JP2009175706A - Lighting device and projection display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting device and an projection display apparatus for moderating a speckle and saving power consumption. <P>SOLUTION: A lighting unit includes: a light source unit 10 having a plurality of solid state light sources, a liquid crystal panel 30 displaying an image in accordance with an image input signal, a light source controlling unit 260 controlling, in accordance with the image input signal, a light amount of color component lights emitted from light source unit 10, and a speckle degree calculating unit 250 calculating a speckle degree that indicates a degree to which the color component lights generate a speckle displayed in accordance with the image input signal. The light source controlling unit 260 includes a first control mode that averagely lowers the amount of light emitted from the plurality of solid state light sources, and a second control mode that preferentially lowers the amount of light emitted from a solid state light source that has an unfavorable light emission efficiency. The light source controlling unit 260 changes a control ratio between a first control mode and a second control mode, in accordance with the speckle degree acquired by the speckle degree calculating unit 250. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an illumination apparatus and a projection display apparatus including a light source unit having a plurality of solid-state light sources that emit the same color component light.

  2. Description of the Related Art Conventionally, a technique using a plurality of solid light sources (for example, laser light sources) in a display device such as a projection video display device is known. In addition, a technique for controlling a solid-state light source in accordance with the luminance of an image (hereinafter, image adaptive light source control) is also known.

  In the video adaptive light source control, when the luminance of the video is low, the amount of light emitted from a plurality of solid state light sources is reduced. In the case of reducing the amount of light, it is common to reduce the power supplied to the solid light source in order from the solid light source having the lowest luminous efficiency among the plurality of solid light sources. Thereby, the power consumption of the display device is suppressed.

By the way, when a solid light source that emits light having a uniform phase, such as LD (Laser Diode), is used, it is known that the light emitted from the solid light source causes speckles on an irradiation surface such as a screen. It has been. In order to suppress such speckle, a technique for adjusting the distance between the solid light source and the irradiation surface has been proposed (for example, Patent Document 1).
Japanese Patent Laid-Open No. 7-115047

  As described above, in video adaptive light source control, it is common to reduce the power supplied to a solid-state light source with poor luminous efficiency. That is, it is assumed that some of the solid light sources are turned off.

  On the other hand, the position of speckle generated by light emitted from the solid light source is different for each solid light source. Therefore, the speckle generated by the light emitted from each solid light source is alleviated by superimposing the light emitted from the plurality of solid light sources.

  However, if some of the solid light sources are turned off, the speckle mitigation effect due to the superposition of light is reduced.

  Accordingly, the present invention has been made to solve the above-described problems, and provides an illumination device and a projection display apparatus that can alleviate speckles while considering suppression of power consumption. For the purpose.

  The illumination device according to the first feature includes a light source unit (light source unit 10) having a plurality of solid light sources that emit the same color component light. The illumination device includes: a light source control unit (light source control unit 260) that controls the amount of the same color component light emitted from the plurality of solid state light sources according to a video input signal; and the video according to the video input signal. And an acquisition unit (speckle degree calculation unit 250) that acquires a speckle degree that is a degree that speckle is generated by the same color component light. The light source control unit emits from the solid-state light source having a low luminous efficiency among the first control mode for reducing the light amount of the same color component light emitted from the plurality of solid-state light sources on average. A second control mode for preferentially reducing the amount of the same color component light. The light source control unit changes a control ratio between the first control mode and the second control mode according to the speckle degree acquired by the acquisition unit.

  According to this feature, the light source control unit can control the first control mode that can relieve speckle and the second power that can suppress power consumption according to the degree of speckle generation (speckle degree) due to the same color component light in the video. Change the control ratio with the control mode. That is, when the speckle degree is high, the control ratio of the first control mode is increased, and when the speckle degree is low, the control ratio of the second control mode is increased. Therefore, speckle can be relaxed while taking into account the suppression of power consumption.

  In the first feature, the lighting device further includes a storage unit (storage unit 240) that stores a hue speckle degree that is a degree that speckles are generated for each hue by the same color component light. The acquisition unit acquires a hue distribution included in the video according to the video input signal, and acquires the speckle degree based on the hue distribution and the hue speckle degree.

  In the first feature, the lighting device further includes a storage unit (storage unit 240) that stores a saturation speckle degree, which is a degree at which speckle is generated for each saturation by the same color component light. The acquisition unit acquires a saturation distribution included in the video according to the video input signal, and acquires the speckle degree based on the saturation distribution and the saturation speckle degree.

  In the first feature, the lighting device further includes a storage unit (storage unit 240) that stores a luminance speckle degree that is a degree that speckle is generated for each luminance by the same color component light. The acquisition unit acquires a luminance distribution included in the video according to the video input signal, and acquires the speckle degree based on the luminance distribution and the luminance speckle degree.

  A projection display apparatus according to a second feature includes an illumination device according to the first feature, display means (liquid crystal panel 30) irradiated with light emitted from the illumination device, and emitted from the display means. Projection means for projecting light.

