JPH0221318Y2 - - Google Patents

Description

[Detailed explanation of the idea] <Industrial application field> The present invention relates to a reading light for a car.

<Prior Art> Conventional reading lights for automobiles include a room lamp with a spot lamp added. This device is designed in advance so that it can irradiate a wide range because the irradiation range remains constant even if the irradiation direction can be changed freely. As a result, the light from the reading light enters the rearview mirror, obstructing rear visibility, and making the inside of the car too bright, which poses a problem for safe driving.

Therefore, in order to be able to freely vary the irradiation range, a lamp with an optical system consisting of an elliptical reflector A, an aperture B, and a lens C as shown in Fig. 5 was proposed, but this lamp had a deep depth. This poses a practical problem because it is difficult to install it in an automobile, which has limited space, and the amount of light decreases significantly as the irradiation range decreases.

Therefore, a lamp was proposed in which the irradiation range could be varied by using a parabolic reflector and moving the focal point of the mirror and the position of the bulb relative to each other in the direction of the optical axis. This lamp has a smaller depth than the lamp with the optical system using the elliptical reflector, and the flexibility of the installation space is improved, but when the irradiation range is expanded, the central part a becomes a little dark, as shown in Figure 2 a. There is a drawback that the middle blur phenomenon occurs.

<Problems to be solved by the invention> The present invention was developed in view of these conventional drawbacks, and it not only allows the irradiation range to be freely varied, but also has a small depth and can be installed in a narrow space. It is an object of the present invention to provide a reading light for an automobile that does not cause the so-called center blur phenomenon even when the irradiation range is widened.

<Means for solving the problems> The inventive reading light for automobiles that achieves the above purpose is:
A reading light for an automobile configured by installing a reflector and a bulb in the lamp body, and a lens installed in front of the reflector, wherein the reflecting surface of the reflector is formed in the shape of a paraboloid of revolution, and the reflector The focal position of the lens can be moved in the optical axis direction with respect to the bulb, and a shade is installed between the bulb and the lens to block direct light from the bulb, and the lens has a large number of concave lens elements each having a rectangular shape in front. It is characterized by being formed in a collective arrangement.

<Operation> When the bulb is located at the focal point of the parabolic reflector, it becomes a spot light with a relatively narrow irradiation range,
As the focal position of the reflecting mirror shifts in the optical axis direction with respect to the bulb, the irradiation range expands. At this time, the reflected light from the reflecting mirror is controlled by the lens. Specifically, the reflected light passing through each concave lens element that makes up the lens is diffused symmetrically in the vertical and horizontal directions, so the light distribution pattern is determined by the front shape of the concave lens element. The light distribution pattern of the lens, which is a collection of concave lens elements, is a nearly rectangular light distribution pattern that is a combination of the outer shape of the lens and the front shape of each concave lens element, and the so-called middle blur phenomenon occurs. Never occurs. Further, the direct light from the bulb is blocked by the shade, and as a result, the entire irradiation range can be illuminated with an even amount of light.

<Example> Hereinafter, an example of implementing the present invention will be described based on the drawings.

Figure 1 shows a cross-sectional view of the reading lamp of the present invention.
2 is a lamp body, 2 is a parabolic reflector, 3 is a bulb, 4 is a shade, 5 is a lens, and B is a support member on the vehicle body side for mounting the reading lamp A. Further, FIG. 2 is a schematic diagram for explaining the optical system and its light distribution pattern, where "a" shows the state where the bulb 3 is located at the focal position F of the reflecting mirror 2, and "a" shows the arrangement when the lens 5 is not present. This is a light pattern, and b is a light distribution pattern when the lens 5 is present. And is reflector 2
The state in which the bulb 3 is deviated from the focal position F (i.e.,
(with the irradiation range expanded), a is lens 5
b is the light distribution pattern when there is no lens 5, and b is the light distribution pattern when the lens 5 is installed.

The lamp body 1 is molded into the required shape as in the conventional case, and inside it there is a parabolic reflector 2, a bulb 3, and a shade 4.
A reading light A is constructed by installing a lens 5 on the front surface. This reading lamp A is attached to a support member B on the vehicle body side so that its illumination direction can be freely changed. That is, lamp body 1
The outer peripheral surface of the light body 1 is formed into a substantially drum shape, and the light body 1 is slidably fitted into a spherical seat B' formed on a support member B on the vehicle body side.

