JP6781029B2 - Light projection device - Google Patents

Description

The present invention relates to a light projection device.

In recent years, a device for projecting light (light projection device) has been attached to a car or the like and is used for various purposes. For example, a technology in which a light projection device for projecting infrared light and a sensor are provided in a car, and the reflected light of the light projected from the light projection device is detected by the sensor to recognize an object around the car. It has been known.
In the light projection device used for such a purpose, in order to improve the accuracy of sensing, the light emitted from the LED (light emitting device) is focused in a predetermined direction and the light is uniformly projected in a predetermined range. Is required to do. As a device that collects light in a predetermined direction and projects the light, for example, as in Patent Document 1, the LED is placed at the focal position of a reflective surface having a radial surface, and the light from the LED is emitted. A technique is known in which light is reflected by this reflecting surface to produce parallel light.

Japanese Unexamined Patent Publication No. 2008-4296

By the way, when an LED with a lens effect package is used as a light emitting device and the light emitting device is arranged so that the LED element coincides with the focal position of the radial surface, a pseudo light source is generated in the lens portion of the light emitting device, and the light projection device. There is a problem that the light collecting property of the LED is deteriorated, and there is a problem that the illumination becomes uneven due to unintended light distribution.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical projection device having good light collecting property and capable of uniformly projecting light.

In order to achieve the above object, the light projection device of the present invention
A light projection device including a light emitting device including an LED element and a lens effect package, and a reflecting member having a parabolic surface for reflecting light from the light emitting device.
The focus of the paraboloid is located between the light emitting surface of the LED element and the center of the pseudo light source by the lens effect package.

In the present invention, the light emitted from the light emitting surface of the LED element passes through the lens effect package of the light emitting device, is reflected by the light emitting surface of the reflecting member, or is directly projected from the light projection device.
Since the light emitted from the light emitting surface of the LED element passes through the lens effect package of the light emitting device, the apex portion of the lens effect package and the like behave like a pseudo light source (pseudo light source). That is, the light emitting device including the LED element and the lens effect package behaves as if it has two types of light sources, an LED element (light source) and a pseudo light source by the lens effect package. The pseudo light source generated is not limited to one depending on the positional relationship between the light emitting surface of the LED element and the lens effect package and the shape of the lens effect package, and the position may also be on the optical axis of the LED element. It is not limited.

When the light emitted from the focal point of the paraboloid is reflected by the paraboloid, it is emitted as parallel light. However, light emitted from a position farther from the paraboloid's focal point will be more focused or diverged when reflected by the paraboloid as the position is farther from the focal point. Therefore, when the light emitting surface (light source) of the LED element is set to the focal position of the paraboloid, the light emitted from the pseudo light source is strongly focused (or diverged). However, as in the present invention, the focal point of the parabolic surface is located between the light emitting surface (light source) of the LED element and the center of the pseudo light source by the lens effect package, so that the light source from the focal point and / Alternatively, the displacement of the position to the pseudo light source can be minimized, and the amount of light emitted from the parabolic surface in a nearly parallel state can be increased as a whole. Here, the center of the pseudo light source is the center of a plurality of generated pseudo light sources, and is calculated as averaging the Z-axis coordinates of each pseudo light source when the optical axis is the Z axis.
Therefore, the light collecting property is good and the light can be projected uniformly.

Further, in the above-mentioned configuration of the present invention,
A condensing lens that collects the light emitted from the light emitting device and the light emitted from the light emitting device and reflected by the paraboloid is provided.
It is preferable that the power of the condenser lens is set so that the focal position of the condenser lens is located on the back side of the light emitting surface of the LED element.

