recycling.

[0003] In place of these materials, there is a tendency to adopt a thermoplastic resin, for example, a polyphenylene sulfide (PPS) resin, in order to reduce the weight and cost. However, although PPS can be recycled, it has the drawback that raw material costs increase and costs increase. In addition, with regard to the light distribution characteristics, BMC which is a sheet metal processing and thermosetting resin
It was inferior to those made of the product, and sometimes it could not be handled depending on the design of the reflector.

Further, a thermoplastic resin having a low specific gravity cannot satisfy all the required performances of a reflector due to insufficient heat resistance and rigidity and an inappropriate coefficient of linear expansion. In particular, in the case of a reflector for a lighting fixture that requires a lighting posture other than vertical, for example, nearly horizontal, in addition to the radiation from the light source, heat transfer due to convection becomes non-uniform, and the heat is trapped upward. The top surface becomes extremely hot.

For example, in a headlight of an automobile, a lamp having a high output is often used instead of a shape and a size, because standards such as a luminous flux reaching distance and a luminous intensity are stipulated. Therefore, the heat generated by the light source is large, and the temperature of a part of the top surface reaches 200 ° C even though the lower surface is 100 ° C or less at the time of lighting. There is also. Therefore,
Since only the top surface of the reflector greatly expands, the parabolic surface is deformed, and the reflected light beam is not radiated as designed, so that there is a problem that the function as the reflector cannot be sufficiently exhibited.

[0006] In particular, in the case of headlights of automobiles, the deviation of the optical axis has a serious effect on safe operation. Therefore, an irradiation test (mis-aiming test: compliant EC regulation 20) is required if the equipment is completed. Done. For example,
In a headlight device used in a vehicle of European specifications, a displacement of a projected image of irradiation light must not exceed a predetermined range immediately after the start of lighting and after one hour has elapsed. Under these conditions, satisfactory results have not been obtained with a conventional thermoplastic resin reflector.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a reflector for a floodlight made of thermoplastic resin, which has solved the drawbacks of the prior art.

[Means for Solving the Problems]

An object of the present invention is to provide a reflector made of a thermoplastic resin in a light emitting device as a light source that emits light in a lighting posture other than vertical, for example, in a horizontal direction or a direction close thereto. The problem is solved by a thermoplastic resin reflector to which a synthetic resin plate having a small expansion coefficient is attached. As the thermoplastic resin as the material, many resins having excellent heat resistance and mechanical strength alone or a blend of these resins can be used.

As a material having a small linear expansion coefficient to be considered here, a synthetic resin plate having a small linear expansion coefficient and excellent heat transfer characteristics can be used. The attachment of these materials can be performed by means such as embedding or bonding. In this case, these materials can be inserted into a mold at the time of molding the reflector main body and can be performed simultaneously, and can also be attached by secondary processing after molding of the reflector main body. The material having a small linear expansion coefficient attached in this manner functions as a linear expansion suppressor when the reflector is heated by turning on the light source.

On the inner surface of the reflector thus formed, a reflective film is formed by vapor deposition or other known means.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be disclosed below with reference to the accompanying drawings showing embodiments. FIG. 1 is a perspective view showing a structural example of a reflector made of a thermoplastic resin. The reflector 1 according to the present invention is intended for a headlight of an automobile, and has a flat structure in which a top surface 2 and a bottom surface 3 are planes, and left and right sides are a rotating parabolic surface 4. The reflector having such a structure has a compact lighting device as a whole and is also preferable in terms of vehicle design. In recent years, the reflector has tended to be used frequently. Because they are close, they will be particularly exposed to high temperatures.

In the reflector of the embodiment shown in FIG. 1, a material 5 having a small coefficient of linear expansion is attached directly above a light source which is both a light emitting body and a heating element. Here, a synthetic resin plate having a small linear expansion coefficient is attached. Such a material having a small linear expansion coefficient functions to dissipate high heat due to radiation from the light source and convection to the outside, and to suppress linear expansion generated on the top surface 3 of the reflector 1.

In this example, polyetherimide or polycarbonate having high heat resistance was used as the thermoplastic resin. Polyetherimide is an engineering plastic with high heat resistance and high rigidity. For example, ULTEM
(Trademark: Japan GE Plastics Co., Ltd.).

In order to confirm the effect of the configuration example shown in FIG. 1, a reflective film was formed on each of a reflector having a similar structure and a conventional structure to which a material having a small linear expansion coefficient was not attached, and the reflector of this embodiment. Thereafter, a light source was attached to a predetermined position and turned on.

Then, irradiation was performed on a screen 7 m in front of the reflector, and the angular displacement of the light cut surface was confirmed 3 minutes after lighting and 1 hour after lighting. As a result, in the reflector having the conventional structure in which nothing is attached to the top surface, a displacement of 0.06 degrees occurs, whereas in the embodiment according to the present invention, no displacement occurs and the displacement is 0 degrees. confirmed.

[0016]

According to the present invention, a reflector made of a thermoplastic resin can be realized as a reflector of a floodlight using a high-power light source. Such a reflector is lightweight and inexpensive, is easy to mold, and can be recycled because it is formed only of a synthetic resin. Therefore, it is possible to obtain a reflector for lighting equipment suitable for a wide range of applications without using a sheet metal processing of a metal plate or a thermosetting resin or a thermoplastic resin having a large specific gravity.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a thermoplastic resin reflector according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reflector 2 Top surface 3 Bottom surface 4 Parabolic surface 5 Material with small linear expansion coefficient

Claims (1)

(57) [Claims] 1. A reflector made of a thermoplastic resin for a light emitting device used in a lighting posture other than vertical, wherein a synthetic resin plate having a small linear expansion coefficient is attached to a part of the top surface of the reflector. A reflector made of a thermoplastic resin.