JP2013250422A - Image projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image projection device for obtaining a stable reflection light output, a stabilized color performance and a prolonged service life of the device by improving the cooling efficiency of a rotational reflection member.SOLUTION: This image projection device 100 includes: light sources 1, 4, 15 of a plurality of colors; a rotational reflection member 11 for modulating the frequency by having flux from the light source of one color, among the plurality of light sources, radiated on a ring-like reflection section 11a composed by a reflection substance; and driving means 10 for rotationally driving the rotational reflection member. In this case, a guide section 20 is arranged in between a rotational center O of a rotational reflection member and a reflection section 11a in the rotational reflection member for guiding the air generated when the driving means rotates in generating an image to the reflection section 11.

Description

  The present invention relates to an image projection apparatus, and relates to a temperature reduction technique for a rotary reflecting member that rotates and reflects a light beam from a light source.

  The projection optical system provided in the image projection apparatus is not actively cooled unlike the cooling of other heat generating parts, but the reflection is uniform at the reflecting part formed by applying the fluorescent material. In order to suppress the increase in surface temperature and the surface temperature, the rotary reflecting member is rotated by a driving means such as a motor.

  However, even if the rotational speed of the motor is increased in order to suppress homogenization of reflection at the reflecting portion and increase in surface temperature, the effect does not increase beyond a certain level. This is because even if the relative speed between the rotary reflecting member and the air is increased, the heat transfer to the air does not proceed beyond a certain level, and the movement of the heat transferred air is small.

  As a cooling technique for an image projection apparatus, a technique for cooling the entire image projection apparatus is generally used as described in Patent Documents 1-3.

  In the image projecting device, in order to obtain a light beam necessary for the projection optical system from a laser light source that is a form of the light source, when performing reflection and frequency conversion of light from the laser light source, The phenomenon that the reflected light output is reduced due to the rise in the surface temperature occurs. In addition, use in a state where the surface temperature of the reflecting portion is high leads to deterioration of the durability and life of the fluorescent material constituting the reflecting portion, stabilizing the brightness and color performance of the image projector, and lengthening the device. It will be negative for life extension.

  It is an object of the present invention to provide an image projection apparatus that can obtain a stable reflected light output by increasing the cooling efficiency of the rotary reflecting member, as well as stabilizing the color performance and extending the life of the apparatus. To do.

  In order to achieve the above-described object, an image projection apparatus according to the present invention irradiates a ring-shaped reflection unit made of a reflective material with a light source of one of a plurality of colors and a light source of one color among the plurality of light sources. A rotary reflecting member that modulates the frequency by this, and a driving unit that rotationally drives the rotary reflecting member. The rotating reflecting member is disposed between the rotation center of the rotating reflecting member and the reflecting portion, and the driving unit is used when generating an image. It has the guide part which guides the air which generate | occur | produces when it rotates to a reflection part.

  According to the present invention, in the rotary reflection member that modulates the frequency by reflecting the light beam from the light source by the reflection unit, the error occurs when the drive unit rotates between the rotation center of the rotary reflection member and the reflection unit. Since the guide part is arranged to guide the air to be reflected to the reflection part, the air blown along with the rotation of the driving means is guided to the reflection part by the guide part, and in addition to the movement of the air surface due to the rotation of the rotary reflection member, Since the movement is applied to the reflecting portion, the cooling efficiency of the rotating reflecting member can be increased. For this reason, in the image projection apparatus, a stable reflected light output can be obtained, the color performance can be stabilized, and the life of the apparatus can be extended.

