JP2010217388A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector enhancing color reproducibility without reducing luminance, and also, having improved manufacturability. <P>SOLUTION: The projector 10 is provided with: a light source; an optical element having a phosphor layer configured to receive light source light emitted from the light source and having a prescribed wavelength range and emit the light having a wavelength range that is insufficient in the light source light; a color wheel 71 configured to take out light of each color having a wavelength region from the visible light components of the light source light; a display element 51; a light source side optical system 62 configured to guide the light source light to the display element 51; a projection side optical system 90 configured to project an image generated by the display element 51 onto a screen; and a projector control means configured to control the light source and the display element 51. The optical element is arranged on the optical path of the light source light between the light source and the display element 51, and the light source light and the light emitted from the phosphor layer of the optical element are guided to the display element 51. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a projector provided with a color wheel.

  2. Description of the Related Art Today, a projector as an image projection apparatus that projects a screen of a personal computer, a video image, an image based on image data stored in a memory card or the like onto a screen is widely used.

  This projector has a built-in light source device composed of a small, high-brightness metal halide lamp, an ultra-high pressure mercury lamp, and the like, and the light source emitted from this light source is transmitted through a light source side optical system to a DMD (digital micromirror). A device is a micromirror display element called a device) or a liquid crystal plate, and a color image is displayed on a screen via a projection side optical system.

  In such a projector, when an ultra-high pressure mercury lamp or the like is used as a light source, there is a problem that color reproducibility of an image projected from the projector is difficult because there is a bias in the emission spectrum of the light source. In general, when an ultra-high pressure mercury lamp is used as the light source, the red component is extremely small compared to the green and blue components, so the occupied area (occupied angle) of each color filter of the color wheel is reduced. A method of controlling the luminance of each color light by signal processing with equality, a method of setting the occupied area of the red filter larger than that of the green and blue filters, and the like are employed.

  However, in the above method, since it is necessary to limit the amount of light emitted from the green and blue filters in order to make the luminance of each color substantially equal, the color reproducibility can be improved, but the luminance of light emitted from the color wheel is reduced. There was a problem such as.

  As a solution to such a problem, Japanese Patent Application Laid-Open No. 2007-156270 (Patent Document 1) includes a color wheel that extracts light of each color wavelength range from a visible light component of light source light emitted from a light source. By absorbing the ultraviolet wavelength band light (ultraviolet light) that is the invisible light component of the light source light, the filter part of each color of the wheel emits light in the same wavelength range as the light extracted from the visible light component of the light source light by the filter. An invention has been proposed in which a phosphor layer is provided.

  According to this proposal, even when the area occupied by the red filter of the color wheel is larger than that of the green and blue filters, the emitted light from the phosphor layer is superimposed on each color light extracted by the color filter. Therefore, it is possible to provide a projector capable of improving the luminance of each color light and improving the color balance and brightness of the projected image.

JP 2007-156270 A

  In the proposal of Patent Document 1, color reproducibility and luminance are achieved by superimposing each color light converted from ultraviolet wavelength band light, which has been regarded as unnecessary light, on each color light extracted from the visible light component of the light source light by a filter. Although it can be improved, in order to compensate for the red light, which is the insufficient wavelength range of the light source, the area occupied by each color filter is formed differently, for example, by increasing the area occupied by the red filter of the color wheel. Therefore, there is a problem that the production efficiency is low.

  The present invention has been made in view of such problems of the prior art, and by arranging an optical element having a phosphor layer on an optical path of light source light between a light source and a display element, Luminance is reduced because light of a predetermined wavelength range, such as ultraviolet wavelength range light, included in the light source light can be converted by a phosphor to compensate for insufficient wavelength range light of the light source light in light emission of a desired wavelength range light. It is an object of the present invention to provide a projector that can improve the color reproducibility without increasing the area occupied by each color filter of the color wheel and improve the production efficiency.

