JPH0760611B2 - Rainbow projection device - Google Patents

Description

Description: TECHNICAL FIELD The present invention has a wide range of optical decoration effects as a large device such as a general household, a store, or a stage device, or a small device such as a toy, a figurine, or a sewing bag. The present invention relates to a rainbow projection device.

2. Description of the Related Art As the prior art, as disclosed by the inventor in Japanese Utility Model Laid-Open No. 60-26084, a linear white light source capable of increasing the light flux by increasing the length of the light source, and a parallel white light source An example of the rainbow projection device includes a flat cylindrical condenser lens disposed in the above and a prism.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The conventional device has a high brightness and a long light source like a tubular halogen lamp for the purpose of obtaining a large and clear rainbow image mainly for store lighting and stage lighting. Using a linear light source that can increase the luminous flux, the light emitted from this is collimated by a cylindrical condenser lens parallel to this, and this is split by a prism to project a rainbow image. Since the light source is horizontally long and the condenser lens is a flat plate, it is possible to project clearly near the center of the rainbow image,
The light emitted from the condenser lens gradually converges from parallel light toward both ends, and as a result of mixing the colored light dispersed by the prism, a clear rainbow image cannot be obtained.

That is, if the condenser lens is a flat plate, as shown in FIG. 6a, the light rays incident from the light source 0 orthogonally to the condenser lens 13 along the 0A cross section perpendicular to the paper surface are parallel rays as shown in FIG. 6b. The light rays along the 0B and 0B ′ cross sections which are incident on the prism from the light source 0 while being inclined to the condenser lens 13 are bent by the distance D1 as shown in FIG. 6c. Incline further and condenser lens 13
As shown in Fig. 6d, the rays incident on the 0C and 0C 'cross sections are strongly bent and converged as the distance becomes further D2, so that the rainbow image separated by the prism is , B, B ′, C, C ′ from the center A to the outside as shown in FIG. 6e.
As the distance from the light source increases, the curvature increases and the color lights are mixed, so that a clear rainbow image cannot be obtained. When the light source 0 is a horizontally long tube, the distance between the light source and the condenser lens 13 further increases. Therefore, the mixture of colored light becomes larger,
It was not possible to obtain a clear rainbow image that fully satisfied the stage lighting and store lighting.

Also, in this case, since a flat-plate cylindrical condenser lens is used, even if the light source is shortened to be close to the point light source and only the rainbow image near the center is used, the luminous flux is only reduced,
There was a problem that the amount of light became insufficient and a clear rainbow image could not be obtained.

Means for Solving the Problems Therefore, according to the present invention, an extremely short linear white light source that is closer to a point light source compared to the size of a light condensing system, and a case where divergent light of the light source goes to the center and both left and right ends The distance is almost the same when heading to, and a cylindrical condenser lens provided by bending the light source in an arc shape so as to obtain parallel light that spreads in a fan shape having a wide width after refraction and the condenser lens. It is intended to provide a rainbow projection device including a washing plate-shaped prism that is provided so that the fan-shaped parallel light is incident on the first refracting surface.

Effect According to the device of the present invention, an extremely short linear white light source that is closer to a point light source compared to the size of a light condensing system such as a condenser lens, and a case where divergent light of the light source goes to the center It has a configuration including a cylindrical condenser lens curved in an arc shape with the light source as a center so as to be parallel light that spreads in a fan shape having a wide width after refraction and has almost the same distance toward both ends. Therefore, as shown in FIG. 5a, the distance from the light source 0 to the arc-shaped condenser lens 3 is 0A when going to the center of the condenser lens, and 0B, 0B ′, OC, 0C ′ when going to the left and right ends of the condenser lens. The ratio of convergent light or divergent light after refraction is extremely small, and therefore, the light that spreads out in a fan shape from the condenser lens is almost perfectly parallel light as shown in FIG. 5b. , After spectroscopy with prism is, as shown in 5c view, both end portions B from the center A, B ', C, C' until the,
A very bright colored light can be obtained and a beautiful rainbow image with a well-shaped shape can be obtained over the whole. By incorporating the rainbow projection device of the present invention into a toy or a figurine, a new lighting toy or interior decoration lighting can be created. it can.