According to such a configuration, the light emitted from the light emitting device and condensed by the paraboloid so as to be uniformly directed in a predetermined direction can be further condensed by the condensing lens, so that the light can be further collected. The lightness can be enhanced. By adjusting the refractive power of the condenser lens, it is possible to irradiate a limited irradiation target with substantially uniform light. Further, among the light emitted from the light emitting device, the light that is not reflected by the light emitting surface and goes directly to the condenser lens travels so as to be diverged from the light emitting device, and this light is condensed by the condenser lens. Therefore, the light collecting property of the light projection device can be further improved.
In the case of a Fresnel lens, the focal position of the condensing lens has a width within a predetermined range, so that the light is most concentrated when a parallel light beam is incident from the exit side of the Fresnel lens and the screen is arranged near the focal point. Defined as a shining point. Further, regarding the focal position of the optical system including the reflecting member and the condensing lens, which will be described later, similarly, when the condensing lens is a Fresnel lens or the like, parallel light is incident from the exit side of the Fresnel lens to be near the focal point. It is defined as the point where the light is most focused when the screen is placed.

Further, in the above-mentioned configuration of the present invention,
It is preferable that the focal point of the optical system including the reflecting member and the condensing lens is located between the focal point of the light emitting surface of the LED element and the focal point of the parabolic surface.

According to such a configuration, the focal point of the optical system including the reflecting member and the condensing lens is located between the focal point of the light emitting surface of the LED element and the focal point of the parabolic surface. As mentioned above, by making the focal point of the parabolic surface located between the LED element (light source) and the center of the pseudo light source by the lens effect package, the light source from the focal point of the parabolic surface or the pseudo light source can be reached. It is possible to minimize the deviation of the position of the light source and increase the amount of light emitted from the light source surface in a nearly parallel state as a whole, but with that alone, the light emitted from the light source surface can be increased. There is a possibility that the light condensing lens collects light more than necessary, or conversely, the light condensing power is insufficient, so that it is not possible to irradiate a substantially uniform light to a desired irradiation range. By locating the focal point of the optical system including the reflecting member and the condensing lens between the focal point of the light emitting surface and the luminous surface of the LED element, the light source and / or pseudo from the focal point of the optical system. It is possible to minimize the deviation of the position to the light source, improve the light condensing property at the desired position and the desired range, and project the light more uniformly.

Further, in the configuration of the present invention, the focal point of the optical system including the reflecting member and the condensing lens is the light emitting surface of the LED element and the light emitting from the light emitting surface of the LED element toward the condensing lens. It is preferably located between the position of 1/3 of the total length of the device.

According to such a configuration, the focus of the optical system including the reflecting member and the condensing lens is 1/3 of the total length of the light emitting device from the light emitting surface of the LED element and the light emitting surface of the LED element toward the condensing lens. It will be located between the position of. If the distance from the LED element to the focal point of the optical system including the reflecting member and the condensing lens is too large, the light emitted from the LED element may be condensed or diverged too much. However, the focal point of the optical system including the reflecting member and the condensing lens is between the light emitting surface of the LED element and the position of 1/3 of the total length of the light emitting device from the light emitting surface of the LED element toward the condensing lens. By locating the light, it is possible to prevent the light emitted from the LED element from being collected or diverged too much, improve the light collecting property at a desired position and a desired range, and project the light more uniformly. Is possible.

Further, in the configuration of the present invention, the condenser lens is preferably a Fresnel lens.

According to such a configuration, the light projection device can be miniaturized.

According to the present invention, light can be projected uniformly with good light collecting property.