  In the second feature, the display means may be a reflection type display means (DMD 530).

  ADVANTAGE OF THE INVENTION According to this invention, the illuminating device and projection type video display apparatus which can relieve a speckle can be provided, considering suppression of power consumption.

  Hereinafter, a projection display apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

  However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Therefore, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[First Embodiment]
(Configuration of projection display device)
Hereinafter, the configuration of the projection display apparatus according to the first embodiment will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a projection display apparatus 100 according to the first embodiment.

  As shown in FIG. 1, the projection display apparatus 100 includes a plurality of light source units 10, a plurality of fly-eye lens units 20, a plurality of liquid crystal panels 30, a cross dichroic prism 40, and a projection lens unit 50. Have.

  The plurality of light source units 10 are a light source unit 10R, a light source unit 10G, and a light source unit 10B. Each light source unit 10 is a unit composed of a plurality of solid state light sources. The solid light source is a light source that emits light having a uniform phase, such as an LD (Laser Diode). The light source unit 10R includes a plurality of solid light sources (10-1R to 10-6R) that emit red component light. The light source unit 10G includes a plurality of solid light sources (10-1G to 10-6G) that emit green component light. The light source unit 10B includes a plurality of solid light sources (10-1B to 10-6B) that emit blue component light.

  Here, as shown in FIG. 2, it should be noted that the light emission efficiency of the plurality of solid state light sources constituting the light source unit 10 has a certain degree of variation. The variation in luminous efficiency is caused by the manufacturing process of the solid light source and changes with time.

  It should be noted that the luminous efficiency is considered to be the amount of light emitted from the solid light source when a certain amount of power is supplied to the solid light source.

  The plurality of fly-eye lens units 20 are a fly-eye lens unit 20R, a fly-eye lens unit 20G, and a fly-eye lens unit 20B. Each fly eye lens unit 20 includes a fly eye lens 21 and a fly eye lens 22. Each of the fly eye lens 21 and the fly eye lens 22 is composed of a plurality of minute lenses. Each microlens condenses the light emitted from each light source unit 10 so that the light emitted from each light source unit 10 is irradiated on the entire surface of each liquid crystal panel 30.

  The plurality of liquid crystal panels 30 are a liquid crystal panel 30R, a liquid crystal panel 30G, and a liquid crystal panel 30B. The liquid crystal panel 30R modulates the red component light by rotating the polarization direction of the red component light. An incident-side polarizing plate 31R that transmits light having one polarization direction (for example, P-polarized light) and shields light having another polarization direction (for example, S-polarized light) on the light incident surface side of the liquid crystal panel 30R. Is provided. On the light exit surface side of the liquid crystal panel 30R, an exit-side polarizing plate 32R that blocks light having one polarization direction (for example, P-polarized light) and transmits light having another polarization direction (for example, S-polarized light). Is provided.

  Similarly, the liquid crystal panel 30G and the liquid crystal panel 30B modulate the green component light and the blue component light by rotating the polarization directions of the green component light and the blue component light, respectively. An incident-side polarizing plate 31G is provided on the light incident surface side of the liquid crystal panel 30G, and an outgoing-side polarizing plate 32G is provided on the light output surface side of the liquid crystal panel 30G. An incident side polarizing plate 31B is provided on the light incident surface side of the liquid crystal panel 30B, and an output side polarizing plate 32B is provided on the light output surface side of the liquid crystal panel 30B.

  The cross dichroic prism 40 combines light emitted from the liquid crystal panel 30R, the liquid crystal panel 30G, and the liquid crystal panel 30B. The cross dichroic prism 40 emits combined light to the projection lens unit 50 side.

  The projection lens unit 50 projects the combined light (image light) emitted from the cross dichroic prism 40 onto a screen or the like.

  In the first embodiment, the light source unit 10 and the fly-eye lens unit 20 constitute an “illuminating device”. It should be noted that the illumination device does not include the liquid crystal panel 30, the cross dichroic prism 40, and the projection lens unit 50. However, the illumination device may have a configuration including another optical element (for example, a condenser lens).

(Function of projection display device)
Hereinafter, functions of the projection display apparatus (illumination apparatus) according to the first embodiment will be described with reference to the drawings. FIG. 3 is a block diagram illustrating functions of the projection display apparatus 100 (control unit 200) according to the first embodiment.

The control unit 200 acquires a video input signal including a red input signal R _in , a green input signal G _in, and a blue input signal B _in . The control unit 200 controls the amount of color component light emitted from each light source unit 10 in accordance with a video input signal (video adaptive light source control). The red input signal R _in , the green input signal G _in, and the blue input signal B _in each have a value in a range from the lowest luminance (for example, “0”) to the highest luminance (for example, “255”).

  Specifically, as shown in FIG. 3, the control unit 200 includes a light source control coefficient calculation unit 210, a drive signal generation unit 220, a display element control unit 230, a storage unit 240, and a speckle degree calculation unit 250. And a light source control unit 260.

