JP2015145929A - image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device that has a wider color gamut.SOLUTION: An image display device 1 includes an active spectrum illumination 2 and a plurality of movable microscopic mirrors, and a digital mirror device 3 that reflects light from the active spectrum illumination. In this case, it is preferable that the image display device 1 includes a screen 4 on which the light reflected by the digital mirror device 3 is projected, although not limited thereto. In this case, it is also preferable that the image display device 1 includes a control device 5 that synchronizes the light-emission of the active spectrum illumination and the operation of the digital mirror device, although not limited thereto.

Description

  The present invention relates to an image display device. Specifically, the present invention relates to an image display device for displaying an image by projecting light from a light source onto a screen, a wall surface, etc., and more specifically, a projector device.

  So-called projectors that project images of light from a light source onto a screen or wall surface can display an image formed on a small display element using an optical member. There is an advantage that can be done.

  On the other hand, the wider the color range (color gamut) that can be expressed as an image, the higher the image quality. Therefore, widening the color gamut of the display device is a very important issue in improving the image quality.

  As a known technique for widening the color gamut of the projector, for example, the following non-patent document 1 realizes a 6-band wide color gamut projection by overlappingly projecting two RGB projectors having different transmission characteristics. Yes.

"High-fidelity video and still-image communication based on spectral information: Natural Vision system and italistics symposium." of SPIE-IS & T Electronic Imaging, SPIE Vol. 6062, 2006.

  However, since the technique described in the above-mentioned non-patent document uses two projectors, there is a problem that geometric correction is necessary and strict projection in pixel units is difficult. In addition, since a normal RGB light source is separated by a filter having two types of characteristics, the transmission characteristics are in a wide band, and there is a problem that a sufficiently wide color gamut cannot be projected for a color gamut that humans can approach. is there.

  In view of the above problems, an object of the present invention is to provide an image display device having a wider color gamut.

  An image display apparatus according to an aspect of the present invention that solves the above problems includes active spectral illumination and a digital mirror device that includes a plurality of movable micromirrors and reflects light from the active spectral illumination.

  Moreover, although not necessarily limited in this viewpoint, it is preferable to provide a screen that projects light reflected by the digital mirror device.

  Moreover, although not necessarily limited from this viewpoint, it is preferable to include a control device that synchronizes the light emission of the active spectral illumination and the operation of the digital mirror device.

  Moreover, although not necessarily limited in this viewpoint, it is preferable that the control device controls the active spectral illumination so that three or more kinds of light in different wavelength ranges are sequentially emitted with a half-value width of 20 nm.

  In this aspect, it is preferable that the control device controls the active spectral illumination so as to emit light in different wavelength ranges in order of six or more light beams with a half-value width of 20 nm.

  In this aspect, the different wavelength ranges are preferably such that the respective peak wavelengths are 460 nm ± 5 nm, 490 nm ± 5 nm, 510 nm ± 3 nm, 520 nm ± 3 nm, 560 nm ± 5 nm, and 640 nm ± 5 nm.

  As described above, according to the present invention, an image display device having a wider color gamut can be provided.

It is a figure showing the outline of the image display device concerning an embodiment. It is a figure which shows the example of the spectrum of the light source of the image display apparatus which concerns on embodiment. It is a figure which shows the color gamut of the image display apparatus which concerns on embodiment. It is the photograph figure of the patch displayed in the image display apparatus which concerns on an Example. It is a figure which shows the result of a comparison with the other apparatus of the image display apparatus which concerns on an Example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention can be implemented in many different forms, and should not be construed as being limited to the following embodiments and examples.

  FIG. 1 is a schematic diagram of an image display apparatus (hereinafter referred to as “this apparatus”) 1 according to the present embodiment. As shown in the figure, the apparatus 1 includes an active spectral illumination 2, a plurality of movable micromirrors, a digital mirror device 3 that reflects light from the active spectral illumination 2, and the digital mirror device 3. And a control device 5 connected to and controlling the active spectral illumination 2 and the digital mirror device 3.

