JPH0222786Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention is applicable to a traffic signal light using a C-9 filament light bulb, a transparent light bulb with a similar shape, or a near-transparent light bulb with a silica diffusion coating, etc. from the light source. The present invention relates to a lens for a traffic signal light that prevents the occurrence of brightness unevenness on the lens display surface at medium and short distances by efficiently controlling the distribution of the emitted light beam. [Prior Art] In conventional lenses for traffic signal lights, a relatively thick diffusive paint is applied to the bulb of the light bulb serving as the light source in order to prevent brightness unevenness from occurring on the lens display surface. As a result, brightness spots on the lens display surface are eliminated, but the apparent light source becomes larger and a considerable amount of light is diffused even from reflected light. It simply consisted of a lens-like element that refracted and directed the light and diffused the light forward and left and right. In addition, the light sources currently used in traffic signal lights are so-called C- because of the requirements for vibration resistance and durability.
It is desired to use a 9-inch light bulb or a transparent light bulb with a similar filament shape, or a nearly transparent light bulb, such as a silica diffusion coated light bulb (hereinafter referred to as a "clear light bulb"). [Problem to be solved by the invention] However, due to its structure, it is difficult to efficiently control light distribution with the conventional traffic signal light lens described above. If a light bulb is used as a light source that is not coated or has a very small amount of coating, only the center of the lens display surface will be bright, as shown in Table 1, and the brightness spots seen from the front will be particularly noticeable on the lens. The problem is that the closer you get to the surface, the more intense it becomes.

[Means to solve the problem]

Hereinafter, the outline of the lens for traffic signal lights according to the present invention will be explained with reference to the drawings. In the drawings, 1 indicates a lens body.
The lens body 1 is preferably integrally molded using a material such as polycarbonate, which has high resistance to heat, breakage, scratches, and other damages, and is made of a material such as red, which is the display color of a traffic light.
It is colored in standard colors, including green and yellow, and is usually circular, but may be square or other shapes as desired. This lens body 1 has an outer surface 3 and an inner surface 4 that are formed into a substantially spherical shape except for an annular rim portion 2 at the outer peripheral edge thereof, and the entire surface of the outer surface 3 is smooth. A plurality of three types of lenticular elements A, B, C are arranged on the entire inner surface 4 of the lens body 1, and other lenticular elements A, B,
They are spaced apart from C and are arranged substantially evenly so as to form a checkerboard pattern in the vertical and horizontal directions. In other words, the light distribution on the lens display surface of the traffic signal light is approximately 300 cd, which is sufficient brightness to be visible from a long distance in front of the traffic signal light.
A lens area that obtains a luminous intensity of about 70 cd to share visibility from a medium distance of about 50m to 60m, and a lens area that gets visibility from a short distance of about 15m to 20m. Therefore, a lens area that can obtain a low luminous intensity of about 20 cd is required. The part that forms the lens area for long distances is lenticular element A, the part that forms the lens area for intermediate distances is lenticular element B, and the part that forms the lens area for short distances is lenticular element C. They are arranged on the inner surface 4 of the main body 1 in predetermined proportions. These lens-like elements A, B, and C are inclined downwardly inside the lens body 1, and are respectively placed on prisms that deflect light in the front downward direction of the lens body 1. It consists of a stack of convex cylindrical microlenses that diffuse light. Therefore, the light distribution over a long distance is naturally directed downward at a small angle, and because of the width of the road, the angle of diffusion in the front left and right directions is also small, so a lens-like element A is formed. The angle of the prism and the diffusion angle of the microlens may also be small. Further, as one approaches from a long distance to a medium distance, and further from a medium distance to a short distance, the angle of the prism forming the lenticular element B and the diffusion angle of the microlens become intermediate, forming the lenticular element C. The angle of the prism and the diffusion angle of the microlens are set to be large. [Operation] The lens body 1 constructed as described above is mounted on the front surface of a parabolic mirror of revolution (not shown),
A light source is placed at the focal point. If a clear light bulb with a C-9 filament is used as this light source, for example, a parabolic mirror of rotation will produce a beam of light with a certain degree of diffusivity, but the inner surface 4 of the lens body 1 A plurality of three types of lens-like elements A uniformly arranged throughout,
The prisms forming each of B and C direct the light beam directly forward and downward according to the angle of each prism, and at the same time, the pattern of the light beam is diffused forward and left and right. Moreover, the lens-like elements A, B, and C are each evenly distributed over the entire inner surface 4 of the lens body 1, making it seem as if there are three lights for long distance, middle distance, and short distance in one lamp. It functions as if it were a built-in device, diffuses light reasonably from medium to short distances, and minimizes the occurrence of brightness unevenness on the lens display surface with the light distribution values shown in Table 2. I can do it.