  The projector of the present invention includes a light source, an optical element having a phosphor layer that receives light in a predetermined wavelength region of light source light emitted from the light source, and emits light in a short wavelength region of the light source light, and the light source light A color wheel that extracts light of each wavelength from the visible light component, a display element, a light source side optical system that guides the light source light to the display element, and an image generated by the display element is projected onto a screen. A projection-side optical system; and projector control means for controlling the light source and the display element, wherein the optical element is disposed on an optical path of the light source light between the light source and the display element. In addition, the light-emitting light from the phosphor layer of the optical element is guided to the display element.

  The optical element can be a reflection mirror.

  The optical element may be a lens.

  Furthermore, the optical element may be configured to have the phosphor layer on a glass or transparent resin plate.

  The predetermined wavelength band light of the light source light is preferably ultraviolet wavelength band light.

  According to the present invention, by disposing an optical element having a phosphor layer on the optical path of the light source light between the light source and the display element, a predetermined wavelength region such as an ultraviolet wavelength region light included in the light source light. Light can be converted by a phosphor to compensate for the insufficient wavelength range light of the light source light in the emission of the desired wavelength range light, so that the color reproducibility can be improved without lowering the luminance and the color wheel It is possible to provide a projector capable of improving the production efficiency by making the occupation area of each color filter equal.

1 is a perspective view showing an external appearance of a projector according to an embodiment of the invention. It is a figure which shows the functional circuit block of the projector which concerns on the Example of this invention. 1 is a schematic plan view showing an internal structure of a projector according to an embodiment of the invention.

  A mode for carrying out the present invention will be described. The projector 10 receives and absorbs an ultra-high pressure mercury lamp as a light source and an ultraviolet wavelength region light in the light source light emitted from the light source, so that the light source light has a short wavelength region light in a desired wavelength region light emission. A reflection mirror 72 in which a red phosphor layer emitting light in a certain red wavelength region is formed on the reflection layer, and three light components in the red, green, and blue wavelength regions, which are the three primary colors of light, are extracted from the visible light component of the light source light. A color wheel 71 formed in a disk shape by adjacent to the fan-shaped color filter of the type in the circumferential direction, a display element 51, and a light source side optical system 62 for guiding light source light to the display element 51, A projection-side optical system 90 that projects an image generated by the display element 51 onto a screen, and a projector control unit that controls the light source and the display element 51 are provided.

  Further, in the projector 10, the reflection mirror 72 is disposed on the optical path of the light source light between the light source and the display element 51, and the color wheel 71 and each color light extracted from the visible light component of the light source light. Light emitted from the phosphor layer of the reflection mirror 72 is guided to the display element 51.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an external perspective view of the projector 10. In this embodiment, left and right indicate the left and right direction with respect to the projection direction, and front and rear indicate the front and rear direction with respect to the traveling direction of the light beam. As shown in FIG. 1, the projector 10 has a substantially rectangular parallelepiped shape, and has a lens cover 19 that covers the projection port on the side of the front panel 12 that is a side plate in front of the main body case. Is provided with a plurality of exhaust holes 17. Further, although not shown, an Ir receiver for receiving a control signal from the remote controller is provided.

  In addition, a key / indicator unit 37 is provided on the top panel 11 which is a main body case. The key / indicator unit 37 includes a power switch key, a power indicator for notifying power on / off, and projection on / off. There are arranged keys and indicators such as a projection switch key for switching, an overheat indicator for notifying when a light source device, a display element, a control circuit or the like is overheated.

  In addition, on the back side of the main body case, there are provided various terminals 20 such as an input / output connector section and a power adapter plug for providing a USB terminal, a D-SUB terminal for image signal input, an S terminal, an RCA terminal, etc. on the rear panel. Yes. A plurality of intake holes 18 are formed in the vicinity of the lower portion of the right side panel 14 which is a side plate of the main body case (not shown) and the left side panel 15 which is the side plate shown in FIG.

