JP2012242708A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a conventional image display device in which a green laser light source device has low oscillation efficiency under a low temperature to cause its start-up time to be increased, thereby preventing a green color from being displayed to prevent a desired image from being displayed immediately after a start-up.SOLUTION: An image forming apparatus includes a control unit for controlling lighting of light source devices for each of a plurality of lighting intervals constituting one frame, and for controlling an output of each color light from a spatial optical modulation element. The control unit allows the light source device for green to be lighted in the lighting allocation interval of the light source device for green from a start-up until an irradiation light amount of the light source device for green becomes not less than a prescribed value (LD_GON=H), and allows the light source device for green to be lighted in place of the light source device to be originally lighted, in at least any of the lighting allocation intervals of the light source devices for colors other than green (LD_GON=H).

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.

  In recent years, a technique using 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 being able to be made and being easy to downsize.

  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 the visual afterimage effect. Since only one spatial light modulation element is required, the size of the apparatus can be reduced. 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.

  However, the green laser light source device has a low oscillation efficiency at low temperatures and takes a long time to start up. For this reason, immediately after the image display device is activated, green cannot be displayed, and a desired image display cannot be performed. For example, when a white image is displayed immediately after startup, green cannot be displayed, and a magenta color that is a mixed color of red and blue is obtained. As a countermeasure, it is possible to wait until the green laser light source device starts up after starting up and to display an image after the green laser light source device starts up, but this gives anxiety to the user and imposes a long standby time.

  The present invention has been devised to solve such problems, and its main purpose is to shorten the time from start-up to video display and also in the standby time until video is displayed. An object of the present invention is to provide an image display device that does not give anxiety to a user.

  The image display device of the present invention is based on video signals based on video signals of red, green, and blue light source devices that output red, green, and blue light components, respectively, and color light components that are output in time division from these light source devices. A spatial light modulator that modulates the light source, and a controller that controls the lighting of the light source device for each of a plurality of lighting sections constituting one frame and controls the output of each color light from the spatial light modulator. The control unit turns on the green light source device in the lighting allocation section of the green light source device until the irradiation light amount of the green light source device is equal to or greater than a predetermined value from the time of startup, In at least one of the lighting allocation sections of the light source devices other than green, the green light source device is turned on instead of the light source device to be originally turned on.

  According to the present invention, the rise time of the green laser light source device at the time of start-up can be shortened, and anxiety given to the user by displaying using a laser light source device other than the green laser light source device at the time of start-up. The feeling can be eliminated and the waiting time can be shortened.

The perspective view which shows the example which incorporated the image display apparatus by this invention in the portable information processing apparatus. Schematic configuration diagram of an optical engine unit built in the optical engine unit shown in FIG. The schematic diagram which shows the condition of the laser beam in the green laser light source device shown in FIG. Functional block diagram of the image display apparatus shown in FIG. The figure which shows the relationship between the conventional lighting sequence which lights a green laser light source device, a red laser light source device, and a blue laser light source device, and performs white display, and operation | movement of a spatial light modulation element The figure which shows the output immediately after starting lighting of a green laser light source apparatus by the conventional lighting sequence shown in FIG. The figure which shows the relationship between the conventional lighting sequence which lights a green laser light source device, a red laser light source device, and a blue laser light source device, and performs blue display, and operation | movement of a spatial light modulation element The figure which shows the relationship between the lighting sequence which lights a green laser light source device, a red laser light source device, and a blue laser light source device by embodiment of this invention, and performs blue display, and operation | movement of a spatial light modulation element The figure which shows the output immediately after starting lighting of a green laser light source device by the lighting sequence of this invention

  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. In the main body 3 of the portable information processing apparatus 2 (for example, a notebook PC), an accommodation space in which a peripheral device such as an optical disk apparatus is accommodated in a replaceable manner, a so-called drive bay is formed on the back side of the keyboard 4. The image display device 1 is attached to the drive bay.

  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 onto 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 condenser lens that collects the excitation laser light output from the semiconductor laser 51, and a rod 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, a base 58 that supports each part, and each part And a cover body 59 covering the.

  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 laser light (a direction orthogonal 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) VO4 (vanadate) with Nd (neodymium), and more specifically, Y of the base material YVO4. It 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 outputs 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 modulation element 25, but in the present embodiment, for convenience, the nth pixel of the spatial light modulation element 25. The pixel voltage signal is described as “LCOS ΔV”.

