JP4998785B2 - 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.

  2. Description of the Related Art Today, data projectors that project an image displayed on a personal computer screen, an image of a video signal, an image based on image data stored in a memory card or the like onto a screen are widely used.

  In many cases, a data projector uses a light source device including a small high-intensity light source lamp such as a metal highland lamp or an ultra-high pressure mercury lamp, and uses light emitted from the light source device as light of three primary colors by a color filter. A display element called a liquid crystal or a DMD (digital micromirror device) is irradiated by a side optical system, and the transmitted light or reflected light of the display element is passed through a lens group which is a projection side optical system having a zoom function. The structure is projected onto the screen.

  In recent years, such projectors have been reduced in size and thickness, and light source devices have been used in small sizes. However, a small light source device has a smaller amount of light than a large light source device, and can reduce the brightness of a projected image. In order to increase the efficiency, it is necessary to increase the utilization efficiency of light emitted from the light source device.

  A general light source device is formed of a light source lamp such as an ultra-high pressure mercury lamp and a reflector for condensing light emitted from the light source lamp. As the shape of this reflector, there are a spheroid shape and a rotary parabolic shape, and many spheroid shapes are used for small light source devices.

  This spheroidal reflector has a feature that when a light source lamp is installed at one focal point and light is emitted toward the reflector, the light converges at the other focal point. By arranging a light guide device such as a rod, most of the light from the light source lamp enters the integrator rod to make the intensity of the light beam uniform, and various optical systems arranged after the light guide device And a light flux with high utilization efficiency in display elements such as DMD.

  However, since the size of the reflector is small in a small light source device, there are many lights that are emitted directly from the light source lamp without irradiating the reflector. Since the light does not enter the light guide device, a lot of unnecessary light is generated.

Therefore, in Japanese Patent Application Laid-Open No. 6-5401 (Patent Document 1), a donut lens is installed in the vicinity of the exit of the reflector, and the light emitted from the light source lamp and directly emitted to the outside without being irradiated on the reflector is reflected in the donut. Proposals have been made to converge on the subject using a lens. According to the invention of this patent document 1, since the utilization efficiency of the light emitted from the light source lamp is increased, it is possible to provide a high-luminance projection image even in a small light source device.
Japanese Patent Laid-Open No. 6-5401

  In the conventional light source device as described above, the amount of light incident on the light guide device in the light emitted from the light source lamp can be increased, but the angle formed with the optical axis in the light incident on the light guide device is There is a problem that there is a large amount of large light, and light having such a large angle with the optical axis is incident on the light guide device, but cannot be used in various optical systems thereafter and becomes unnecessary light.

  The present invention has been made in view of the above-described problems of the prior art, and has a high use efficiency of light emitted from a light source lamp, and a light source device that emits light close to parallel to the optical axis and the light source. It aims at providing the projector provided with the apparatus.

The light source device of the present invention is disposed in the vicinity of the exit of the reflector incorporating the light source lamp, and reflects the light emitted from the exit with the optical axis of the reflector as the rotation center axis, in the direction of the rotation center, A condensing device having a second reflecting surface that reflects light reflected by the first reflecting surface in the direction along the rotation center axis with the optical axis as a rotation center axis inside the first reflection surface ; The first reflecting surface is frustoconical, the second reflecting surface is conical, and the angle that intersects the optical axis of the first reflecting surface is greater than the angle that intersects the optical axis of the second reflecting surface, The reflector has a paraboloid shape or a spheroid shape, and the light source lamp is arranged behind the focal position of the reflector .

  The condensing device is a truncated cone-shaped rotator prism having a conical cut-out recess at the center of the bottom surface of the truncated cone, the outer peripheral side surface of the rotator prism as the first reflecting surface, and the side surface of the cut-out recess The second reflecting surface is used.

  The condensing device includes a first reflecting mirror having a truncated cone shape and a second reflecting mirror having a conical shape arranged inside the first reflecting mirror.

The projector of the present invention, comprising a light source device, a color wheel, a light guide device, a light source side optical system, a display device, a projection side optical system, a cooling fan, and a projector control unit, the It is characterized by this.

  ADVANTAGE OF THE INVENTION According to this invention, the utilization efficiency of the light inject | emitted from a light source lamp is high, and the light source device which inject | emits the light close | similar to an optical axis, and a projector provided with this light source device can be provided.

  The projector 1 of the best mode for carrying out the present invention includes a light source device 61, a color wheel 85, a light guide device 81, a light source side optical system 70, a display element 51, a projection side optical system 90, A cooling fan 111 and projector control means 101 are provided.

