JPS5944703A - Illuminator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a lighting device suitable for spotlights used in nail stands, studios, and the like. [Technical Background of the Invention] As shown in Figure GL1, this type of illumination device has a lens l such as a spherical plano-convex lens or a Fresnel lens arranged in front of a light source 2, and the distance between the light source 2 and the lens l is It is common practice to completely change the spot opening angle by changing the spot. In this case, the light distribution characteristics as shown in FIG. 2 are obtained. In other words, when the light source 2 is installed at point a of the optical axis A of the lens 1, the curve B becomes f &), and when the light source 2 is installed at the point b of the optical axis A (f &), the curve becomes In other words, the light distribution characteristics have a longer tail.In other words, the outline of the irradiation pattern becomes blurred, making it difficult to form a sharp spot.The reason for this is that as shown in Figure 63, light passes through the lens L. The maximum value θhθ2θ3 of the angle of each point with the optical axis A of the irradiated light is 01>θ2>θ
3 and would be different, so it was deemed unavoidable. [Object of the Invention] The present invention was made in consideration of the circumstances mentioned above.1. I was so excited,
Change the lamp position and change the size of the L-C spot °C
An object of the present invention is to provide an illumination device which can always form a clear spot without blurring the outline of the spot irradiation pattern. [Summary of the Invention] The present invention provides a method for cutting a condensing lens placed opposite a lamp through an optical axis. ■The entire feature is that the shape is formed by a part of a circle whose center is a point displaced from the optical axis. [Embodiment of the Invention] An embodiment of the present invention will be described with reference to FIGS. 4 and 5. 11 is a lamp, and C12 is a condenser lens. +1. Center of lens 12

[3 and light emitting part 1 of lamp ll
4 are arranged so that they are substantially on the optical axis X. 2. The condensing lens J2 is formed by a part of a circle whose cross-sectional shape passing through the optical axis Kff is centered at a point displaced from the optical axis X. In other words, as shown in FIG. 5, the lens 12 is formed by parts of two circles on both sides of the optical axis X, each having a point C2d displaced from the optical axis X as the center of the circle. Points c and d are located closer to the lens 12 than the lamp 1, respectively. Although the condensing lens 12 is shown in a concave shape at the center in FIGS. 4 and 5,
This part Q'' is formed into a continuous curved surface as shown by the dotted line (
7 is fine. Next, the effect VC will be explained. Light emitting part 1 of lamp 11
The light emitted from 4 is irradiated in front of 1'C through 12 condensing lenses. Since the condensing lens 12 is formed by a part of a circle whose centers c and d are displaced from the optical axis X, as shown in FIG. Maximum value ψ8. ψ2. ψ3 is ψ1−Fψ2
key ψ3, and the light output passing through each part of the lens is light [1
The difference between the maximum value of Ill]X and the bevel angle can be made smaller than in the case of conventional lenses. In this case, as shown in FIG. 6, the light distribution does not become long, and a sharp spot with a clear irradiation pattern can be formed. Also, move the lamp 11 along the XK and change the spot opening angle to determine the diameter of the irradiation pattern. It was confirmed that the same tendency as described above was exhibited even when the temperature was changed. That is, if we look at the relationship between the light output angle of each part of the lens and the distance from the center of the lens, we can see that the conventional plano-convex lens shown by the dotted line in FIG. 7 and the lens of the present invention shown by the solid line in FIG. In the device of this embodiment, the range showing the maximum aperture angle is wider than when mounting with a conventional lens. In other words, the light distribution shown in Figure 6 with clear breaks in the light distribution can be obtained, and even if the position of the lamp and lens is changed and the spot opening angle is changed, a sharp irradiation pattern can always be obtained. . Although the present invention has been described above in detail based on the illustrated embodiments, it is possible to implement the present invention in various ways. For example, a reflector may be provided on the back of the lamp. [Effects of the Invention] As described in detail above, the present invention provides a condenser lens disposed opposite to the lamp in a one-sided shape that passes through the optical axis. Since it is formed by a part of a circle centered on a point displaced from the optical axis, it is possible to reduce the difference in the maximum value of the angle that the light passing through each part of the lens makes with the optical axis. The outline of the pattern becomes clear and sharp spot lighting is possible.

[Brief explanation of the drawing]

Figures 1 to 3 show all conventional examples, Figure 1 is a schematic diagram of the illumination device, Figure 2 is a light distribution diagram, Figure 3 is an explanatory diagram of the light output range f at each point of the lens, and Figure 4 Figures 6 to 6 show an embodiment of the present invention, Figure 4 is a schematic diagram of the illumination ψJ device, Figure 5 is an explanatory diagram of the light output range at each point of the lens, Figure 6 is a light distribution diagram, and Figure 7 is a diagram showing a comparison of the light output range at each point of the lens. 11...U/B 12...Lens% Applicant
Toshiba Electric Co., Ltd. Agent Patent Attorney Ko' + rf []:l Yoshihiro f 1 Illustration 2 Agony 3 O + 5 Account 6 Loichi 6 &-

Claims (3)

[Claims] (1) It comprises a lamp and a condensing lens installed opposite to the lamp, and the condensing lens has a cross-sectional shape passing through the optical axis that is part of a circle centered at a point displaced from the optical axis. A lighting device characterized in that: (2) The illumination device according to claim (1), characterized in that the lenses are formed by parts of two circles on both sides of the optical axis, the centers of which are points displaced from the optical axis. . (3) Claim (1) or (3) characterized in that the center of the circle of the lens is located closer to the lens than the lamp.
2) The lighting device described.