JP2012145684A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to reduce the hue shift of intermediate color, particularly the intermediate color displayed by combining a red color and a green color having high luminosity.SOLUTION: An image display device includes: red, green, and blue color laser light source devices that output a red, a green, and a blue color laser beam, respectively; a spatial optical modulation element that modulates the laser beam output from each laser light source device in a time-sharing fashion sequentially based on an image signal; and a controller that controls lighting of the laser light source device for each plurality of lighting intervals constituting one frame and the output of each color laser beam in the spatial optical modulation element. The green color laser light source device outputs a green color laser light beam having a higher y value than a standard green color on a CIExy chromaticity diagram. The controller is configured to light the laser light source device in a lighting order including a GR lighting pattern in which the laser light source device lights in the order of a green color and a red color in one frame.

Description

  The present invention relates to a time-division display type image display device including a laser light source device using a semiconductor laser as a light source.

  2. Description of the Related Art In recent years, a technique that uses a semiconductor laser as a light source of a projection-type image display device that projects a screen on a screen has attracted attention. This semiconductor laser has better color reproducibility, instantaneous lighting, longer life, and higher power consumption compared to mercury lamps that have been widely used in image display devices. There are various advantages such as the ability to reduce the size and the ease of miniaturization.

  In an image display device using such a semiconductor laser, in order to form a color image, three laser light source devices of red, green and blue and a spatial light modulation element made up of one liquid crystal display element are used. A technique based on a time division display method (field sequential method) in which laser beams of respective colors emitted from a laser light source device are sequentially incident on a spatial light modulator is known (see Patent Document 1). In this time division display method, each color image projected on the screen is recognized as a color image by a visual afterimage effect, and only one spatial light modulation element is required. Convenient for planning.

JP 2010-91927 A

  In such a time-division display method, one frame is divided into a plurality of lighting sections (subframes), and each of the red, green, and blue laser light source devices is turned on for each lighting section, and is synchronized with this lighting timing. Then, the output of each color laser beam is controlled by the spatial light modulator. In particular, in order to display an intermediate color, it is only necessary to output a laser beam of a color necessary for expressing the hue of the intermediate color among red, green and blue by a spatial light modulator, for example, when displaying yellow Will output red and green laser light.

  However, the liquid crystal display element used for the spatial light modulation element has a characteristic that the response at the time of rising is low and the transmittance gradually increases in accordance with the application of the control voltage. For this reason, when the intermediate color is displayed as described above, the output of the color that comes first in the lighting order becomes small, and this causes color misregistration. For example, when the laser light source device is turned on in the order of red, green, and blue, and the yellow output is displayed, the red output that comes first in the lighting order is smaller than the green output, and thus shifted to the green side. Displayed in yellow-green. In particular, red and green have high visibility, and there arises a problem that color shift is conspicuous in an intermediate color displayed by a combination of red and green.

  The present invention has been devised to solve such problems of the prior art, and its main purpose is to shift the hue of intermediate colors, particularly intermediate colors displayed with a combination of red and green with high visibility. An object of the present invention is to provide an image display device configured to reduce the above.

  The image display device of the present invention includes red, green, and blue laser light source devices that output red, green, and blue color laser beams, respectively, and each color laser light that is sequentially output in time division from these laser light source devices. A spatial light modulation element that modulates light based on a video signal, and controls lighting of the laser light source device for each of a plurality of lighting sections constituting one frame, and controls the output of each color laser light from the spatial light modulation element The green laser light source device outputs a green laser beam having a y value higher than the standard green color on the CIExy chromaticity diagram, and the control unit displays green and red in one frame. The laser light source device is turned on in a lighting order including a GR lighting pattern that lights up in order.

  According to the present invention, when displaying an intermediate color displayed with a combination of red and green, the green output that comes first in the lighting order is reduced due to the rising response of the spatial light modulator, but this green output is insufficient. Since it acts to cancel out the hue shift of the green laser light itself emitted from the green laser light source device, the hue shift of the displayed intermediate color can be reduced.

1 is a perspective view showing a notebook information processing apparatus 2 that incorporates an image display apparatus 1 according to an embodiment. Schematic configuration diagram of an optical engine unit 21 built in the optical engine unit 13 shown in FIG. The schematic diagram which shows the condition of the laser beam in the green laser light source apparatus 22 shown in FIG. Functional block diagram of the image display device 1 shown in FIG. CIExy chromaticity diagram showing the hue of each color laser beam emitted from each of the red, green and blue laser light source devices 22 to 24 shown in FIG. The figure which shows the order of lighting each laser light source device 22-24 of red, green, and blue shown in FIG. 1, and the polarity of the spatial light modulation element 25 The figure which shows each control signal in the case of displaying yellow by the prior art example shown to FIG. 6 (A), the operation | movement of the spatial light modulation element 25, and the condition of an output waveform The figure which shows the condition of each control signal in the case of displaying yellow by 1st Embodiment shown to FIG. 6 (B), operation | movement of the spatial light modulation element 25, and an output waveform The figure which shows the condition of each control signal in the case of displaying yellow according to 2nd Embodiment shown in FIG.6 (C), operation | movement of the spatial light modulation element 25, and an output waveform The figure which shows the condition of each control signal in the case of displaying yellow by 3rd Embodiment shown in FIG.6 (D), operation | movement of the spatial light modulation element 25, and an output waveform The figure which shows the condition of each control signal in the case of displaying cyan by 3rd Embodiment shown in FIG.6 (D), operation | movement of the spatial light modulation element 25, and an output waveform

