JP2006254165A - Projection display unit and display control method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To flexibly cope with a wide range of requests, from emphasis on brightness to emphasis on color regeneration. <P>SOLUTION: A color division means (30) includes three large-area spectral regions (R region 30a, G region 30b, B region 30c), respectively corresponding to the three primary colors of light, one middle-area spectral region (W region 30d) corresponding to white light, and two small-area spectral regions (sR region 30e, sB region 30f) positioned on both sides of the above middle-area spectral region and adjacent to either one of the large-area spectral regions. By driving a space light modulation means with R image, G image and B image in synchronism with each of the R region, the G region and the B region, color regeneration can be improved. Meanwhile, by driving the space light modulation means with a W image, even during a predetermined time before and after switching the R region, the G region and the B region, image brightness can be improved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projection display device such as a projector and a display control method thereof, and more particularly to a projection display device that enlarges and projects a color image on a screen or the like and a display control method thereof.

  The colors we see in everyday life are expressed in the colors of objects (object colors) expressed with paints and paints, and the three primary colors of light on display screens such as projection displays, television receivers, and personal computer displays. There are two types of light colors (light source colors).

  One of the differences between object color and light source color is the combination of primary colors. The primary colors of the object colors are magenta (Magenta or its English notation Magenta is abbreviated as M), yellow (yellow or its English notation Yellow is abbreviated as Y), blue green (cyan or its English notation Cyan. The primary light source colors are blue (blue or blue for the English notation B for short), green (green or green for the English notation Green for short), Red (red or its English notation Red is abbreviated as R). However, strictly speaking, the primary color “blue” of the light source color is not “purple blue” but “blue purple”. However, in this specification, it is unified to “blue” for convenience of explanation. That is, it is assumed that the three primary colors of the light source color are “red (R)”, “green (G)”, and “blue (B)”.

  One of the other differences between the object color and the light source color is the way the colors appear when the primary colors are mixed (color mixing effect). In other words, in the case of an object color, the more light is absorbed, the more light is absorbed, so the amount of reflected light is subtractively reduced, and the color gradually becomes dull. This is called subtractive color mixing. On the other hand, in the case of the light source color, mixing the colors directly increases the amount of light, and the colors become more vivid. This is called additive color mixing.

  A display device such as a projection display device is composed of a large number of pixels composed of three primary color dots of light, and variously utilizing the above “additive color mixture” by adjusting the brightness of each dot. Express the color.

  Here, the way of feeling the color is subjective, but if expressed on a certain scale, it can be expressed by three of hue (Hue), brightness (Brightness) and saturation (Saturation). These are called the three attributes of color. Hue is a difference in color and has the same meaning as what we usually perceive or express as “color”, such as red, green, and blue. Lightness refers to the brightness of a color. The brightest color is white and the darkest color is black. Saturation is the vividness of color. As the saturation decreases, it becomes a color that does not feel a “dull” color, and as the saturation increases, it becomes a “glare” color.

  FIG. 17 is a CIE chromaticity diagram (particularly, a CIExy chromaticity diagram with the coordinate axis set to xy) defined by the International Commission on Illumination (CIE). This chromaticity diagram is a schematic representation of the three attributes of color, and the broken line in the shape of a sail of a yacht is a spectral locus in the visible light range (about 380 nm to 780 nm). All colors visible to the human eye can be placed inside this spectral trajectory. On the same locus, several black circles are put for convenience, but the numerical value written in each black circle indicates the color wavelength (420 nm, 480 nm,..., 700 nm) in the xy coordinates. Represents. In addition, there is no special meaning in those numerical values. It is merely an example.

  A triangular figure drawn inside the spectrum locus is a color reproduction region of a color CRT (Cathode Ray Tube). The larger the area of the triangular figure, the more colors can be reproduced. Each vertex of the triangular figure is a color coordinate of red (R), green (G), and blue (B), and W, which is located at substantially the center of the triangular figure, is a standard light source color (white). The closer to W, the lower the “chromaticity”. Chromaticity refers to the color that is independent of luminance among the elements that we perceive as being particularly related to color, and in many cases, chromaticity is divided into “hue” and “saturation”.

  Thus, in the CIExy chromaticity diagram, the chromaticity of all colors, that is, “hue” and “saturation” can be represented by xy coordinates. In addition, “brightness” among the three attributes of color can be expressed by another axis (z-axis). That is, this CIExy chromaticity diagram represents one surface obtained by cutting a three-dimensional figure extending in the front and back direction of the drawing perpendicularly to the z axis, and represents lightness at a position orthogonal to the z axis, that is, the position of the circular cut. . The origin position of the z-axis is zero brightness, and the higher the 3D figure, the wider the dynamic range of brightness.

  Based on such basic knowledge of colors, a conventional projection display device (hereinafter referred to as a conventional device) will be described (for example, see Patent Document 1).

  FIG. 18A is a structural diagram of a color wheel used in a conventional apparatus. The color wheel is an optical device for splitting white light into three primary colors (RGB) of light on the time axis. Although the basic color wheel has only three regions of RGB, here, in addition to RGB, the one having a white light transmission region (W) is shown. That is, the illustrated color wheel 1 divides a glass disk having a motor shaft attachment portion 2 in the center portion into four equal portions by 90 degrees radially, and each divided portion is divided into a red spectral region (R region 1a), a green portion. Spectral region (G region 1b), blue spectral region (B region 1c), and white light transmission region (W region 1d).

  The color wheel 1 is driven to rotate by a motor (not shown), and a white spot light 3 from a light source (not shown) is irradiated to a predetermined portion of the color wheel 1 at the time of rotation. It has become.

  The size of the spot light 3 is sufficiently smaller than the sizes of the R region 1a, the G region 1b, the B region 1c, and the W region 1d. Therefore, for example, if the rotation direction of the color wheel 1 is counterclockwise as viewed in the drawing, when the spot light 3 is irradiated on the R region 1a, red light is extracted from the color wheel 1, and When the light 3 is irradiated on the G region 1b, green light is extracted from the color wheel 1, and when the spot light 3 is irradiated on the B region 1c, blue light is extracted from the color wheel 1, When the spot light 3 is irradiated on the W region 1d, white light is extracted from the color wheel 1.

  18B to 18D show a state when the spot light 3 crosses the boundary line 4 of the region (hereinafter referred to as a cross-border state). As will be described in detail later, in this cross-border state, the spot light 3 is irradiated on a single region (R region 1a in the figure) as shown in FIG. From FIG. 18C, an irradiation state straddling two regions (R region 1a and G region 1b in the figure) is performed, and then a single region (FIG. 18D) is again obtained. Then, transition is made to the irradiation state to the G region 1b).

  The duration of FIG. 18C in the cross-border state, that is, the duration of the irradiation state across the two regions (R region 1a and G region 1b in the figure) is the diameter of the spot light 3, that is, FIG. As shown in (), the angle increases in proportion to the angle α between the boundary line 4 between the two regions and the circumscribed line 5 of the spot light 3. For example, when the angle α is set to 30 degrees for convenience, the spot light 3 is irradiated 15 degrees before and after the boundary line 4 between the two regions, that is, while the angle α (= 30 degrees) is being irradiated, FIG. Continue the state.

FIG. 19 is a timing chart for driving the color wheel in the conventional apparatus. In this figure, an R image, a G image, a B image, and a W image are image signals given to the light modulation elements (see DMD 33 described later: FIG. 2) in a time division manner. The R image is a red image extracted from the RGB frame image, the G image is a green image extracted from the frame image, the B image is a blue image extracted from the frame image, and the W image is extracted from the frame image. It is a white image (image with only luminance information). Note that the W image (white image) can be created by combining the R image, the G image, and the B image at a predetermined ratio, as shown in the following equation (1).
W = 0.299R + 0.587G + 0.114B (1)

  As shown in this figure, the R image, the G image, the B image, and the W image are synchronized with the rotation position of the color wheel 1 (the positions of the R region 1a, the G region 1b, the B region 1c, and the W region 1d). A color image is displayed on the screen by irradiating the screen with an illumination beam consisting of red, green, blue and white modulated light that is sequentially applied to the light modulation elements and modulated by these images. can do.