  The spatial light modulation element 25 is a reflective liquid crystal display element, so-called LCOS (Liquid Crystal On Silicon), and the laser light 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 the 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 of 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 The sign is inverted according to the reference voltage signal (LCOS VCOM).

  FIG. 5 is a diagram showing a relationship between a conventional lighting sequence in which white display is performed by turning on the green laser light source device 22, the red laser light source device 23, and the blue laser light source device 24, and the operation of the spatial light modulator 25. .

  In the conventional example shown in FIG. 5, one frame is divided into three lighting sections (subframes), and each frame is displayed to light green, red, and blue once. Lights up in blue order.

  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 lighting permission signal (LD ON) is output from the control unit 76 to the laser light source control unit 71, the red lighting signal (LD RON), the green lighting signal (LD GON), and the blue lighting signal (LD BON) are turned on. 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 white, the spatial light modulator 25 may modulate the red, green, and blue lasers, and the absolute value of the pixel voltage signal (LCOS | ΔV |) is the same for all of red, green, and blue. In the lighting sections A1 to A6, B1 to B6, and C1 to C3, the lowest 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, laser light is output to the spatial light modulator 25 in the order of red, green, and blue.

  However, the green laser light source device 22 has a low oscillation efficiency at low temperatures, and takes a long time to start up. FIG. 6 is a diagram showing an output immediately after the green laser light source device 22 starts to be turned on by the conventional lighting sequence shown in FIG. As shown in FIG. 6, it takes about 90 seconds after the start-up until the green output becomes stable and reaches, for example, a predetermined value of 0.25 W or more. For this reason, green cannot be displayed for a while after the image display device 1 is activated, or the amount of light that can be balanced with the laser light of other colors cannot be obtained, and a desired image display cannot be performed. Problems arise. For example, when a white image is displayed immediately after startup, green cannot be displayed, and a magenta color that is a mixed color of red and blue is obtained. Moreover, the display color changes with time and gradually approaches the display color that should normally be. Such an abnormal display color change state occurs not only in the white image but also in other images and videos. Therefore, since the user sees an image or video having a display color different from what he / she has as a prejudice, the image display device 1 may have failed even though it is not actually a failure. It will be misunderstood.

  In order to solve this problem, for example, there are the following means. FIG. 7 is a diagram showing a relationship between a conventional lighting sequence for performing blue display by turning on the green laser light source device 22, the red laser light source device 23, and the blue laser light source device 24, and the operation of the spatial light modulator 25. . As shown in FIG. 7, only blue is projected for a certain period of time from when the image display device 1 is activated until the output of the green laser light is considered to be stable. That is, a so-called blue background may be displayed. Then, even if the output of the green laser is not stable, no abnormality is seen in the projected image, so there is no problem.

  Here, when displaying blue, the blue light may be modulated by the spatial light modulation element 25, and the absolute value (LCOS | ΔV |) of the pixel voltage signal is determined by the blue lighting sections A3, A6, B3, B6, At C3, the minimum voltage is reached, and the output (luminance) is at the maximum level (255).

  However, this method can avoid the problem that an image or video having an abnormal display color change is displayed for a while immediately after startup due to the startup delay of the green laser light source device 22. The startup time of the device 1 is not shortened, and is insufficient for resolving the anxiety given to the user.

  In order to further improve this, for example, the control shown in FIG. 8 may be performed. FIG. 8 shows the relationship between the lighting sequence in which the green laser light source device 22, the red laser light source device 23, and the blue laser light source device 24 are turned on to perform blue display and the operation of the spatial light modulator 25 according to the embodiment of the present invention. FIG.

  In this embodiment, in addition to the sections A2, A5, B2, B5, and C2 in which the green laser light source device 22 is lit normally, the sections in which the laser light source devices other than green are lit (in FIG. 8, the red lighting section A1 and In A4, B1, B4, and C1), the green laser light source device 22 is turned on. In other words, the lighting allocation sections A 1, A 4, B 1, B 4, and C 1 of the red laser light source device 23 are originally devoted to the lighting of the green laser light source device 22. In addition, the additional lighting sections A1, A4, B1, B4, and C1 of the green laser light source device 22 are adjacent to the normal lighting sections A2, A5, B2, B5, and C2 of the green laser light source device 22. As a result, the overall lighting section of the green laser light source device 22 is lengthened, thereby promoting the heat generation of the excitation laser and improving the excitation efficiency. As a result, the startup time of the green laser light source device 22 can be shortened. it can. Although it takes time to start up the green laser light source device 22 at a low temperature, the startup time can be shortened by the heat generated by the laser itself by taking this embodiment.