The reflecting mirror 2 is made of metal or synthetic resin and has a reflecting surface shaped like a paraboloid of revolution.
is made movable relative to the bulb 3 in the optical axis direction. When the focal position F of this reflecting mirror 2 is configured to be movable in the optical axis direction with respect to the bulb 3, the bulb 3
There are cases in which the reflector 2 is fixed and movable in the optical axis direction, and cases in which the reflector 2 is fixed and the bulb 3 is movable in the optical axis direction. In the example, the bulb 3 is fixed and the reflecting mirror 2 is movable in the optical axis direction. That is, in the illustrated embodiment, a male thread-shaped protrusion 6 is formed protrudingly on the outer circumferential surface of a parabolic reflector 2 molded using a synthetic resin material, and is formed on the inner circumferential surface of the lamp body 1. By screwing freely into the female screw-shaped concave groove 7 and rotating it by holding the operating part 2a, the reflecting mirror 2 is moved forward and backward, and the focal position F of the reflecting mirror 2 is set to the light with respect to the bulb 3. It is configured to be movable in the axial direction. It should be noted that the means for making the focal point F of the reflecting mirror 2 movable in the optical axis direction with respect to the bulb 3 is not limited to that of the illustrated embodiment, and it is understood that any suitable means may be employed. Should.

The shade 4 blocks the direct light X from the bulb 3 from being irradiated forward, and is formed into a substantially cylindrical shape, with matte black paint applied to its outer surface, and between the bulb 3 and the lens 5. The lens 5 or the lamp body 1 or the bulb socket 8 is fixed thereto.

When the irradiation range is expanded, that is, when the focal point F of the reflector 2 is shifted from the bulb 3 in the optical axis direction, the lens 5 controls the reflected light y from the reflector 2 to produce an appropriate image without so-called middle blur. A concave lens element 5 with a rectangular shape on the front is used to obtain a light distribution pattern.
A, 5b, . Each concave lens element 5 that constitutes this lens 5
As shown in FIGS. 3 and 4, a, 5b... are formed into a rectangular shape with a substantially square front shape and the same shape and size, and each side of the rectangle is formed with one side of each adjacent concave lens element. A large number of lenses are regularly arranged together to form the lens 5 so as to be shared. Each concave lens element 5a, 5b... has a predetermined light distribution pattern by itself, and the light distribution pattern has a shape that is almost similar to the front shape of the concave lens element 5a, 5b..., and the outer shape of the lens 5 as a whole. The light distribution pattern is a composite of the front shapes of the concave lens elements 5a, 5b, . . . . That is, in the reading lamp of the present invention, the circular shape of the lens 5 and the concave lens elements 5a, 5
A light distribution pattern is obtained in which the rectangular shapes b... are synthesized.

When the bulb 3 is located at the focal point F of the parabolic reflector 2, all of the reflected light y becomes parallel light and passes through the lens 5, as shown in FIG. The outer shape (circle) of the lens 5 is diffused at an angle commensurate with the diffusion angle of each concave lens element 5a, 5b, and the irradiation range is relatively narrow as shown in FIG. It becomes a spot light that is synthesized with the shape (circular).
As the focal point F of the reflecting mirror 2 shifts in the optical axis direction with respect to the bulb 3, the reflected light y tilts toward the center as shown in FIG. 2, widening the irradiation range, but 5a, 5b..., as shown in FIG. As a result, the irradiation range can be freely varied without causing the middle blur phenomenon.

<Effects of the invention> Since the reading light for automobiles of the invention is constructed in this way,
In addition to being able to freely vary the irradiation range,
Even if the irradiation range is expanded, the so-called center blur phenomenon does not occur.

Moreover, since the direct light x from the bulb is blocked by the shade, the influence of direct light can be eliminated, and as a result, a nearly uniform amount of light is obtained over the entire irradiation range, and at the same time, the irradiation range is expanded. You will be able to maintain the same brightness even at times.

Furthermore, since a lens constructed by assembling a parabolic reflector and a large number of concave lens elements having a rectangular shape on the front is used, the depth can be small and it can be easily installed even in a narrow space.

Therefore, the intended purpose can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of the implementation of the present invention;
The figure is a schematic diagram for explaining the optical system and its light distribution pattern, Figure 3 is a front view of the lens, and Figure 4 is the third
A sectional view taken along the line 4-4 in the figure, and FIG. 5 are schematic diagrams showing a conventional example. In the figure, 1 is the lamp body, 2 is the reflector, 3 is the bulb, 4
5 is a shade, 5 is a lens, 5a, 5b, . . . are concave lens elements, and F is a focal position of a reflecting mirror.

Claims (1)

[Scope of utility model registration request] A reading light for an automobile configured by installing a reflector and a bulb in the lamp body, and a lens installed in front of the reflector, wherein the reflecting surface of the reflector is formed in the shape of a paraboloid of revolution, and the reflector The focal position of the lens can be moved in the optical axis direction with respect to the bulb, and a shade is installed between the bulb and the lens to block direct light from the bulb, and the lens has a large number of concave lens elements each having a rectangular shape in front. A reading light for an automobile characterized by being formed in a collective arrangement.