  Here, the projection display device has two usage styles, that is, an application that emphasizes color reproducibility such as a home theater, and an application that emphasizes brightness such as a presentation. When emphasizing color reproducibility, the color purity of each color region (R region 1a, G region 1b, and B region 1c) of the color wheel 1 may be increased so as to be as close to the primary color as possible. However, in this case, the light transmittance is reduced, and brightness cannot be secured. Therefore, this case is not suitable for presentation use. Conversely, if the transmittance of each color region (R region 1a, G region 1b, and B region 1c) of the color wheel 1 is increased in order to obtain sufficient brightness, the color purity is impaired, which is not suitable for home theater use. Become. The brightness can be secured by increasing the light amount of the light source, but there are limits in terms of heat generation and power consumption.

  From such a background, in the illustrated conventional apparatus, the driving time of the W image can be varied. That is, as shown by the arrow “A” in FIG. 19, the W image drive time is lengthened to ensure brightness, while the W image drive time is shortened to ensure color reproducibility. Thus, it can be adapted to the above two applications.

  In the prior art, a period in which the spot light 3 crosses the boundary line 4 between the two regions (a period in which the spot light is in the above-mentioned boundary state), that is, the spot light 3 has a boundary between the R region 1a and the G region 1b and Although there is no description about a period of 15 degrees (α / 2) before and after crossing the boundary of the B region 1c, for example, if this period is driven with a W image, it is considered that the brightness can be further increased. .

  FIG. 20 is a timing chart for driving a color wheel that is driven with a W image even in a cross-border state. As shown in this figure, the drive period of the W image is not limited to the W area 1d of the color wheel 1, but 15 degrees (= α) before and after the boundary of each area, that is, the boundary line between the R area 1a and the G area 1b. 15 degrees before and after the boundary line between the G area 1b and the B area 1c, 15 degrees before and after the boundary line between the B area 1c and the W area 1d, and 15 degrees before and after the boundary line between the W area 1d and the R area 1a. For this reason, the total driving period of the W image is an angle of the W region 1d + 3α = 90 degrees + 30 degrees + 30 degrees + 30 degrees. It becomes possible to drive with an image, and the brightness can be further increased.

Japanese Patent Application Laid-Open No. 2004-45589

  However, in the above-described conventional apparatus, when the W image is driven for a long period of 180 degrees corresponding to approximately half of the circumference of the color wheel 1, it is preferable in that the brightness can be increased, but on the other hand, the W image However, only the R and G and B images and their complementary color images (C image, M image, and Y image) are unbalanced.

  FIG. 21 is a CIExy chromaticity diagram of the conventional apparatus and a conceptual diagram of brightness for each image. In this CIExy chromaticity diagram, each vertex of the triangular figure is color coordinates of red (R), green (G), and blue (B), respectively, similarly to the CIExy chromaticity diagram. C (cyan) is a complementary color of G and B (G + R), M (magenta) is a complementary color of R and B (R + B), and Y (yellow) is a complementary color of R and G (R + G).

  When the brightness of each image of R, G, B, C, M, Y, and W is compared, as shown in FIG. 5B, it is generally “R: G: B: C: M: Y: W = 1: 1: 1: 2: 2: 2: 9 ”, and the value of W is extremely high. This is because, as described above, the W image is driven over a long period of 180 degrees corresponding to approximately half of the circumference of the color wheel 1.

  Generally, the proper ratio of R, G, B, C, M, Y and W is about “1: 1: 1: 2: 2: 2: 3”, ie, R, G, B and C, M and Y are about “1: 2”, and R, G, B, and W are about “1: 3”. It is said that an ideal balance between color and brightness can be obtained at this ratio, but the ratio of the conventional apparatus is far from this balance, so there is a problem that the color looks dull.

  Accordingly, an object of the present invention is to enable the drive pattern of each region of the color wheel and each image to be changed flexibly, and thus to be able to meet a wide range of demands from brightness emphasis to color reproducibility emphasis. To provide a display device and a display control method thereof.

According to a first aspect of the present invention, a light source that generates white spot light, a color dividing unit that color-divides the spot light from the light source in a time-division manner, and each of the color-divided divided colors is a space in an image signal. Spatial light modulation means for performing light modulation, projection means for projecting light modulated by the spatial light modulation means, and an image for selecting an image signal applied to the spatial light modulation means in synchronization with the color division of the color division means Signal selection means, and the color dividing means includes three large area spectral regions corresponding to each of the three primary colors of light, one medium area spectral region corresponding to white light, and both sides of the medium area spectral region. Two small-area spectral regions that are positioned adjacent to any one of the large-area spectral regions, and the image signal selection means is configured such that the color division of the color dividing means is an arbitrary large area. Is done by spectral region A color information image signal corresponding to the large area spectral region is selected during the interval, and a luminance information image signal is selected while being performed by the medium area spectral region or the small area spectral region. This is a projection display device.
Here, the “white spot light” refers to a light beam that is narrowly narrowed and contains at least light having a wavelength in the visible light region. This light beam is preferably parallel light. However, in practice, if the spot can be maintained within a short distance from the light source to the spatial light modulation means through the color dividing means, it has a slight spread. It may be a light beam. The “spatial light modulating means” modulates the spot light according to the pixel information of the image signal, and is, for example, a DMD or a liquid crystal device.
According to a second aspect of the present invention, there is provided a light source that generates white spot light, a color dividing unit that color-divides the spot light from the light source in a time-division manner, and a space for each of the color-divided divided colors by an image signal. Spatial light modulation means for performing light modulation, projection means for projecting light modulated by the spatial light modulation means, and an image for selecting an image signal applied to the spatial light modulation means in synchronization with the color division of the color division means Signal selection means, and the color dividing means includes three large area spectral regions corresponding to each of the three primary colors of light, one medium area spectral region corresponding to white light, and both sides of the medium area spectral region. Two small-area spectral regions that are positioned adjacent to any one of the large-area spectral regions, and the image signal selection means is configured such that the color division of the color dividing means is an arbitrary large area. Is done by spectral region In the meantime, the image signal of color information corresponding to the large area spectral region is selected, and when switching from any large area spectral region to another large area spectral region, the luminance is maintained for a predetermined time before and after the switching. When the image signal of information is selected and the color division of the color dividing unit is performed by the small area spectral region and the medium area spectral region, the switching is performed from the large area spectral region to the small area spectral region. The projection display device is characterized in that the image signal of the luminance information is selected for a predetermined time and before a predetermined time after switching from the small area spectral region to the large area spectral region.
According to a third aspect of the present invention, there is provided a color division step of time-dividing white spot light, a spatial light modulation step of spatially modulating each of the divided colors by an image signal, and the spatial light. A projection step of projecting light modulated by the modulation step; and an image signal selection step of selecting an image signal to be given to the spatial light modulation step in synchronization with a color division timing of the color division step, the color division step Is one of three large area spectral regions corresponding to each of the three primary colors of light, one medium area spectral region corresponding to white light, and one of the large area spectral regions located on both sides of the medium area spectral region. And a color wheel having two small-area spectral regions adjacent to each other, and the image signal selection step is performed when the color division of the color division step is performed by an arbitrary large-area spectral region. Done A color information image signal corresponding to the large area spectral region is selected during the interval, and a luminance information image signal is selected while being performed by the medium area spectral region or the small area spectral region. This is a display control method.
According to a fourth aspect of the present invention, there is provided a color dividing step of color-dividing white spot light in a time division manner, a spatial light modulation step of spatially modulating each of the divided colors by an image signal, and the spatial light. A projection step of projecting light modulated by the modulation step; and an image signal selection step of selecting an image signal to be given to the spatial light modulation step in synchronization with a color division timing of the color division step, the color division step Is one of three large area spectral regions corresponding to each of the three primary colors of light, one medium area spectral region corresponding to white light, and one of the large area spectral regions located on both sides of the medium area spectral region. And a color wheel having two small-area spectral regions adjacent to each other, and the image signal selection step is performed when the color division of the color division step is performed by an arbitrary large-area spectral region. Done In the meantime, the image signal of color information corresponding to the large area spectral region is selected, and when switching from any large area spectral region to another large area spectral region, the luminance is maintained for a predetermined time before and after the switching. When the image signal of information is selected and the color division in the color division step is performed by the small area spectral region and the medium area spectral region, the switching is performed from the large area spectral region to the small area spectral region. The display control method is characterized in that an image signal of luminance information is selected for a predetermined time before and after a predetermined time after switching from the small area spectral region to the large area spectral region.

