JP2008241977A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of compatibly achieving a high color saturation type and a high luminance type. <P>SOLUTION: The projector 2 includes: a plurality of illuminating light sources 18 emitting predetermined color illuminating light, wherein at least one color illuminating light source 18g has a plurality of light source units 18gC and 18gL; and a light source color switching part 16 for selectively lighting the desired light source unit out of the illuminating light source, the plurality of light source units 18gC and 18gL. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projector.

  Projection-type image display devices that convert image signals into optical signals and enlarge and project them onto a screen, etc., used for presentations and video appreciation, etc., projectors using LEDs as light sources can display very high saturation due to the narrow wavelength characteristics of LEDs. It is attracting attention because it is possible.

  In order to realize a projector that displays a high-saturation image, three LEDs having a dominant wavelength that can include as large a human-visible color range as possible shown in the chromaticity diagram (color space) of FIG. Select a color. Assume that 450 nm, 520 nm, and 650 nm are selected as specific main wavelengths. The brightness of the projector at this time will be considered based on the relationship between luminous efficiency and wavelength in FIG. A parabola 70 represents the relationship between luminous efficiency and wavelength in photopic vision. A parabola 72 represents the relationship between luminous efficiency and wavelength in dark place vision. As shown by the parabola 70 in photopic vision, even if the light has the same power, the light perception when 555 nm is set to 1 tends to decrease the visual efficiency even if the wavelength is higher or lower. It becomes substantially 0 when reaching 400 nm and 700 nm.

  Therefore, when the same power is applied to light with wavelengths of 450 nm and 650 nm, the brightness perceived by humans is relatively very weak = dark compared to light with a wavelength of 520 nm. Conversely, if the wavelength is selected with emphasis on brightness, the saturation will be very narrow. Furthermore, the optimal saturation and brightness differ between the case where you want to enjoy a movie in the dark and the case where you want to open a curtain in the daytime and watch a TV etc. with a projector, and this may not be easily achieved with a single projector. It was a challenge.

  The present invention has been made paying attention to such conventional problems, and the purpose thereof is a plurality of types according to the viewing situation, for example, a high saturation type suitable for watching a movie in a dark place. Another object of the present invention is to provide a projector that can achieve both a high-luminance type suitable for watching TV in a bright place.

  The projector according to the present invention is a projector, and is a plurality of illumination light sources that emit illumination light of a predetermined color, and the illumination light source of at least one color has a plurality of light source units. And a light source color switching unit for selecting and lighting a desired light source unit among the plurality of light source units.

  According to the present invention, it is possible to deal with a wide range of characteristics of the light source unit by switching the light source unit to be used. Thereby, for example, a projector capable of switching between a high saturation type and a high luminance type is provided.

  In this projector, the plurality of light source units may be configured to be independently detachable. According to this, it becomes easy to realize a projector that can widely cope with the characteristics of the light source unit.

  The projector may include an image adjustment unit that performs image adjustment on an image signal to be displayed, and a control unit that controls the image adjustment unit. This facilitates natural color reproduction when switching the light source unit.

  In the projector, the control unit may switch the content of the image adjustment by selection of the light source color switching unit. According to this, it becomes easy to realize a projector that can widely cope with the characteristics of the light source unit.

  In the projector, the light source unit may include an information profile unit that stores unique information, and the control unit may switch the content of the image adjustment according to information in the information profile unit. According to this, it becomes easy to realize a projector that can widely cope with the characteristics of the light source unit.

  In this projector, the image adjustment is performed based on an image correction table, and the projector stores a plurality of stored image corrections based on switching between a storage unit that stores a plurality of image correction tables and the light source unit. You may have a correction table selection part which selects the image correction table used for the said image adjustment from a table. According to this, it becomes easy to realize a projector that can widely cope with the characteristics of the light source unit.

  In the projector, the image adjustment is performed based on an image correction table, and the projector includes a table calculation unit for generating an image correction table used for the image adjustment based on switching of the light source unit. May be. According to this, it becomes easy to realize a projector that can widely cope with the characteristics of the light source unit.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)

  First, the external appearance of the projector will be described.

