JP4941704B2 - Light source device and projector - Google Patents

Description

  The present invention relates to a light source device and a projector including the light source device.

  Today, data projectors are widely used as image projection apparatuses that project screen display images, video images, and the like of personal computers onto a screen. This projector uses a high-intensity light source, and a lamp unit in which a concave reflecting mirror as a reflector is attached to a small high-intensity discharge lamp such as a metal highland lamp or an ultra-high pressure mercury lamp is incorporated in the projector as a projector light source device. There are many cases.

  In this light source device, a device using a spheroid reflector is often used. A high-intensity discharge lamp is installed at the elliptical focal point of the reflector, and light emitted toward the front and rear is transmitted to the spheroid. The light is reflected by a surface reflector and condensed on a light guide device such as a light tunnel or a light guide rod. In addition to the spheroid reflector, a parabolic or aspheric reflector is also frequently used.

  The light from the light source device incorporating a high-intensity discharge lamp such as an ultra-high pressure mercury lamp is composed of a red filter, a green filter, and a blue filter, and is red using a color wheel that rotates at a rotation speed of 120 times per second, The green, blue light is passed through the light guide device after passing through the light guide device and the like, and is then condensed by a lens onto a micromirror display element generally called DMD. A color image is displayed on the screen according to the amount of light in the on state reflected toward the projection port.

  Here, DMD means that a minute mirror cell is swung by a control signal, the direction of reflected light is controlled, and the light incident on the display element is reflected by the light source side optical system in the direction of the projection lens which is the projection side optical system. The on-state light and the off-state light reflected in the direction of the light absorbing plate are used, and the color image is projected onto the screen by controlling the time during which the red, green, and blue light is turned on.

In recent years, the size of projectors has been reduced, and the light source device disposed inside the small projector has also been reduced in size. For this reason, it has been proposed to use a light emitting diode instead of a discharge lamp as a light source of the light source device as described above. For example, Japanese Patent Laying-Open No. 2005-283817 (Patent Document 1) proposes an invention in which a light emitting diode is arranged at the elliptical focal point of a semi-elliptical spherical reflector centered on the optical axis.
JP 2005-283817 A

  However, in a light source device using a light emitting diode as a conventional light source, the size of the light source device can be reduced. However, the brightness of the projected image is low because the light emitting diode alone has a lower luminance than the discharge lamp. It was a problem. Also, a proposal has been made to increase the luminance by using a plurality of light emitting diodes. However, when a plurality of light emitting diodes are used in this way, light beams from a plurality of bright spots are efficiently combined into a light guide device. There was a problem that it was difficult to collect light.

The present invention has been made in view of the problems of the prior art as described above, even when a plurality of different emitters emission colors as a light source, the efficiency of light beams from a plurality of bright points It is intended light source device capable of Ku condensing, and to provide a projector using the light source device.

A light source device of the present invention includes a light source, a reflector, and a condensing lens, the light source is composed of a plurality of different light emitters emission colors Rutotomoni, different light emitters of the emission color the reflector Are arranged in the order of the emission wavelength along the rotation center axis of
The condensing lens refracts light bundles emitted from a plurality of light emitters having different emission colors and reflected by the reflector to collect light so as to reduce an angle difference of the light bundles for each color. And

Further, the emission color different emitters, in order from the longest emission wavelength, is inside or al placed distant reflector from the condenser lens, the condenser lens, the exit surface has a concave surface of revolution Is desirable.
In that case, the condensing lens condenses so as to reduce the angle formed with the optical axis.
The illuminants of different emission colors are arranged in order from the longest emission wavelength from the inside of the reflector farther from the condensing lens, and the condensing lens has an exit surface having a concave rotating surface. Also good.
The condensing lens may have an incident surface perpendicular to the rotation center axis of the reflector.
The condensing lens may have a shape having a rotation center axis whose radial cross section is triangular.
The light emitter may be a red light emitting diode, a green light emitting diode, or a blue light emitting diode.
There may be a case where any or all of the light emitters having different light emission colors are used.