  According to a first aspect of the present invention, there is provided a red, green, and blue laser light source device that outputs red, green, and blue laser beams, respectively, and a time-division method from the laser light source devices. A spatial light modulation element that modulates each color laser light that is sequentially output based on a video signal, and lighting of the laser light source device for each of a plurality of lighting sections constituting one frame, and at the spatial light modulation element A control unit for controlling the output of each color laser beam, wherein the green laser light source device outputs a green laser beam having a y value higher than the standard green color on the CIExy chromaticity diagram. The laser light source device is turned on in a lighting order including a GR lighting pattern that lights in the order of green and red in the frame.

  According to this, when displaying an intermediate color that is displayed in a combination of red and green, the green output leading to the lighting order becomes smaller due to the rising response of the spatial light modulation element, but this green output shortage is Since it acts to cancel out the hue shift of the green laser light itself emitted from the green laser light source device, the hue shift of the displayed intermediate color can be reduced.

  In this case, a configuration in which the RG lighting pattern and the GR lighting pattern that are lit in the order of red and green are mixed in one frame is possible, but in order to reduce the color misregistration of the intermediate color displayed by the combination of red and green. The GR lighting pattern may be the same number of times or more than the RG lighting pattern in one frame.

  According to a second aspect of the present invention, in the first aspect of the invention, the control unit turns on the laser light source device so that the number of times of red and green lighting in one frame is greater than the number of times of blue lighting. .

  According to this, since the number of times of red and green lighting with high visibility is higher than the number of times of blue lighting, even if the switching speed of each light source or the response speed of the spatial light modulator is not high, color braking (rainbow phenomenon) ) Can be efficiently reduced.

  According to a third aspect, in the first or second aspect, the control unit controls the laser light source devices in a lighting order having a GBG lighting pattern that lights in the order of green, blue, and green in one frame. It is set to light up.

  According to this, when displaying an intermediate color displayed in a combination of green and blue, the first green output in the lighting order is reduced due to the rising response of the spatial light modulator, while the second blue in the lighting order is displayed. Since the output of the third green is large and the size of the output is substantially the same, the first green output in the lighting sequence is reduced, so that the green output becomes smaller than blue and the green laser light source device emits. Since it acts to cancel the hue shift of the green laser light itself, the hue shift of the displayed intermediate color can be reduced.

  According to a fourth aspect of the present invention, in the first to third aspects of the invention, when the number of lighting sections constituting one frame is an odd number, the control unit sets the polarity of the spatial light modulation element for each lighting section. And switching so that the corresponding lighting sections in the adjacent frames have opposite polarities.

  According to this, since the polarity of the spatial light modulation element is reversed for each lighting section exceeding one frame, the residual charge generated in the spatial light modulation element can be reliably canceled for each lighting section. Burn-in of the spatial light modulator can be prevented.

  According to a fifth invention, in the first to fourth inventions, the green laser light source device is excited by a semiconductor laser that outputs an excitation laser beam and an excitation laser beam that is output from the semiconductor laser. A solid-state laser element that outputs infrared laser light, and a wavelength conversion element that converts the wavelength of the infrared laser light output from the solid-state laser element and outputs green laser light.

  According to this, a high output green laser beam can be output. In this case, since the green laser beam having a higher y value than the standard green color is output, the present invention is effective.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing an example in which an image display device 1 according to the present invention is built in a portable information processing device 2. The main body 3 of the portable information processing device 2 has a storage space in which a peripheral device such as an optical disk device can be replaced, that is, a so-called drive bay, formed on the back side of the keyboard 4. A device 1 is attached.

  The image display device 1 includes a housing 11 and a movable body 12 provided so as to be able to be taken in and out of the housing 11. The movable body 12 includes an optical engine unit 13 in which optical components for projecting laser light onto the screen S are accommodated, and a control unit 14 in which a substrate for controlling the optical components in the optical engine unit 13 is accommodated. The optical engine unit 13 is supported by the control unit 14 so as to be rotatable in the vertical direction.