According to the present invention, when the color division timing of the color division unit is changed from one of the three primary colors of light to another color division, the image signal is switched to the image signal corresponding to the color division after the replacement. It is done.
Here, the color dividing means is positioned on both sides of the three large area spectral regions corresponding to the three primary colors of light, one medium area spectral region corresponding to white light, and the large area spectral region. Two small area spectral regions adjacent to one of the area spectral regions. For example, the three large area spectral regions correspond to an R region, a G region, and a B region in an example described later. The medium area spectral region corresponds to the W region in the embodiment, and the two small area spectral regions correspond to the sR region and the sB region in the embodiment.
In such a configuration, the spatial light modulator is driven by the R image, the G image, and the B image in synchronization with each of the R region, the G region, and the B region, and is synchronized with the sR region, the W region, and the sB region. If the spatial light modulation means is driven with a W image, the color reproducibility can be improved. On the other hand, the spatial light modulation means can also be used for a predetermined time before and after switching between the R area, the G area, and the B area. If it is driven with, the brightness of the image can be improved.

  Embodiments of the present invention will be described below with reference to the drawings, taking a projector as an example. It should be noted that the specific details or examples in the following description and the illustrations of numerical values, character strings, and other symbols are only for reference in order to clarify the idea of the present invention, and the present invention may be used in whole or in part. Obviously, the idea of the invention is not limited. In addition, a well-known technique, a well-known procedure, a well-known architecture, a well-known circuit configuration, and the like (hereinafter, “well-known matter”) are not described in detail, but this is also to simplify the description. Not all or part of the matter is intentionally excluded. Such well-known matters are known to those skilled in the art at the time of filing of the present invention, and are naturally included in the following description.

  FIG. 1 is an external view of a projector 10 as a projection display device. The projector 10 shown as one example has a housing 11 having a shape designed in an arbitrary design (in the illustrated example, a rectangular parallelepiped shape), and is hidden behind the cover 12 on the front surface of the housing 11. A projection lens 34 is provided. The cover 12 is normally in the illustrated position and hides (protects) the projection lens 13, but the projection lens 34 is exposed so as to face a screen (not shown) by sliding the cover 12 manually. To do.

  The projection lens 34 is for projecting a light image formed by the DMD 33 described later. Here, the focus and the projection magnification (zoom) can be arbitrarily changed.

  A main body operation display unit 14, a top cover 15, and a speaker 16 are disposed on the top surface of the housing 11. The main body operation display unit 14 is constituted by a flat display device (a liquid crystal display panel, an organic display panel, an EL panel, or the like) with a touch panel, and the main body operation display unit 14 has various operation buttons necessary for each operation state. When a corresponding button is touch-operated in a graphical display, an operation event signal is generated, and when an operation abnormality occurs, the contents thereof are displayed as a character string or a graphic.

  The speaker 16 amplifies and outputs the video information and the audio information of the presentation software when projecting the video or executing arbitrary presentation software.

  A main body subkey 17 that is normally hidden and invisible is provided under the top cover 15, and this main body subkey 17 is used when performing detailed operation settings other than button operations displayed on the main body operation display unit 14. The upper surface cover 15 is appropriately opened and operated.

  FIG. 2 is an internal block diagram of the projector 10. The projector 10 includes a speaker 16, an audio processing unit 18, a display driving unit 19, a main body operation display unit 14 (a flat display device 14a, a touch panel 14b), an operation unit 20 including a main body subkey 17, a central control unit 21 (image signal selection means). ), Input / output connector 22, input / output I / F 23, image conversion unit 24, video RAM 25 (including at least an R image plane 25a, a G image plane 25b, and a B image plane 25c), a projection encoder 26, a projection drive unit 27, and a reflector 28, light source 29, color wheel 30 (color division means), color wheel drive motor 31, color wheel rotation angle sensor 32, DMD 33 (spatial light modulation means), projection lens 34 (projection means), focus / zoom drive motor 35, cooling fan 36, cooling fan drive motor 37, etc. It contains the phrase.

  The central control unit 21 graphically displays necessary operation buttons on the flat display device 14 a of the main body operation display unit 14 via the display drive unit 19. When an arbitrary operation button is touch-operated by the user, the touch coordinates are detected by the touch panel 14b, and the central control unit 21 specifies the type of the touch-operated button based on the detected coordinates, and the specification result (For example, a projection condition setting mode such as focus and zoom and a display control mode described later).

  Further, the central control unit 21 is necessary for setting the resolution of the input image, the selection of the used terminal of the input connector unit 20, the presence / absence of sound, etc., on the flat display device 14a of the main body operation display unit 14 via the display driving unit 19. Graphical display of operation buttons. When an arbitrary operation button is touch-operated by the user, the touch coordinates are detected by the touch panel 14b, and the central control unit 21 specifies the type of the touch-operated button based on the detected coordinates, and the specification result The setting operation corresponding to is executed.

  For example, when the resolution of the input image is XGA (1024 × 768 pixels), the input terminal of the input connector unit 20 is an RCA terminal, and there is sound, the input / output I / F 23 is controlled and the terminal of the input / output connector 22 is controlled. (RCA terminal) is selected, an input image and sound from an external device added to the terminal are taken in, and they are transferred to the image conversion unit 24 and the sound processing unit 18.

  Further, the central control unit 21 gives a display control mode (hereinafter referred to as a first display control mode) emphasizing color reproducibility and brightness priority to the flat display device 14a of the main body operation display unit 14 via the display drive unit 19. When a button for selecting a display mode (hereinafter referred to as a second display control mode) is displayed and the user touches and selects an appropriate one of the buttons according to the use at that time, the touch coordinates are displayed. Is detected by the touch panel 14b, and the central control unit 21 specifies the type of the touch-operated button (first display control mode, second display control mode) based on the detected coordinates, The corresponding display control mode is executed.

  The audio processing unit 18 amplifies the sound and outputs the sound through the speaker 16, and the image conversion unit 24 converts the input image into a predetermined format and transfers the converted image to the projection encoder 26.

  The projection encoder 26 develops and stores the received image signal in the video RAM 25 (R image → R image plane 25a, G image → G image plane 25b, B image → B image plane 25c), and then the video RAM 25 Are stored in the order of R image, G image, and B image, and the W image is generated from the R image, G image, and B image (see the previous equation (1)).

  The projection drive unit 27 drives the DMD 33 with a frame image of, for example, 30 frames / second composed of the R image, the G image, the B image, and the W image.

  A DMD (Digital Micro-mirror Device) 33 is a semiconductor integrated optical switch in which a large number of minute movable mirrors are spread on a plane. The size of the movable mirror is, for example, a dozen μm square, and the movable mirror is attached to the column so that the inclination changes by about ± 10 degrees when the mirror is on and off. A memory element is formed immediately below the mirror, and the on / off state of the mirror is switched by the positive electric field effect of the memory element. The amount of light reflected by the DMD 33 is maximum (white gradation) when the mirror is turned on and is minimum (black gradation) when the mirror is turned off, but the switching speed (switching speed between on and off) of each mirror is set every second. Since the number of times can be increased to 500,000 times or more, the amount of reflected light of the DMD 33 can be set to an intermediate gradation (gray scale) by changing the switching ratio of each mirror.

  When such a DMD 33 is irradiated with a high-intensity white spot light Pa from a light source 29 such as an ultra-high pressure mercury lamp disposed in the reflector 28, the reflected light Pb is turned on and off for each mirror of the DMD 33 and its switching. The light modulation is performed for each pixel corresponding to the ratio (the light modulation is performed for each pixel in accordance with the content of the image signal), and this reflected light Pb is projected onto a screen (not shown) via the projection lens 34, thereby the on-screen. An enlarged image of the image signal can be projected onto the screen.

  However, in the illustrated example, the number of DMDs 33 is one, and the spot light Pa emitted from the light source 29 is “white light”. In this case, only a monochrome image can be projected on the screen. Therefore, in actuality, the color wheel 30 is disposed in front of the light source 29 so that the color wheel 30 is rotationally driven by the color wheel driving motor 31 and the image signal is developed and stored in the video RAM 25. The video signal components for each of the three primary colors (RGB) of light are developed and stored. In the present embodiment, as will be described later, in addition to the R image, the G image, and the B image, a W image is also required. For this W image, for example, using the above equation (1), The R image, the G image, and the B image are obtained by calculation.

