JP5005399B2 - Lighting device - Google Patents

Description

  The present invention relates to an illumination device that projects illumination light such as a pattern having a desired shape.

  Generally, a light emitting diode (LED) has an advantage of low power consumption and long life. Moreover, since the LED can be handled as a point light source, a reflector or the like is not particularly required. Therefore, in recent years, it is expected that the LED is applied as a light source of various illumination devices as the output of the LED increases.

As this type of illumination device, for example, in Patent Document 1, a film on which a design is printed is disposed between an illumination unit using an LED as a light source and a lens barrel on which first and second convex lenses are mounted. Thus, a portable projection display device (illumination device) that projects illumination light of a desired design is disclosed.
Utility Model Registration No. 3118682

  By the way, in this type of illumination device, particularly in a small illumination device suitable for portable use, a slight positional deviation (such as an optical axis distance deviation) of each optical member greatly affects the quality of the irradiated image. . If this is dealt with and the dimensions and the like of each optical member and the housing are formed with high accuracy, the manufacturing cost may increase.

  An object of this invention is to provide the illuminating device which can project a high quality irradiation image with an inexpensive structure.

An illumination device according to an aspect of the present invention includes a total reflection type collimation lens that converts light emitted from a light source into parallel light, a projection lens that projects light converted into parallel light by the collimation lens, and the collimation lens. And a light guide unit interposed between the projection lens and the projection lens. The light guide unit is a light shielding unit that restricts light incident on the projection lens from the collimation lens. A slit for inserting a mask opens in the peripheral surface.

  According to the illumination device of the present invention, a high-quality irradiation image can be projected with an inexpensive configuration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings relate to an embodiment of the present invention, FIG. 1 is a cross-sectional view of a main part of the illumination device, FIG. 2 is an exploded perspective view of the illumination device, FIG. 3 is an explanatory view showing the behavior of light incident on the collimation lens, FIG. These are principal part sectional drawings which show the modification of an illuminating device.

  As shown in FIGS. 1 and 2, the illuminating device 1 of the present embodiment includes, for example, a light source unit 10 that uses a surface-mounted light emitting diode (LED) 12 as a light source, and a lens optical system that is connected to the light source unit 10. The unit 20 is accommodated in the housing 5 to constitute a main part.

  In this embodiment, the housing | casing 5 is comprised with the substantially cylindrical member with a bottom by which the one end side was obstruct | occluded, for example. On the outer periphery of the other end side (open end side) of the housing 5, a male screw portion 5a for screwing an annular stopper 6 described later is engraved.

  The light source unit 10 includes, for example, a disk-shaped LED substrate 11 slidably in contact with the inner periphery of the housing 5, and an LED 12 having a single convex lens 13 fixed to an emission plane 12 a at a substantially central portion of the LED substrate 11. Is mounted by soldering or the like. The light source unit 10 is inserted from the open end side of the housing 5 and disposed at the bottom of the housing 5.

  The lens optical system unit 20 includes a total reflection type collimation lens 21 that converts light emitted from the LED 12 into parallel light, a projection lens 22 that projects light converted into parallel light by the collimation lens 21, and these collimation lenses 21. And a light guide 23 interposed between the projection lens 22 and the projection lens 22.

  In the collimation lens 21, for example, a lens portion 30 disposed on the optical axis O of the LED 12 and a reflector portion 31 disposed on the peripheral portion of the lens portion 30 are integrally formed of a light-transmitting resin molded product. It is comprised with the optical member made.

  In the present embodiment, the lens unit 30 is composed of, for example, a single-convex lens in which an incident surface (first incident surface) 30a is formed as a spherical surface and an output surface (first output surface) 30b is formed as a flat surface. Has been. The incident surface 30a of the lens unit 30 is directly opposed to the light emitting unit of the LED 12 via the one-convex lens 13. A light beam having a small emission angle is incident on the incident surface 30a. The

  In addition, the reflector unit 31 reflects, for example, an incident surface (second incident surface) 31a that surrounds the light emitting unit of the LED 12 around the incident surface 30a of the lens unit 30, and incident light from the incident surface 31a. It has a reflecting surface 31b and an emitting surface (second emitting surface) 31c that emits the reflected light from the reflecting surface 31b.

  For example, the incident surface 31 a is configured by a curved surface having a tapered cylindrical shape in which the front end portion is continuous with the peripheral portion of the incident surface 30 a of the lens unit 30 and the base portion is in contact with the LED substrate 11. Among them, a light beam having a large radiation angle is incident. Further, the reflecting surface 31b is formed of, for example, a curved surface having a substantially rotating parabolic shape with the optical axis O as the center, and totally reflects incident light from the incident surface 31a in the direction of the optical axis O. In addition, the emission surface 31 c is formed, for example, as a flat surface flush with the emission surface 30 b of the lens unit 30.

  In the collimation lens 21 having such a configuration, for example, as shown in FIG. 3, the lens unit 30 refracts incident light from the incident surface 30 a in the direction of the optical axis O to form substantially parallel light, The light exits from the exit surface 30b. The reflector unit 31 reflects the incident light from the incident surface 31a in the direction of the optical axis O by the reflecting surface 31b to form substantially parallel light, which is emitted from the emission surface 31c.

  For example, the light guide 23 is formed of a light-transmitting resin molded product having a substantially cylindrical shape that is in sliding contact with the inner periphery of the housing 5. The incident surface of the light guide unit 23 is bonded to, for example, the emission surface (emission surfaces 30b and 31c) of the collimation lens 21 via a transparent adhesive.