Further, the washing plate prism provided so that the fan-shaped parallel light obtained by the condenser lens is incident on the first refracting surface,
The surfaces constituting the second refracting surfaces are opposed to the plane of the first refracting surface in a washing plate shape, and as a whole, the plate-like surface along the first refracting surface is parallel to that obtained by the condenser lens. Since it spreads in a flat plate shape along the fan-shaped spread direction of the light width, there is an effect that the entire device can be configured in a flat plate shape as a main position of the fan of the rainbow spread.

In addition, since the condenser lens is provided by curving in an arc shape with a linear white light source close to a point light source as the center, the width of the fan-shaped projected rainbow image increases as the projection distance increases, and the spectral distribution increases. Each of the latter colors overlaps each other to show pure colored light, which has the effect of making it clearer, and in order to prevent the mixing of colored light that occurs due to the close projection distance, a point is set to the center of the arc of the condenser lens. If the position of the light source is adjusted so that the light emitted from the condenser lens forms a rainbow image at the rainbow projection position, a clear rainbow image can be obtained even at a short distance.

Example In the principle diagram of the device of the present invention shown in FIGS. 1 and 2,
Reference numeral 1 is a white light bulb, and 2 is a filament close to a point light source which is the light source. Reference numeral 3 is a cylindrical condenser lens which is curved in an arc shape with the midpoint of the filament 2 as the center, and 4 is a prism which receives parallel light spreading in a fan shape around the light source condensed by the cylindrical condenser lens 3 on the first refracting surface.

The light emitted from the filament 2 is made parallel to the paper surface by the cylindrical condenser lens 3 as shown in the second drawing, and the light ray 0A along the plane perpendicular to the ridgeline of the prism 4 is centered,
Light rays 0B and 0C spread in a fan shape toward the circular arc of the condenser lens 3 and enter the prism 4.

That is, as shown in FIG. 5a, the distance from the light source 0 to the arc-shaped condenser lens 3 is 0A when it is toward the center of the condenser lens and when it is toward both left and right ends of the condenser lens.
0B, 0B ', OC, 0C' are almost the same, and the ratio of convergent light or divergent light after refraction is extremely small.Therefore, the light emitted in a fan shape from the condenser lens is as shown in FIG. 5b. It becomes almost perfect parallel light throughout.

The light incident on the prism 4 is refracted by the first and second refracting surfaces of the prism and spreads in a substantially conical shape obliquely below the paper surface, and each light changes from red to purple due to the spectral action of the prism. As shown in FIG. 5c, the light is dispersed and projected as an arc-shaped rainbow on the projection plane parallel to the paper from the center A to both ends B, B ', C, C'.

Also, as shown by A, A1, and A2 in FIG. 2, the respective colored lights emitted from the prism 4 are all refracted in the same angle at the same angle condition to be incident on the prism 4, so that the same colored light is emitted. Overlap to form a rainbow image that is spectrally divided into the seven colors of the rainbow.

Further, in this case, as the projection distance increases, the width of the projected rainbow image also increases, and the respective colors of the spectrum overlap with each other to show pure colored light. In order to prevent mixing of colored light caused by the short projection distance, if the light after refraction by the cylindrical condenser lens 3 is not made to be a perfect parallel light but is configured so as to focus at the projection distance, it is clear even at a short distance. You can get a nice rainbow image.

On the other hand, as shown in FIG. 3, the prism 3 is not a single triangular prism but a plurality of small triangular prisms are arranged in parallel to obtain the same prism spectral effect. Therefore, the washing plate prism 4 is used instead. Can be used. In general, a relatively expensive optical glass is used for color separation, so if it is made into a washing plate, the material will be saved. Furthermore, instead of the optical glass, a transparent plastic that is easy to process, lightweight and inexpensive. It is also possible to mold the material.

FIG. 4 shows an embodiment of the device of the present invention using a washing plate-shaped prism, and cost reduction, size reduction and weight reduction of the entire device are achieved.

That is, in the figure, 10 is an inner case, and the outer case (not shown) is optically coated around the periphery except for the prism 4. Reference numeral 1 is a light bulb serving as a white light source, 2 is a filament thereof, 3 is a cylindrical condenser lens having an arc shape around the light bulb 1, and 4 is a washing plate prism. In addition, 11 is a conductive wire that supplies electricity to the light bulb 1.