  FIG. 3A is a front view of the color wheel 30. In the color wheel 30 of the present embodiment, three regions of the disk-shaped transparent plate divided into four equal portions of 90 degrees are respectively formed as an R region 30a, a G region 30b, and a B region 30c. The center portion (the 60 ° portion excluding 15 ° on both sides) is set as the W region 30d, and the 15 ° portions on both sides of the W region 30d are set in the sR region 30e (small area spectroscopic region) and the sB region 30f (small size). Area spectral region). The R region 30a and the sR region 30e are regions having spectral characteristics of “red” light in the visible light region. Similarly, the B region 30c and the sB region 30f are regions having spectral characteristics of “blue” light, and the G region 30b is a region having spectral characteristics of “green” light. The W region 30d is a transparent region that transmits the entire light in the visible light region. Note that “s” in the sR region 30e and the sB region 30f is a mere identification symbol for distinguishing from the R region 30a and the G region 30b.

  The respective regions on the color wheel 30 are arranged in the order of R region 30a → G region 30b → B region 30c → sR region 30e → W region 30d → sB region 30f in the clockwise direction as viewed in the drawing. The region 30e is located between the B region 30c and the W region 30d, and the sB region 30f is located between the W region 30f and the R region 30a.

  The area of each of the R region 30a, the G region 30b, the B region 30c, the W region 30d, the sR region 30e, and the sB region 30f is the same and the maximum in the R region 30a, the G region 30b, and the B region 30c. Since 30d is the next, and the sR region 30e and the sB region 30f have the same area and the smallest, the R region 30a, the G region 30b, and the B region 30c correspond to the “large-area spectral region” described in the gist of the invention. The region 30d corresponds to the “medium area spectral region” described in the gist of the invention, and the sR region 30e and the sB region 30f correspond to the “small area spectral region” described in the gist of the invention.

  A circular opening 30g for attaching the shaft of the color wheel driving motor 31 is formed in the central portion of the transparent plate of the color wheel 30. Further, a predetermined position (in the figure, the outer peripheral edge of the transparent plate of the color wheel 30). A reference hole 30i that indicates a reference position for detecting the rotation angle of the color wheel 30 is formed at a position deviated 15 degrees in the clockwise direction from the boundary line 30h between the R region 30a and the sB region 30f.

  FIG. 3B is a correspondence diagram between the color wheel 30 and the color wheel rotation angle sensor 32. The color wheel rotation angle sensor 32 includes a U-shaped body 32c having a light emitting portion 32a and a light receiving portion 32b built in, and the body 32c sandwiches the vicinity of the outer peripheral edge of the transparent plate of the color wheel 30 in a non-contact state. The light from the light emitting part 32a that has passed through the reference hole 30i of the wheel 30 is received by the light receiving part 32b, and an intermittent rotation angle detection signal CP corresponding to the presence or absence of the light is output.

  FIG. 3C is a waveform diagram of the rotation angle detection signal CP. The rotation angle detection signal CP maintains a low level while the light from the light emitting unit 32a is blocked by the transparent plate, but rises to a high level when the light from the light emitting unit 32a passes through the reference hole 30i of the transparent plate. . Since the color wheel 30 is rotationally driven at a predetermined speed by the color wheel driving motor 31, the light from the light emitting portion 32a passes through the reference hole 30i of the transparent plate for a moment. Accordingly, the rotation angle detection signal CP instantaneously rises to a high level once for each rotation of the color wheel 30. If the rising point of the high level is 0 degree, the rotation angle detection signal CP is changed from the high level to the high level. The rotation angle (0 to 360 degrees) of the color wheel 30 that changes every moment in the period up to can be expressed.

  4A and 4B are diagrams showing the spectral characteristics of each region of the color wheel 30. FIG. 4A shows the spectral characteristics of the R region 30a and the sR region 30e, FIG. 4B shows the spectral properties of the G region 30b, and FIG. The spectral characteristics of the region 30c and the sB region 30f are shown. In these figures, the vertical axis represents light transmission intensity, and the horizontal axis represents light wavelength. The wavelength of green light is shorter than the wavelength of red light, and the wavelength of blue light is even shorter. Three areas (R, G, B) divided by broken lines in the figure indicate wavelength bands for convenience of red light, green light, and blue light. As shown in FIG. 5A, the spectral characteristic of red light is obtained by increasing the transmittance of the R region 30a and the sR region 30e. Similarly, as shown in FIG. (B), the spectral characteristic of green light is obtained by increasing the transmittance of the G region 30b, and as shown in FIG. (C), the spectral characteristic of blue light is It is obtained by increasing the transmittance of the B region 30c and the sB region 30f.

  FIG. 5 is a correspondence diagram between the spot light Pa emitted from the light source 29 and the color wheel 30. In this figure, the optical axis P of the spot light Pa is fixed at a predetermined position on the radius of the color wheel 30, and the spot light Pa is relatively moved in the circumferential direction of the color wheel 30 as the color wheel 30 rotates. It is designed to move.

  Here, when the left and right circumscribing lines La and Lb of the spot light Pa intersect at the rotation center O of the color wheel 30, the intersection angle θ and each of the sR region 30e and the sB region 30f formed in the color wheel 30 The diameter (AB) of the spot light Pa may be set so that the angle (30 degrees) that is twice the angle (15 degrees) is equal. Since θ = 30 degrees now, the diameter (AB) of the spot light Pa is given by “2 × OA × (sin θ / 2)”. OA is the distance from the rotation center O of the color wheel 30 to the point A of the spot light Pa. For example, if OA = 10 mm, AB = 5.18 mm. Therefore, if the diameter of the spot light Pa is 5.18 mm, each angle of the sR region 30e and the sB region 30f formed on the color wheel 30 (15 The angle (30 degrees) twice the angle (degrees) and the crossing angle θ can be matched.

  6 to 9 are diagrams showing the rotation state of the color wheel 30. For example, FIG. 6A is a state diagram when the rotation angle of the color wheel 30 is 0 degrees, and FIG. 6B is the same rotation. FIG. 6C is a state diagram when the rotation angle is 90 degrees, FIG. 7A is a state diagram when the rotation angle is 150 degrees, and FIG. ) Is a state diagram when the rotation angle is 180 degrees, FIG. 7C is a state diagram when the rotation angle is 240 degrees, FIG. 8A is a state diagram when the rotation angle is 255 degrees, FIG. 8B is a state diagram when the rotation angle is 270 degrees, FIG. 8C is a state diagram when the rotation angle is 285 degrees, and FIG. 9A is a state when the rotation angle is 315 degrees. FIG. 9B is a state diagram when the rotation angle is 330 degrees, and FIG. 9C is a state diagram when the rotation angle is 345 degrees.

  Of these rotation angles, 0 degrees is when the reference hole 30 i formed in the color wheel 30 coincides with the position of the color wheel rotation angle sensor 32. When the color wheel 30 is rotated counterclockwise on the basis of the rotation angle (0 degree) at this time, the rotation angle gradually increases, and when the color wheel 30 makes one rotation, it returns to 0 degree again. Thereafter, this change in the rotation angle is repeated.

  Here, each rotation angle (0 degree, 60 degree, 90 degree, 150 degree, 180 degree, 240 degree, 255 degree, 270 degree, 285 degree, 315 degree, 330 degree and 345 degree) is unique. Is an angle. That is, if the rotation direction of the color wheel 30 is a counterclockwise direction toward the drawing, 0 degree is an angle immediately after the spot light Pa exits the sB region 30f (see FIG. 6A), and 60 degrees. Is the angle immediately before the spot light Pa enters the G region 30b (see FIG. 6B). Further, 90 degrees is an angle immediately after the spot light Pa exits the R region 30a (see FIG. 6C), and 150 degrees is an angle just before the spot light Pa enters the B region 30c (FIG. 7 (c)). a)). Further, 180 degrees is an angle immediately after the spot light Pa exits the G region 30b (see FIG. 7B), and 240 degrees is an angle just before the spot light Pa enters the sR region 30e (FIG. 7 ( c)).

  Further, 255 degrees is an angle at which the spot light Pa straddles two areas (B area 30c and sR area 30e) (see FIG. 8A), and 270 degrees is also the area where the spot light Pa is two areas (sR area). 30e and the W region 30d) (see FIG. 8A).