It shows the embodiment of this invention, and is the side view of the light projection apparatus. The same is a rear view of the light projection device. The same is a side view of the reflective member. It is a figure which shows the position of the focal point of the reflection member. It is a figure which shows the position of the focal point of the condenser lens. It is a figure which shows the position of the focal point of the optical system which is composed of a reflection member and a condenser lens. Similarly, it is a figure which displayed the light distribution by a light emitting device and a reflecting member in Cartesian coordinates when the position of the focal point of a reflecting surface and the position of an LED element are matched. Similarly, it is a figure which displayed polar coordinates and the like the light distribution distribution by a light emitting device and a reflecting member when the position of the focal point of a reflecting surface and the position of an LED element are matched. It is the figure which displayed the light distribution by a light emitting device and a reflecting member in Cartesian coordinates when the focal point of the reflecting surface is located between the LED element and the center of a pseudo light source. It is the figure which displayed the light distribution distribution by a light emitting device and a reflecting member in polar coordinates, etc., when the focal point of the reflecting surface is located between the LED element and the center of a pseudo light source. It is the figure which displayed the light distribution of the light projection apparatus in Cartesian coordinates. In the same figure, the light distribution of the light projection device is displayed in polar coordinates and the like.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The light projection device of the present embodiment is, for example, provided in a car and projects infrared light, and the reflected light of the projected light is detected by a sensor provided in the car to surround the car. It is used to grasp the outer shape of an object and to measure the distance to the object.

As shown in FIG. 1, the light projection device 1 includes a light emitting device 2, a reflecting member 3, a condenser lens 4, and a mounting member 5. It should be noted that FIG. 1 is displayed by transmitting the front side portion of the light projection device 1 in FIG. 1 so that the inside of the light projection device 1 can be easily understood.
The reflecting member 3 and the condenser lens 4 are arranged in a state where their optical axes are aligned with each other. Further, the line passing through the center of the light emitted from the light emitting device 2 coincides with the optical axis of the reflecting member 3 and the condenser lens 4. Hereinafter, the optical axis of the reflecting member 3 and the condenser lens 4 and the line passing through the center of the light emitted from the light emitting device 2 are collectively referred to as an optical axis X.

Further, the light emitting device 2 includes an LED element 20, a lens effect package 21, and a substrate 22. Further, the LED element 20 is an infrared LED that emits infrared light from a light emitting surface. The lens effect package 21 is a resin member having a lens effect, but may be made of glass or the like.

The LED element 20 is provided at the center of one surface 22a of the square plate-shaped substrate 22. Further, the shape of the LED element 20 is a square plate shape. Further, the light from the LED element 20 is emitted centering on the direction perpendicular to the substrate 22 (optical axis X direction).
A dome-shaped lens effect package 21 is provided on the surface 22a so as to cover the LED element 20. Further, the lens effect package 21 is arranged so that the optical axis X passes through the apex of the dome-shaped lens effect package 21. That is, the optical axis of the lens effect package 21 and the optical axis X are in the same state. Further, as shown in FIG. 2, electrodes (anode 23a and cathode 23b) are provided on the other surface 22b of the substrate 22, and the LED element 20 is caused by a current flowing from the anode 23a toward the cathode 23b. The light emitting surface of is designed to emit light.
That is, the LED element 20 provided on the substrate 22 is enclosed in the lens effect package 21 to form one light emitting element that emits infrared light. Therefore, for example, an LED with a lens such as a chip LED with a lens or a bullet-shaped LED can be used as the light emitting device 2.
Since the light emitted from the light emitting surface of the LED element 20 passes through the lens effect package 21 of the light emitting device 2, the apex portion of the lens effect package 21 and the like behave like a pseudo light source (pseudo light source). That is, the light emitting device 2 including the LED element 20 and the lens effect package 21 behaves as if it has two types of light sources, the LED element 20 (light source) and the pseudo light source by the lens effect package 21. The pseudo light source generated is not limited to one depending on the positional relationship between the light emitting surface of the LED element 20 and the lens effect package 21 and the shape of the lens effect package 21, and the position may also be the position of the LED element 20. It is not limited to the optical axis. Then, the centers of these pseudo light sources are calculated as averaging the Z-axis coordinates of each pseudo light source when the optical axis is the Z axis. In the LED light emitting device covered with the lens effect package 21 having a convex shape in the optical axis direction, the center of the pseudo light source often comes near the apex of the lens effect package 21, so in the following embodiment, the pseudo light source is used. The center of the lens effect package 21 will be described as being near the apex of the lens effect package 21.