  In this image display device 1, the movable body 12 is stored in the housing 11 when not in use, and the movable body 12 is pulled out of the housing 11 when in use, and the optical engine unit 13 is rotated to remove the optical body from the optical engine unit 13. The laser light can be appropriately projected on the screen S by adjusting the projection angle of the laser light.

  FIG. 2 is a schematic configuration diagram of the optical engine unit 21 built in the optical engine unit 13 shown in FIG. The optical engine unit 21 includes a green laser light source device 22 that outputs green laser light, a red laser light source device 23 that outputs red laser light, a blue laser light source device 24 that outputs blue laser light, and a video signal. The spatial light modulator 25 that modulates the laser light from each of the laser light source devices 22 to 24, the laser light from each of the laser light source devices 22 to 24 is reflected and irradiated to the spatial light modulator 25, and the spatial light modulation A polarized beam splitter 26 that transmits the modulated laser light emitted from the element 25, a relay optical system 27 that guides the laser light emitted from each of the laser light source devices 22 to 24 to the polarized beam splitter 26, and the polarized beam splitter 26. And a projection optical system 28 that projects the modulated laser light onto the screen S.

  The optical engine unit 21 displays a color image by a so-called field sequential method. Laser beams of each color are sequentially output from the laser light source devices 22 to 24 in a time-sharing manner, and an image by the laser beam of each color is visually displayed. It is recognized as a color image by the afterimage effect.

  The relay optical system 27 includes collimator lenses 31 to 33 that convert the laser beams of the respective colors emitted from the laser light source devices 22 to 24 into parallel beams, and the laser beams of the respective colors that have passed through the collimator lenses 31 to 33 in a predetermined direction. First and second dichroic mirrors 34 and 35 guided to, a diffusion plate 36 for diffusing the laser light guided by the dichroic mirrors 34 and 35, and a field lens for converting the laser light that has passed through the diffusion plate 36 into a convergent laser 37.

  Assuming that the side from which the laser light is emitted from the projection optical system 28 toward the screen S is the front side, the blue laser light is emitted backward from the blue laser light source device 24, and green with respect to the optical axis of the blue laser light. The green laser light and the red laser light are emitted from the green laser light source device 22 and the red laser light source device 23 so that the optical axes of the laser light and the red laser light are orthogonal to each other. , And the green laser light are guided to the same optical path by the two dichroic mirrors 34 and 35. That is, the blue laser light and the green laser light are guided to the same optical path by the first dichroic mirror 34, and the blue laser light, the green laser light, and the red laser light are guided to the same optical path by the second dichroic mirror 35.

  The first and second dichroic mirrors 34 and 35 are formed with films for transmitting and reflecting laser light of a predetermined wavelength on the surface, and the first dichroic mirror 34 transmits blue laser light. And reflects the green laser light. The second dichroic mirror 35 transmits red laser light and reflects blue laser light and green laser light.

  Each of these optical members is supported by the housing 41. The housing 41 functions as a radiator that dissipates heat generated by the laser light source devices 22 to 24, and is formed of a material having high thermal conductivity such as aluminum or copper.

  The green laser light source device 22 is attached to an attachment portion 42 formed on the housing 41 in a state of protruding toward the side. The attachment portion 42 is provided in a state of protruding in a direction perpendicular to the side wall portion 44 from a corner portion where the front wall portion 43 and the side wall portion 44 that are respectively positioned in front and side of the accommodation space of the relay optical system 27 intersect. ing. The red laser light source device 23 is attached to the outer surface side of the side wall 44 while being held by the holder 45. The blue laser light source device 24 is attached to the outer surface side of the front wall portion 43 while being held by the holder 46.

  The red laser light source device 23 and the blue laser light source device 24 are configured by a so-called CAN package, and the optical axis is positioned on the central axis of the can-shaped exterior portion with the laser chip that outputs the laser light supported by the stem. The laser beam is emitted from a glass window provided in the opening of the exterior part. The red laser light source device 23 and the blue laser light source device 24 are fixed to the holders 45 and 46 by, for example, press-fitting into the mounting holes 47 and 48 formed in the holders 45 and 46. The heat generated by the laser chips of the blue laser light source device 24 and the red laser light source device 23 is transmitted to the housing 41 through the holders 45 and 46 to be dissipated, and each of the holders 45 and 46 has a thermal conductivity such as aluminum or copper. It is made of a high material.

  The green laser light source device 22 includes a semiconductor laser 51 that outputs excitation laser light, a FAC (Fast-Axis Collimator) lens 52 that is a condensing lens that condenses the excitation laser light output from the semiconductor laser 51, and a rod. A lens 53, a solid-state laser element 54 that outputs a basic laser beam (infrared laser beam) when excited by an excitation laser beam, and converts a wavelength of the basic laser beam to output a half-wavelength laser beam (green laser beam) A wavelength conversion element 55, a concave mirror 56 that forms a resonator together with the solid-state laser element 54, a glass cover 57 that prevents leakage of excitation laser light and fundamental wavelength laser light, and a base 58 that supports each part, And a cover body 59 that covers each part.