  This light source device 61 is disposed in the vicinity of the exit port 66 of the spheroid reflector 63 incorporating the light source lamp 62, and rotates the light emitted from the exit port 66 with the optical axis X of the reflector 63 as the rotation center axis. A first reflecting surface 77 that reflects in the direction, and a light that is reflected on the inner side of the first reflecting surface 77 by the first reflecting surface 77 with the optical axis X as the rotation center axis, in a direction along the rotation center axis. A light collecting device having two reflecting surfaces 78 is provided.

  The condensing device 64 is a truncated cone-shaped rotator prism having a conical cut-out recess at the center of the bottom surface of the truncated cone, the outer peripheral side surface of the rotator prism being a first reflecting surface, The side surface of the recess is the second reflecting surface.

  The angle at which the first reflecting surface 77 intersects with the optical axis X is larger than the angle at which the second reflecting surface 78 intersects with the optical axis X, the reflector 63 has a paraboloid shape or the light source lamp is the focal point of the reflector. It is arrange | positioned back rather than a position, It is characterized by the above-mentioned.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The projector 1 according to the present invention has a built-in control circuit as projector control means, and has a projection port 93 provided with a lens cover 92 on the front plate 3 of the case which is a substantially rectangular parallelepiped as shown in FIG. On the top plate 2 of the case, a key as a power switch 10, a manual image quality adjustment key 12, an automatic image quality adjustment key 13, a power lamp indicator 11, a light source lamp indicator 14, a key and indicators such as an overheat indicator 15, and a speaker inside A sound expansion hole 16 disposed on the inside, and an open / close lid 17 having sub-keys for fine adjustment of image quality and image and various operation settings of the projector 1, and a back plate (not shown) connected to a power connector or a personal computer Various signal input terminals such as a terminal, a video terminal for inputting an image signal, and a mini D-sub terminal are provided.

  In addition, the left side plate of the case is formed with an intake hole, and the right side plate 5 is formed with an exhaust hole 8, and a front foot member 18 is mounted in front of the bottom plate so that the amount of protrusion can be adjusted. Is equipped with a fixed rear foot member 19 that adjusts the amount of protrusion of the front foot member 18 to change the front height of the projector 1 so that an image can be projected according to the height of the screen. is there.

  As shown in FIG. 2, the control circuit as the projector control means of the projector 1 includes a control unit 38, an input / output interface 22, an image conversion unit 23, a display encoder 24, a display drive unit 26, and the like. Thus, the image signals of various standards input from the input / output connector unit 21 are unified into image signals of a predetermined format suitable for display by the image conversion unit 23 via the input / output interface 22 and the system bus (SB). After being converted to, it is sent to the display encoder 24.

  The display encoder 24 develops and stores the transmitted image signal in the video RAM 25, generates a video signal from the stored contents of the video RAM 25, and outputs the video signal to the display drive unit 26.

  A display driving unit 26 to which a video signal is input from the display encoder 24 drives a display element 51, which is a spatial light modulation element (SOM), at an appropriate frame rate in response to an image signal sent thereto. The light from the light source device 61 is incident on the display element 51 through various optical systems, thereby forming an optical image with the reflected light of the display element 51 and not shown through a projection system lens group serving as a projection side optical system. An image is projected and displayed on a screen, and the movable lens group 97 of the projection system lens group is driven by a lens motor 45 for zoom adjustment and focus adjustment.

  The image compression / decompression unit 31 performs a recording process for sequentially writing the luminance signal and color difference signal of the image signal into a memory card 32 which is a removable recording medium by compressing the data by processing such as ADTC and Huffman coding, Reads out the image data recorded in the memory card 32, decompresses each image data constituting a series of moving images in units of one frame, sends them to the display encoder 24 via the image conversion unit 23, and stores them in the memory card 32. It is possible to display a moving image or the like based on the image data.

  The control unit 38 controls the operation of each circuit in the projector 1, and includes a ROM that stores operation programs such as a CPU and various settings in a fixed manner, a RAM that is used as a work memory, and the like. .

  An operation signal of a key / indicator unit 37 composed of a main key and an indicator provided on the upper surface plate 2 of the main body case is directly sent to the control unit 38, and a key operation signal from the remote controller is sent to the Ir receiving unit 35. And the code signal demodulated by the Ir processing unit 36 is sent to the control unit 38.

  An audio processing unit 47 is connected to the control unit 38 via a system bus (SB). The audio processing unit 47 includes a sound source circuit such as a PCM sound source, and converts the audio data into analog data in the projection mode and the playback mode. The speaker 48 can be driven to emit loud sounds.

