JPH0896293A - Deflected beam illumination prism plate for traffic signal - Google Patents

Abstract

PURPOSE: To prevent signal beams on two roads from being overlappedly detected by mutually combining two specific triangle pole prisms like a triangle pole, applying ground glass treatment to the triangle pole and arranging plural triangle poles in parallel like a panel so that two sides to which a black mask material is stuck are mutually fitted. CONSTITUTION: Two triangle pole prisms having the internal angle (light transmission angle) of a critical angle (41.8 deg.) are mutually combined like a triangle pole. The side faces (two right and left faces with narrow width) are treated by ground glass treatment 2 and a light shielding black mask material 2 is stuck to the faces. Plural prism poles are arranged in parallel like a panel so that the side faces are fitted to each other in the same direction. Light beams of various angles made incident upon the prism plate are transmitted through the prism 1 when the angles are the internal angle of a critical angle on each face of the prism 1 or reflected when the angles exceed the internal angle and a part of the light disappears on a black mask surface 43. Transmitted light through the prism plate becomes beam illumination deflected to the left or right direction and the illumination can not be observed from the outside of the beam. Thereby a signal can be illuminated at an angle in a necessary range opposed to the signal by controlling the angle by the prism 1.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflected beam illumination prism plate attached to an illumination window of a traffic signal.

2. Description of the Related Art Up to now, there has been used a mechanism of vertically arranging black vertical plates in front of a traffic signal lighting window.

[Problems to be Solved by the Invention] In this type of traffic light, there is an unclear defect that signal lights on two road surfaces are duplicated under the condition of location, and the present invention solves this problem. It is for doing.

[Means for Solving the Problems] Critical angle (4
Two triangular prisms with an internal angle (angle of light transmission) of 1.8 °) are alternately combined into a prism shape. The side surfaces (two left and right narrow sides) are subjected to frosted glass treatment and a light-shielding black mask material is attached. A large number of these prism columns are arranged side by side in the same direction to form a panel. The present invention is a deflected beam illumination prism plate for a traffic signal having the above structure.

[Operation] Light of various angles incident on the deflected beam illuminating prism plate is transmitted on each surface of the prism at an inner angle of the critical angle and is reflected at an inner angle of the critical angle. Disappears on the black mask surface. The transmitted light from the prism plate illuminates the beam polarized to the left or right, and the illumination cannot be seen from the outside of the beam.

[Embodiment] Two triangular prisms having an inner angle (light transmitting angle) of a critical angle (41.8 °) are alternately combined in a prism shape. The side surfaces (two left and right narrow sides) are subjected to frosted glass treatment and a light-shielding black mask material is attached. A large number of these prism columns are arranged side by side in the same direction to form a panel. Light of various angles incident on the prism plate is transmitted on each surface of the prism at an inner angle of the critical angle, is reflected at an inner angle of the critical angle, and a part of the light disappears on the black mask surface. The transmitted light from the prism plate becomes beam illumination that is deflected to the left or right. This prism plate is attached to the illumination window of the traffic signal to perform polarized beam illumination.

[Advantages of the Invention] The illumination light of a traffic signal is polarized into a beam, and the angle is adjusted by a prism so that the illumination is reflected at an angle within a required range where the signal faces, and the signal light is observed outside the beam. Can not. This prism plate is a flat plate, and it is easy to obtain an area suitable for the purpose, and it is also used for indoor lighting by a beam and a spotlight by stacking it vertically and horizontally.

[Brief description of drawings]

FIG. 1 is a perspective view of a triangular prism (part) and a black mask surface configuration.

FIG. 2 is a plan view of the prism plate configuration (portion) and the flow of light.

FIG. 3 is a perspective view of the prism plate of the present invention.

[Explanation of symbols]

 1 triangular prism 2 black mask surface 3 frosted glass surface 4 incident light 5 transmitted light 6 reflected light 7 annihilation light

Claims (1)

[Claims] 1. Two triangular prisms having an inner angle (light transmitting angle) of a critical angle (41.8 °) are alternately combined into a prism shape, and the side surfaces (two narrow left and right surfaces) of the prism are combined. Is a deflected beam illumination prism plate for traffic signals, in which a large number of prism columns, which have been subjected to frosted glass treatment and have a black mask material attached thereto, are arranged side by side in a panel shape so that their side faces are aligned.