  FIG. 1 is a diagram showing an external appearance of a projector according to the first embodiment. The main body 10 of the projector 2 according to the present embodiment is substantially box-shaped. A projection lens 12 is provided in the center of the front side of the main body 10. On the upper surface of the main body 10, an operation unit 14 that turns on / off the power of the projector 2, zooms the projection lens 12, and performs an image timing determination operation, and a desired light source among a plurality of light source units. And a light source color switching unit 16 for selecting and lighting the unit.

  The light source color switching unit 16 is a high-saturation type (C side in the figure) suitable for watching the projector 2 in a dark place, and a high-brightness type (suitable for watching the TV 2 or the like in a bright place). (L side in the figure). The light source color switching unit 16 is a manual lever. It may be switched by a motor operation or the like by a button operation.

  FIG. 2 is a diagram illustrating a configuration of the projector according to the first embodiment. The projector 2 according to the present embodiment is a three-plate projector that includes three (three) liquid crystal light valves to be described later and synthesizes and emits light after separately modulating red light, green light, and blue light. Therefore, various color images can be projected and displayed on a screen based on an image signal output by an external device (a playback device such as a video deck and a DVD player or a personal computer). In addition, one of two types of LED units that emit green irradiation light having predetermined wavelength and luminance characteristics, which will be described later, is selected, and image adjustment optimal for this is performed.

  Specifically, the projector 2 includes a plurality of illumination light sources 18r, 18g, and 18b that emit illumination light of a predetermined color (hereinafter also referred to as “illumination light source 18” when not distinguished), a light modulation unit 20r, 20g, 20b, and a cross dichroic prism 22. Note that the projector 2 actually includes an audio signal processing unit, a speaker, and the like, but illustration and description thereof are omitted to facilitate understanding of the present invention.

  The illumination light source 18g includes an LED unit 18gC as a first light source unit and an LED unit 18gL as a second light source unit. The LED unit 18gC includes one LED (light emitting diode) that is disposed on a substrate (not shown) and emits green light Lg. This LED is an LED used for the high saturation type. For example, the wavelength of the light source color is 520 nm. The LED unit 18gL includes a single LED that is disposed on a substrate (not shown) and emits green light Lg. This LED is an LED used for a high luminance type. For example, the wavelength of the light source color is 550 nm.

  Electric power is supplied to one of the LED units 18gC and 18gL from the power supply contact according to the selection of the light source color switching unit 16. Note that the LED units 18gC and 18gL may be wired in advance, and position recognition may be performed to supply power to either one. Since the LED units 18gC and 18gL can be supplied with the same power from a light source driving unit described later, when the LED unit 18gC is used, the high-saturation type projector 2 is used, and when the LED unit 18gL is used, the LED unit 18gL is high. A luminance type projector 2 can be realized. The LED units 18gC and 18gL can be detached from the side surface of the projector 2 or the like. The LED units 18gC and 18gL have an information profile unit 58 that stores information specific to each.

  The illumination light source 18r is provided with an LED as one illumination light source that is disposed on a substrate (not shown) and emits red light Lr. The illumination light source 18b includes an LED as a single illumination light source that is disposed on a substrate (not shown) and emits blue light Lb. In the present embodiment, each of the illumination light sources 18 is composed of one LED, but a plurality of LEDs may be arranged in a matrix.

  The light modulation unit 20g is a unit that optically modulates the green light Lg emitted by the LED unit 18gC or the LED unit 18gL, and includes a polarizing plate 26 as a polarization conversion element and a liquid crystal light valve 28g. The light modulator 20r is a unit that optically modulates the red light Lr emitted from the illumination light source 18r, and includes a polarizing plate 26 and a liquid crystal light valve 28r. The light modulator 20b is a unit that optically modulates the blue light Lb emitted from the illumination light source 18b, and includes a polarizing plate 26 and a liquid crystal light valve 28b.