  Next, projector control means of the projector 10 will be described with reference to the block diagram of FIG. The projector control means 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. Image signals of various standards input from the input / output connector unit 21 are input / output. The image conversion unit 23 converts the image signal into a predetermined format suitable for display via the interface 22 and the system bus (SB), and outputs the image signal to the display encoder 24.

  The display encoder 24 develops and stores the input 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 driver 26.

  The display driving unit 26 drives the display element 51, which is a spatial light modulation element (SOM), at an appropriate frame rate corresponding to the image signal output from the display encoder 24, and is emitted from the light source device 63. A light beam is incident on the display element 51 via the light source side optical system, thereby forming an optical image with the reflected light of the display element 51, and an image is displayed on a screen (not shown) via a projection system lens group serving as a projection side optical system. Is projected and displayed. The movable lens group 97 of the projection side optical system is driven by the lens motor 45 for zoom adjustment and focus adjustment.

  Further, the image compression / decompression unit 31 performs a recording process in which the luminance signal and the color difference signal of the image signal are data-compressed by a process such as ADCT and Huffman coding, and are sequentially written in a memory card 32 which is a detachable recording medium. Further, the image compression / decompression unit 31 reads out the image data recorded on the memory card 32 in the reproduction mode, decompresses individual image data constituting a series of moving images in units of one frame, and converts the image data into the image conversion unit 23. Is output to the display encoder 24 and the processing for enabling the display of a moving image or the like based on the image data stored in the memory card 32 is performed.

  The control unit 38 controls operation of each circuit in the projector 10, and includes a ROM that stores operation programs such as a CPU and various settings fixedly, and a RAM that is used as a work memory. .

  An operation signal of a key / indicator unit 37 composed of a main key and an indicator provided on the upper panel 11 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 processor 36 is output to the controller 38.

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

  Further, the control unit 38 controls the power supply control circuit 41. The power supply control circuit 41 turns on the discharge lamp that is the light source of the light source device 63 when the power switch key is operated. Further, the control unit 38 causes the cooling fan drive control circuit 43 to perform temperature detection using a plurality of temperature sensors provided in the light source device 63 and the like, and controls the rotation speed of the cooling fan based on the temperature detection result. Further, the control unit 38 causes the cooling fan drive control circuit 43 to keep the cooling fan rotating even after the discharge lamp of the light source device 63 is turned off by a timer or the like, and further stops the light source device 63 depending on the result of temperature detection by the temperature sensor. Then, control such as turning off the power of the projector main body is also performed.

  Next, the internal structure of the projector 10 will be described. FIG. 3 is a schematic plan view showing the internal structure of the projector 10. As shown in FIG. 3, the projector 10 has a power supply control circuit board 102 with a power supply circuit block 101 and the like attached in the vicinity of the right panel 14, and a sirocco fan type blower 110 arranged in the approximate center. A control circuit board 103 is disposed near 110, a light source device 63 is disposed near the front panel 12, and an optical system unit 70 is disposed near the left panel 15. Further, the projector 10 is airtightly divided into an intake side space chamber 121 on the rear panel 13 side and an exhaust side space chamber 122 on the front panel 12 side by a partition wall 120 in the housing, and the blower 110 has a suction port 111 is disposed in the intake side space chamber 121 and the discharge port 113 is positioned at the boundary between the exhaust side space chamber 122 and the intake side space chamber 121.

  The optical system unit 70 includes an illumination side block 78 located in the vicinity of the light source device 63, an image generation block 79 located on the back panel 13 side, and a projection side block located between the illumination side block 78 and the left panel 15. It is a substantially U-shape composed of 80 and 3 blocks.

  The illumination side block 78 includes a part of the light source side optical system 62 that guides the light emitted from the light source device 63 to the display element 51 provided in the image generation block 79. As the light source side optical system 62 included in the illumination side block 78, the light guide device 75 that converts the light beam emitted from the light source device 63 into a light beam having a uniform intensity distribution, and condenses light transmitted through the light guide device 75. There is a condensing lens.

