JPH10232997A - Signal lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the visual field angle of a signal lamp by providing a Fresnel lens provided with a luminous flux paralleling means whose focus position is a light source position in the state of being inclined forward between a light source and a front surface cover and turning the outer diameter of the reflection part of the light source to be less than the specified ratio of the outer diameter of the Fresnel lens. SOLUTION: The Fresnel lens 4 provided with the luminous flux paralleling means whose focus position is the light source position is provided in the state of being inclined forward (3-10 degrees) between the light source 2 provided with the reflection part for radiating diffused light only to a front part and a front surface cover lens 3 and the outer diameter of the light source 2 is made less than the 30 percent of the outer diameter of the Fresnel lens 4. Thus, external light L is transmitted through the prism of the Fresnel lens 4 and is made less than a critical angle for causing total reflection on a boundary surface with air and the light is transmitted through the Fresnel lens 4 and made incident on the side of the light source 2. Incident external light beams are horizontally distributed at a position corresponding to an incident angle (sun altitude 60 degrees - 10 degrees) by the left and right refraction prisms of the front surface lens cover 3 at the lower part of the light source 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traffic light provided with a means for preventing the occurrence of a false lighting phenomenon in a traffic light located at an intersection or the like.

[0002]

2. Description of the Related Art Conventionally, signal lights are combined with blinking lights of, for example, red, blue, yellow, and the like, and are sequentially blinked according to traffic conditions to display a change in color. However, when the light is directly incident on the morning sun or the Xiyang, it passes through the lens of the signal light and is reflected by the internal reflecting mirror, causing a false lighting phenomenon.

Therefore, a signal lamp using a Fresnel lens as a means for preventing false lighting has been proposed on February 3, 1990 (Japanese Patent Application No. 1-2).
No. 4502) has been filed. According to the present invention, as shown in FIG. 8, a light source b for lighting is supported at a substantially central portion of a lamp body a, and a front opening is sealed by a front lens c made of a translucent material colored in a predetermined color. In addition, a Fresnel lens d that refracts and deflects the light emitted from the light source b into a parallel light beam is interposed between the front lens c and the light source b.

Therefore, the radiation L emitted from the light source b is
External light L1 such as sunlight is refracted and deflected to a parallel light beam by the Fresnel lens d, and passes through the Fresnel lens d to irradiate the inside of the lamp body a. Since it does not have a reflection effect, no false lighting phenomenon occurs.

In other words, the above-mentioned invention makes it possible to effectively use the emitted light by refracting and deflecting the emitted light of the light source into a parallel light beam by means of a Fresnel lens. The purpose of this is to prevent the false lighting phenomenon.

[0006]

However, according to the Road Traffic Law, the light radiated from the signal light is determined so as to be emitted in a horizontal range and a range of 45 degrees below and to the right and left. This is because, as shown in FIG. 9, the signal light f viewed from the car e stopped at the intersection stop line is located in the direction of about 45 degrees, so that the luminance of the signal light decreases unless it is emitted in the range of 45 degrees below. This is because it becomes difficult to identify the lighting due to, for example, the lighting.

That is, in the above-mentioned conventional invention, the viewing angle of the signal light is narrowed by refracting and deflecting the radiated light from the light source into a parallel light beam by the Fresnel lens. There is a problem that it is impossible to establish an emission range up to 45 degrees below.

In view of the above, an object of the present invention is to provide a signal lamp which secures a viewing angle while taking advantage of the Fresnel lens in order to solve the above-mentioned problems.

[0009]

The above object of the present invention can be achieved by a signal light having the following structure. That is, the gist of the invention is to carry a light source provided with a reflecting portion for radiating diffused light only in the front at the center of the lamp unit body in which the interior of the housing is non-reflective, and to forwardly and downwardly emit a light beam at the front opening end. A colored translucent front cover lens on which innumerable prisms for refraction are formed is mounted, and a light beam collimator whose focal position is the light source position is provided between the light source and the front cover lens. The Fresnel lens provided with the means is provided in a forward tilted state, and the outer diameter of the reflection part of the light source is
A signal lamp characterized in that the outer diameter of the Fresnel lens is 30% or less.

Therefore, as shown in FIG. 5, a colorless and translucent Fresnel lens 4 which is a convex lens formed by concentrically connecting prisms on the entire surface is provided vertically, and a light beam is emitted only in front of the optical axis focal length F. When the radiating light source 2 is arranged, the luminous flux from the center of the light source 2 passes through the Fresnel lens 4 to become horizontal parallel rays LF, and positions A and B shifted from the rays.
The light flux from the point becomes light rays LA and LB having a spread.

Then, as shown in FIG. 6, the light beams are directed to the horizontal and lower left and right directions 45 according to the light distribution specification defined by the Road Traffic Act.
A number of prisms A for refracting light rays are arranged on the front cover lens 3 made of a colored translucent material in order to emit light in a range up to a certain degree. The effect of the prism A is that when a horizontal light beam enters from the light source 2 side, the light beam is directed downward 5 degrees left and right 10 degrees.
Refraction. Based on this prism A, 10
The light distribution can be controlled by arranging the prism B refracting right and left downward by 20 degrees at a predetermined position.

A parallel ray L of the sun, which is external light, has a sun altitude of 4
When the light enters the front lens cover-3 in the range of 0 to 5 degrees (sunlight is blocked by the hood of the signal lamp from vertical to 40 degrees, and is attenuated in the atmosphere from 5 degrees to the horizontal position. The lamp light source is brighter), and the refraction of the prisms A and B of the front lens cover-3 adds the light downward by 5 to 20 degrees. Therefore, in terms of the sun altitude, the external light in the range of 60 to 10 degrees Enters the Fresnel lens 4 surface.