  The polarizing plate 26 has substantially the same shape and the same size as the liquid crystal light valves 28r, 28g, and 28b (hereinafter also referred to as “liquid crystal light valve 28” when not distinguished). The polarizing plate 26 is disposed between the illumination light source 18 and the liquid crystal light valve 28 and emits the respective color lights Lr, Lg, Lb (hereinafter referred to as “color light L” unless otherwise distinguished). Is linearly polarized and enters the liquid crystal light valve 28.

  The liquid crystal light valve 28 is, for example, a transmissive light modulation element, and is based on image signals DSr, DSg, DSb (hereinafter also referred to as “image signal DS” when not distinguished) output from the image adjustment unit. Are modulated. The liquid crystal light valve 28 converts the image signal DS into an LV drive signal, and displays an image on the light valve by driving the liquid crystal. The three color lights modulated by the liquid crystal light valve 28 enter the cross dichroic prism 22.

  The cross dichroic prism 22 combines the light emitted from the liquid crystal light valve 28 and guides it to the projection lens 12. The cross dichroic prism 22 is formed by bonding four right-angle prisms, and a dielectric multilayer film that reflects red light Lr and a dielectric multilayer film that reflects blue light Lb are arranged in a cross shape on the inner surface thereof. . These dielectric multilayer films combine the three color lights to form light representing a color image.

The projection lens 12 enlarges the projection light Lp emitted by the cross dichroic prism 22 and projects it onto the screen 30. The projection lens 12 enlarges and projects the aerial image on the screen 30.
(Second Embodiment)

  FIG. 3 is a diagram showing functional blocks of the projector according to the second embodiment. The projector 2 according to the present embodiment includes an image adjustment unit 32 that performs image adjustment on an image signal to be displayed, a control unit 50 that controls the image adjustment unit 32, and a storage unit 52 that stores a plurality of image correction tables 60. It is equipped with.

  The image adjustment unit 32 performs image adjustment based on the image correction table 60. The image adjustment unit 32 is controlled by the control unit 50. The image adjustment unit 32 performs gain adjustment on the image converter 34 that performs predetermined signal processing on the image signal VS supplied from the image signal supply device 100 that is an external device, and the input image signal DS supplied from the image converter 34. A gain adjustment unit 36, an offset adjustment unit 38 that performs offset adjustment on the image signal DS, a gamma correction unit 40 that performs gamma correction on the image signal DS, a color temperature adjustment unit 42 that performs color temperature adjustment on the image signal DS, A 3D-LUT adjustment unit 44 that performs 3D-LUT (lookup table) adjustment on the image signal DS, a color unevenness correction unit 46 that performs color unevenness correction processing on the image signal DS, and an image signal that has been subjected to various adjustments and corrections And an image data driving unit 48 for driving the liquid crystal light valve 28 based on the DS.

  The image converter 34 converts the input image signal VS into an image signal DS that can be input to the liquid crystal light valve 28 and outputs the image signal DS. The image signal DS includes a vertical synchronization signal, a horizontal synchronization signal, and a clock signal as timing signals. As the image data output as the image signal DS, 24-bit image data per pixel is continuously output for each pixel. The image data of one pixel is composed of 8-bit color data for each of R, G, and B colors. The image converter 34 converts RGB image data from 8 bits to 10 bits, and performs 8-bit / 10-bit conversion for performing processing to improve the gradation of the image, and Yuv (luminance + color difference) that is easy to perform image expansion processing from RGB image data. As Yuv conversion to convert to image data, and image expansion processing to make Yuv image data more beautiful and sharp, monochrome expansion, saturation expansion, and sharpness processing, and return to RGB image data again, for each color RGB conversion that facilitates correction is performed. In the following description, image data included in the image signal DS may be referred to as “image data DS” for convenience of description, and only the image signal excluding the timing signal may be referred to as “image signal DS”.

  The gain adjustment unit 36 adjusts the image data DS so that the output characteristic of light with respect to the image data DS changes to a desired characteristic. Adjustment is made so that a bright portion of the projected image displayed on the screen 30 can be seen more clearly.