  The green laser light source device 22 is fixed by attaching the base 58 to the mounting portion 42 of the housing 41, and a required width (for example, 0.5 mm) between the green laser light source device 22 and the side wall portion 44 of the housing 41. The following gaps are formed. This makes it difficult for the heat of the green laser light source device 22 to be transmitted to the red laser light source device 23, suppresses the temperature rise of the red laser light source device 23, and allows the red laser light source device 23 with poor temperature characteristics to operate stably. Can do. Further, in order to secure a required optical axis adjustment allowance (for example, about 0.3 mm) of the red laser light source device 23, a required width (for example, 0.3 mm or more) is provided between the green laser light source device 22 and the red laser light source device 23. ) Is provided.

  FIG. 3 is a schematic diagram showing a state of laser light in the green laser light source device 22 shown in FIG. The laser chip 61 of the semiconductor laser 51 outputs excitation laser light having a wavelength of 808 nm. The FAC lens 52 reduces the spread of the first axis of the laser beam (the direction perpendicular to the optical axis direction and along the drawing sheet). The rod lens 53 reduces the spread of the slow axis of laser light (in the direction perpendicular to the drawing sheet).

The solid-state laser element 54 is a so-called solid-state laser crystal, and is excited by excitation laser light having a wavelength of 808 nm that has passed through the rod lens 53 to output fundamental wavelength laser light (infrared laser light) having a wavelength of 1064 nm. This solid-state laser element 54 is obtained by doping an inorganic optically active substance (crystal) made of Y (yttrium) VO ₄ (vanadate) with Nd (neodymium), and more specifically, YVO _{4 as} a base material. The Y is doped by substitution with Nd ⁺³ which is an element that emits fluorescence.

  On the side of the solid-state laser element 54 facing the rod lens 53, a film having a function of preventing reflection of excitation laser light having a wavelength of 808 nm and high reflection of fundamental wavelength laser light having a wavelength of 1064 nm and half-wavelength laser light having a wavelength of 532 nm. 62 is formed. On the side of the solid-state laser element 54 facing the wavelength conversion element 55, a film 63 having an antireflection function for a fundamental wavelength laser beam having a wavelength of 1064 nm and a half wavelength laser beam having a wavelength of 532 nm is formed.

  The wavelength conversion element 55 is a so-called SHG (Second Harmonics Generation) element, which converts the wavelength of a fundamental wavelength laser beam (infrared laser beam) having a wavelength of 1064 nm output from the solid-state laser element 54 to a half-wavelength laser having a wavelength of 532 nm. Light (green laser light) is generated. This wavelength conversion element 55 is provided with a periodic polarization reversal structure in which a region where polarization is reversed and a region as it is are alternately formed in a ferroelectric crystal. A fundamental wavelength laser beam is incident in the arrangement direction. As the ferroelectric crystal, for example, a material obtained by adding MgO to LN (lithium niobate) is used.

  On the side of the wavelength conversion element 55 facing the solid-state laser element 54, a film 64 having functions of preventing reflection of the fundamental wavelength laser light having a wavelength of 1064 nm and highly reflecting the half wavelength laser light having a wavelength of 532 nm is formed. On the side of the wavelength conversion element 55 facing the concave mirror 56, a film 65 having an antireflection function for the fundamental wavelength laser beam having a wavelength of 1064 nm and the half wavelength laser beam having a wavelength of 532 nm is formed.

  The concave mirror 56 has a concave surface on the side facing the wavelength conversion element 55, and this concave surface has a function of high reflection with respect to a fundamental wavelength laser beam with a wavelength of 1064 nm and antireflection with respect to a half wavelength laser beam with a wavelength of 532 nm. A film 66 is formed. As a result, the fundamental wavelength laser beam having a wavelength of 1064 nm resonates and is amplified between the film 62 of the solid-state laser element 54 and the film 66 of the concave mirror 56.

  In the wavelength conversion element 55, a part of the fundamental wavelength laser light having a wavelength of 1064 nm incident from the solid-state laser element 54 is converted into a half-wavelength laser light having a wavelength of 532 nm, and the fundamental wavelength of 1064 nm that has passed through the wavelength conversion element 55 without being converted is converted. The wavelength laser beam is reflected by the concave mirror 56 and is incident on the wavelength conversion element 55 again, and is converted into a half-wavelength laser beam having a wavelength of 532 nm. The half-wavelength laser light having a wavelength of 532 nm is reflected by the film 64 of the wavelength conversion element 55 and emitted from the wavelength conversion element 55.