  In the present embodiment, the active spectroscopic illumination 2 emits light projected on the screen 4 and is a device capable of emitting light in various wavelength regions every predetermined period. Since the present apparatus 1 can use the active spectral illumination 2 to sequentially output light in a desired color region (close to a single color) every predetermined period, the observer is close to this single color. By dividing the light in the color region into time and seeing it in a short time, it can be synthesized in the brain and recognized as one color image.

  In the present embodiment, as described above, the time interval of light emitted by the active spectral illumination 2 is preferably short enough to allow an observer to recognize a plurality of single-color images as one color image. Although not limited, the time for emitting light in one wavelength range is 3 ms or more and 30 ms or less, more preferably 16 ms or less, and the repetition time for emitting light in a plurality of wavelength ranges is 20 ms or more and 100 ms or less. More preferably, it is in the range of 25 ms or more and 50 ms or less.

  The number of wavelength regions emitted by the active spectroscopic illumination 2 is not limited, but is required to be at least 3 or more, and preferably 6 or more. In this case, the wavelength range is not limited. However, when the number of wavelength regions (color regions) is 6 or more, at least each peak wavelength is 460 nm ± 3 nm, 490 nm ± 3 nm, 510 nm ± 3 nm. Preferably, it includes 520 nm ± 3 nm, 560 nm ± 3 nm, and 640 nm ± 3 nm.

  In the present embodiment, in the wavelength region of the light emitted by the active spectral illumination 2, at least one, preferably the full width at half maximum of all the wavelength regions is preferably 20 nm or less. By doing so, the light of each wavelength region can be made a color region closer to a single color, and an image display device with a wider color gamut can be obtained.

  As the structure of the active spectral illumination 2, a known structure can be adopted, and the configuration is not particularly limited. For example, a light source, a spectral member that splits light emitted from the light source, and a spectral member It is preferable that the light extraction member which extracts the light of a desired wavelength area | region among the lights disperse | distributed by 1 is provided. The light source is preferably a light source that includes the entire wavelength range of the light to be extracted. The light source is not limited, and examples thereof include a xenon lamp and a tungsten halogen lamp. Further, the spectroscopic member is not limited as long as it can be dispersed, but for example, a diffraction grating, a prism, or the like can be used. Also, the light extraction member is not limited as long as it can extract the dispersed light in a desired direction. For example, it is preferable to include a digital mirror device.

  Further, as described above, the digital mirror device 3 according to the present embodiment includes a plurality of movable micromirrors, and can reflect light from the active spectral illumination 2 in a desired direction. More specifically, a plurality of minute mirrors are arranged in a matrix on an integrated circuit formed on a conductive substrate, and a plurality of light beams incident on the mirror area are moved by moving each mirror movably. By dividing into regions and controlling the respective reflection directions, the light intensity at each pixel of the displayed image can be adjusted. That is, by using the digital mirror device 3, it is possible to obtain a monochromatic image expressed by the light intensity. In addition, as a digital mirror device, what is generally marketed can be used.

  In the present embodiment, the screen 4 projects the light reflected by the digital mirror device 3, and the projected light is displayed as an image. A commercially available screen 4 can be used as the screen 4 and is not particularly limited.

  In the present embodiment, the screen 4 is an example of an object to be projected, and is not limited as long as the observer can recognize light as an image by projecting light, and may be a wall surface of a building, for example.

  In the present embodiment, a control device 5 is provided. The control device 5 is electrically connected to the active spectral illumination 2 and the digital mirror device 3, and the timing at which the active spectral illumination 2 emits light and the digital mirror device 3 displays an image of light intensity on the screen 4. Therefore, it has a function of synchronizing the timing of the mirror drive performed for this purpose. By doing so, it is possible to form an image of light intensity for each light emission of the active spectral illumination, and by displaying this in order in a short time, the observer can recognize it as a color image. .