  The control unit 38 controls the power supply control circuit 41.When the lamp switch key is operated, the power supply control circuit 41 turns on the light source lamp of the light source device, and the cooling fan drive control circuit 43 further includes: The temperature is detected by a plurality of temperature sensors provided in the light source device, etc., and the rotation speed of the cooling fan is controlled, and the rotation of the cooling fan is continued even after the lamp of the light source device is turned off by a timer, Further, depending on the result of temperature detection by the temperature sensor, control such as stopping the light source device and turning off the power of the projector main body is also performed.

  As shown in FIG. 3, a circuit board 103 having projector control means 101 and a lamp power supply circuit 102 is disposed in the vicinity of the front plate 3 in the projector 1, and in the vicinity of the exhaust hole 8 in the right plate 5. A cooling fan 111 is disposed in the vicinity of the back plate 4, and a plurality of air intake holes 9 are formed in the left side plate 6 so that outside air can be taken into the projector 1.

  In addition, a light source device 61 that is supplied with electric power from the lamp power supply circuit 102 via a lead wire 74 and includes a condensing device 64 is disposed, and light emitted from the light source device 61 is transmitted on the optical axis of the light source device 61. Multiple lens groups such as a color wheel 85 with red, green, and blue filters that color the light, a light guide device 81 that equalizes the intensity of light transmitted through the color wheel 85, and a condensing lens A light source side optical system 70 composed of the above, a reflection mirror 88 that reflects light on the display element 51, and the like are arranged.

  Further, a display element 51 that displays an image by controlling the reflection of incident light by arranging a plurality of pixels in a matrix in the row direction and the column direction at a position where the reflected light from the reflection mirror 88 is irradiated. Has been placed. Further, a projection-side optical system 90 including a fixed lens group 98 and a movable lens group 97 that project the light emitted from the display element 51 onto a projection surface such as a screen is disposed in the vicinity of the left side plate 6.

  The display element 51 is a display element 51 that does not have a means for coloring incident light such as a color filter. In this embodiment, a micromirror display element generally abbreviated as DMD (Digital Micromirror Device) is used. . The horizontal to vertical ratio of the micromirror display element is usually 4 to 3.

  The micromirror display element is configured to convert light incident from an incident direction tilted in one direction with respect to the front direction into front-state on-state rays and oblique off-state rays by switching the tilt directions of the plurality of micromirrors. The light is incident on the micromirror tilted in one tilt direction and is turned into an on-state light beam reflected in the front direction by the micromirror, and is reflected in the other tilt direction. The light incident on the tilted micromirror is reflected by the micromirror in an oblique direction to form an off-state light beam, and the off-state light beam is absorbed by the light-absorbing plate. An image is displayed by dark display by reflection on the screen.

  As shown in FIGS. 4 and 5, the light source device 61 includes a light source lamp 62, a reflector 63, and a rotating prism serving as a light condensing device 64. The light source lamp 62 is formed of a spherical light emitting portion 71 and a sealing portion formed to project at a symmetrical position on the outer surface of the light emitting portion 71 on the optical axis X passing through the center of the light emitting portion 71. The center of the light emitting portion 71 is arranged behind the focal position of the reflector 63. The sealing portion located on the front side is the first sealing portion 72, the sealing portion located on the rear side is the second sealing portion 73, and the leading ends of the first sealing portion 72 and the second sealing portion 73 A lead wire 74 for supplying electricity to the light source lamp 62 is drawn out from the section.

  When the light source lamp 62 is arranged behind the focal position in this way, the light emitted to the reflector 63 does not converge to one point, but the light emitted from the light source lamp 62 is on the inner surface of the reflector 63. Since the amount of irradiated light increases, the amount of light emitted from the exit port 66 after being reflected by the reflector 63 also increases, and the amount of light incident on the rotating prism increases.

  The reflector 63 is a rotating ellipsoidal rotating body having the optical axis X as a central axis, and the inner surface is mirror-finished to be a reflecting surface. Further, an emission port 66 for emitting light is formed in the front, and a rear opening 67 through which the second sealing portion 73 of the light source lamp 62 is inserted is formed in the rear.

