JPH0654104U - Resin reflector - Google Patents

Abstract

(57) [Summary] [Purpose] The conventional resin reflector using total internal reflection has a problem that efficiency is reduced due to light leakage at the reflecting surface or internal vignetting due to changes in the incident angle. According to the present invention, a resin reflector 1 is provided in which a reflection surface 23 of a total reflection prism cut 2 is provided with correction angles α and β corresponding to an incident angle of light emitted from a light source 3 incident on an incident surface 21. By so doing, the reflecting surface 23 is made to correspond to an optimum state in response to a change in the incident angle with respect to the incident surface 21,
The problem is solved by letting light be emitted from the emission surface 22 without being lost due to light leakage from the reflection surface 23 or vignetting inside the resin reflector 1 at any incident angle.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a reflector used for directing emitted light from a light source as parallel light to a vehicle lamp in the irradiation direction. Specifically, a total reflection prism cut is formed on a housing-shaped member made of transparent resin. The present invention relates to a resin reflector which is provided with a reflection function without forming a reflection surface such as aluminum vapor deposition.

[0002]

[Prior art]

 3 and 4 show the structure of a conventional resin reflector 90. The resin reflector 90 is made of a transparent resin as shown in FIG. In addition, a plurality of total reflection prism cuts 91, each of which includes an incident surface 91a directed to the light source 80 disposed on the inner surface side, an emission surface 91b directed in the irradiation direction, and a reflective surface 91c disposed on the back side, are provided. The total reflection prism cut 91 directs the emitted light from the light source 80 as parallel light in the irradiation direction.

Here, FIG. 4 shows an example in which the structure of the total reflection prism cut 91 is extremely simplified, and the incidence surface 91a and the emission surface 91b are substantially perpendicular to each other. In addition to being provided, the reflecting surface 91c is set at 45 ° with respect to the incident surface 91a and the emitting surface 91b. At this time, assuming that the incident light from the light source 80 is orthogonal to the incident surface 91a, the light incident from the incident surface 91a has a refractive index of the member including the resin reflector 90 and the reflecting surface 91c. Due to the difference from the refractive index of the atmosphere in contact with the air, the light is totally reflected by the reflection surface 91c and emitted from the emission surface 91b, and the reflector can be formed without performing post processing such as aluminum vapor deposition.

At this time, if the emission surface 91b or the like is made a Fresnel cut with the light source 80 as the focal point, the light emitted from the emission surface 91b is converted into parallel light. Under the above conditions, when the light incident from the incident surface 91a reaches the reflection surface 91c, it is within the angle of total reflection, and the efficiency of the total reflection prism cut 91 is about 100%.

[0005]

[Problems to be solved by the device]

 However, in the above-described conventional configuration, when the light from the light source 80 is incident as downward as shown in FIG. 5, for example, when the incident light Z reaches the reflecting surface 91 c, the total reflection angle exceeds the total reflection angle. It leaks from the reflecting surface 91c and causes a decrease in efficiency.

Although not shown, when the light from the light source 80 is incident as upward light, the reflection angle by the reflection surface 91c becomes shallow, so that the light is incident on the incident surface 91a and then from the emission surface 91b. A long distance is required before the light is emitted, the correspondence between the incident surface 91a and the emission surface 91b is disturbed, vignetting occurs, and the efficiency is similarly reduced. As a result, the resin reflector 90 is removed. There was a problem that the adopted lamp became dark, and it was an issue to solve this problem.

[0007]

[Means for Solving the Problems]

 As a concrete means for solving the above-mentioned conventional problems, the present invention radiates light emitted from a light source by using a total reflection prism cut formed of a transparent resin and having an entrance surface, a reflection surface and an exit surface. In the resin reflector configured to direct the light as parallel light in the irradiation direction, the reflection surface of the total reflection prism cut is provided with a correction angle corresponding to the incident angle of the emitted light from the light source incident on the incident surface. The problem is solved by providing a resin reflector that is characterized by

[0008]

【Example】

 Next, the present invention will be described in detail based on an embodiment shown in the drawings. Reference numeral 1 in FIG. 1 denotes a resin reflector of the present invention, which is a main part, and an entrance surface 21 and an exit surface 22 are provided on the surface of the resin reflector 1 facing the light source 3 of the total reflection prism cut 2 of the resin reflector 1. As in the conventional example, a reflecting surface 23 is provided on the back side to convert the emitted light from the light source 3 into parallel light traveling in the irradiation direction.