  In the present embodiment, the control device 5 is described as a configuration different from the active spectral illumination 2 and the digital mirror device 3, but it is not necessarily required to be provided as a configuration different from the active spectral illumination 2 and the digital mirror device 3. Alternatively, a configuration including a circuit having the same function as that of the control device 5 may be used. In this case, for example, when image information to be displayed by the digital mirror device 3 is rewritten, a circuit that emits the signal is provided, and the active spectroscopic illumination 2 receives this signal and synchronizes so as to emit the wavelength of light corresponding to the image information. It is good also as providing the circuit which takes.

  In the present embodiment, it is also preferable to include an information processing device 6 that outputs image data to the digital mirror device 3 and the control device 5. The digital mirror device 3 adjusts the angle of each micromirror so as to sequentially form images based on the image data output from the information processing apparatus 6. The image data may be image data received from the outside of the apparatus, but the image data optimized for the light of each color region by the information processing apparatus 6 so as to correspond to the active spectral illumination of the apparatus 1 separately. It is preferable that The image data may be provided with color information and intensity information for all pixels, or may be data that is only the difference from the image data displayed in the previous frame.

  As described above, an image display device having a wider color gamut can be provided by combining these devices.

  Next, an image display method using the present apparatus 1 will be described. First, prior to display, various parameters such as the number of color areas to be emitted, the peak wavelength (or wavelength range), and the emission time thereof are set for the active spectral illumination 2. Here, regarding the setting of the light emission time, it is preferable to set a frame period, more preferably to set a frame period and a subframe period. Here, the “frame period” refers to the time for repeating light emission of the entire set color areas, and the “subframe interval” refers to the time for light emission of each set color area within the frame period. . Specifically, when the number of color regions to be emitted is set to 6, light of each color region is emitted by 3 ms, and after a 1 ms interval, light of these six color regions is repeatedly emitted, the subframe period is 4 ms (3 ms + 1 ms), and the frame period is 24 ms (4 ms × 6).

  On the other hand, the control device 5 first outputs a frame trigger signal indicating the start of one frame period to at least one of the active spectral illumination 2 and the digital mirror device 3. After receiving this frame trigger signal, the active spectral illumination 2 sequentially emits light in a plurality of wavelength regions according to preset contents, and waits until the next frame trigger signal is input after the light emission is completed. When setting the subframe period, the control device 5 sequentially outputs the subframe trigger signal to the active spectral illumination 2 after the frame trigger signal, and the active spectral illumination 2 receives the subframe trigger signal in advance, It emits light in the set next wavelength region and waits until the next subframe trigger signal or frame trigger signal is output.

  Also, after receiving the frame trigger signal from the control device 5, the digital mirror device 3 also drives a plurality of micromirrors based on the image data received in advance or sequentially from the information processing device, and changes the angle to the state corresponding to the image data. Adjust. In the active spectroscopic illumination 2, since it is necessary to emit light in a plurality of wavelength regions within one frame and combine these lights into one color image, it is necessary to change the state of the micromirror for each of these light regions. Therefore, the rotation angle of the minute mirror is changed based on the image data for each set subframe period. Even in this case, as described above, when a subframe period is provided, the control device 5 outputs a subframe trigger signal to the digital mirror device 3 and receives the subframe trigger signal. The rotation may be changed to wait until the next subframe trigger signal is received.

  Then, by repeating the above operation for each frame, the observer can recognize it as a color image for each frame.

  In this example, the control device 5 actively generates a frame trigger signal and a sub-frame trigger signal. However, the control device 5 is not provided as a separate configuration, and the circuit of the digital mirror device 3 or the active spectral illumination 2 is provided. For example, the digital mirror device 3 starts the change process of the rotation angle of the micro mirror based on the next image data after completing the change process of the rotation angle of the micro mirror based on the image data for each subframe period. When the trigger signal is emitted before and the active spectral illumination 2 receives this trigger signal, the active spectral illumination 2 may emit light in a specific wavelength region, and this process may be repeated every subframe period. By doing in this way, it can implement | achieve with a simple structure, without providing the control apparatus 5 specially.