The figure which shows schematic structure of the image projector which concerns on this invention, and the outline of an optical path. FIG. 3 is an enlarged perspective view showing a configuration in the vicinity of a reflection rotating member that is a main part of the image projector according to the present invention. (A) is a disassembled perspective view which shows the structure of a reflection rotating member and a cover member, (b) is a perspective view which shows the state which incorporated the reflection rotating member and the cover member, and the flow of cooling air. (A) is a perspective view which shows the structure of the thermal radiation part formed in the reflective rotation member, (b) is sectional drawing of a reflective rotation member. The expansion perspective view which shows another structure of the reflection rotation member vicinity used as the principal part of the image projector which concerns on this invention. (A) is a disassembled perspective view which shows another structure of the reflection rotating member and cover member shown in FIG. 5, (b) is a perspective view which shows the state which incorporated the reflection rotating member and the cover member, and the flow of cooling air. (A) is the figure which shows the form which made the heat dissipation part the multiple ring shape, (a) is the figure which shows the form which made the heat dissipation part the discontinuous pin shape, (c) the form which constituted the heat dissipation part in the rib shape FIG.

  The present invention reduces the decrease in the reflected light output due to the increase in the surface temperature of the reflecting portion of the rotary reflecting means in which the reflecting portion is made of a fluorescent material that converts the frequency of the light beam from the light source. Embodiments of the present invention will be described below with reference to the drawings.

  An image projection apparatus 100 shown in FIG. 1 includes a projection optical system that uses laser light sources (LEDs) as a plurality of light sources. Reference numeral 1 denotes an LED that is a light source that emits a luminous flux of one of the three primary colors of light. A condensing lens 2 that condenses and emits the light flux from each light source 1 is disposed opposite to the light source 1. The light beam condensed and emitted by the condensing lens 2 passes through the diffusive reflector 3 and the reflecting mirror 7 disposed so as to face the condensing lens 2 and is reflected and becomes a reflection rotating member that constitutes a wavelength conversion unit. The light is irradiated onto the reflective rotating plate wheel 11 by the imaging lenses 8 and 9 disposed in front of the rotating plate wheel 11. The reflection rotating plate wheel 11 includes a reflection portion 11a made of a reflective material (fluorescent material). The light flux that has passed through the imaging lenses 8 and 9 and has been guided to the reflection rotating plate wheel 11 is reflected by the reflecting portion 11a, and its frequency is changed.

  The light flux whose frequency has been changed passes through the imaging lenses 8 and 9 again, is reflected in the direction of the reflecting mirror 12 in parallel with the reflecting mirror 7, and is also reflected by the reflecting mirror 12, and is a rod integrator that serves as a light quantity uniformizing means. Proceed in the direction of 16.

  The light beams from the light sources 4 and 15 serving as the light sources of the remaining two colors among the three primary colors of light are the light collecting lenses 5 and 6 and the light collecting lenses 13 and 13 disposed in the irradiation direction, respectively. 14 are respectively condensed and proceed in the direction of the reflecting mirror 12. The light from the light source 4 is reflected by the reflection mirror 12 and travels in the rod direction of the rod integrator 16. The light from the light source 15 passes through the reflecting mirror 12 and travels in the same way toward the rod of the rod integrator 16.

Each light beam introduced into the rod integrator 16 is homogenized by passing through the rod integrator 16. The homogenized light beam is then directed to an image reflection element (not shown) to create an image. In FIG. 1, the state of the light flux after the rod integrator 16 is omitted.
In this embodiment, the light source 1 emits a green laser beam, the light source 4 emits a blue laser beam, and the light source 15 emits a red laser beam.

The configuration of the reflection and wavelength conversion unit that receives and modulates the laser beam and reflects the green beam will be described with reference to FIGS.
The reflection / wavelength conversion unit includes a disk-like reflection rotating plate wheel 11 and a motor 10 serving as a driving means for rotationally driving the wheel. For example, the green laser beam condensed by the lens in FIG. 1 is collected on a reflection rotating plate wheel 11 having a reflecting portion 11a formed on a surface 11A that is a first surface by applying a reflective material in a ring shape. The point A in the figure is irradiated and reflected. The reflection rotating plate wheel 11 has its rotation center O directly connected to the output shaft 10 a serving as the rotation center of the motor 10, and rotates integrally with the rotation of the motor 10. For example, a metal substrate such as aluminum or stainless steel or a glass substrate such as sapphire is used as the reflective rotating plate wheel 11 as a material having high heat resistance and good thermal conductivity.