  In the present embodiment, the lighting sections A3, A6, B3, B6, and C3 of the blue laser light source device 24 are not additionally used for lighting the green laser light source device 22. As for the lighting time of the blue laser light source device 24, for example, as in FIG. 7, only blue is projected for a certain time from when the image display device 1 is started until the output of the green laser light is considered to be stable. To do. That is, if a so-called blue background is displayed, even if the output of the green laser is not stable, no abnormality is seen in the projected image, so this is not a problem.

  FIG. 9 is a diagram showing an output when the green laser light source device according to the present invention is activated. After the start-up, the green output is shortened to 20 seconds, for example, until it stabilizes to a predetermined value of 0.25 W or more, so that the desired image display time can be shortened from 90 seconds to 20 seconds. As a result, it is possible to quickly switch to displaying a video desired by the user.

  Further, until the irradiation light quantity of the green laser light source device 22 becomes equal to or larger than a predetermined value, the section in which the green laser light source device 22 is turned on (in FIG. 8, the lighting sections A1, A2, A4, A5, B1, B2, In B4, B5, C1, and C2), the spatial light modulation element 25 is controlled so that the light emitted from the green laser light source device 22 is not projected to the outside, and the light source devices other than green are turned on (blue in FIG. 8). In the lighting sections A3, A6, B3, B6, and C3), the anxiety given to the user is eliminated by controlling the spatial light modulation element 25 so that the light emitted from the light source device is projected to the outside. be able to.

  In the present embodiment, the blue background is displayed for a certain time immediately after the image display device 1 is activated. However, if any of the lighting sections of the laser light source device other than the green light source is used for the lighting of the green laser light source and the green laser light is controlled not to be projected to the outside when the green laser light source is turned on, a display image is displayed. Does not have to be limited to a blue back. For example, a blue back may be displayed when normal, and a red back may be displayed when abnormal. Or you may make it display the start-up time meter using other than green and display the remaining time until start-up, or display the company logo, device operation method, and notes using other than green , Etc. may be displayed. In this case, while increasing the number of sections in which the green laser light source device 22 is turned on, blue and red are turned on every other frame in the section in which the light source devices other than green are turned on to perform color expression.

  As described above, according to the present invention, the startup time of the green laser light source device at the time of startup can be shortened, and at the time of startup, display is performed using a laser light source device other than the green laser light source device, It is possible to eliminate anxiety given to the user and shorten the waiting time.

  An image display device according to the present invention has an effect of shortening the start-up time of a green laser light source device at a low temperature, and includes a time-division display type image display device including a laser light source device using a semiconductor laser as a light source. Useful as.

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 (4)

Red, green, and blue light source devices that output red, green, and blue color lights, respectively;
A spatial light modulation element that modulates each color light output from each of these light source devices in a time-sharing manner based on a video signal;
A control unit that controls lighting of the light source device for each of a plurality of lighting sections constituting one frame, and controls output of each color light in the spatial light modulation element,
The control unit turns on the green light source device in the lighting allocation section of the green light source device until the irradiation light amount of the green light source device becomes equal to or more than a predetermined value from the time of startup, and the green light source device An image display device characterized in that the green light source device is turned on instead of the light source device to be originally turned on in at least one of the lighting allocation sections of the other light source devices. The section in which the green light source device is lit in place of the light source device to be originally lit in the one frame is adjacent to the lighting allocation section of the green light source device. Image forming apparatus. In the section in which the green light source is turned on until the irradiation light amount of the green light source device is equal to or greater than a predetermined value from the time of startup, the emitted light from the green light source device is not projected to the outside. The image display apparatus according to claim 1, wherein the spatial light modulation element is controlled. 4. The spatial light modulation element according to claim 3, wherein the spatial light modulator is controlled so that light emitted from the light source device is projected outside in at least one of the sections in which the light source devices other than green are turned on. Image display device.