  As described above, according to this embodiment, an image display apparatus having a wider color gamut can be provided. Specifically, the present apparatus 1 can continuously emit a plurality of light in a color region close to a single color by using active spectral illumination, and the color region by irradiating and reflecting this light on a digital mirror device. A high-definition light intensity image close to a single color can be obtained every time. Since the active spectral illumination can arbitrarily determine the number of light regions, a wider color gamut can be achieved. In addition, by using active spectral illumination, light of various color regions can be extracted by one illumination, and there is no need to combine a plurality of light sources and devices as in the above-described known technology, and a complicated optical system. There is also an advantage that it can be simply configured without the necessity. By providing these control devices for synchronization, it becomes possible to control each frame, and it is also possible to change the number of colors and the wavelength range according to time and place, so that an image display device with a wide color gamut can be obtained. Will be able to provide.

  Here, this device was actually prototyped and the effect was confirmed. This will be specifically described below. First, as an active spectral illumination, a variable wavelength light source OL490 manufactured by Gooch and Housego was used. In addition, the digital mirror device adopts a digital mirror device built in DLP Light Craft (registered trademark) (DLP projector) manufactured by Texas Instruments, and light from the active spectral illumination is incident on this DLP. It was made to be. The DLP projector has a built-in system for driving the digital mirror device. By inputting image data, the micro mirror can be driven in accordance with the timing.

  In addition, the active spectral illumination was set to emit light in 6 regions each having a peak wavelength of 460 nm, 490 nm, 510 nm, 520 nm, 560 nm, and 640 nm every 20 ms. The spectral distribution of this light source is shown in FIG. 2, and the resulting display color gamut is shown in FIG. As shown in these drawings, it can be seen that a very wide color gamut can be achieved on the CIExy chromaticity diagram by using the active spectral illumination according to the present embodiment.

  On the other hand, the active spectroscopic illumination and the digital mirror device are connected to the information processing apparatus so that the image data can be output to the digital mirror device, and the signal emitted for each sub-frame emitted from the DLP projector. Is used as a sub-frame trigger signal, and this is output to the active spectral illumination.

Then, using an image display device, the patch was projected onto a screen (KIKUCHI, WPA-ST100), and the effect was confirmed. This photograph is shown in FIG. Although the figure differs greatly from the actual projected color due to the limitations of the camera's spectral sensitivity and display device, it can be confirmed that a wider color gamut can be projected visually compared to other projectors. It was. 5 and the table below, the color gamut of the image display apparatus of the present embodiment and the color gamuts of three existing projectors are compared, and in particular, the color gamut according to the standard (sRGB, NTSC) is compared in Table 1. Results are shown. Also from this result, it was confirmed that the image display apparatus of this example was very excellent.

  The present invention has industrial applicability as an image display device.

Claims (6)

Active spectral illumination,
An image display apparatus comprising: a plurality of movable micromirrors, and a digital mirror device that reflects light from the active spectral illumination. The image display apparatus of Claim 1 provided with the screen which projects the light reflected by the said digital mirror device.   The image display apparatus according to claim 1, further comprising: a control device that synchronizes light emission of the active spectral illumination and operation of the digital mirror device.   The image display device according to claim 3, wherein the control device controls the active spectral illumination so that three or more kinds of light in different wavelength ranges are sequentially emitted with a half-value width of 20 nm.   The image display device according to claim 3, wherein the control device controls the active spectral illumination so that light of different wavelength ranges is emitted in order with six or more kinds of light with a half-value width of 20 nm. 6. The image display device according to claim 5, wherein the different wavelength ranges are any of peak wavelengths of 460 nm ± 5 nm, 490 nm ± 5 nm, 510 nm ± 3 nm, 520 nm ± 3 nm, 560 nm ± 5 nm, and 640 nm ± 5 nm.