As shown in FIG. 3, the reflective member 3 includes a reflective surface 30 and a mounting portion 31. Further, the shape of the reflecting surface 30 is a rotating paraboloid with the apex cut off. That is, the reflective surface 30 is provided with circular openings (first opening 32, second opening 33) at both ends, and the inner diameter gradually increases from the first opening 32 side to the second opening 33 side. It has a widened shape.
Further, the first opening 32 of the reflecting surface 30 is provided with a mounting portion 31 integrally with the reflecting surface 30. Further, the mounting portion 31 has a conical tubular shape and has a shape extending from the first opening 32 toward the opposite side thereof.
The optical axis of the reflection member 3 described above coincides with the central axis of the rotating paraboloid of the reflection surface 30. Further, the reflective surface 30 may be formed of a material that reflects light by itself, or may be plated to reflect light. That is, the reflecting surface 30 may be capable of reflecting light.

As shown in FIGS. 1 and 2, a square frame-shaped mounting member 5 having a side having a side substantially the same length as the diameter of the opening is formed in the opening of the mounting portion 31 opposite to the reflective member 3. It is provided. Further, the light emitting device 2 is fitted in the frame of the mounting member 5. That is, the light emitting device 2 is attached to the reflection member 3 by the attachment member 5. Further, the thicknesses of the mounting member 5 and the substrate 22 are substantially the same, the lens effect package 21 projects from the mounting member 5 and the substrate 22 toward the reflective member 3, and the apex of the lens effect package 21 is the first. It is in a state of protruding toward the reflecting surface 30 side from the opening 32.

Further, the condenser lens 4 is adhered to the reflecting surface 30 (second opening 33) so as to cover the second opening 33 of the reflecting surface 30 (see FIGS. 1 and 3). Further, the condenser lens 4 is a Fresnel lens. Further, the central axis (optical axis) of the condenser lens 4 coincides with the optical axis X.
The condensing lens 4 may be a spherical or aspherical convex lens or the like, and may be a lens capable of condensing light from the reflecting member 3 side. Further, the condensing lens 4 may be fitted in the second opening 33 or may be attached to the reflecting surface 30 via an attachment member for attaching the condensing lens 4.

Next, the position of the focal point of each member will be described.
FIG. 4 shows the position of the focal point A of the reflecting surface 30 of the reflecting member 3. The focal point A of the reflecting surface (paraboloid) 30 is located between the light emitting surface of the LED element 20 of the light emitting device 2 and the lens effect package 21 (between the light emitting surface of the LED element 20 and the center of the pseudo light source). (See Fig. 1). Further, the focal point A of the reflecting surface 30 is located on the optical axis X. Therefore, as shown in FIG. 4, the light L emitted from the focal point A and reflected by the reflecting surface 30 travels in the direction parallel to the optical axis X. On the contrary, the light L traveling parallel to the optical axis X and entering the reflecting member 3 passes through the focal point A after being reflected by the reflecting surface 30.

FIG. 5 shows the position of the focal point of the condenser lens 4. The focal point of the condenser lens 4 is located behind the LED element 20 with respect to the direction in which the light from the LED element 20 travels (see FIG. 1). That is, the focal point of the condenser lens 4 is located on the back side of the light emitting surface of the LED element. Further, in the condenser lens 4 of the present embodiment, the focal position is not fixed to one. That is, each of the concentric convex portions of the Fresnel lens, which is the condenser lens 4, has a focal point at a different position. All the focal points of these condenser lenses 4 are located behind the LED element 20 with respect to the direction in which the light from the LED element 20 travels. Further, all the focal points of these condenser lenses 4 are located on the optical axis X.
The reason why the focal position of the condenser lens 4 is not fixed to one in this way is to adjust the range in which the light is to be projected from the light projection device 1 and the uniformity of the projected light. A condenser lens 4 in which the focal position is fixed to one may be used depending on the application of the light projection device 1. Further, when it is desired to strengthen the condensing action of the condensing lens 4, the focal point of the condensing lens 4 is located in front of the light emitting surface of the LED element 20 with respect to the direction in which the light from the LED element 20 travels. You may do so. Further, a part of each focal point of the condenser lens 4 may be located in front of the light emitting surface of the LED element 20 with respect to the direction in which the light from the LED element 20 travels.