  In addition, a slit 23a is opened on the peripheral surface of the light guide 23, and a light shielding mask 33 for limiting light incident on the projection lens 22 from the collimation lens 21 is inserted into the slit 23a. In the present embodiment, the light-shielding mask 33 is made of a light-shielding film having openings 33a (for example, star-shaped openings) corresponding to a desired pattern or the like, and is converted into parallel light by the collimation lens 21. The transmitted light is allowed to pass only through the opening 33a.

  For example, the projection lens 22 is formed of a light-transmitting resin molded product in which a lens portion 36 is integrally formed inside an annular flange portion 35 that is in sliding contact with the inner periphery of the housing 5. The lens portion 36 is formed of a single convex lens in which the incident surface 36a is formed as a flat surface with the flange portion 35, and the emission surface 36b is formed as a spherical surface. The projection lens 22 has an incident surface 36 a side bonded to, for example, an output surface of the light guide 23 via a transparent adhesive, and receives parallel light incident from the collimation lens 21 via the opening 33 a of the light shielding mask 33. Project.

  Here, different optical materials can be appropriately used for the collimation lens 21, the light guide unit 23, and the projection lens 22. For example, the collimation lens 21 and the light guide 23 are made of different optical materials, and the collimation lens 21 generates parallel light with high accuracy by increasing the refractive index at the exit surfaces 30b and 31c of the collimation lens 21. It becomes possible. Further, for example, the light guide 23 and the projection lens 22 are made of different optical members, and the focal position on the incident side of the projection lens 22 is adjusted, thereby shortening the overall length of the lens optical system unit 20. It becomes possible to plan efficiently.

  The collimation lens 21, the light guide unit 23, and the projection lens 22 are adhered to each other in a state of being positioned with high accuracy by, for example, strict machine setting of the assembling apparatus. Then, the lens optical system unit 20 in which the respective members are positioned with high accuracy in advance is inserted from the open end side of the housing 5. Accordingly, the lens optical system unit 20 is connected to the light source unit 10 in the housing 5, and the LED 12 is accommodated in the space formed by the incident surfaces 30 a and 31 a of the collimation lens 21.

  Further, a spacer 38 made of an annular elastic body that comes into contact with the flange portion 35 of the projection lens 22 is inserted into the housing 5, and the spacer 38 is pressed by a stopper 6 screwed into the housing 5. Accordingly, the lens optical system unit 20 is elastically biased toward the light source unit 10 and is held in the housing 5 in a state where the optical members 21, 23, and 22 are positioned with high accuracy with respect to the LED 12, respectively. Is done.

  According to such an embodiment, the collimation lens 21 and the projection lens 22 are accommodated in the housing 5 in a state in which the lens optical system unit 20 is configured by being integrally connected in advance via the light guide 23. As a result, the optical members 21, 23, and 22 can be accurately placed without relative positioning of the optical members 21, 23, and 22 in the housing 5, and the high-cost configuration can be achieved. A quality irradiation image can be projected. In this case, by configuring the collimation lens 21 with a total reflection type collimation lens, sufficient parallel light can be formed even when the emission surfaces (emission surfaces 30b and 31c) are flush with each other. In addition, by forming the exit surface of the collimation lens 21 in a flat manner in this way, positioning at the time of connection with the light guide unit 23 can be realized with high accuracy and easily. Similarly, with respect to the lens portion 36 of the projection lens 22, positioning at the time of connection with the light guide portion 23 is easily realized with high accuracy by employing a single convex lens in which the incident surface 36 a is a flat surface. be able to.

  Further, by forming the slit 23a in the light guide portion 23, even when the lens optical system unit 20 is integrally connected in advance, an arbitrary light shielding mask 33 can be inserted into and removed from the lens optical system unit 20. It is possible to easily realize the projection of an irradiation image such as a pattern.

  In addition, by configuring and connecting the optical members 21, 22, and 23 with individual members, even when the lens optical system unit 20 is configured with a resin molded product, distortion or the like that occurs during molding is suppressed. Thus, a highly accurate lens optical system unit 20 can be realized.

  Here, instead of the above-described lens optical system unit 20 composed of a combination of resin molded products, for example, as shown in FIG. 4, a collimation lens 21, a light guide unit 23, It is also possible to employ a lens optical system unit 120 in which the projection lens 22 is integrally formed.

Cross section of the main part of the lighting device Disassembled perspective view of lighting device Explanatory diagram showing the behavior of light incident on the collimation lens Sectional drawing of the principal part showing a modification of the lighting device

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Illuminating device, 5 ... Housing, 5a ... Male screw part, 6 ... Stopper, 10 ... Light source unit, 11 ... LED board, 12 ... Light emitting diode (light source), 12a ... Output plane, 13 ... Uniconvex lens, 20 ... Lens optical unit, 21 ... collimation lens, 22 ... projection lens, 23a ... slit, 23 ... light guide, 30 ... lens, 30a ... entrance surface, 30b ... exit surface, 31 ... reflector, 31a ... entrance surface, 31b ... Reflective surface, 31c ... Exit surface, 33 ... Light-shielding mask, 33a ... Opening portion, 35 ... Flange portion, 36 ... Lens portion, 36a ... Injection surface, 36b ... Exit surface, 38 ... Spacer, 120 ... Lens optical system unit

Claims (2)

A total reflection type collimation lens that converts light emitted from the light source into parallel light;
A projection lens for projecting light converted into parallel light by the collimation lens;
A light guide unit interposed between the collimation lens and the projection lens, and a lens optical system unit integrally connected ;
The illumination device according to claim 1, wherein a slit for inserting a light shielding mask for restricting light incident on the projection lens from the collimation lens is opened on a peripheral surface of the light guide unit. The lighting device according to claim 1, wherein at least one of the collimation lens, the projection lens, and the light guide unit is made of an optical material having a refractive index different from that of other members.

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