Furthermore, the reflector is a rotational ellipsoid shape, it is desirable that emission of green are arranged in the vicinity of the focal point of the reflector.
Further, the reflexology data及 beauty the condensing lens may be a full rotation, or semi-rotary member having a common axis of rotation.
A plurality of light emitters having different emission colors may be arranged in an annular shape around the central axis of rotation of the reflector and the condenser lens.

The projector of the present invention includes a light source device, a light source side optical system, a display element that generates a projection image, a projection side optical system that projects the projection image, and projector control means, and the light source side optical system Includes a light guide device, a light source side lens group, and a reflection mirror, and the light source device is any one of the light source devices described above .

The reflector and the condensing lens may be a semi-rotary body having a common rotation axis, and the rotation axis may be arranged to intersect the optical axis of the light guide device.
The reflector and the condensing lens may be a full-rotary body having a rotation center axis that coincides with the optical axis of the light guide device .

According to the present invention, even when a plurality of different emitters emission colors as a light source, a plurality of possible source device be efficiently good Ku condensing the light beam from the bright points, and the light source device The projector used can be provided.

  The projector 100 according to the best mode for carrying out the present invention includes a light source device 210, a light source side optical system 220, a display element 230 that generates a projection image, a projection side optical system 250 that projects the projection image, and a projector. The light source side optical system 220 includes a light guide device 224, a light source side lens group 226, and a mirror 228.

The light source device 210 includes a light source 211, a reflector 212, and a condenser lens 215. The light source 211 is composed of a plurality of light emitters having different emission colors, and the reflector 212 is a semi-elliptical spherical surface having one opening. a shape, a condenser lens 215 is for radial section has a rotation center axis in the shape that is triangular.

  The light source 211 includes light emitters having different emission colors in order of wavelength along the rotation center axis of the reflector 212. The light emitters are a red light emitting diode 211R, a green light emitting diode 211G, and a blue light emitting diode 211B. is there. The green light emitting diode 211G is disposed near the focal position of the reflector, the red light emitting diode 211R is disposed inside the focal position of the reflector 212, and the blue light emitting diode 211B is disposed on the exit side from the focal position of the reflector 212. It is.

  According to this best mode, even when a plurality of light emitting diodes are used as a light source, it is possible to efficiently synthesize light beams from a plurality of bright spots and collect a large amount of light on the light guide device. A light source device and a projector using the light source device can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The projector according to the present invention has a built-in microcomputer as a projector control means, and has a projection port 123 having a lens cover 121 on the front panel 120 of a case that is a substantially rectangular parallelepiped as shown in FIG. On the top panel 110 of the case are keys and indicators such as a power switch 111, manual image quality adjustment key 113, automatic image quality adjustment key 114, power lamp indicator 112, light source lamp indicator 115, overheat indicator 116, and speaker inside. It has a loudspeaker hole 118 and an open / close lid 119, and a back panel (not shown) has various signal input terminals such as a power connector, a USB terminal connected to a personal computer, a video terminal for inputting image signals, and a mini D-sub terminal. A projector 100 having

  The upper lid 119 has subkeys for fine adjustment of image quality and image and various operation settings of the projector 100. An intake port is provided on the left side panel of the case and an exhaust port is provided on the right side panel 140. A port 145 is provided and has a cooling fan inside.

  In addition, the front panel 170 has a forefoot member 170 that can adjust the amount of protrusion at the front of the bottom panel, and a fixed rear foot member 175 at the rear left and right of the bottom panel. By changing the front height of the projector 100, it is possible to project an image according to the height of the screen.

  In the projector 100, as shown in FIG. 2, a light source 211 such as a light emitting diode is disposed inside the reflector 212, and includes a light source device 210 having a condenser lens 215, and a light source side optical system 220. A color wheel 221, a light guide device 224, and a plurality of light source side lens groups 226 and one mirror 228 as an illumination side optical system.

  Further, an image is displayed by controlling the reflection of incident light by arranging a plurality of pixels in a matrix in a row direction and a column direction, and a circuit board 180 on which a lamp power supply circuit 187 and a projector control means 181 are attached. The projector 100 incorporates a display element 230 and a fixed lens group 253 and a movable lens group 255, which are projection-side optical systems 250 that project light emitted from the display element 230 onto a projection surface such as a screen.