  The rotating prism serving as the light concentrator 64 has a truncated cone shape, is disposed near the exit 66 of the reflector 63 incorporating the light source lamp 62, and has a conical cutout recess at the center of the bottom surface of the truncated cone. The inclined side surface of the rotator prism is the first reflecting surface 77 and the side surface of the notch recess is the second reflecting surface 78. The light axis X of the reflector 63 is emitted from the exit 66 with the frustoconical rotation center axis. The first reflecting surface 77 that reflects the reflected light in the direction of the rotation center, and the light reflected by the first reflecting surface 77 with the optical axis X as the rotation center axis inside the first reflection surface 77 is substantially parallel to the rotation center axis. A second reflecting surface 78 having a conical shape reflecting in various directions, and formed so that the angle of the first reflecting surface 77 intersects with the optical axis X is larger than the angle of the second reflecting surface 78 intersecting with the optical axis X. It is a thing.

  The rotating body prism reflects the light beam reflected from the reflector 63 and emitted from the exit port 66 toward the optical axis X direction by the first reflecting surface 77, and the light reflected by the first reflecting surface 77 is It is converted into a light bundle in a direction along the optical axis X by the two reflecting surfaces 78, and is emitted to the outside from the upper surface. The area approximates the cross-sectional area of the light guide device 81 and is almost parallel to the optical axis X. It can be a light beam.

  As shown in FIG. 3, the color wheel 85 has a thin disk shape, and has a color filter for sequentially coloring white light emitted from the light source device 61 on the plane. It is arranged to be located on the top. The center of the color wheel 85 is connected to a wheel motor 86, and the rotation is controlled by the wheel motor 86.

  The light guide device 81 has a rectangular parallelepiped shape having an entrance surface and an exit surface, and is disposed on the exit surface side of the color wheel 85 with the optical axis X of the light source device 61 as the central axis, and the intensity of the incident light bundle Is made uniform and then injected into the subsequent optical system.

  The lens group as the light source side optical system 70 is a lens that transmits the color beam 85 through the color wheel 85, collects the light beam whose intensity is uniformed by the light guide device 81, and irradiates the light beam to the reflection mirror 88. The mirror 88 projects light from the direction inclined in one direction with respect to the front direction to the display element 51 by reflecting the light beam transmitted through the light source side optical system 70 toward the display element 51. .

  The projection-side optical system 90 includes a fixed lens barrel containing a fixed lens group 98 and a movable lens group 97 which is engaged with the fixed lens barrel and can move forward and backward in the axial direction by a rotating operation. The projection-side optical system 90 includes a lens barrel and forms a zoom lens by a combination of a plurality of lenses incorporated in these lens barrels.

  As described above, the projector 1 converts the light emitted from the light source lamp 62 into a light bundle having a small cross-sectional area and being almost parallel to the optical axis X by the reflector 63 and the rotating prism, and sequentially colors the light by the color wheel 85. The intensity distribution of the colored light bundle can be made uniform by the light guide device 81, and can be projected toward the display element 51 by the light source side optical system 70 and the reflection mirror 88.

  When the light from the light source device 61 is stabilized after a predetermined time has elapsed since the power was turned on, the single color of each color is displayed on the display element 51 in synchronization with the projection period of the light of each color that has been transmitted through the color wheel 85. By sequentially writing the image data, a single color image of each color is sequentially formed on the display element 51 by the on-state light beam reflected in the front direction of the display element 51, and single color image light of each color sequentially emitted from the display element 51 is projected. The image is enlarged and projected onto the projection plane by the lens groups 97 and 98 of the side optical system 90, and a full-color image in which three color single-color images are superimposed on the projection plane is displayed.

  According to the present embodiment, the light source device 61 is provided by disposing the condensing device 64 having the first reflecting surface 77 having the truncated cone shape and the second reflecting surface 78 having the conical shape in the vicinity of the exit 66 of the reflector 63. The light beam emitted from the light beam can be converted into light nearly parallel to the optical axis X, and the cross-sectional area of the light beam can be converted to an area approximate to the cross-sectional area of the light guide path of the light guide device 81. Therefore, the crossing angle with the optical axis X is large, and because of its high diffusivity, light that becomes unnecessary light in the light source side optical system 70 and the projection side optical system 90 can be reduced, and light use efficiency can be increased. Thus, it is not necessary to use a large lens to eliminate diffused light, and a small projector can be provided.

  In addition, by using a rotating prism as the light collector 64, the light irradiated to the first reflecting surface 77 and the second reflecting surface 78 is totally reflected, so that there is little light loss and the light emitted from the light source lamp 62 is emitted. The utilization efficiency can be further increased.

  Furthermore, by making the angle intersecting the optical axis X of the first reflecting surface 77 larger than the angle intersecting the optical axis X of the second reflecting surface 78, the light emitted from the light source device 61 becomes more parallel to the optical axis X. The light can be close to.