  Here, the laser beam B1 incident on the wavelength conversion element 55 from the solid-state laser element 54, converted in wavelength by the wavelength conversion element 55, and emitted from the wavelength conversion element 55, and once reflected by the concave mirror 56 and converted in wavelength. In the state where the laser beam B2 incident on the element 55, reflected by the film 64 and emitted from the wavelength conversion element 55 overlaps with each other, the half-wavelength laser light having a wavelength of 532 nm and the fundamental wavelength laser light having a wavelength of 1064 nm interfere with each other. Cause output to drop.

  Therefore, here, the wavelength conversion element 55 is inclined with respect to the optical axis direction so that the laser light beams B1 and B2 do not overlap each other by the refraction action on the entrance surface and the exit surface. Interference between the wavelength laser beam and the fundamental wavelength laser beam having a wavelength of 1064 nm is prevented, so that a decrease in output can be avoided.

  The glass cover 57 shown in FIG. 2 is formed with a film that does not transmit these laser beams in order to prevent the excitation laser beam having a wavelength of 808 nm and the fundamental wavelength laser beam having a wavelength of 1064 nm from leaking to the outside. ing.

  FIG. 4 is a functional block diagram of the image display device 1 shown in FIG. The control unit 14 includes a laser light source control unit 71 that controls the laser light source devices 22 to 24 for each color, a video signal conversion unit 72 that converts a video signal input from the portable information processing device 2, and an output signal thereof. The image display control unit 74 including the spatial light modulation element control unit 73 that controls the spatial light modulation element 25 and the power supplied from the portable information processing device 2 to the laser light source control unit 71 and the image display control unit 74. The power supply part 75 to supply and the main control part 76 which controls each part collectively are provided.

  Based on the image display signal input from the image display control unit 74, the main control unit 76 permits the lighting of the laser light source devices 22 to 24 as a control signal for controlling the lighting of the laser light source devices 22 to 24 of the respective colors. A lighting permission signal (LD ON) and a red lighting signal (LD RON), a green lighting signal (LD GON) and a blue lighting signal (LD BON) for lighting the red, green and blue laser light source devices 22 to 24 respectively. These control signals are generated and output to the laser light source controller 71.

  The laser light source control unit 71 generates drive control signals (Ig, Ir, and Ib) for controlling application of drive current to the laser light source devices 22 to 24 based on the control signal input from the main control unit 76. It outputs to the laser light source devices 22-24.

  The spatial light modulator control unit 73 is configured to control the operation of the spatial light modulator 25 based on the video signal output from the video signal converter 72 as a reference voltage signal (LCOS VCOM) and a pixel voltage signal (LCOS). ΔV) is generated, and these control signals are output to the spatial light modulator 25. In actuality, the pixel voltage signal (LCOS ΔV) has the same number of signals as the number of pixels of the spatial light modulator 25, but in the present embodiment, for convenience, the nth pixel of the spatial light modulator 25 is present. The pixel voltage signal is described as “LCOS ΔV”.

  The spatial light modulation element 25 is a reflection type liquid crystal display element, so-called LCOS (Liquid Crystal On Silicon), and the laser beam transmitted through the liquid crystal layer formed on the silicon substrate is reflected by the reflection layer on the silicon substrate and emitted. It is the thing of the structure to make it. In this spatial light modulation element 25, the output (luminance) of the laser light increases or decreases in accordance with the pixel voltage signal (LCOS ΔV) input from the spatial light modulation element control unit 73, and the time from the laser light source devices 22 to 24 for each color. A desired hue can be displayed by increasing or decreasing the output of the laser light of each color input in the division.

  The spatial light modulator 25 is controlled in polarity (p and n) based on the reference voltage signal (LCOS VCOM) input from the spatial light modulator control unit 73, and the pixel voltage signal (LCOS ΔV) is Positive and negative are inverted according to the reference voltage signal (LCOS VCOM).

  FIG. 5 is a CIExy chromaticity diagram illustrating the hues of the laser beams of the respective colors emitted from the red, green, and blue laser light source devices 22 to 24. Here, the hues of display colors when intermediate colors (yellow and cyan) are displayed in each of the conventional example and the first to third embodiments described later are also shown.

  Red laser light emitted from the red laser light source device 23 (x = 0.719, y = 0.281), emission color of the green laser light source device 22 (x = 0.170, y = 0.796), and blue laser light emitted from the blue laser light source device 24 ( x = 0.161, y = 0.014) hues deviating from standard red (x = 0.640, y = 0.330), standard green (x = 0.300, y = 0.600), and standard blue (x = 0.150, y = 0.060), respectively However, in particular, the green laser light emitted from the green laser light source device 22 is greatly deviated from the standard green color.