  As shown in FIGS. 2, 3 (a), and 3 (b), the motor 10 is provided on the surface 11 </ b> A of the reflection rotating plate wheel 11 between the rotation center O and the reflecting portion 11 a during image generation. A plurality of convex fins 20 serving as guide portions for guiding the air generated when rotating to the reflection portion 11a are arranged. Each fin 20 extends radially on the surface 11 </ b> A toward the reflecting portion 11 a and is formed integrally with the reflecting rotating plate wheel 11. Needless to say, when the processing is restricted by the shape or the like, the reflecting rotary plate wheel 11 and the fins 20 may be formed separately and then integrated.

  For this reason, as shown in FIG. 3B, when the motor 10 rotates, the reflection rotating plate wheel 11 is pushed to the outer peripheral side due to the curved shape of each fin 20 and is positioned on the outer peripheral side. The airflow F1 guided by the reflecting portion 11a is generated.

  A cover member 21 is provided at the rotation center O and the reflection portion 11 a so as to cover the entire fins 20. The cover member 21 has a bottomed cylindrical shape, and a suction port 22 serving as an introduction portion for introducing air from the outside of the cover into the cover member is positioned on the extended line of the rotation center O of the reflective rotating plate wheel 11. The bottom surface 21a is formed so as to penetrate the motor 10 in the axial direction. The cover member 21 has a discharge hole 23 serving as a discharge portion that discharges air in the cover toward a specific portion of the reflection portion 11a.

  In this embodiment, the specific portion of the reflecting portion 11a is a point A that is reflected by being irradiated with a laser beam as shown in FIG. The discharge hole 23 is formed in the wall surface 21b located in the radial direction of the cover member 21 so that the air is directed to the point A. The discharge hole 23 faces a point A, which is a specific part of the reflection part 11a, so that the vicinity of the reflection part of the laser beam from the light source 1 in the reflection part 11a can be concentrated and cooled. It is formed on the cover member 21 and provided on the reflective rotating plate wheel 11 so that the point A is located in the discharge region B.

  In this embodiment, the cover member 21 is formed so that the portion of the wall surface 21b where the discharge hole 23 is formed protrudes in the outer peripheral direction while avoiding the point A where the laser beam is irradiated. And the discharge port 23 is formed in the edge part of this protrusion part so that A point may be located in the discharge area | region B of air, and the structure which blows air to A point from the rotation direction of the reflective rotating plate wheel 11 It is said that.

  With such a configuration, when the motor 10 rotates, as shown in FIG. 3B, the air from the outside is sucked into the inside of the cover member 21 as the air flow F along the rotation, as shown in FIG. . The air sucked from the suction port 22 becomes an air flow F1 due to the curved shape of each fin 20 and is guided to the reflecting portion 11a, so that the reflecting portion 11a and the reflecting rotating wheel 11 are cooled. Further, the air flowing toward the reflecting portion 11a becomes an air flow F2 in the cover member 21, and is sent out from the discharge hole 23 in the rotation direction, and is included in the surroundings included at point A of the reflecting portion 11a that is reflected by being irradiated with the laser beam. Will be cooled.

  For this reason, since the movement of the air by ventilation by the fin 20 is added to the reflection part 11a besides the movement of the air surface by rotation of the reflection rotation wheel 11 alone like the past, the cooling efficiency of the reflection rotation wheel 11 can be improved. For this reason, in the image projection apparatus 100, a stable reflected light output can be obtained, the color performance can be stabilized, and the life of the apparatus can be extended.