〔Example〕

FIGS. 1 to 7 show an example of an arrangement of lenticular elements A, B, and C on the inner surface 4 of the lens body 1, and the lenticular elements A and B, as well as A and C, are arranged alternately in the vertical direction. As an array pattern in series with
These are arranged alternately in the horizontal direction to form a checkerboard stripe pattern, so that the beam width distribution of light directed to medium and short distances and the beam width distribution of light directed to long distances are moderate. By selecting the prism angles of the lens-like elements B and C so that the light distribution in the vertical cross section that is overlapped and combined is smoothly attenuated in the forward and downward direction,
It is constructed so that uniform brightness can be maintained on the lens display surface. FIG. 8 shows that on the inner surface 4 of the lens body 1, an AZone made up of a group of lenticular elements A, a BZone made up of a group B of lenticular elements, and a CZone made up of a group of lenticular elements C, respectively. Each lens-like element A,
This figure shows a state in which the angles of the prisms B and C are determined and a target light distribution R is formed. In this case AZone
The light distribution is obtained by refracting around α° forward and downward, the light distribution in BZone is also around β°, and the light distribution in CZone is also obtained by refracting around γ° (α° < β° < γ°). It goes without saying that the lens for traffic signal lights according to the present invention is also effective when used with ordinary light source light bulbs. [Effect of the invention] Since the lens for a traffic signal light according to the present invention is configured as described above, even when a clear light bulb is used as the light source of a traffic light device, brightness spots do not occur on the lens display surface, and it can be seen from a long distance. It is possible to provide a lens for a traffic signal light that has excellent display performance over the entire area up to short distances.

[Brief explanation of drawings]

Fig. 1 is a partial front view of the lens body used in the lens for traffic signal lights according to the present invention, Fig. 2 is a sectional view taken along the line A-A in Fig. 1, and Fig. 3 is an enlarged sectional view taken along the line B-B in Fig. 1. , Fig. 4 is an enlarged sectional view taken along the line C-C in Fig. 1, and Fig. 5
The figures are an enlarged sectional view taken along the line D-D in Fig. 1, Fig. 6 is an enlarged sectional view taken along the line E-E in Fig. 1, Fig. 7 is an enlarged view of section F in Fig. 2, and Fig. 8 is an enlarged sectional view taken along the line D-D in Fig. 1. 3 is a graph showing the light distribution state of each zone composed of a group of lens-like elements. 1... Lens body, 2... Annular rim portion, 3...
Outer surface, 4... Inner surface, A... Lenticular element for long distance, B... Lenticular element for intermediate distance, C... Lenticular element for short distance.

Claims (1)

[Claims for Utility Model Registration] A lens body 1 made of a colored translucent material has a plurality of lens-like elements A, B, and C arranged approximately equally on the spherical inner surface 4, as described above. Each lenticular element A, B, C has the inner surface 4
Other lenticular elements A of the same type over substantially the entire surface of
The lens-like elements A are spaced apart from B and C and arranged in a checkerboard pattern in the vertical and horizontal directions, and the lens-like elements A are inclined downwardly inside the lens body 1 and are arranged in front of the lens body 1 at a narrow angle. It has a shape in which a convex cylindrical microlens that diffuses light in the front left and right directions of the lens body 1 at a narrow angle is stacked vertically on a prism that deflects light downward, and the lens-like element B is a lens. A convex cylindrical microlens that is tilted downward inside the main body 1 and deflects the light forward and downward of the lens main body 1 at a medium angle, and on top of the prism that deflects the light to the front and left and right directions of the lens main body 1 at a medium angle. The lens-like element C has a shape in which the lenses are stacked vertically, and the lens-like element C is inclined downwardly inside the lens body 1 and is placed on a prism that deflects light forward and downward of the lens body 1 at a wide angle. A lens for a traffic signal light, characterized in that it has a shape in which convex cylindrical micro lenses are stacked to diffuse light in front and left and right directions of a lens body 1.