  The image generation block 79 includes, as the light source side optical system 62, an optical axis conversion mirror 74 that changes the optical axis direction of the light beam emitted from the light guide device 75, and light reflected by the optical axis conversion mirror 74 as a display element. A plurality of condensing lenses for condensing on 51 and an irradiation mirror 84 for irradiating the display element 51 with a light beam transmitted through these condensing lenses at a predetermined angle. Further, the image generation block 79 includes a DMD serving as a display element 51, and a display element cooling device 53 for cooling the display element 51 is disposed on the rear panel 13 side of the display element 51. Prevents high temperatures.

  The projection-side block 80 includes a lens group of the projection-side optical system 90 that emits light that is reflected by the display element 51 and forms an image to the screen. The projection-side optical system 90 includes a fixed lens group 93 built in a fixed lens barrel and a movable lens group 97 built in a movable lens barrel, and is a variable focus lens having a zoom function, and is movable by a lens motor. Zoom adjustment and focus adjustment are enabled by moving the lens group 97.

  Further, in the internal structure of the projector 10, members having a temperature lower than that of the light source device 63 are arranged in the intake side space chamber 121. Specifically, the power supply control circuit board 102 and the blower 110 are arranged. A control circuit board 103, an image generation block 79 of the optical system unit 70, a projection side block 80 of the optical system unit 70, and a condenser lens in the illumination side block 78 of the optical system unit 70. .

  On the other hand, in the exhaust-side space chamber 122, a light source device 63 that has a relatively high temperature, a light guide device 75 provided in the illumination-side block 78 of the optical system unit 70, and an exhaust temperature reducing device 114 are arranged.

  The light source device 63 according to the present invention includes a reflector having a reflective film on the inner surface and an opening in the front, and a discharge lamp such as an ultra-high pressure mercury lamp as a light source built in the reflector. It is what has. The emission spectrum of the discharge lamp is such that the red wavelength band component is smaller than the green and blue wavelength band components. That is, the light source light emitted from this light source lacks red wavelength band light.

  Then, a reflection mirror 72 is arranged in the emission direction of the light source device 63, and further, in the emission direction of the reflection mirror 72, red, which is the three primary colors of light from the visible light component of the light source light reflected by the reflection mirror 72, A color wheel 71 for extracting green and blue wavelength band light is disposed. The reflection mirror 72 and the color wheel 71 are optical elements that constitute the light source side optical system 62. The light source light emitted from the light source device 63 is reflected by the reflection mirror 72, and the color wheel 71 is filtered. The transmitted wavelength band light of each color is arranged to be incident on the light guide device 75 described above.

  The color wheel 71 is formed in a disk shape by adjoining three kinds of fan-shaped color filters in which red, green and blue film layers are deposited on the surface of the optical glass in the circumferential direction. is there. Specifically, the red filter is formed so as to transmit only the red wavelength band light of the irradiated light and reflect the other wavelength band light. Similarly, the green filter is formed to transmit only the green wavelength band light, and the blue filter is configured to transmit only the blue wavelength band light.

  The color wheel 71 is constituted by a filter having the same area in which red, green, and blue filters are equally divided. The color wheel 71 is emitted from the light source device 63 and irradiated to the vicinity of the outer peripheral portion of the wheel surface by rotating at a rotational speed of about 120 times per second by a wheel motor driven and controlled by the control unit 38. Red, green, and blue wavelength band light can be sequentially extracted from the visible light component of the light source light.

  On the reflection layer of the reflection mirror 72 disposed on the optical path of the light source light between the light source device 63 and the color wheel 71, the ultraviolet wavelength region light included in the light source light emitted from the light source is received. Thus, a phosphor layer containing a red phosphor that emits red wavelength band light that is insufficient wavelength band light of the light source light is formed.