  The circuit board 180 is provided with a projector control means 181 by a microcomputer. The projector control means 181 controls the operation of each circuit in the projector. When the power switch 111 is turned on, the light source device 210 The light source 211 is turned on, and the cooling fan 190 is driven at a rated speed according to the output of the light source 211 and the fan shape and arrangement of the cooling fan 190, and outside air is taken in from the intake port 155 of the left side panel 150, and the right side panel The projector 100 is put into a standby state while the internal air is discharged from the 140 exhaust ports 145.

  When the power switch 111 is turned off, the light source 211 is turned off, and the cooling fan 190 is continuously driven for a predetermined time of about several minutes by a timer to cool the projector 100 and then stop all operations. It also performs control such as making it happen.

  The display element 230 is a display element 230 having no means for coloring incident light such as a color filter. In this embodiment, a micromirror display element 230 generally abbreviated as DMD (Digital Micromirror Device) is used. ing.

  This micromirror display element 230 converts light incident from an incident direction inclined in one direction with respect to the front direction, by switching the on-state light beam in the front direction and off in the oblique direction by switching the inclination direction of the plurality of micromirrors. The image is displayed by being reflected separately from the state light beam, and the light incident on the micromirror tilted in one tilt direction is turned into the on-state light beam reflected in the front direction by this micromirror, and the other tilt The light incident on the micromirror tilted in the direction is reflected in an oblique direction by this micromirror to make off-state light, and this off-state light is absorbed by the light-absorbing plate, and bright display by reflection in the front direction, An image is displayed by dark display by reflection in an oblique direction.

  As shown in FIG. 3, the light source device 210 includes a light source 211 composed of a plurality of light emitters having different emission colors, a reflector 212, and a condenser lens 215. This light emitter is composed of a red light emitting diode 211R, a green light emitting diode 211G, and a blue light emitting diode 211B.

  The reflector 212 has a semi-elliptical spherical shape in which an ellipse is half-rotated about the rotation center axis. The reflector 212 has a reflection film on the inner surface and has an exit port by opening one end. In the light source 211, light emitters having different emission colors are arranged in the order of the emission wavelengths along the rotation center axis of the reflector 212. Specifically, the green light emitting diode 211G is arranged at the focal point of the reflector 212, and the red light emitting diode. 211R is disposed on the inside of the reflector 212 from the position of the green light emitting diode 211G, and the blue light emitting diode 211B is disposed on the opening side of the reflector 212 from the position of the green light emitting diode 211G.

  The condensing lens 215 is disposed in the vicinity of the exit of the reflector 212, has a cross section of a substantially right triangular shape located on the rotation center axis, and a radial section that is half-rotated by the rotation center axis. It is a right-angled triangular half-rotator. Further, the oblique side surface is arranged so as to come to the injection port side of the reflector 212. The condensing lens 215 refracts the light beam emitted and diffused from different bright spots at the incident surface to reduce the angle formed with the optical axis, and further refracts the light beam at the output surface to further reduce the angle formed with the optical axis. The condensed light bundle is emitted and then incident on the light guide device 224.

That is, the condensing lens 215 is made of a translucent material such as glass or resin like a prism. In this condensing lens 215, since the refractive index sequentially increases in the order of red light, green light, and blue light whose emission wavelengths become shorter , as shown in FIG. 4, the green light emitter is placed at the focal position of the reflector 212. The red light emitter is placed inside the focal position of the reflector 212, and the blue light emitter is placed closer to the opening than the focal position of the reflector 212. The reflected light of the reflector 212 in blue light is relative to the rotation center axis. Even if the reflected light of the reflector 212 in the red light is reflected with the smallest crossing with respect to the rotation center axis, the blue light whose reflection light largely intersects with the rotation center axis is refracted greatly to greatly refract the blue light. Can be made smaller and the angle difference between the red light, green light, and blue light intersecting with the rotation center axis can be made smaller and incident on the light guide device 224.

  In this way, the light emitted from the light emitting diodes 211R, 211G, and 211B of each color is reflected by the reflecting surface of the reflector 212 and incident on the incident surface of the condenser lens 215, and then refracted by the condenser lens 215 and emitted. Light bundles emitted from the surface are emitted as light bundles, and the light bundles condensed by the condenser lens can be emitted to the light guide device 224 disposed on the optical axis.