FIG. 6 shows the focal position of the optical system 40 composed of the reflecting member 3 and the condenser lens 4.
As described above, since the condenser lens 4 has a plurality of focal points, there are also a plurality of focal positions of the optical system 40, but all the focal points of the optical system 40 are located within 1 mm from the light emitting surface of the LED element 20. There is. Further, all the focal points of the optical system 40 are located on the optical axis X.
It should be noted that all the focal points of the optical system 40 do not have to be located within 1 mm from the light emitting surface of the LED element 20. For example, when a parallel light beam is incident from the exit side of the condenser lens 34 of the optical system 40 and the screen is arranged near the focal point, the point where the light is most focused is located within 1 mm from the light emitting surface of the LED element 20. If so, most of the light emitted from the LED element 20, reflected by the reflecting surface 30, and condensed by the condenser lens 4 can be guided in a direction close to the direction parallel to the optical axis X.

Further, when a parallel light beam is incident from the exit side of the condenser lens 34 of the optical system 40 and the screen is arranged near the focal point, the points where the light is most focused are the light emitting surface of the LED element 20 and the LED element 20. It is located between the light emitting surface of the light emitting device 2 and the position of 1/3 of the total length of the light emitting device 2 toward the condenser lens 34.

Next, with respect to the light emitting device 2 and the reflecting member 3 of the present embodiment, a simulation performed by changing the position of the light emitting device 2 will be described.
In this simulation, the reflective surface 30 of the reflective member 3 has the same shape (R = 1.2, K = -1), and by changing the position of the light emitting device 2, the LED element 20 and the LED element 20 with respect to the focal point A of the reflective surface 30 The relative position of the lens effect package 21 was changed, and the light distribution in each case was investigated. 7 to 10 show the light distribution obtained by this simulation. Note that this simulation is performed excluding the condenser lens 4, and the light distribution in FIGS. 7 to 10 shows the light distribution by the light emitting device 2 and the reflecting member 3. Further, the simulation is performed with the reflectance of the reflecting surface 30 being 95%.

7 and 8 show simulation results when the position of the focal point A of the reflecting surface 30 is matched with the position of the light emitting surface of the LED element 20. FIG. 7 is a display of the light distribution in Cartesian coordinates, and FIG. 8 is a display of the light distribution in polar coordinates and the like.
When the focal position of the reflecting surface 30 is matched with the position of the light emitting surface of the LED element 20, the full width at half maximum (FWHM) is ± 6 °, and the light emitted from the light emitting device 2 and the reflecting member 3 is emitted. It has a spread. The reason why the light spreads in this way is that a pseudo light source is generated in the lens effect package 21 of the light emitting device 2.

Here, the pseudo light source will be described. The light emitted from the LED element 20 undergoes internal reflection and refraction when passing through the lens effect package 21, and it appears as if the light is emitted from the vicinity of the lens effect package 21 (note that the LED element 20 is infrared). Since it emits light, it cannot be seen with the naked eye). That is, the lens effect package 21 seems to behave as a light source, and the lens effect package 21 acts as a pseudo light source. Further, the pseudo light source appears at a plurality of places in the lens effect package 21, but the center of the pseudo light source is often near the apex of the lens effect package 21.