  Further, by arranging the light source lamp 62 behind the focal point of the reflector 63, the amount of light emitted to the reflecting surface of the reflector 63 can be increased, and the amount of light incident on the rotating prism can also be increased. The utilization efficiency of the light emitted from the lamp 62 can be increased.

  In the above-described embodiment, the rotating body prism is used as the light collecting device 64. However, the first reflecting mirror having the truncated cone side surface shape and the truncated cone shape disposed inside the first reflecting mirror. It may be a second reflection mirror, and may be a curved surface having a curved rotational shape as well as the first reflecting surface 77 and the second reflecting surface having a linear rotational shape. .

  Since the same effect can be obtained by using a member other than the rotating prism as described above, the design can be easily changed, and the cost can be reduced by using an inexpensive reflecting mirror as compared with the prism.

  In addition, although the ellipsoidal reflector 63 is used, various rotating spherical reflectors 63 such as a rotating paraboloid reflector 63 and a rotating deformed ellipsoidal reflector 63 having an annular focal point are used. By using the condensing device 64, the utilization efficiency of light emitted from the light source lamp 62 can be increased.

  By using the condensing device 64 in this way, the use efficiency of the light emitted from the light source lamp 62 can be increased without being influenced by the shape of the reflector 63, the diameter of the light beam is small, and the light Since the light can be converted into light that is nearly parallel to the axis X, the degree of freedom in designing the projector 1 during the manufacturing process can be increased.

  In addition, this invention is not limited to the form of the above Example, A change and improvement are possible freely in the range which does not deviate from the summary of invention.

1 is a perspective view of a projector according to an embodiment of the invention. FIG. 3 is a control block diagram of the projector according to the embodiment of the invention. FIG. 3 is a top view of the projector according to the embodiment of the present invention with the top plate removed. The perspective view of the light source device which concerns on the Example of this invention. The figure which shows the cross section of the light source unit which concerns on the Example of this invention, and shows a light path typically.

Explanation of symbols

1 Projector 2 Top plate
3 Front plate 4 Back plate
5 Right side plate 6 Left side plate
8 Exhaust hole 9 Intake hole
10 Power switch 11 Power indicator
12 Manual image quality adjustment key 13 Automatic image quality adjustment key
14 Light source indicator 15 Overheat indicator
16 Loudspeaker 17 Open / close lid
18 Forefoot member 19 Rear foot member
21 I / O connector 22 I / O interface
23 Image converter 24 Display encoder
25 Video RAM 26 Display driver
31 Image compression / decompression unit 32 Memory card
35 Ir receiver 36 Ir processor
37 Key / Indicator section
38 Control unit 41 Power control circuit
43 Cooling fan drive control circuit 45 Lens motor
47 Audio processor 48 Speaker
51 Display element 61 Light source device
62 Light source lamp 63 Reflector
64 Concentrator 66 Outlet
67 Rear aperture 70 Light source side optical system
71 Light emitting part 72 First sealing part
73 Second sealing part 74 Lead wire
77 First reflective surface 78 Second reflective surface
81 Light guide device 85 Color wheel
86 Wheel motor 88 Reflective mirror
90 Projection-side optical system 92 Lens cover
93 Projection port 97 Movable lens group
98 Fixed lens group 101 Projector control means
102 Lamp power circuit 103 Circuit board
111 Cooling fan

Claims (4)

A first reflecting surface that is disposed near the exit of the reflector that incorporates the light source lamp, reflects the light emitted from the exit with the optical axis of the reflector as the central axis of rotation, and the inner side of the first reflective surface And a second reflecting surface that reflects light reflected by the first reflecting surface in the direction along the rotation center axis with the optical axis as the rotation center axis .
The first reflecting surface has a truncated cone shape, the second reflecting surface has a conical shape,
The angle that intersects the optical axis of the first reflecting surface is greater than the angle that intersects the optical axis of the second reflecting surface,
The reflector has a paraboloid shape or a spheroid shape, and a light source lamp is disposed behind the focal position of the reflector . The condensing device is a truncated cone-shaped rotator prism having a conical cut-out recess at the center of the bottom surface of the truncated cone, the outer peripheral side surface of the rotator prism as the first reflecting surface, and the side surface of the cut-out recess The light source device according to claim 1 , wherein the light source device is a second reflecting surface. 2. The light source according to claim 1 , wherein the condensing device includes a first reflecting mirror having a truncated cone side surface shape and a second reflecting mirror having a conical shape disposed inside the first reflecting mirror. apparatus. The light source device according to any one of claims 1 to 3 ,
Color wheel,
A light guide device;
A light source side optical system;
A display element;
A projection-side optical system;
A cooling fan,
Projector characterized by comprising a projector control means.

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