  FIG. 6 is a diagram showing the order in which each of the red, green, and blue laser light source devices 22 to 24 is turned on and the polarity of the spatial light modulation element 25. FIG. The case according to the first embodiment, the case according to the second embodiment in (C), and the case according to the third embodiment are shown in (D).

  In the conventional example shown in FIG. 6 (A), one frame is divided into six lighting sections (subframes), and double-speed display is performed in which green, red, and blue are each lit twice in one frame. The RGB lighting pattern of lighting in the order of red, green and blue is repeated twice.

  In the first embodiment shown in FIG. 6B, as in the conventional example shown in FIG. 6A, one frame is divided into six lighting sections, and green, red, and blue are each twice in one frame. Although the display is double-speed display, the GR lighting pattern for lighting in the order of green and red is reversed in one frame by reversing the order of lighting of red and green in the conventional example shown in FIG. Exists twice.

  In the second embodiment shown in FIG. 6C, there are two GR lighting patterns that turn on in the order of green and red in one frame, as in the first embodiment shown in FIG. 6B. However, here, one frame is divided into five lighting sections, and the last (sixth) lighting section for lighting blue in the first embodiment shown in FIG. 6B is deleted. The number of times of red and green lighting is two times, while the number of times of blue lighting is one.

  As described above, in the second embodiment, the number of times of red and green lighting with high visibility is higher than the number of times of blue lighting, so that color braking (rainbow phenomenon) can be reduced.

  Further, in this second embodiment, since the number of lighting sections constituting one frame is an odd number, the polarity of the spatial light modulator 25 is reversed for each lighting section of each frame, and If the polarity of the spatial light modulation element 25 is the same in each frame, the last lighting section of the frame and the first lighting section of the next frame have the same polarity, and the residual charge generated in the spatial light modulation element 25 is changed to the lighting section. Can not be counteracted every time.

  Therefore, here, the polarity of the spatial light modulator 25 is reversed for each lighting section, and the corresponding lighting sections in adjacent frames are switched so as to have opposite polarities. As a result, the polarity of the spatial light modulation element 25 is reversed for each lighting section exceeding one frame, so that the residual charge generated in the spatial light modulation element 25 can be reliably canceled for each lighting section. Thus, the burn-in of the spatial light modulator 25 can be prevented.

  In the third embodiment shown in FIG. 6D, one frame is divided into five lighting sections as in the second embodiment shown in FIG. 6C, but here, FIG. The GR lighting pattern at the head of the frame in the second embodiment shown in C) is replaced with an RG lighting pattern that lights in the order of red and green, and one RG lighting pattern and one GR lighting pattern are included in one frame. There are times. In the third embodiment, there is a GBG lighting pattern that lights in the order of green, blue, and green in one frame.

  In the third embodiment, similarly to the second embodiment shown in FIG. 6C, the number of times of red and green lighting with high visibility is higher than the number of times of blue lighting. Rainbow phenomenon) can be reduced.

  In the third embodiment, as in the second embodiment shown in FIG. 6C, since the number of lighting sections constituting one frame is an odd number, the polarity of the spatial light modulator 25 Are switched for each lighting section, and the corresponding lighting sections in adjacent frames are switched so as to have opposite polarities, so that the polarity of the spatial light modulator 25 exceeds one frame for each lighting section. Therefore, the residual charge generated in the spatial light modulation element 25 can be surely canceled for each lighting section, and the spatial light modulation element 25 can be prevented from being burned.

  FIG. 7 is a diagram showing the status of each control signal, the operation of the spatial light modulator 25, and the output waveform when yellow is displayed according to the conventional example shown in FIG.

  As described above (see also FIG. 4), the lighting permission signal (LD ON), the red lighting signal (LD RON), the green lighting signal (LD GON), and the blue lighting signal (LD BON) are mainly used. When the controller 74 outputs the laser light source controller 71 and the lighting permission signal (LD ON) is turned on, it responds to the red lighting signal (LD RON), green lighting signal (LD GON), and blue lighting signal (LD BON). Thus, the red, green and blue laser light source devices 22 to 24 are turned on.

  Further, the reference voltage signal (LCOS VCOM) and the pixel voltage signal (LCOS ΔV) are output from the spatial light modulation element control unit 73 to the spatial light modulation element 25, and the spatial light modulation element 25 according to the reference voltage signal (LCOS VCOM). Are switched, the transmittance of the spatial light modulator 25 is changed according to the pixel voltage signal (LCOS ΔV), and the output (luminance) of each color laser beam is adjusted.

  Here, when displaying yellow (255, 255, 0 (RGB 8 bits, the same applies hereinafter)), the spatial light modulator 25 may output red and green, and the absolute value (LCOS | ΔV |) of the pixel voltage signal is In the red and green lighting sections, the minimum voltage is obtained, and the output (luminance) is the maximum level (255). Here, since the RGB lighting pattern that lights in the order of red, green, and blue is adopted, the spatial light modulator 25 outputs laser light in the order of red and green.