  As shown in FIG. 4A and FIG. 4B, the back surface 11 </ b> B is located on the opposite side (motor 10 side) to the front surface 11 </ b> A having the plurality of fins 20, and becomes the second surface of the reflective rotating wheel 11. Is provided with a ring-shaped heat-dissipation convex portion 24 serving as a heat-dissipating portion that increases the surface area of the second surface. In this embodiment, the heat radiation convex part 24 is made of the same material as that of the reflective rotary wheel 11 and is formed integrally with the reflective rotary wheel 11.

  This heat radiating convex part 24 protrudes toward the direction of the motor 10 from the back surface 11B so that the area | region (width) of the reflection part 11a of the reflective rotation wheel 11 in the back surface 11B side may be located in an own area | region (width). In addition, the air contact area (surface area) of the reflective rotating wheel 11 on the back surface 11B side is increased.

  For this reason, the reflection rotating wheel 11 is configured so as to be able to release the heat generated in the reflecting portion 11a to the surroundings from the heat radiating convex portion 24 with the rotation thereof. That is, on the back surface 11B located on the opposite side to the front surface 11A on which the reflecting portion 11a of the reflecting rotating wheel 11 is formed, a heat dissipating portion for cooling the reflecting portion 11a and the reflecting rotating wheel 11 is disposed. . Therefore, the cooling of the reflecting portion 11a is mainly cooled by the heat radiation from the heat radiating convex portion 24 and the entire reflecting rotating wheel 11, and the vicinity of the point A in the reflecting portion 11a is always discharged from the discharge hole 23 while the motor 10 is rotating. Can be cooled by air flow. That is, as the drive motor 10 rotates, the compressed air collected around the rotation center of the reflection rotating wheel 11 and sucked into the suction port 22 is directed toward the reflection portion 11 a of the reflection rotation wheel 11 inside the cover member 21. It is blown and the surface temperature of the reflection part 11a can be lowered.

  With reference to FIGS. 5, 6A, and 6B, another formation of the cover member and the emission portion provided in the reflection and wavelength conversion portion will be described. The configuration of the reflection / wavelength converter shown in FIGS. 5, 6 (a), and 6 (b) is basically the same as that of the wavelength converter shown in FIGS. 2, 3 (a), and 3 (b). The configuration is similar to the configuration. The difference between the two is that, in the configurations shown in FIGS. 5, 6A, and 6B, the shape of the cover member and the discharge portion that discharges air in the cover toward a specific portion of the reflection portion 11a. The installation form of the discharge hole is different. For this reason, the cover member of the present embodiment is given the reference numeral 121, the discharge hole is given the reference numeral 123, and is distinguished from the cover member 21 and the discharge hole 23 described above. The reference numerals and descriptions used in FIGS. 2, 3A, and 3B are used.

  In FIG. 5, FIG. 6 (a), FIG. 6 (b), a cover member 121 is provided at the rotation center O of the reflection rotating plate wheel 11 and the reflection portion 11a so as to cover the entire fins 20. The cover member 121 has a bottomed cylindrical shape, and a suction port 22 serving as an introduction portion for introducing air from the outside of the cover into the cover member is positioned on the extended line of the rotation center O of the reflective rotating plate wheel 11. The bottom surface 121a is formed so as to penetrate the motor 10 in the axial direction. The cover member 121 has a discharge hole 123 serving as a discharge portion that discharges air in the cover toward a specific portion of the reflection portion 11a.

  As shown in FIGS. 5 and 6B, the specific portion of the reflecting portion 11a is a point A that is reflected by being irradiated with a laser beam. The discharge hole 123 is formed in the wall surface 121b positioned in the radial direction of the cover member 121 so that the air is directed to the point A. That is, the discharge hole 123 faces a point A which is a specific part in the reflection part 11a so that the vicinity of the reflection part of the laser beam from the light source 1 in the reflection part 11a can be cooled in a concentrated manner. The cover member 121 is formed on the reflection rotating plate wheel 11 so that the point A is located in the air discharge region B.