  This red phosphor layer is composed of a uniformly dispersed red phosphor such as cadmium borate (Cd2B2O5) or yttrium oxide (Y2O3), and a binder carrying this phosphor. Emits light in the wavelength range.

  Therefore, when the light source light is emitted from the light source of the light source device 63 to the reflection mirror 72, the phosphor in the phosphor layer of the reflection mirror 72 is excited by absorbing the ultraviolet wavelength band light included in the light source light. Emits light in the red wavelength region.

  As a result, the light emitted from the reflection mirror 72 is combined light in which red light, which is light emitted from the phosphor, is superimposed on the light source light. In other words, the light emitted from the reflection mirror 72 is irradiated to the red, green, and blue color filters of the color wheel 71 as white light supplemented with red light that is insufficient wavelength range light of the light source light, whereby each filter Therefore, each color light is emitted with a substantially uniform intensity.

  Therefore, the red light extracted from the visible light component of the light source light by the color wheel 71 and the red light emitted from the red phosphor layer of the reflection mirror 72 are incident on the light guide device 75 and are incident on the light guide device 75. The light beam is guided to the display element 51 through the light source side optical system 62.

  Then, the display element 51 is time-division controlled by the display drive unit 26 corresponding to each color light time-divided by the rotation of the color wheel 71, so that the image generated by the display element 51 is converted into the projection-side optical system 90. Through the screen.

  Thus, by arranging the reflecting mirror 72 having the phosphor layer on the optical path of the light source light between the light source and the color wheel 71, the ultraviolet wavelength region light included in the light source light is converted by the phosphor. Therefore, since the insufficient wavelength band light of the light source light can be compensated, the color reproducibility of the projected image can be improved without reducing the luminance.

  In addition, since the area occupied by the color filters of the color wheel can be made equal to have the same shape, it is possible to provide a projector capable of improving manufacturing efficiency. Furthermore, since the short wavelength band light can be supplemented by using the ultraviolet wavelength band light that is unnecessary light included in the light source light, the utilization efficiency of the light source light can be increased.

  And this invention is not limited to the above Example, A change and improvement are possible freely in the range which does not deviate from the summary of invention. For example, for an optical element having a phosphor layer, the light source light is condensed on the light guide device 75 between the light source device 63 and the color wheel 71 without being limited to the case where the reflecting mirror 72 is provided with the phosphor layer. When the lens to be arranged is arranged, a phosphor layer can be formed on the surface of the lens. Further, the optical element having the phosphor layer may include a phosphor layer on a plate material such as glass or transparent resin disposed on the optical path of the light source light. Further, by forming this phosphor layer on the light source light incident surface of the color wheel 71, the color reproducibility can be improved without lowering the luminance as described above. As described above, by providing phosphor layers in various optical elements, it is possible to easily improve color reproducibility without providing new parts.

  In addition, by providing a phosphor layer on the reflection layer of the reflection mirror 72, the emitted light of the phosphor emitted to the reflection layer side of the reflection mirror 72, which is an optical element, is emitted to the color wheel 71 side to emit the phosphor. It is preferable because the utilization efficiency of the emitted light can be improved.

  Further, the optical element having this phosphor layer can be disposed between the color wheel 71 and the display element 51. In this case, the red filter constituting the color wheel 71 is formed so as to transmit not only the red wavelength band light but also the ultraviolet wavelength band light, and the green and blue filters are only the green and blue wavelength band light as described above. Is formed so as to reflect other wavelength band light including ultraviolet wavelength band light.

  Thereby, when the light source light is irradiated to the green and blue filters of the color wheel 71, only the light in the green and blue wavelength regions is emitted from the green and blue filters and guided to the display element 51. When the light source light is irradiated to the red filter of the color wheel 71, the red filter emits red wavelength band light and ultraviolet wavelength band light, and is arranged between the color wheel 71 and the display element 51. The ultraviolet wavelength band light is converted into red wavelength band light by the phosphor layer of the optical element. That is, when the light source light is irradiated to the red filter of the color wheel 71, the red light emitted from the red filter can be superimposed on the red light emitted from the red filter and guided to the display element 51. As described above, the color reproducibility can be improved.