  The offset adjustment unit 38 adjusts the image data DS so that the output characteristic of light with respect to the image data DS changes to a desired characteristic. Adjustment is made so that the dark part of the projected image displayed on the screen 30 can be seen more clearly.

  The gamma correction unit 40 corrects the image data DS so that the output characteristic of light with respect to the image data DS changes to a desired characteristic. The projection image displayed on the screen 30 is corrected so that it looks like a smooth or sharp image.

  The color temperature adjustment unit 42 corrects the image data DS so that the output characteristic of light with respect to the image data DS changes to a desired characteristic. The color of the projected image displayed on the screen 30 is adjusted so that it looks like a bluish image or a reddish image. The color temperature adjustment is performed in combination with changing the output of the light source color.

  The 3D-LUT adjustment unit 44 corrects the image data DS so that the output characteristic of light with respect to the image data DS changes to a desired characteristic. The 3D-LUT adjustment unit 44 converts the input RGB image data to “make it look more vivid at the store”, “to suit viewing in a bright living room”, “when watching a movie in a dark room” Correct the output according to the purpose, such as “Adjusting the gradation to the color”.

  The color unevenness correction unit 46 corrects the image data DS so that the output characteristic of light with respect to the image data DS changes to a desired characteristic. The image data DS is corrected so as to suppress color unevenness occurring in the projected image displayed on the screen 30. In this embodiment, color unevenness is corrected by adding / subtracting correction data to / from the image data DS.

  Here, the various adjustments and corrections described above are performed based on the image correction table 60. Specifically, the image correction table 60 includes output values for input values in various adjustments and corrections.

  The image data driving unit 48 drives the liquid crystal light valve 28 based on the image signal DS subjected to various adjustments and corrections. The liquid crystal light valve 28 modulates the illumination light emitted from the illumination light source 18 based on the image signal DS. The modulated light (image light) is projected and displayed on the screen 30 by the projection lens 12 with a zoom function.

  Although not shown, the liquid crystal light valve 28 according to the present embodiment includes three light valves that modulate the color signals of the three colors (R, G, and B), and an image adjustment unit. 32 has a function of processing image signals DS for three colors.

  The control unit 50 switches the contents of the image adjustment according to the selection of the light source color switching unit 16. The control unit 50 switches the contents of the image adjustment according to the information in the information profile unit 58. The control unit 50 controls the image adjustment unit 32. The control unit 50 is composed of a CPU and the like.

  The control unit 50 includes a table calculation unit 54 and a correction table selection unit 64. The table calculation unit 54 generates an image correction table 60 used for image adjustment based on the switching between the LED units 18gC and 18gL. The correction table selection unit 64 selects the image correction table 60 used for image adjustment from the plurality of image correction tables 60 stored in the storage unit 52 based on the switching of the LED units 18gC and 18gL.

  The storage unit 52 stores a plurality of image correction tables 60. Various nonvolatile memories such as EPROM, EEPROM, and FROM are used for the storage unit 52.

  Here, the information profile part 58 as information which LED unit 18gC, 18gL has is demonstrated. The LED units 18gC and 18gL each have a memory therein, and an information profile section 58 is written in the memory. The information profile unit 58 includes a solid serial number, light source chromaticity, light source chromaticity, light source luminance, luminance / current characteristics, luminance / temperature data, operating temperature range, luminance / degradation characteristics, illumination light source There are mounting position deviation information, light source unevenness information, LUT generation parameters, and the like.

  If the same light source unit was used before, the data of the solid serial number can be quoted from inside the projector.

  The chromaticity of the light source is used as basic data for generating a 3D-LUT suitable for the light source in addition to the color temperature adjustment described above.

  The luminance of the light source and the luminance / current characteristics are used as basic data for generating a 3D-LUT suitable for the light source, similarly to the chromaticity of the light source.

  The brightness / temperature data and the operating temperature range are used for cooling the light source unit at a temperature corresponding to each characteristic. It is used to measure the temperature of the light source unit and control the temperature or current so that the luminance does not decrease.