  Further, 285 degrees is an angle immediately after the spot light Pa exits the sR region 30e (see FIG. 8C), and 315 degrees is an angle just before the spot light Pa enters the sB region 30f (FIG. 9 ( a)).

  330 degrees is an angle at which the spot light Pa straddles two regions (W region 30d and sB region 30f) (see FIG. 9B), and 345 degrees also includes the spot light Pa in two regions (sB region). 30f and the R region 30a) (see FIG. 9C).

  When the rotation angle changes of the color wheel 30 are put together, they can be classified into the following three patterns.

<Pattern in which spot light Pa is applied to a single region>
Between 0 degree to 60 degrees, 90 degrees to 150 degrees, 180 degrees to 240 degrees, 285 degrees to 315 degrees, since the spot light Pa is located in a single region, it is a pure one from the color wheel 30. Only one color of light is extracted. That is, between 0 degrees and 60 degrees, since the spot light Pa is located only in the R region 30a, only pure red light is extracted from the color wheel 30. Similarly, between 90 degrees and 150 degrees, since the spot light Pa is located only in the G region 30b, only pure green light is extracted from the color wheel 30. Further, since the spot light Pa is located only in the B region 30c between 180 degrees and 240 degrees, only pure blue light is extracted from the color wheel 30, and between 285 degrees and 315 degrees. Since the spot light Pa is located only in the W region 30d, only pure white light is extracted from the color wheel 30.

<Pattern irradiated with spot light Pa over two regions>
Between 60 degrees to 90 degrees, 150 degrees to 180 degrees, 240 degrees to 255 degrees, 270 degrees to 285 degrees, 315 degrees to 330 degrees, 345 degrees to 360 degrees (0 degrees), the spot light Pa is in two regions. Therefore, the color wheel 30 takes out the mixed color of these two areas. That is, since the spot light Pa is located between the R region 30a and the G region 30b between 60 degrees and 90 degrees, the color wheel 30 has a yellow color that is a mixed color (R + G) of these two areas. Light is extracted. This mixed color (yellow) linearly changes from yellow close to red to yellow close to green as the rotation angle of the color wheel 30 increases from 60 degrees to 90 degrees.

  Similarly, between 150 degrees and 180 degrees, since the spot light Pa is located across the G area 30b and the B area 30c, the color wheel 30 is a mixed color (G + B) of these two areas. Cyan light is extracted. The mixed color (cyan) linearly changes from cyan close to green to cyan close to blue as the rotation angle of the color wheel 30 increases from 150 degrees to 180 degrees. Further, since the spot light Pa is located between the B region 30c and the sR region 30e between 240 degrees and 255 degrees, magenta that is a mixed color (B + R) of these two regions from the color wheel 30. Light is extracted. The mixed color (magenta) linearly changes from magenta close to blue to magenta close to red as the rotation angle of the color wheel 30 increases from 240 degrees to 255 degrees.

  In addition, since the spot light Pa is located between the sR region 30e and the W region 30d between 270 degrees and 285 degrees, the brightness that is a mixed color (R + W) of these two regions from the color wheel 30. Variable red light is extracted. “Brightness variable” red light means a color that increases in brightness according to the proportion of W, and a color that turns white with no color when it becomes brightest. The mixed color (luminance variable red) is linear from luminance half-red to white (colorless) that uniformly includes red and white as the rotation angle of the color wheel 30 increases from 270 degrees to 285 degrees. Changes.

  In addition, since the spot light Pa is located between the W region 30d and the sB region 30f between 315 degrees and 330 degrees, the luminance which is a mixed color (W + B) of these two regions from the color wheel 30. Variable blue light is extracted. The mixed color (luminance variable blue light) linearly changes from white (color without color) to luminance half-blue as the rotation angle of the color wheel 30 increases from 315 degrees to 330 degrees.

  Further, since the spot light Pa is located between the sB region 30f and the R region 30a between 345 ° and 360 °, the color wheel 30 displays magenta that is a mixed color (B + R) of these two regions. Is taken out. The mixed color (magenta) linearly changes from magenta close to blue to magenta close to red as the rotation angle of the color wheel 30 increases from 345 degrees to 360 degrees.

<Pattern irradiated with spot light Pa over three regions>
Between 255 degrees to 270 degrees and 330 degrees to 345 degrees, the spot light Pa is located across three regions. For this reason, the mixed color of these three regions is extracted from the color wheel 30. That is, at 255 degrees, the spot light Pa is located over the B region 30c and the sR region 30e. However, after a little over 255 degrees, the spot light Pa further straddles the W region 30d. For this reason, magenta that is a mixed color (B + R) of the B region 30c and the sR region 30e is initially taken out between 255 degrees and 270 degrees. When the white of the W region 30d starts to be added and finally reaches 270 degrees, the luminance is reduced to half-red including the red color of the sR region 30e and the white color of the W region 30d.

  Similarly, at 330 degrees, the spot light Pa is located over the W area 30d and the sB area 30f. However, after a little over 330 degrees, the spot light Pa further extends over the R area 30a. . For this reason, between 330 degrees and 345 degrees, the luminance half-blue color that is the uniform mixed color (W + B) of the W region 30d and the sB region 30f is taken out at first, but this mixed color ( When the red color of the R region 30a starts to be added to W + B) and finally reaches 345 degrees, the red color of the sB region 30f and the red color of the R region 30a are evenly included.

  FIG. 10 is a correspondence diagram between the change in the rotation angle of the color wheel 30 and the light color extracted from the color wheel 30. As described above, the reference rotation angle (0 degree) of the color wheel 30 is synchronized with the instantaneous rise timing of the rotation angle detection signal CP to the high level. When the rotation angle of the color wheel 30 is at this reference rotation angle (0 degree), since the spot light Pa is immediately after exiting the sB region 30f, the spot light Pa as a whole is adjacent to the sB region 30f. The region 30a is irradiated. Therefore, when the rotation angle is 0 degree, the light color extracted from the color wheel 30 becomes pure “red” which is the transmitted light of the R region 30a. Similarly, when the rotation angle of the color wheel 30 is 0 degree to 60 degrees, the spot light Pa is still located in the R region 30a, so that the light color extracted from the color wheel 30 is still the R region 30a. The pure “red”, which is the transmitted light, is maintained.

  Next, when the rotation angle of the color wheel 30 is more than 60 degrees and less than 90 degrees, the spot light Pa straddles the R region 30a and the G region 30b (crosses the border), so the spot light Pa In total, these two regions (R region 30a and G region 30b) are irradiated. Therefore, when the rotation angle exceeds 60 degrees and is less than 90 degrees, the light color extracted from the color wheel 30 is a mixed color (yellow) of red and green, which is the simultaneous transmitted light of the R region 30a and the G region 30b. . The yellow color changes linearly from yellow close to red to yellow close to green as the rotation angle increases from 60 degrees to 90 degrees. In the figure, the R figure and the G figure are joined by a diagonal line that falls to the left in the range of 60 degrees to 90 degrees. This is linearly from yellow close to red to yellow close to green. This is for schematically showing the change. That is, in the range of 60 degrees to 90 degrees, the area of the R figure gradually decreases, while the area of the G figure gradually increases, so that the color of the transmitted light in the angle range is yellow close to red. It changes linearly from yellow to near green.

  Next, when the rotation angle of the color wheel 30 is 90 degrees, the spot light Pa completely enters the G region 30b, and therefore the spot light Pa irradiates the G region 30b as a whole. Therefore, when the rotation angle is 90 degrees, the light color extracted from the color wheel 30 becomes pure “green” which is the transmitted light of the G region 30b. Similarly, when the rotation angle of the color wheel 30 is between 90 degrees and 150 degrees, the spot light Pa is still located in the G area 30b, so that the light color extracted from the color wheel 30 is still the G area 30b. The pure “green”, which is the transmitted light, is maintained.