  That is, the optical element including the phosphor layer is not limited to the case where the optical element is disposed on the optical path of the light source light between the light source of the light source device 63 and the color wheel 71, and the color wheel 71 and the display element 51 The color reproducibility of the projected image can also be improved by arranging them on the optical path of the light source light in the same manner as described above. Therefore, for example, the lens of the illumination side block 78 shown in FIG. 3, the optical axis conversion mirror 74, the optical element such as the light guide device 75 can be provided with a phosphor layer, and the red filter portion of the color wheel 71 can be provided. Since the red phosphor layer can be formed on the emission surface, the degree of freedom in designing the projector 10 can be improved.

  And the fluorescent substance of a fluorescent substance layer is not limited to a red fluorescent substance, Various fluorescent substance which can light-emit short wavelength range light of light source light is employable. For example, if the insufficient wavelength band light in the light source light is a green wavelength band component, the use efficiency of the light source light can be improved by adopting a phosphor that absorbs the ultraviolet wavelength light of the light source light and emits green wavelength light. It is possible to improve the color reproducibility without improving the luminance. Similarly, if both the red and green wavelength band lights are insufficient in the emission spectrum of the light source light, a light source light light between the light source and the display element 51 is formed using a phosphor layer in which red and green phosphors are mixed. By providing the optical element disposed on the road, the same effects as described above can be obtained.

  Further, the phosphor of the phosphor layer is not limited to the one that absorbs the ultraviolet wavelength region light, but absorbs the purple wavelength region light reflected by each color filter of the color wheel 71 and the excess wavelength region light of the light source light. Thus, a phosphor that emits light in a short wavelength region may be used.

10 Projector 11 Top panel
12 Front panel 13 Back panel
14 Right panel 15 Left panel
17 Exhaust hole 18 Intake hole
19 Lens cover 20 Various terminals
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 section
41 Power supply control circuit 43 Cooling fan drive control circuit
45 Lens motor 47 Audio processor
48 Speaker 51 Display element
53 Display element cooling device 62 Light source side optical system
63 Light source device 70 Optical system unit
71 Color wheel 72 Reflection mirror
74 Optical axis conversion mirror 75 Light guide device
78 Lighting block 79 Image generation block
80 Projection side block 84 Irradiation mirror
90 Projection side optical system 93 Fixed lens group
97 Movable lens group 101 Power supply circuit block
102 Power supply control circuit board 103 Control circuit board
110 Blower 111 Air inlet
113 Discharge port 114 Exhaust temperature reduction device
120 Partition wall 121 Inlet side space
122 Exhaust space room

Claims (5)

A light source;
An optical element having a phosphor layer that receives light in a predetermined wavelength region of light source light emitted from the light source and emits light in a short wavelength region of the light source light;
A color wheel for extracting light in the wavelength region of each color from the visible light component of the light source light;
A display element;
A light source side optical system for guiding the light source light to the display element;
A projection-side optical system that projects an image generated by the display element onto a screen;
Projector control means for controlling the light source and the display element,
The optical element is disposed on an optical path of the light source light between the light source and the display element, and light emitted from a phosphor layer of the optical element is guided to the display element together with the light source light. A projector configured as described above.   The projector according to claim 1, wherein the optical element is a reflection mirror.   The projector according to claim 1, wherein the optical element is a lens.   The projector according to claim 1, wherein the optical element has a configuration in which the phosphor layer is provided on a plate material made of glass or transparent resin. 5. The projector according to claim 1, wherein the predetermined wavelength band light of the light source light is ultraviolet wavelength band light.

Images