  On the other hand, the spatial light modulator 25 has low responsiveness when the output (luminance) rises. The spatial light modulator 25 has a characteristic that when the output (brightness) is increased, the control voltage is decreased, but at this time, the transmittance gradually increases (LC operation in FIG. 7). For this reason, when displaying yellow, since the transmissivity gradually increases in the red lighting section with the lighting order first, the red output is limited, and the red output is compared to the green. Becomes smaller (the output waveform in FIG. 7).

  On the other hand, as described above, the green laser light (x = 0.170, y = 0.796) emitted from the green laser light source device 22 has a higher y value than the standard green color (x = 0.300, y = 0.600). This hue deviation of the green laser light acts to shift the hue of the display color to the green side, and is shown in FIG. 5 due to a synergistic effect with the shortage of red output due to the rising response of the spatial light modulator 25. As shown, the standard yellow color (x = 0.470, y = 0.465) is displayed in a yellowish green color greatly deviating to the green side.

  FIG. 8 is a diagram showing the status of each control signal, the operation of the spatial light modulator 25, and the output waveform when yellow is displayed according to the first embodiment shown in FIG. 6B.

  In the first embodiment, there are a plurality of GR lighting patterns that are lit in the order of green and red in one frame. The RG lighting pattern is not included. That is, there are more GR lighting patterns than one RG lighting pattern in one frame. For this reason, when displaying yellow (255, 255, 0), the spatial light modulator 25 outputs laser light in the order of green and red. At this time, due to the rising response of the spatial light modulator 25, the green output whose lighting order is first is limited, and the green output is smaller than the red output.

  On the other hand, as described above, the green laser light (x = 0.170, y = 0.796) emitted from the green laser light source device 22 has a higher y value than the standard green color (x = 0.300, y = 0.600). The hue shift of the laser light itself acts to cancel out the green output shortage caused by the rising response of the spatial light modulator 25. For this reason, the displayed hue shift of yellow can be reduced, and the hue of the display color can be brought close to standard yellow as shown in FIG.

  FIG. 9 is a diagram showing the status of each control signal, the operation of the spatial light modulator 25, and the output waveform when yellow is displayed according to the second embodiment shown in FIG. 6C.

  In the second embodiment, as in the first embodiment shown in FIG. 8, there are a plurality of GR lighting patterns that are output in the order of green and red in one frame. The RG lighting pattern is not included. That is, there are more GR lighting patterns than one RG lighting pattern in one frame, and the number of red and green lightings with high visibility is higher than the number of blue lightings in each frame. Thereby, even if the switching speed of each light source and the response speed of the spatial light modulation element 25 are not high, color braking (rainbow phenomenon) can be efficiently reduced.

  In addition, when displaying yellow continuously over a plurality of frames, the second and subsequent frames from the start of lighting, that is, the GR lighting pattern at the head after frame B is the GR at the tail of the immediately preceding frame. It is continuous to the lighting pattern. For this reason, in the first red lighting section of the GR lighting pattern at the head of each of the second and subsequent frames from the start of lighting, there is no decrease in output at the rise of the spatial light modulator 25, and the red output does not decrease. Therefore, when displaying yellow (255, 255, 0), the green output shortage due to the rising response of the spatial light modulator 25 and the hue shift of the green laser light itself emitted from the green laser light source device 22 are offset. As shown in FIG. 5, the display color can be brought close to standard yellow.

  Further, the number of lighting sections constituting one frame is an odd number, the polarity of the spatial light modulation element 25 is reversed for each lighting section, and the corresponding lighting sections in adjacent frames are switched so as to have opposite polarities. It is said. As a result, the polarity of the spatial light modulation element 25 is reversed for each lighting section exceeding one frame, so that the residual charge generated in the spatial light modulation element 25 can be reliably canceled for each lighting section. Burn-in of the light modulation element 25 can be prevented.

  FIG. 10 is a diagram showing the status of each control signal, the operation of the spatial light modulator 25, and the output waveform when yellow is displayed according to the third embodiment shown in FIG. 6 (D).

  In the third embodiment, as in the first and second embodiments shown in FIGS. 8 and 9, there is a GR lighting pattern that lights in the order of green and red in one frame. For this reason, when displaying yellow (255, 255, 0), the shortage of the green output due to the rising response of the spatial light modulator 25 and the hue shift of the green laser light itself emitted from the green laser light source device 22 are offset. Thus, as shown in FIG. 5, the display color can be brought close to standard yellow.