When the position of the focal point A of the reflecting surface 30 is aligned with the position of the light emitting surface of the LED element 20, the light emitted from the LED element 20 as a light source and reflected by the reflecting surface 30 becomes parallel light and becomes light. It will travel parallel to the axis X. However, the light emitted (appearing to be) from the lens effect package 21 as a pseudo light source is emitted from a position deviated from the focal point A of the reflecting surface 30 and is reflected by the reflecting surface 30, so that it is not parallel light. Instead, it travels at an angle with respect to the parallel light (optical axis X). Further, as the position where the light is emitted moves away from the position of the focal point A, the light emitted from that position is reflected by the reflecting surface 30 and then travels at an angle with respect to the parallel light (optical axis X). turn into. Therefore, when the position of the focal point A of the reflecting surface 30 is matched with the position of the light emitting surface of the LED element 20, the distance between the center of the pseudo light source (near the apex of the lens effect package 21) and the focal point A of the reflecting surface 30 is Since it becomes long, the light from the pseudo light source has an angle with respect to the parallel light (optical axis X), and the light condensing property of the light emitted from the light emitting device 2 and the reflecting member 3 deteriorates.

9 and 10 show simulation results when the focal point A of the reflecting surface 30 is placed between the light emitting surface of the LED element 20 and the center of the pseudo light source (near the apex of the lens effect package 21). FIG. 9 shows the light distribution distribution in Cartesian coordinates, and FIG. 10 shows the light distribution distribution in polar coordinates and the like.
By arranging the position of the focal point A of the reflecting surface 30 between the light emitting surface of the LED element 20 and the center of the pseudo light source, the half-value width (FWHM) becomes ± 4.5 °, and the focal point A of the reflecting surface 30 It can be confirmed that the light collecting property is improved and the light can be uniformly projected in a predetermined range as compared with the case where the position is matched with the position of the LED element 20.

By arranging the focal point A of the reflecting surface 30 between the light emitting surface of the LED element 20 and the center of the pseudo light source in this way, the amount of light reflected by the reflecting surface 30 and becomes light close to parallel light is increased. be able to. In other words, as a whole, the deviation width in the direction in which the light travels with respect to the optical axis X can be minimized.

Next, the simulation result of the light projection device 1 of the present embodiment will be described.
The focal point A of the reflecting surface 30 of the reflecting member 3 is located between the light emitting surface of the LED element 20 of the light emitting device 2 and the apex of the lens effect package 21. Further, the focal points of the optical system 40 composed of the reflecting member 3 and the condenser lens 4 are all located within 1 mm from the light emitting surface of the LED element 20. Further, when a parallel light beam is incident from the exit side of the condenser lens 34 of the optical system 40 and the screen is arranged near the focal point, the points where the light is most focused are the light emitting surface of the LED element 20 and the LED element 20. It is located between the light emitting surface of the light emitting device 2 and the position of 1/3 of the total length of the light emitting device 2 toward the condenser lens 34. Further, the simulation is performed assuming that the reflectance of the reflecting surface 30 is 95%.
11 and 12 show the simulation results of the light projection device 1 of the present embodiment. FIG. 11 shows the light distribution distribution displayed in Cartesian coordinates, and FIG. 12 shows the light distribution distribution displayed in polar coordinates and the like.
In the light projection device 1 of the present embodiment, the radiation intensity of light is 80% or more of the maximum value in the range of ± 7 °. The full width at half maximum (FWHM) is ± 9.4 °. Therefore, it can be confirmed that the light can be focused in a narrow range. In addition, it can be confirmed that the light can be projected uniformly and evenly within the focused range.