At this time, since the back surface C of the Fresnel lens 4 is flat, the external light L passes through the prism of the Fresnel lens 4 and undergoes total reflection at the boundary surface C with air, and the light beam is reflected outward and downward. Pseudo emission occurs.

If the Fresnel lens 4 is tilted forward by 3 to 10 degrees to prevent this phenomenon, as shown in FIG. Then, the light passes through the Fresnel lens 4 and enters the light source.

The incoming external light beam is not focused as a point by the left and right refraction prisms of the front lens cover-3 below the light source, but is horizontally dispersed at a position corresponding to the incident angle (sun altitude of 60 degrees to 10 degrees). However, the light ray LF emitted from the light source,
The emission angles of LA and LB and the focal position of the external light L on the light source side hardly change even if the Fresnel lens 4 which is a convex lens is inclined forward due to the characteristics.

When the external light L is condensed at the lower part on the light source side, the light source 2 having the reflection surface 7 is not provided at that position, and if the light is applied to the housing 6 using a non-reflective material, the external light is attenuated. The light does not go outside and no pseudo light emission occurs. Here, the diameter of the reflection surface 7 from which external light does not enter the light source 2 having the reflection surface is 2 × f, where f is the focal length of the Fresnel lens 4.
X tan θ.

Unless external light up to a solar altitude of 10 degrees is allowed to enter the reflecting surface 7 of the light source 2, the basic prism A of the front lens cover 3 adds 5 degrees, so that it becomes 15 degrees, and the depth of the lamp unit 1 When f is set to 60% or less of the effective diameter P of the Fresnel lens 4 in order to reduce as much as possible, 2 × P × 0.6 × tan15 = 0.32 × P, which is about 30% of the effective diameter of the Fresnel lens 4.

When the solar altitude is 10 degrees or less, the dispersed light of the external light enters the reflecting surface 7 of the light source 2, but since the amount of the luminous flux is small, the luminous flux on the side of the light source 2 prevails, and the brightness of the light on / off is high. The difference can be secured.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings showing the embodiments. As shown in FIG. 1, a Fresnel lens 4 and an effective diameter of 320 mm
It is attached by tilting forward with the support 5 in the range of -10 degrees.
Then, the focal length of the Fresnel lens 4 is set to one half of the effective diameter of the Fresnel lens, and the reflecting surface 7
The light source 2 having the outer diameter φ60 mm is provided.

At the open end of the lamp unit body 1,
The front cover lens 3 made of a colored translucent material is mounted. The housing 6 of the lamp unit main body 1 is non-reflective, and for that purpose, the inner surface is made of black or a non-reflective material is used. Therefore, it is also possible to use a lamp unit body 1 having a shape as shown in FIG.

Next, as shown in FIG. 3, the light source 2 is
In addition, a surface light source that emits diffused light forward only by the reflection plate 8, for example, a reflector-bulb is used, and light is emitted only to the front surface of the Fresnel lens 4.

Also, as shown in FIG.
Has a large number of prisms formed on the back surface thereof, and this prism refracts horizontal light rays from a light source downward and left and right to control light distribution. So prism A
The refraction angle .theta.4 refracts a horizontal ray 5 degrees downward and 10 degrees left and right. Prism B whose refraction angle θ5 is downward 10
It is formed to be refracted by 20 degrees left and right. Therefore, the horizontal light beam LF can be emitted by the front cover lens 3 in a range of light distribution specifications specified by the Road Traffic Law and up to 45 degrees below left and right.

[0023]

As described above, according to the present invention, a light source, a Fresnel lens, and a front cover that radiate only in the forward direction are provided.
By combination with a lens, it is possible to efficiently emit the radiated light from the light source in a horizontal direction and in a range of 45 degrees below and to the left and right, and high-luminance lighting can be performed. Furthermore, since the housing does not require a reflecting mirror, it is possible to prevent false lighting due to sunlight, and it is possible to accurately distinguish between lighting and turning off.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an internal mechanism of the present invention.

FIG. 2 is an explanatory view showing another embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a power supply according to the present invention.

FIG. 4 is a partially enlarged explanatory view of the front cover lens of the present invention.

FIG. 5 is a diagram illustrating the operation of the Fresnel lens of the present invention.

FIG. 6 is an explanatory diagram of the operation of the Fresnel lens and the front lens cover of the present invention.

FIG. 7 is an operation explanatory view showing prevention of false lighting by a signal lamp according to the present invention.

FIG. 8 is an explanatory view showing an example of a signal light using a conventional Fresnel lens.

FIG. 9 is an explanatory diagram showing a light distribution state of a signal light at an intersection.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lamp unit main body 2 Light source 3 Front cover lens 4 Fresnel lens 5 Support 6 Housing 7 Reflecting surface

Claims (3)

[Claims] 1. A light source having a reflecting portion for radiating diffused light only forward is carried in a central portion of a lamp unit main body in which the interior of the housing is non-reflective, and a luminous flux is directed downward and left and right at the front opening end. A front cover lens having a number of prisms for forming an infinite number of prisms for refracting light, and furthermore, a light beam parallel between the light source and the front cover lens, the focal position of which is the light source position. A signal lamp characterized in that a Fresnel lens provided with an image forming means is provided in a forwardly inclined state, and an outer diameter of a reflecting portion of the light source is set to 30% or less of an outer diameter of the Fresnel lens. 2. The signal lamp according to claim 1, wherein said Fresnel lens is a totally convex lens in which prisms are concentrically connected on the entire surface. 3. The signal lamp according to claim 1, wherein the front cover lens is formed of a prism that refracts a horizontal ray in a range of 5 degrees to 10 degrees downward and 10 degrees to 20 degrees in the right and left directions. .