  Next, when the rotation angle of the color wheel 30 exceeds 150 degrees and is less than 180 degrees, the spot light Pa straddles the G region 30b and the B region 30c (crosses the border), so the spot light Pa In total, these two regions (G region 30b and B region 30c) are irradiated. Therefore, when the rotation angle is greater than 150 degrees and less than 180 degrees, the light color extracted from the color wheel 30 is a mixed color (cyan) of green and blue, which is the simultaneously transmitted light of the G region 30b and the B region 30c. . The cyan linearly changes from cyan close to green to cyan close to blue as the rotation angle increases from 150 degrees to 180 degrees. In the figure, the G figure and the B figure are joined by a slanting slanting line in the range of 150 to 180 degrees. This is linearly from cyan close to green to cyan close to blue. This is for schematically showing the change. That is, in the range of 150 to 180 degrees, the area of the G figure gradually decreases, while the area of the B figure gradually increases, so that the color of transmitted light in the angle range is cyan close to green. It changes linearly from cyan to near blue.

  Next, when the rotation angle of the color wheel 30 is 180 degrees, since the spot light Pa completely enters the B region 30c, the spot light Pa irradiates the B region 30c as a whole. Therefore, when the rotation angle is 180 degrees, the light color extracted from the color wheel 30 becomes pure “blue” which is the transmitted light of the B region 30 c. Similarly, when the rotation angle of the color wheel 30 is between 180 degrees and 240 degrees, the spot light Pa is still located in the B area 30c, so that the light color extracted from the color wheel 30 is still the B area 30c. The pure “blue”, which is the transmitted light, is maintained.

  Next, when the rotation angle of the color wheel 30 is more than 240 degrees and less than 255 degrees, the spot light Pa straddles the B region 30c and the sR region 30e (crosses the border), so the spot light Pa In total, these two regions (B region 30c and sR region 30e) are irradiated. Therefore, when the rotation angle exceeds 240 degrees and is less than 255 degrees, the light color extracted from the color wheel 30 is a mixed color (magenta) of blue and red, which is the simultaneously transmitted light of the B region 30c and the sR region 30e. . The magenta linearly changes from magenta close to blue to magenta close to red as the rotation angle increases from 240 degrees to 255 degrees. In the figure, the figure of B and the figure of sR are joined by a slanting line at the lower left in the range of 240 degrees to 255 degrees. This is linearly from magenta close to blue to magenta close to red. This is for schematically showing the change. That is, in the range of 240 degrees to 255 degrees, the area of the B figure gradually decreases, while the area of the sR figure gradually increases, so that the color of the transmitted light in the angle range is magenta close to blue. It changes linearly from magenta close to red.

  Next, when the rotation angle of the color wheel 30 is more than 255 degrees and less than 270 degrees, the spot light Pa straddles the B region 30c, the sR region 30e, and the W region 30d (beyond the border). The entire light Pa irradiates these three regions (B region 30c, sR region 30e, and W region 30d). Therefore, when the rotation angle exceeds 255 degrees and is less than 270 degrees, the light colors extracted from the color wheel 30 are blue, red, and white light that is simultaneously transmitted through the B region 30c, the sR region 30e, and the W region 30d. Mixed colors (brightness variable magenta). The brightness-variable magenta linearly changes from magenta close to blue to magenta whose brightness is increased through magenta close to red as the rotation angle increases from 255 degrees to 270 degrees. In the figure, the B figure, the sR figure, and the W figure are joined to each other by slanting lines at the lower left in the range of 255 to 270 degrees. This is from magenta close to blue to magenta close to red. This is to schematically show a state in which the brightness changes linearly to magenta with increased brightness. That is, in the range of 255 degrees to 270 degrees, the area of the B figure gradually decreases, while the area of the sR figure and the area of the W figure gradually increase. The color linearly changes from magenta close to blue to magenta with increased brightness through magenta close to red.

  Next, when the rotation angle of the color wheel 30 exceeds 270 degrees and is less than 285 degrees, the spot light Pa straddles (crosses over) the sR region 30e and the W region 30d. In total, these two regions (sR region 30e and W region 30d) are irradiated. Therefore, when the rotation angle is greater than 270 degrees and less than 285 degrees, the light color extracted from the color wheel 30 is a mixed color of red and white (the brightness variable red color) that is the simultaneous transmitted light of the sR region 30e and the W region 30d. )become. The brightness-variable red color changes linearly from pure red to red with increased brightness as the rotation angle increases from 270 degrees to 285 degrees. In the figure, the sR figure and the W figure are joined by slanting lines at the lower left in the range of 270 to 285 degrees. This is linear from pure red to red with increased brightness. This is for schematically showing the state of change. That is, in the range of 270 degrees to 285 degrees, the area of the sR figure gradually decreases, while the area of the W figure gradually increases, so that the color of the transmitted light in the angle range is from pure red. It changes linearly to red with increased brightness.

  Next, when the rotation angle of the color wheel 30 is 285 degrees, the spot light Pa completely enters the W region 30d, and therefore the spot light Pa irradiates the W region 30d as a whole. Therefore, when the rotation angle is 285 degrees, the light color extracted from the color wheel 30 becomes pure “white” which is the transmitted light of the W region 30 d. Similarly, when the rotation angle of the color wheel 30 is between 285 degrees and 3150 degrees, the spot light Pa is still located in the W area 30d, so that the light color extracted from the color wheel 30 is still in the W area 30d. The pure “white”, which is the transmitted light, is maintained.

  Next, when the rotation angle of the color wheel 30 exceeds 315 degrees and is less than 330 degrees, the spot light Pa straddles the W region 30d and the sB region 30f (crosses the border), so the spot light Pa In total, these two regions (W region 30d and sB region 30f) are irradiated. Therefore, when the rotation angle is greater than 315 degrees and less than 330 degrees, the light color extracted from the color wheel 30 is a mixed color of white and blue (blue with variable brightness) that is the simultaneous transmitted light of the W region 30d and the sB region 30f. )become. Then, the brightness-variable blue color linearly changes from bright blue close to white to blue with half the brightness as the rotation angle increases from 315 degrees to 330 degrees. In the drawing, the figure of W and the figure of sB are joined with a slanting line in the lower left in the range of 315 to 330 degrees. This is linearly from blue close to white to blue with half the luminance. This is for schematically showing the change. That is, in the range of 315 degrees to 330 degrees, the area of the W figure gradually decreases, while the area of the sB figure gradually increases, so that the color of the transmitted light in the angle range is close to white. It changes linearly from blue to half-brightness blue.

  Next, when the rotation angle of the color wheel 30 exceeds 330 degrees and is less than 345 degrees, the spot light Pa straddles (crosses over) the W region 30d, the sB region 30f, and the R region 30a. The entire light Pa irradiates these three regions (W region 30d, sB region 30f, and R region 30a). Therefore, when the rotation angle exceeds 330 degrees and is less than 345 degrees, the light colors extracted from the color wheel 30 are white, blue, and red light that is simultaneously transmitted through the W region 30d, the sB region 30f, and the R region 30a. It becomes a mixed color (cyan with variable brightness). Then, as the rotation angle increases from 330 degrees to 345 degrees, the brightness-variable cyan linearly changes from cyan close to white to pure cyan including blue and red evenly through cyan with half the brightness. In the figure, the W figure, the sB figure, and the R figure are joined to each other by slanting lines to the left in the range of 330 to 345 degrees. This is to schematically show a state of linearly changing to pure cyan including blue and red evenly. That is, in the range of 330 degrees to 345 degrees, the area of the W figure gradually decreases, while the area of the sB figure and the area of the R figure gradually increase. The color changes linearly from cyan close to white to pure cyan containing evenly blue and red through cyan with half the luminance.

  Next, when the rotation angle of the color wheel 30 exceeds 345 degrees and is less than 360 degrees, the spot light Pa straddles (crosses the border) the sB region 30f and the R region 30a. In total, these two regions (sB region 30f and R region 30a) are irradiated. Therefore, when the rotation angle exceeds 345 degrees and is less than 360 degrees, the light color extracted from the color wheel 30 is a mixed color (yellow) of blue and red, which is the simultaneous transmitted light of the sB region 30f and the R region 30a. . The yellow color changes linearly from yellow close to blue to yellow close to red as the rotation angle increases from 345 degrees to 360 degrees. In the figure, the sB figure and the R figure are joined by a slanting slanting line in the range of 345 ° to 360 °, but this is linear from yellow close to blue to yellow close to red. This is for schematically showing the change. That is, in the range of 345 degrees to 360 degrees, the area of the sB figure gradually decreases, while the area of the R figure gradually increases, so that the color of transmitted light in the angle range is yellow that is close to blue. It is changing linearly from yellow to yellow close to red.