Here, in the present invention, a decrease in efficiency is prevented by providing a correction angle on the reflecting surface 23. First, a state in which downward light is incident on the incident surface 21 will be described. In this state, when the light incident on the incident surface 21 reaches the reflection surface 23 and exceeds the total reflection angle, the reflection surface 23 is provided with a correction angle α so that the inclination is gentle. Therefore, the efficiency is improved by reflecting the total amount of light from the incident surface 21.

The above correction can theoretically be performed by inclining the incident surface 21 so that the incident surface 21 is bent, but the incident surface 21 is undercut when the resin reflector 1 is formed. However, it is practically impossible to form it, so that it cannot be carried out. However, when the correction is performed by the reflecting surface 23, no problem occurs in molding.

When the light incident on the incident surface 21 is upward light, the correction angle β is corrected in the direction of increasing the inclination of the reflective surface 23 as shown in FIG. The correction at this time is carried out so that the light entering from the incident surface 21 and reflected by the reflecting surface 23 is correctly directed to the opposite emitting surface 22, whereby, for example, the light entering from a certain incident surface 21 is incident. It is intended to prevent the light reflected by the reflecting surface 23 from reaching the other incident surface 21 and becoming vignetting, thereby reducing the internal loss and improving the efficiency. In actual implementation, the above-mentioned leakage and vignetting occur in competition, so even in the case of downward light, correction may be performed to increase the inclination. Anything that improves

As described above, the present invention makes it possible for the light incident on the incident surface 21 to be emitted from the emitting surface 22 in the total amount of light without causing light leakage or vignetting. It is assumed that the efficiency of the total reflection prism cut 2 is not left or right due to the incident angle with respect to 21, and that the efficiency of approximately 100% can be expected for this total reflection prism cut 2.

It should be noted that although the above description makes no reference to color, as is clear from the above description, the light emitted from the light source 3 is once transmitted through the inside of the resin reflector 1, so that the resin reflector 1 is formed. The color depends on the color of the resin member to be processed. This means that if the resin reflector 1 is made of a colorless and transparent material, a so-called white light color is obtained, and if it is made of a colored material such as red transparent, a corresponding light color is obtained. For example, it is not necessary to color the outer lens 4 provided on the front surface of the resin reflector 1 for setting the light distribution characteristic.

[0014]

[Effect of device]

 As described above, according to the present invention, the reflection surface of the total reflection prism cut has the correction angle corresponding to the incident angle of the emitted light from the light source incident on the incident surface. As it does not cause light leakage from the reflecting surface or loss due to vignetting inside the resin reflector, it enables highly efficient reflection at any incident angle. As the amount of light is emitted from the emission surface, the efficiency of this type of resin reflector is improved and an extremely excellent effect on performance improvement is achieved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a resin reflector according to the present invention as an example of correction for downward light.

FIG. 2 is a sectional view showing an example of correction for upward light in the same embodiment.

FIG. 3 is a cross-sectional view showing a conventional example.

FIG. 4 is a cross-sectional view showing an enlarged main part of a conventional example.

FIG. 5 is an explanatory diagram showing an operation of a conventional example.

[Explanation of symbols]

 1 ... Resin reflector 2 ... Total reflection prism cut 21 ... Incident surface 22 ... Emission surface 23 ... Reflection surface 3 ... Light source 4 ... Outer lens α, β ... Correction angle

Claims (1)

[Scope of utility model registration request] 1. A resin reflector, which is made of a transparent resin and is configured to direct emitted light from a light source as parallel light in the irradiation direction by a total reflection prism cut formed of an incident surface, a reflective surface, and an outgoing surface. The resin reflector, wherein the reflection surface of the total reflection prism cut is provided with a correction angle corresponding to an incident angle of light emitted from a light source incident on the incident surface.