  Further, as shown in FIG. 5, the light source device 210 is disposed to be inclined with respect to the bottom surface of the projector 100, and the rotation axes of the reflector 212 and the condenser lens 215 are inclined so as to intersect with the optical axis of the light guide device 224. The light guide device 224 is directed toward the incident side end. By arranging the rotation axis in such a manner, the space in the housing of the projector 100 can be used efficiently, and more light beams can be emitted so as to enter the light guide device 224.

  The light emitting diodes 211R, 211g, and 211b that are the light sources 211 of the light source device 210 are time-division controlled by the projector control unit 181 so that the light emitting diodes 211R, 211g, and 211b of the respective colors blink according to the projection image. By individually controlling, the light fluxes of the respective colors are emitted to the display element 230 at different times.

  In a conventional projector, a discharge lamp or the like that emits only white light is used as a light source. Therefore, it is necessary to color light with a color wheel or the like. In this embodiment, each color that emits red, green, and blue light is emitted. Since the light emitting diode is used, the display element can be irradiated with the three primary colors of light without coloring the light with a color wheel or the like, and thus a projection image can be provided without the color wheel.

  Further, the light source side optical system 220 that makes the light bundle condensed by the light source device 210 enter the micromirror display element 230 includes a color wheel 221, a light guide device 224, a light source side lens group 226 that is a plurality of lenses, and The mirror 228. The color wheel 221 has a thin disk shape and has red, green, and blue color filters on a plane. The color wheel 221 is emitted from the light source 211. This is to increase the color purity of light in red light, green light, and blue light.

  Furthermore, the light guide device 224 is disposed at a position where the incident surface faces the emission side of the color wheel 221 and emits light incident from the incident surface as light having a uniform intensity distribution from the emission surface.

  The mirror 228 of the light source side optical system 220 reflects the light emitted from the light source device 210 and transmitted through the light guide device 224 and the light source side lens group 226 toward the micromirror display element 230, thereby displaying a micromirror. Light is projected onto the element 230 from a direction inclined in one direction with respect to the front direction.

  The projection-side optical system 250 includes a fixed lens barrel that contains a fixed lens group 253, and a movable lens group 255 that is engaged with the fixed lens barrel and that can move forward and backward in the axial direction by a rotating operation. The projection-side optical system 250 includes a lens barrel and forms a zoom lens by a combination of a plurality of lenses incorporated in these lens barrels.

  In this way, the projector 100 emits light of each color of the light source device 210 in one direction, makes light incident on the light source side optical system 220 from the light source device 210 uniform by the light guide device 224, The light source side optical system 220 can project toward the micromirror display element 230 by the lens and the mirror 228.

  Then, the light emitted from the light source 211 of the light source device 210 sequentially writes single-color image data of each color on the micromirror display element 230, so that the micromirror is reflected by the on-state light beam reflected in the front direction of the micromirror display element 230. A single-color image of each color is sequentially formed on the display element 230, and the single-color image light of each color sequentially emitted from the micromirror display element 230 is enlarged by the lens groups 253 and 255 of the projection-side optical system 250 and projected onto the projection surface In this case, a full-color image in which three-color single-color images of the respective colors are superimposed is displayed on the projection surface.

  In the light source device used in the conventional projector, only one high-intensity discharge lamp is installed at the focal point of the reflector. However, since the light source device using the light emitting diode uses a plurality of light sources, it is out of focus. It is necessary to install a light source at the position, so that the light beam emitted to the light guide device diffuses, and a lot of useless light that cannot enter the light guide device is generated.

However, by using the light source device 210 of the present embodiment, the light beam emitted from the reflector 212 in a diffused state because it is emitted from a plurality of light emitting diodes is converted into a light guide device 224 as a condensed light beam. Since the light can be emitted, the light from the light source 211 can be used without waste, and as a result, a projection image with high luminance can be provided.
Further, since the reflector 212 has a semi-elliptical spherical shape, the light source device 210 as a whole is thin and can be easily accommodated in the thin projector 100.