In the light projection device having such a configuration, the focal point A of the reflecting surface (elephant surface) 30 is located between the light emitting surface of the LED element 20 of the light emitting device 2 and the apex of the lens effect package 21. A is located between the light source (light emitting surface of the LED element 20) and the center of the pseudo light source by the lens effect package 21. Therefore, the distance from the focal point A to the center of the light source (LED element 20) and / or the pseudo light source can be shortened, and the light is emitted from the reflecting surface 30 in a state close to parallel (in a direction close to parallel to the optical axis X). The amount of light produced can be increased. Therefore, it has good light-collecting property and can project uniformly.
When the focal point A is set so that the distance from the light emitting surface of the LED element 20 to the focal point A and the distance from the apex of the lens effect package 21 to the focal point A are equal, the light is emitted from the LED element 20 as a light source and reflected. The angle with respect to the optical axis X is equal between the direction in which the light reflected by the surface 30 travels and the direction in which the light emitted from the apex of the lens effect package 21 as a pseudo light source and reflected by the reflection surface 30 travels. Therefore, by setting the focal point A so that the distance from the light emitting surface of the LED element 20 to the focal point A and the distance from the apex of the lens effect package 21 to the focal point A are equal, the LED element 20 and the lens effect package 21 The angle with respect to the optical axis X in the direction in which the light emitted from the apex of the lens and reflected by the reflecting surface 30 travels can be minimized. However, since the amount of light emitted from the LED element 20 as a light source and the amount of light emitted from the lens effect package 21 as a pseudo light source may not be equal, the focus A may have different amounts of light. The position may be adjusted as appropriate.

Further, since the light projection device having such a configuration includes the condensing lens 4 that collects the light reflected by the reflecting surface 30, the light is emitted from the light emitting device 2 and is in a state close to parallel light by the reflecting surface 30. The resulting light can be condensed in a predetermined direction and in a predetermined range by the condensing lens 4. Therefore, as compared with the case where the condensing lens 4 is not provided, the condensing property of the light projection device 1 can be improved, and the light can be uniformly projected in a predetermined range. Further, the reflecting surface 30 creates light in a state close to parallel light, and the light is condensed by the condenser lens 4, so that the light can be easily condensed toward a desired range.
Further, the light emitted from the light emitting device 2 and directed to the condensing lens 4 without hitting the reflecting surface 30 travels so as to be diverged from the light emitting device 2, but this light can be condensed by the condensing lens 4. Therefore, the light collecting property of the light projection device 1 can be further improved.

Further, in the light projection device having such a configuration, when a parallel light beam is incident from the exit side of the condenser lens 34 of the optical system 40 including the reflection member 3 and the condenser lens 4 and the screen is arranged near the focal point. Since the point at which the light is most focused is located between the light emitting surface of the LED element 20 and the position of 1/3 of the total length of the light emitting device 2 from the light emitting surface of the LED element 20 toward the condensing lens 34. , Prevents the light emitted from the LED element 20 from being excessively focused or diverged and projected from the light projection device 1, enhances the light condensing property at a desired position and a desired range, and projects the light more uniformly. can do.

1 Light projection device 2 Light emitting device 3 Reflective member 4 Condensing lens 20 LED element 21 Lens effect package 30 Reflective surface (paraboloid)
40 optics

Claims (5)

A light projection device including a light emitting device including an LED element and a lens effect package, and a reflecting member having a parabolic surface for reflecting light from the light emitting device.
A light projection device characterized in that the focal point of the paraboloid is located between the light emitting surface of the LED element and the center of a pseudo light source by the lens effect package. A condensing lens that collects the light emitted from the light emitting device and the light emitted from the light emitting device and reflected by the paraboloid is provided.
The light projection device according to claim 1, wherein the power of the condensing lens is set so that the focal position of the condensing lens is located on the back side of the light emitting surface of the LED element. The light projection apparatus according to claim 2, wherein the focal point of the optical system including the reflecting member and the condensing lens is located between the focal point of the light emitting surface of the LED element and the focal point of the radial surface. .. The focus of the optical system including the reflecting member and the condensing lens is a position of 1/3 of the total length of the light emitting device and the light emitting surface of the LED element toward the condensing lens. The light projection device according to claim 2, wherein the light projection device is located between the two. The light projection device according to any one of claims 2 to 4, wherein the condensing lens is a Fresnel lens.