  In this embodiment, the discharge port 123 is formed to penetrate the wall surface 121b in the radial direction so that the point A is located in the air discharge region B, and from the direction of the rotation center O of the reflective rotating plate wheel 11. It is set as the structure which blows air to A point.

  With such a configuration, when the motor 10 rotates, as shown in FIG. 6B, air from the outside is sucked into the suction port 22 as an air flow F inside the cover member 121 with the rotation. . The air sucked from the suction port 22 becomes an air flow F1 due to the curved shape of each fin 20 and is guided to the reflecting portion 11a, so that the reflecting portion 11a and the reflecting rotating wheel 11 are cooled. The air flowing toward the reflecting portion 11a becomes an air flow F2 in the cover member 121, is emitted outward from the discharge hole 123, and is surrounded by a point A of the reflecting portion 11a that is reflected by being irradiated with a laser beam. Will be cooled.

  For this reason, since the movement of the air by ventilation by the fin 20 is added to the reflection part 11a besides the movement of the air surface by rotation of the reflection rotation wheel 11 alone like the past, the cooling efficiency of the reflection rotation wheel 11 can be improved. For this reason, in the image projection apparatus 100, a stable reflected light output can be obtained, the color performance can be stabilized, and the life of the apparatus can be extended.

  In the form shown in FIG. 4, the heat radiating portion formed on the back surface 11 </ b> B of the reflective rotating wheel 11 has a ring shape, but is not limited to such a shape, for example, as shown in FIG. The ring-shaped heat radiation portions 24 may be arranged in multiples (here, double) having the same center so as to protrude from 11B to the motor 10 side. If the rotation of the reflective rotating wheel 11 is not hindered, as shown in FIG. 7 (b), it may be a heat dissipating part 124 having a discontinuous pin shape so as to protrude from the back surface 11B to the motor 10, Or as shown in FIG.7 (c), you may comprise as the intermittent rib-shaped thermal radiation part 224 so that it may protrude from the back surface 11B to the motor 10 side.

1, 4, 15 Light source 10 Driving means 11 Rotating reflecting member 11a Reflecting portion 20 Guide portion (convex fin)
21, 121 Cover member 22 Introduction part 23, 123 Emission part 24, 124, 224 Heat radiation part 100 Image projection apparatus O Rotation center of the rotating reflecting member

Japanese Patent No. 472568 Japanese Patent No. 4636212 Japanese Patent No. 4720956

Claims (7)

A light source of a plurality of colors, and a rotary reflecting member that modulates the frequency by irradiating a light beam from the light source of one color among the plurality of light sources onto a ring-shaped reflection unit made of a reflective material;
Drive means for rotating the rotary reflecting member;
The rotating reflection member includes a guide unit that is disposed between the rotation center of the rotation reflection member and the reflection unit and guides air generated when the driving unit rotates during image generation to the reflection unit. An image projection apparatus characterized by the above.   The image projection apparatus according to claim 1, wherein the guide member is a convex fin that extends radially from the rotation center of the rotation reflection member toward the reflection portion on the rotation reflection member.   The image projection apparatus according to claim 1, further comprising a cover member that covers a guide portion provided on the rotary reflection member.   The cover member is formed on an extension line of the rotation center of the rotary reflection member, and an introduction portion that introduces air into the cover from the outside of the cover, and a discharge portion that discharges air in the cover toward the reflection portion. The image projection apparatus according to claim 3, further comprising:   The rotation reflecting member is plate-shaped, and has a heat radiating portion having an increased surface area on a second surface located on the opposite side of the first surface having the guide portion. .   6. The image projection apparatus according to claim 5, wherein the heat radiating portion is made of the same material as the rotary reflecting member and is formed integrally with the rotary reflecting member.   The image projection device according to claim 5, wherein the heat radiating portion is formed in a ring shape protruding from the second surface, a discontinuous pin shape, or a rib house shape.

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