  In addition, unlike a discharge lamp used as a light source in the past, a light emitting diode emits light in a substantially constant direction. Therefore, unlike a conventional discharge lamp, light is not emitted in all directions. However, it is possible to provide a sufficient amount of light, and unlike the discharge lamp, since the temperature does not become high, the projector 100 can be made smaller.

  Furthermore, since the light is collected by the condenser lens 215, the area of the entrance of the light guide device 224 can be made small, and the light irradiated to the micromirror display element can also be made a useless beam bundle. it can.

  In the light source device 210 described above, the reflector 212 has a semi-elliptical spherical shape, but may have a semi-rotating parabolic shape. When such a paraboloidal reflector 212 is used, convergent light can be obtained by arranging a plurality of light emitters on the outer side of the reflector 21 from the focal position. Then, the condensing lens 215 is disposed in the vicinity of the opening of the rotary parabolic reflector 212, and the red, green, and blue light emitters are disposed along the rotation center axis of the reflector 21. Thus, even if the incident surface of the subsequent light guide device 224 is formed small, it can be condensed.

  Further, as the spheroid shape of the reflector, an aspherical shape obtained by correcting the ellipse shape of the spheroid shape in order to draw out the characteristics of the light source can be used. Since this aspherical reflector has an excellent function of condensing the light emitted from the light source onto the light guide device, compared to a normal spheroidal reflector, it can project a projected image with higher brightness. It becomes like this.

  In the light source device 210 described above, the reflector 212 has a semi-elliptical spherical shape. However, as shown in FIG. 6, the reflector 212 may have an elliptical spherical shape that is rotated once around the optical axis. In this case, the condensing lens 215 is also an all-rotary body, and the optical axes of the reflector 212, the condensing lens 215, and the light guide device 224 are all the same. By using such a reflector 212 and a condensing lens 215, it becomes possible to arrange more light sources 211 than those of the above-described half-rotating body inside the reflector 212, and a projector capable of projecting a high-brightness projection image Can be provided.

  In addition, since a light emitting diode is used as the light emitter of the light source 211, a projector thinner than the conventional projector can be provided. Note that the amount of light incident on the light guide device 224 is greater for all rotating body reflectors and condensing lenses, so that the entire rotating body is superior in terms of brightness of the projected image. The light source device 210 using a reflector of a rotating body or a condensing lens is superior in terms of thinning the projector.

  In the figure, the light source 211 is arranged in red, blue, and green one by one. However, a plurality of light emitting diodes can be provided to provide a projected image with higher brightness. For example, a plurality of light emitting diodes can be arranged in a ring around the rotation center axis. By laying a plurality of light emitting diodes in this way, the function of the condenser lens 215 of this embodiment can be further utilized.

  By arranging a plurality of light emitting diodes in this way, the brightness of each color is also increased, and not only when the color purity is increased using a color wheel but also without using a color wheel, red light, blue The display element can be irradiated with light or green light, and when the color wheel is not used, the projector can be further miniaturized.

In the light source device 210 described above, the long- wavelength light emitters are arranged inside the reflector, and the short- wavelength light emitters are arranged near the opening of the reflector. On the contrary, as shown in FIG. It is also possible to arrange the short wavelength inside the reflector and the long wavelength near the opening of the reflector.

  In this way, the condensing lens 215 in the case of arranging the light emitter as the light source 211 is arranged on the optical axis with the bottom of a substantially right triangle having a radial cross section as the rotation center axis, and the opposite side is on the exit side of the reflector 212. The rotating body is arranged. Also in this case, similar to the light source device 210 described above, it is possible to emit a bundle of light rays collected at the entrance of the light guide device 224. As the reflector 212, an aspherical shape obtained by correcting a curved surface such as a spheroid shape, a paraboloid shape, or a spheroid shape can be used.

  In addition, although the condensing lens 215 described so far uses a substantially right-angled triangular cross section, depending on the distance from the light guide device and the distance from the reflector 212, the radial cross section may be an isosceles triangle. Other triangular shapes are also possible.

  The present invention is not limited to the embodiments described above, and can be freely changed and improved without departing from the gist of the invention.