  As the luminance / degradation level characteristic, the luminance degradation characteristic is written as information because the luminance of the light source unit decreases according to the degradation state. The degree of deterioration is determined by driving power and time (for example, driving average power × time).

  The mounting position deviation information of the illumination light source and the unevenness information of the light source part may be written with a deviation from the center position of the light source unit, the light emission luminance distribution of the surface emitting LED, etc. in order to correct the illumination unevenness. Good.

  Since the LUT generation parameters may differ depending on the chromaticity, the LUT generation parameters corresponding to the light source can be adjusted so that the LUT generation can be finely corrected even in LUTs created for the same purpose. You may prepare. The information updated and stored in the LED units 18gC and 18gL includes a light source deterioration degree. The light source deterioration degree may be corrected for luminance and chromaticity according to the deterioration degree, or a warning regarding replacement of the light source may be given. An LED unit without information in advance inside the projector may be used.

  Here, the change of the image correction table 60 in the control unit 50 will be described. The control unit 50 controls the image adjustment unit 32 that performs image adjustment on the image signal to be displayed. The image adjustment unit 32 performs image adjustment based on the image correction table 60 stored in the storage unit 52.

  The image correction table 60 includes a solid number for performing image adjustment by the image adjustment unit 32, luminance-current characteristics, luminance-correction data, luminance-time correction data, and the like. Note that when only the difference in the green light source color is to be corrected, it is sufficient that only the difference in the green color can be identified (by a barcode, memory information, etc.).

  Since the optimum values of the image correction table 60 differ depending on the LED units 18gC and 18gL, the image correction table 60 corresponding to the LED units 18gC and 18gL is prepared or generated on the storage unit 52, and the light source color switching unit 16 selects the image correction table 60. The image correction table 60 is switched.

  The control unit 50 switches the contents of the image adjustment performed by the image adjustment unit 32 according to the selection of the light source color switching unit 16. The correction table selection unit 64 of the control unit 50 is configured so that the image adjustment unit 32 uses the plurality of image correction tables 60 stored in the storage unit 52 based on the switching of the LED units 18gC and 18gL by the selection of the light source color switching unit 16. The image correction table 60 used for image adjustment is selected. Alternatively, based on the switching of the LED units 18gC and 18gL by the selection of the light source color switching unit 16, the control unit 50 uses the information of the information profile unit 58 in which the LED units 18gC and 18gL store unique information. The content of the image adjustment performed by the adjustment unit 32 may be switched.

  At this time, the image correction table 60 is switched based on the switching of the LED units 18 gC and 18 gL by the selection of the light source color switching unit 16 by the correction table selection unit 64 of the control unit 50. From the image correction table 60, the image correction table 60 used by the image adjustment unit 32 for image adjustment is selected. Alternatively, even if the table calculation unit 54 of the control unit 50 generates the image correction table 60 used by the image adjustment unit 32 for image adjustment based on the switching of the LED units 18gC and 18gL by the selection of the light source color switching unit 16. Good.

  The control unit 50 controls the image adjustment of the image to be displayed by sending the image adjustment result performed by the image adjustment unit 32 to the light source drive unit 56 as a light source drive control signal. The light source driving unit 56 is a circuit that can freely change the luminance of the light source according to the driving current, the driving voltage, and the driving time. The LED unit may be integrated with RGB in addition to replacing only green, or RGB may be replaced separately.

  FIG. 4 is a diagram illustrating a change in chromaticity (saturation) in the chromaticity diagram accompanying the selection of the light source color switching unit according to the second embodiment. In the chromaticity diagram, there is a characteristic that the outer side becomes higher in saturation than the center of the triangular region. When the triangular area becomes smaller, the display is in a color with relatively low saturation.

  The saturation change of the present embodiment indicates the saturation change when the LED units 18gC and 18gL that emit green illumination light are switched.

  A triangular area indicated by a solid line 66 is a case where the LED unit 18gC that emits high-saturation type green illumination light is selected. A triangular area indicated by a broken line 68 is a case where the LED unit 18gL that emits green light of high luminance type is selected.