  Thus, according to the color wheel 30 of the present embodiment, “red light (R)” is extracted when the rotation angle is between 0 degrees and 60 degrees, and the rotation angle exceeds 60 degrees and between 90 degrees. The “red and green mixed color light (R → Y → G)” that linearly changes from yellow close to red to yellow close to green is extracted, and when the rotation angle exceeds 90 degrees and 150 degrees, “Green light (G)” is extracted, and “green and blue mixed color light (G → Cyan) changes linearly from cyan close to green to cyan close to blue within the same rotation angle exceeding 150 degrees and 180 degrees. → B) ”, and“ blue light (B) ”can be extracted when the rotation angle exceeds 180 degrees and is between 240 degrees.

  In addition, when the rotation angle exceeds 240 degrees and between 285 degrees, it changes linearly from magenta close to blue to magenta close to red and then to pure red and red with higher brightness. “Blue, red and white Of mixed color light (B → magenta → R → W) ”, the same rotation angle exceeds 285 degrees and between 315 degrees,“ white light (W) ”is extracted, the rotation angle exceeds 315 degrees and 360 It is possible to take out “mixed light of white, blue and red (W → B → magenta → R)” that linearly changes from blue, which has been increased in luminance to pure magenta to red through magenta.

  FIG. 11 is a diagram illustrating a schematic flowchart of a control program executed by the central control unit 21 of the projector 10. In this control program, first, after turning on the light source (lighting the light source 29) and rotating the color wheel (starting the operation of the color wheel driving motor 31) (step S10), the display control mode branching process is executed (step S11). ). The display control mode is a display control mode appropriately designated by the user by touching the option button displayed on the flat display device 14a of the main body operation display unit 14 as described above. More specifically, the display control mode emphasizes color reproducibility (first display control mode) and the brightness priority display mode (second display control mode).

  When the “first display control mode” is determined by the branch process in step S11, the first display control mode process is executed (step S12). When the “second display control mode” is determined, the second display control mode is executed. A control mode process is executed (step S13).

  In any display control mode, after displaying the image of one frame, the display end of the image is determined (step S14). If the display is not ended, the branching process of step S11 is repeated again while the display ends. If there is, the light source is turned off and the color wheel is stopped (step S15), and then the program is terminated.

  FIG. 12 is a flowchart of the first display control mode program. In this figure, first, the rotation angle of the color wheel 30 is fetched and set to a variable CA (step S12a).

  Next, it is determined whether or not “345 degrees <CA <75 degrees” (step S12b). If the determination result is affirmative (YES), the DMD 33 is driven with the R image read from the video RAM 25 (step S12c). ).

  Next, it is determined whether or not “75 degrees <CA <165 degrees” (step S12d). If the determination result is affirmative (YES), the DMD 33 is driven with the G image read from the video RAM 25 (step S12e). ).

  Next, it is determined whether or not “165 degrees <CA <255 degrees” (step S12f). If the determination result is affirmative (YES), the DMD 33 is driven with the B image read from the video RAM 25 (step S12g). ).

  Next, it is determined whether or not “255 degrees <CA <345 degrees” (step S12h). If the determination result is affirmative (YES), based on the R image, G image, and B image read from the video RAM 25. The DMD 33 is driven by the generated W image (for example, according to the previous equation (1)) (step S12i).

  FIG. 13 is a diagram showing a flowchart of the second display control mode program. In this figure, first, the rotation angle of the color wheel 30 is fetched and set to a variable CA (step S13a).

  Next, it is determined whether or not “0 degree <CA <60 degrees” (step S13b). If the determination result is affirmative (YES), the DMD 33 is driven with the R image read from the video RAM 25 (step S13c). ).

  Next, it is determined whether or not “60 degrees <CA <90 degrees” (step S13d). If the determination result is affirmative (YES), based on the R image, G image, and B image read from the video RAM 25. The DMD 33 is driven by the generated W image (for example, according to the previous equation (1)) (step S13e).

  Next, it is determined whether or not “90 degrees <CA <150 degrees” (step S13f). If the determination result is affirmative (YES), the DMD 33 is driven with the G image read from the video RAM 25 (step S13g). ).

  Next, it is determined whether or not “150 degrees <CA <180 degrees” (step S13h). If the determination result is affirmative (YES), based on the R image, G image, and B image read from the video RAM 25. The DMD 33 is driven by the generated W image (for example, according to the previous equation (1)) (step S13i).

  Next, it is determined whether or not “180 degrees <CA <240 degrees” (step S13j). If the determination result is affirmative (YES), the DMD 33 is driven with the B image read from the video RAM 25 (step S13k). ).

  Next, it is determined whether or not “240 degrees <CA <360 degrees” (step S13m). If the determination result is affirmative (YES), based on the R image, G image, and B image read from the video RAM 25. The DMD 33 is driven by the generated W image (for example, according to the previous equation (1)) (step S13n).

  FIG. 14 is a conceptual time sequence diagram of the first display control mode and the second display control mode described above. In these figures, the uppermost row represents the position (rotation angle) of the color wheel, and the second row from the top represents the illumination light beam extracted from the color wheel. Further, P1 below it represents the first display control mode, and P2 represents the second display control mode.

  The illumination luminous flux is common to each mode, 0 to 60 degrees is red (R), more than 60 degrees and less than 90 degrees is a mixture of red (R) and yellow (Y), and 90 to 150 degrees is green. (G), green (G) and blue (B) mixed colors exceeding 150 degrees and less than 180 degrees, blue (B), red (R) and white (W) exceeding 240 degrees and less than 285 degrees The mixed color of 285 degrees to 315 degrees is white (W), exceeds 315 degrees, and less than 360 degrees is a mixed color of white (W), blue (B), and red (R).

  The two display control modes (P1, P2) are different in terms of the driving time of each of the R, G, and B driving images and the way of using the W image.

  First, the first display control mode (P1) will be described. In this mode, the DMD 33 is driven with an R image while the position (rotation angle) of the color wheel is 345 degrees to 75 degrees, and the rotation angle is 75 degrees to 165. The DMD 33 is driven with a G image during the rotation, the DMD 33 is driven with a B image when the rotation angle is 165 to 255 degrees, and the DMD 33 is driven with a W image when the rotation angle is 255 to 345 degrees. That is, in the first display control mode (P1), the DMD 33 is driven in the order of R image → G image → B image → W image →..., And R image, G image, B image, and W image. Each driving time is the same time corresponding to 90 degrees in rotation angle.

  Next, the second display control mode (P2) will be described. In this mode, the DMD 33 is driven with an R image while the color wheel position (rotation angle) is 0 degrees to 60 degrees, and the rotation angle is 90 degrees to The DMD 33 is driven with a G image for 150 degrees, the DMD 33 is driven with a B image while the rotation angle is 180 degrees to 240, and the rotation angles are 60 degrees to 90 degrees, 150 degrees to 180 degrees, and 240 degrees to 240 degrees. The DMD 33 is driven with a W image for 360 degrees. That is, in the second display control mode (P2), the DMD 33 is driven in the order of R image → W image → G image → W image → B image → W image →. The driving time of the G image and the B image is set to the same time corresponding to 60 degrees in rotation angle, and the remaining time is set as the driving time of the W image.

  FIG. 15 is a CIExy chromaticity diagram in the first display control mode (P1) and a conceptual diagram of brightness for each image. In this figure, the size of the triangular figure on the chromaticity diagram is slightly narrower than that of the conventional device (see FIG. 21), but each image of R, G, B, C, M, Y and W The brightness ratio of “1.5: 1.5: 1.5: 3: 3: 3: 8” is R, G, B compared to the ratio of the conventional device (see FIG. 21). , C, M, Y, and W are nearly ideal ratios. Therefore, according to the first display control mode (P1), it is possible to obtain a projection image in which the brightness and the hue are balanced, and in particular, it is suitable for an application that emphasizes color reproducibility such as a home theater. it can.

  FIG. 16 is a CIExy chromaticity diagram in the second display control mode (P2) and a conceptual diagram of brightness for each image. In this figure, the size of the triangular figure on the chromaticity diagram is the same as that of the conventional device (see FIG. 21). Also, the ratio of the brightness of each of the R, G, B, C, M, Y, and W images is “1: 1: 1: 2: 2: 2: 8”, which is the ratio of the conventional apparatus (see FIG. 21). Therefore, according to the second display control mode (P2), it is possible to obtain a projected image with sufficient brightness as compared with the first display control mode (P1). It can be suitable for.