1 is a perspective view of a projector according to one embodiment of the present invention. Explanatory drawing of the internal structure of the projector of one Example of this invention. The perspective view of the light source device of one Example of this invention. Sectional drawing of the light source device of one Example of this invention. FIG. 3 is an explanatory diagram illustrating an arrangement of a light source device according to an embodiment of the present invention in a projector. Sectional drawing of the light source device of the other Example of this invention. Sectional drawing of the light source device of another Example of this invention.

Explanation of symbols

100 Projector 110 Top panel
111 Power switch 112 Power lamp indicator
113 Manual image quality adjustment key 114 Automatic image quality adjustment key
115 Light source lamp indicator 116 Heating indicator
118 Loudspeaker 119 Open / close lid
120 Front panel 121 Lens cover
123 Projection port 130 Rear panel
140 Right side panel 145 Exhaust port
150 Left side panel 155 Air intake
160 Bottom panel 170 Forefoot member
175 Rear foot member 180 Circuit board
181 Projector control means 187 Lamp power circuit
190 Cooling fan 210 Light source device
211 Light emitting diode 211R Red light emitting diode
211G Green light emitting diode 211B Blue light emitting diode
212 Reflector 215 Condenser lens
220 Light source side optical system 221 Color wheel
224 Light guide device 226 Light source side lens group
228 Mirror 230 Micro mirror display element
250 Projection-side optics 253 Fixed lens group
255 Movable lens group

Claims (15)

A light source, a reflector, and a condenser lens;
The light source is composed of a plurality of light emitters having different emission colors, and the plurality of light emitters having different emission colors are arranged in the order of emission wavelengths along the rotation center axis of the reflector,
The condensing lens has a rotation center axis that is the same as the rotation center axis of the reflector, and refracts a light beam emitted from a plurality of light emitters having different emission colors and reflected by the reflector, for each color. light source and wherein the output surface for condensing so as to reduce the mutual angular difference between light beams has a conical shape that is not parallel to the incident plane. The light source device according to claim 1, wherein the condenser lens has a shape in which an emission surface has a concave surface or a convex rotation surface. The illuminants with different emission colors are arranged from the inside of the reflector farther from the condenser lens in order from the longer emission wavelength,
The condenser lens, the light source apparatus according to claim 1 or claim 2 exit surface and having a concave surface of revolution. The condenser lens, the light source apparatus according to claim 1 or claim 2, characterized in that a shape for condensing so as to reduce the angle between the optical axis. The illuminants with different emission colors are arranged from the inside of the reflector farther from the condenser lens, in order from the shortest emission wavelength,
The condenser lens, the light source apparatus according to claim 1 or claim 2 exit surface and having a plane of rotation of the convex surface. The condenser lens, the light source device according to any one of claims 1 to 5 incident surface, characterized in that it is perpendicular to the rotational center axis of the reflector. The condenser lens, the light source device according to any one of claims 1 to 6 radial cross section, characterized in that a shape having a rotation center axis that is triangular. The light emitter is a red light emitting diode, a green light emitting diode, the light source device according to any one of claims 1 to 7, characterized in that a blue light-emitting diode. The light source device according to any one of claims 1 to 8, characterized in that any or all of the different light emitters of the light-emitting color is plural. Wherein a reflector is a rotational ellipsoid shape, a light source device according to any one of claims 1 to 9 green luminous body, characterized in that it is arranged in the vicinity of the focal point of the reflector. The light source device according to any one of claims 1 to 10 , wherein the reflector and the condenser lens are a full-rotation body or a half-rotation body having a common rotation axis. A luminous body a plurality of different light emitting colors, according to any one of claims 1 to 11, characterized in that it is arranged annularly around the rotational center axis of the reflector and the converging lens Light source device. A light source device;
A light source side optical system;
A display element for generating a projection image;
A projection-side optical system that projects a projection image;
Projector control means,
The light source side optical system includes a light guide device, a light source side lens group, and a reflection mirror,
The light source device
A projector comprising the light source device according to any one of claims 1 to 12 . The reflector and the converging lens is a semi-rotary member having a common axis of rotation, according to claim 13, characterized in that the rotary shaft is arranged so as to intersect with the optical axis of the light guide device Projector. The projector according to claim 13 , wherein the reflector and the condenser lens are all rotating bodies having a rotation center axis coinciding with an optical axis of the light guide device.

Images