  On the other hand, in the third embodiment, since the GR lighting pattern at the head of the frame in the second embodiment is replaced with the RG lighting pattern, the GR lighting pattern is one time as compared with the second embodiment. It is running low. That is, the GR lighting pattern exists the same number of times as the RG lighting pattern in one frame. However, when displaying yellow continuously over a plurality of frames, the second and subsequent frames from the start of lighting, that is, the RG lighting pattern at the head after frame B is the GR at the tail of the previous frame. Since it is continuous with the lighting pattern, there is no decrease in output at the time of rising in the spatial light modulation element 25 in the first red lighting section of the RG lighting pattern, and the red output is not reduced. For this reason, also in the third embodiment, the display color can be brought close to standard yellow as much as in the second embodiment.

  Further, in each frame, the number of red and green lights with high visibility is higher than the number of blue lights. Thereby, even if the switching speed of each light source and the response speed of the spatial light modulation element 25 are not high, color braking (rainbow phenomenon) can be efficiently reduced.

  Further, the number of lighting sections constituting one frame is an odd number, the polarity of the spatial light modulation element 25 is reversed for each lighting section, and the corresponding lighting sections in adjacent frames are switched so as to have opposite polarities. It is said. As a result, the polarity of the spatial light modulation element 25 is reversed for each lighting section exceeding one frame, so that the residual charge generated in the spatial light modulation element 25 can be reliably canceled for each lighting section. Burn-in of the light modulation element 25 can be prevented.

  FIG. 11 is a diagram showing the status of each control signal, the operation of the spatial light modulator 25, and the output waveform when cyan is displayed according to the third embodiment shown in FIG. 6 (D).

  As described above, the blue laser light (x = 0.161, y = 0.014) emitted from the blue laser light source device 24 has a lower y value than the standard blue color (x = 0.150, y = 0.060) on the CIExy chromaticity diagram. . The hue deviation of the blue laser light itself acts to shift the hue of the display color to the indigo side.

  On the other hand, in the third embodiment, there is a GBG lighting pattern that lights in the order of green, blue, and green in one frame. For this reason, due to the rising response of the spatial light modulator 25, the output of the first green light in the lighting order is small. On the other hand, the second blue and the third green in the lighting order have large outputs, and the output sizes are substantially the same.

  For this reason, the green output becomes smaller than the blue output by the first green output in the lighting sequence, and the hue shift caused by the high y value of the green laser light (x = 0.170, y = 0.796) is offset. Acts as follows. For this reason, the hue shift of the displayed cyan can be reduced, and can be brought close to the standard cyan (x = 0.225, y = 0.330) as shown in FIG. That is, in the third embodiment shown in FIG. 6D, FIG. 10 and FIG. 11, in addition to yellow displayed by red and green having high visibility, cyan displayed by blue and green approaches the standard color. be able to.

  The image display device according to the present invention has an effect of reducing the hue shift of intermediate colors, particularly the intermediate colors displayed with a combination of red and green having high visibility, and uses a semiconductor laser as a light source. It is useful as a time division display type image display device equipped with

DESCRIPTION OF SYMBOLS 1 Image display apparatus 22 Green laser light source apparatus 23 Red laser light source apparatus 24 Blue laser light source apparatus 25 Spatial light modulation element 54 Solid state laser element 55 Wavelength conversion element 71 Laser light source control part 72 Video signal conversion part 73 Spatial light modulation element control part 74 Image display controller 76 Main controller

Claims (5)

Red, green and blue laser light source devices for outputting red, green and blue laser beams, respectively;
A spatial light modulation element that modulates each color laser light sequentially output from each of these laser light source devices based on a video signal;
A control unit that controls lighting of the laser light source device for each of a plurality of lighting sections constituting one frame, and controls the output of each color laser beam in the spatial light modulation element,
The green laser light source device outputs green laser light having a y value higher than standard green on the CIExy chromaticity diagram,
The control unit causes the laser light source device to light up in a lighting order including a GR lighting pattern that lights in the order of green and red in one frame.   The image display device according to claim 1, wherein the control unit turns on the laser light source device so that the number of times of red and green lighting in one frame is greater than the number of times of blue lighting.   3. The image according to claim 1, wherein the control unit turns on the laser light source device in a lighting order having a GBG lighting pattern that lights in the order of green, blue, and green in one frame. 4. Display device.   The controller reverses the polarity of the spatial light modulation element for each lighting section when the number of lighting sections constituting one frame is an odd number, and the corresponding lighting sections in adjacent frames have opposite polarities. The image display device according to claim 1, wherein switching is performed as follows.   The green laser light source device includes a semiconductor laser that outputs excitation laser light, a solid-state laser element that is excited by the excitation laser light output from the semiconductor laser and outputs infrared laser light, and a solid-state laser element The image display apparatus according to claim 1, further comprising: a wavelength conversion element that converts the wavelength of the output infrared laser light and outputs green laser light.

Images