In this case, as is clear from FIG. 3, the washing plate-shaped prism 4 may be formed in a space in which parallel light from the cylindrical condenser lens 3 is obliquely received by the entire first refraction surface, and The birefringent surface is composed of a series of many surfaces arranged in parallel with each other at an extremely narrow interval with respect to the first refracting surface, and as a whole, a continuous second bending surface is formed by connecting ridge lines parallel to the first bending surface. Since the size of the washing plate-shaped prism 4 spreads flatly along the fan-shaped spreading direction of the parallel light width obtained by the condenser lens, the entire device spreads a rainbow. It can be configured as a small and thin flat plate as a main position of the fan.

A specific example suitable for a compact lighting toy or the like having these configurations is as follows.
The thickness of the filament 2 is about 0.2 mm, the length is about 1.5 mm, the focal length of the condenser lens 3 is about 14 mm, the radius of the arc of the condenser lens 3 (the radius of curvature from the center of the light source to the main point of the condenser lens) about 14 mm, the condenser The width of the lens 3 is about 10 mm,
Center angle of arc about 90 °, miniature bulb output 4.4W, luminous flux 85Lumen
Is. Also, when constructing a powerful rainbow projector, a high-luminance discharge lamp such as a metal halide lamp is used as the light source.
If the dimensions of the respective parts are proportionally increased, a relatively compact and powerful projection device can be obtained.

Effects As described above, according to the device of the present invention, an extremely short linear white light source that is closer to a point light source compared to the size of the condensing system, and a case where the divergent light of the light source goes to the center and both left and right ends are provided. A cylindrical condenser lens curved in an arc shape with the light source as the center so as to become parallel light that spreads in a fan shape having a wide width after refraction and has almost the same distance when heading, and is obtained by the condenser lens. Since the fan-shaped parallel light is incident on the first refracting surface and the washing plate-shaped prism is provided, the distance from the light source to the arc-shaped condenser lens is
Almost the same when going to the center of the condenser lens and when going to the left and right ends of the condenser lens, the ratio of convergent light or divergent light after refraction is extremely small. Therefore, the light that spreads out in a fan shape from the condenser lens is the whole. Since it is a nearly perfect parallel light over the entire range, it has an effect that extremely bright colored light is obtained after the spectrum and a beautiful rainbow image with a regular shape is obtained over the whole area, and the fan shape obtained by the condenser lens of the device of the present invention. The washing plate-shaped prism provided so that the parallel light of the first refracting surface is incident on the first refracting surface as a whole while the parallel light substantially matching the width of the cylindrical condenser lens is obliquely received. Is a series of a number of surfaces arranged in parallel to the first refracting surface at extremely narrow intervals, and as a whole, a structure of a second refracting surface that is continuous with ridge lines parallel to the first refracting surface. Therefore, the size of the washing plate-shaped prism spreads flatly along the fan-shaped spreading direction of the width of the parallel light obtained by the condenser lens. The position can be made small and thin like a flat plate, and by incorporating this into a toy or a figurine, there is an effect that a new lighting toy or interior decoration lighting can be created.

[Brief description of drawings]

FIG. 1 is a front view showing the principle of the optical system of the device of the present invention, and FIG.
FIG. 3 is a vertical sectional side view taken along the line II-II, FIG. 3 is a vertical sectional side view showing the principle of an optical system of an embodiment of the device of the present invention in the same manner as FIG. 2, and FIG. FIG. 6a is a perspective view showing a partial cutaway view of a main part of an embodiment of the optical system in the figure, and FIGS. 5a to 5c are explanatory views for explaining the operation of the main part of the device of the present invention.
FIGS. 6C to 6E are explanatory views for explaining the mode of action of the main part of the conventional device. 1 ... White light bulb 2 ... Filament 3 ... Arc-shaped cylindrical condenser lens 4 ... Prism

Claims (1)

[Claims] 1. A very short linear white light source that is closer to a point light source compared to the size of a condensing system, and the distances when the divergent light of the light source goes to the center and to the left and right ends are almost the same. In order to obtain parallel light that spreads in a fan shape with a wide width after refraction, the cylindrical condenser lens provided by bending the light source in an arc shape and the fan-shaped parallel light obtained by the condenser lens are Rainbow projection device including a washing plate-shaped prism provided so as to enter one refracting surface