  Thus, according to the present embodiment, the display control mode (first display control mode) emphasizing color reproducibility and the display control mode (second display control mode) prioritizing brightness are selected and used. For example, it is possible to realize a highly convenient projector 10 that can be widely used from a home theater to a presentation.

  In the above embodiment, the color wheel 30 has a structure in which the R region 30a, the G region 30b, the B region 30c, the sR region 30e, the W region 30d, and sB are clockwise as shown in FIG. The region 30f is arranged, that is, the small area spectral region is a red light transmission region (sR region 30e) and the small area spectral region is a blue light transmission region (sB region 30f). Is just one example of a possible embodiment. The small area spectral region and the small area spectral region need only have different spectral characteristics from the adjacent regions. For example, the small area spectral region is a red light transmission region and the small area spectral region is a green light transmitting region. It may be a transmissive region. In this case, the R region 30a, the G region 30b, the B region 30c, the small area spectral region (red), the W region 30d, and the small area spectral region (green) may be arranged in the clockwise direction.

In the above description, the angle of the small area spectral region is set to 15 degrees because it is just half the size of the light source spot diameter (see Pa in FIG. 5). The small-area spectral region is desirably a size that is at least half the diameter of the light source spot, and when the size is exactly half, the color balance is the best and the W luminance is high.
In short, in the above embodiment, the size ratio of the spot light Pa is set to a size corresponding to an angle twice the angle (θ) of the small area spectral region or the small area spectral region, but this is the best mode. It is not limited to this, For example, it is good also as the angle ((theta)) of a small area spectroscopic area or a small area spectroscopic area or less. That is, the spot light Pa may have a size ratio that does not protrude from the small area spectral region or the small area spectral region.
In addition, as described above, the size ratio of the spot light Pa is not changed, but the size of the spot light Pa is fixed, and the angle of the small area spectral region of the color wheel is fixed. It may be changed, or both the size of the spot light Pa and the angle of the small area spectral region may be changed.

1 is an external view of a projector 10. FIG. 3 is an internal block diagram of the projector 10. FIG. 2 is a front view of a color wheel 30. FIG. 3 is a diagram illustrating spectral characteristics of each region of the color wheel 30. FIG. 4 is a correspondence diagram between a spot light Pa emitted from a light source 29 and a color wheel 30. FIG. FIG. 6 is a diagram (1/4) showing a rotation state of the color wheel 30. FIG. 4B is a diagram (2/4) showing a rotation state of the color wheel 30. FIG. 4C is a diagram (3/4) showing a rotation state of the color wheel 30. FIG. 4B is a diagram (4/4) showing a rotation state of the color wheel 30. 4 is a correspondence diagram between a change in the rotation angle of the color wheel 30 and a light color extracted from the color wheel 30. FIG. It is a figure which shows the schematic flowchart of the control program run by the central control part 21 of the projector 10. FIG. It is a figure which shows the flowchart of a 1st display control mode program. It is a figure which shows the flowchart of a 2nd display control mode program. It is a conceptual time sequence diagram of the first and second display control modes. It is a CIExy chromaticity diagram of a 1st display control mode, and the conceptual diagram of the brightness for every image. It is a CIExy chromaticity diagram of a 2nd display control mode, and the conceptual diagram of the brightness for every image. It is a CIE chromaticity diagram. It is a figure which shows the structure when the color wheel used in the conventional apparatus, and the spot light 3 cross the boundary line 4 of an area | region. It is a drive timing diagram of the color wheel in a conventional apparatus. FIG. 4 is a timing chart for driving a color wheel that is driven by a W image even in a cross-border state. It is a CIExy chromaticity diagram of a conventional device and a conceptual diagram of brightness for each image.

Explanation of symbols

Pa Spot Light 10 Projector (Projection Display)
21 Central control unit (image signal selection means)
29 Light source 30 Color wheel (color division means)
30a R region (large area spectral region)
30b G region (large area spectral region)
30c B region (large area spectral region)
30d W region (medium area spectral region)
30e sR region (small area spectroscopic region)
30f sB region (small area spectroscopic region)
33 DMD (spatial light modulation means)
34 Projection lens (projection means)

Claims (4)

A light source that generates white spot light;
Color dividing means for color-splitting the spot light from the light source in a time-sharing manner;
Spatial light modulation means for spatially modulating each of the color-divided divided colors with an image signal;
Projection means for projecting light modulated by the spatial light modulation means;
An image signal selection means for selecting an image signal to be given to the spatial light modulation means in synchronization with the color division of the color division means,
The color dividing means includes three large area spectral regions corresponding to each of the three primary colors of light, one medium area spectral region corresponding to white light, and the large area spectral region located on both sides of the medium area spectral region. Two small area spectral regions adjacent to any of the regions,
And the image signal selection means comprises:
While the color division of the color dividing means is performed by an arbitrary large area spectral region, an image signal of color information corresponding to the large area spectral region is selected,
In addition, the projection display apparatus is characterized in that an image signal of luminance information is selected while being performed by the medium area spectral region or the small area spectral region. A light source that generates white spot light;
Color dividing means for color-splitting the spot light from the light source in a time-sharing manner;
Spatial light modulation means for spatially modulating each of the color-divided divided colors with an image signal;
Projection means for projecting light modulated by the spatial light modulation means;
An image signal selection means for selecting an image signal to be given to the spatial light modulation means in synchronization with the color division of the color division means,
The color dividing means includes three large area spectral regions corresponding to each of the three primary colors of light, one medium area spectral region corresponding to white light, and the large area spectral region located on both sides of the medium area spectral region. Two small area spectral regions adjacent to any of the regions,
And the image signal selection means comprises:
While the color division of the color dividing unit is performed by an arbitrary large area spectral region, an image signal of color information corresponding to the large area spectral region is selected and another color spectral region is selected from the arbitrary large area spectral region. When switching to the large area spectral region, select the image signal of the luminance information for a predetermined time before and after the switching,
Further, while the color division of the color dividing unit is performed by the small area spectral region and the medium area spectral region, the small area spectral region and a predetermined time before switching from the large area spectral region to the small area spectral region. A projection display device that selects an image signal of luminance information until a predetermined time after switching to a large area spectral region. A color splitting process for splitting white spot light in a time-sharing manner;
A spatial light modulation step of spatially modulating each of the color-divided divided colors with an image signal;
A projection step of projecting the light modulated by the spatial light modulation step;
An image signal selection step of selecting an image signal to be given to the spatial light modulation step in synchronization with a color division timing of the color division step;
The color dividing step includes three large area spectral regions corresponding to each of the three primary colors of light, one medium area spectral region corresponding to white light, and the large area spectral region located on both sides of the medium area spectral region. Implemented with a color wheel having two small area spectral regions adjacent to any of the regions,
The image signal selection step selects an image signal of color information corresponding to the large area spectral region while the color division of the color division step is performed by an arbitrary large area spectral region, A display control method, wherein an image signal of luminance information is selected while being performed by a medium area spectral region or a small area spectral region. A color splitting process for splitting white spot light in a time-sharing manner;
A spatial light modulation step of spatially modulating each of the color-divided divided colors with an image signal;
A projection step of projecting the light modulated by the spatial light modulation step;
An image signal selection step of selecting an image signal to be given to the spatial light modulation step in synchronization with a color division timing of the color division step;
The color dividing step includes three large area spectral regions corresponding to each of the three primary colors of light, one medium area spectral region corresponding to white light, and the large area spectral region located on both sides of the medium area spectral region. Implemented with a color wheel having two small area spectral regions adjacent to any of the regions,
The image signal selection step selects an image signal of color information corresponding to the large area spectral region while the color division of the color division step is performed by an arbitrary large area spectral region, When switching from any large area spectral region to another large area spectral region, select the image signal of the luminance information for a predetermined time before and after the switching,
In addition, while the color division in the color division step is performed by the small area spectral region and the medium area spectral region, the small area spectral region and a predetermined time before switching from the large area spectral region to the small area spectral region. A display control method comprising: selecting an image signal of luminance information until a predetermined time after switching from a large area spectral region to a large area spectral region.

Images