  Since the wavelength of the light source color of the LED unit 18gC is 520 nm and the wavelength of the light source color of the LED unit 18gL is 550 nm, the LED unit 18gC has a relatively large saturation and the LED unit 18gL has a relatively small saturation. Become. Further, as described with reference to FIG. 6, the LED unit 18gL is darker by about 20% than the LED unit 18gL from the relationship between visual efficiency and wavelength. When the LED unit 18gL is used, red and blue are too dark for a single color and cannot be balanced with green, so other colors are added to make it brighter (B → B ′, R → R ′).

  The light modulation device is not limited to a transmission type liquid crystal display device, but a reflection type liquid crystal display device (Liquid Crystal On Silicon, LCOS), DMD (Digital Micro mirror Device), GLV (Grating Light Valve), etc. Also good.

  According to the present embodiment, A projector with both high saturation and high brightness can be realized. 2. At that time, natural image display is possible. 3. The projector performance can also be improved (higher brightness and higher saturation) as the LED saturation and light emission luminance efficiency improve. 4). A projector with reduced color unevenness and brightness unevenness and stable brightness can be realized. 5. A projector without color misregistration can be realized.

It is a figure which shows the external appearance of the projector which concerns on 1st Embodiment. It is a figure which shows the structure of the projector which concerns on 1st Embodiment. It is a figure which shows the functional block of the projector which concerns on 2nd Embodiment. It is a figure which shows the chromaticity (saturation) change in the chromaticity diagram accompanying the selection of the light source color switching part which concerns on 2nd Embodiment. It is a figure which shows the relationship between a wavelength and a visible light area | region. It is a figure which shows the relationship between a wavelength and luminous efficiency.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Projector 10 ... Main body 12 ... Projection lens 14 ... Operation part 16 ... Light source color switching part 18gC ... LED unit (1st light source unit) 18gL ... LED unit (2nd light source unit) 18r, 18g, 18b ... Light source 20r for illumination , 20g, 20b ... light modulation unit 22 ... cross dichroic prism 26 ... polarizing plate 28r, 28g, 28b ... liquid crystal light valve 30 ... screen 32 ... image adjustment unit 34 ... image converter 36 ... gain adjustment unit 38 ... offset adjustment unit 40 ... Gamma correction unit 42 ... Color temperature adjustment unit 44 ... 3D-LUT adjustment unit 46 ... Color unevenness correction unit 48 ... Image data drive unit 50 ... Control unit 52 ... Storage unit 54 ... Table calculation unit 56 ... Light source drive unit 58 ... Information profile 60: Image correction table 64: Correction table Le selector 66 ... solid 68 ... dashed 70,72 ... parabolic 100 ... image signal supply apparatus.

Claims (7)

A projector,
A plurality of illumination light sources that emit illumination light of a predetermined color, wherein the illumination light source of at least one color has a plurality of light source units;
A light source color switching unit for selecting and lighting the desired light source unit among the plurality of light source units;
Including a projector. The projector according to claim 1, wherein
The projector according to claim 1, wherein each of the plurality of light source units is configured to be independently detachable. In the projector according to claim 1 or 2,
An image adjustment unit for performing image adjustment on an image signal to be displayed;
A control unit for controlling the image adjustment unit;
Including a projector. The projector according to claim 3, wherein
The control unit switches the content of the image adjustment according to selection of the light source color switching unit. The projector according to claim 3, wherein
The light source unit has an information profile part for storing information unique to each,
The projector, wherein the control unit switches contents of the image adjustment according to information of the information profile unit. In the projector according to claim 4 or 5,
The image adjustment is performed based on an image correction table,
The projector is
A storage unit for storing a plurality of image correction tables;
A projector comprising: a correction table selection unit that selects an image correction table to be used for the image adjustment from the plurality of stored image correction tables based on switching of the light source unit. In the projector according to claim 4 or 5,
The image adjustment is performed based on an image correction table,
The projector is
A projector comprising: a table calculation unit for generating an image correction table used for the image adjustment based on switching of the light source unit.

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