The light source control coefficient calculation unit 210 acquires a video input signal including a red input signal R _in , a green input signal G _in, and a blue input signal B _in . Subsequently, the light source control coefficient calculation unit 210 calculates a reduction rate (control coefficient) of the light amount of the color component light emitted from each light source unit 10 for each light source unit 10. The reduction rate (control coefficient) is a value in the range of 0-1.

Specifically, the light source control coefficient calculation unit 210 acquires the distribution of the red input signal R _in corresponding to each pixel included in one frame (video). Subsequently, the light source control coefficient calculation unit 210 calculates a control coefficient of the red input signal R _{in according} to a ratio (for example, maximum luminance / maximum luminance) between the maximum luminance and the maximum luminance of the red input signal R _in . The light source control coefficient calculation unit 210, the ratio between the average value and the maximum luminance of the red input signal R _in (e.g., an average value / maximum luminance) in response to, and calculate the control coefficients of a red input signal R _in Good. Light source control coefficient calculation unit 210, the ratio of the weighted average value and the maximum luminance of the red input signal R _in (e.g., weighted average value / maximum luminance) in response to, and calculates the control coefficient of the red input signal R _in May be.

Similarly, the light source control coefficient calculation unit 210 calculates control coefficients for the green input signal G _in and the blue input signal B _in .

The drive signal generation unit 220 acquires a video input signal including a red input signal R _in , a green input signal G _in, and a blue input signal B _in . The drive signal generation unit 220 acquires control coefficients for the red input signal R _in , the green input signal G _in, and the blue input signal B _in from the light source control coefficient calculation unit 210. Subsequently, the drive signal generation unit 220 corrects the video input signal according to the control coefficient in order to compensate for the decrease in the light amount of the color component light emitted from the light source unit 10, and outputs the video output signal (drive signal). Generate.

Specifically, the drive signal generator 220 multiplies the red input signal R _in and the inverse of the control coefficient of the red input signal R _in to obtain the red output signal R _out . Similarly, the drive signal generator 220 multiplies the green input signal G _in and the inverse of the control coefficient of the green input signal G _in to obtain the green output signal G _out . The drive signal generator 220 multiplies the blue input signal B _in and the inverse of the control coefficient of the blue input signal B _in to obtain the blue output signal B _out .

In this way, the drive signal generation unit 220 generates a video output signal (drive signal) including the red output signal R _out , the green output signal G _out and the blue output signal B _out .

The display element control unit 230 acquires a video output signal (drive signal) including the red output signal R _out , the green output signal G _out and the blue output signal B _out from the drive signal generation unit 220. The display element control unit 230 controls each liquid crystal panel 30 according to the video output signal (drive signal).

  The storage unit 240 stores, for each color component light, the hue speckle degree, which is the degree that speckle is generated for each hue by the color component light emitted from the light source unit 10.

  The hue speckle degree is a value in the range of 0 to 1. Hue speckle degree “1” means that speckle is likely to occur. Hue speckle degree “0” means that speckle hardly occurs.

(Calculation of hue speckle degree)
In the following, the degree of occurrence of speckle for each hue (hue speckle degree R) by the red component light emitted from the light source unit 10R will be exemplified with reference to FIGS. 4 (a) and 4 (b).

  FIG. 4A is a diagram illustrating the hue speckle degree R acquired by speckle contrast measurement. As shown in FIG. 4A, the hue speckle degree R is the highest in the red hue R, and the hue speckle degree R is the second highest in the magenta hue Mg. On the other hand, the hue speckle degree R is relatively low in the yellow hue Ye, the green hue G, the cyan hue Cy, and the blue hue B.

  FIG. 4B is a diagram illustrating the hue speckle degree R acquired by subjective evaluation. As shown in FIG. 4B, the hue speckle degree R is the highest in the magenta hue Mg, and the hue speckle degree R is the second highest in the red hue R. On the other hand, the hue speckle degree R is relatively low in the yellow hue Ye, the green hue G, the cyan hue Cy, and the blue hue B.

  Here, it has been described that the speckle degree of hue “0” is less likely to cause speckle. However, since noise due to unevenness of the screen is measured to about 0.3, the speckle degree of hue is 0.3 or less. It should be noted that speckle is hardly visible.

  It should be noted that the storage unit 240 stores the degree of occurrence of speckle for each hue (hue speckle degree G) by the green component light emitted from the light source unit 10G. Similarly, it should be noted that the storage unit 240 stores the degree to which speckle is generated for each hue by the blue component light emitted from the light source unit 10B (hue speckle degree B).

  The speckle degree calculation unit 250 obtains, for each color component light, a speckle degree that is the degree that speckle is generated by the color component light emitted from the light source unit 10 in a frame (video) displayed according to the video input signal. calculate. That is, the speckle degree calculation unit 250 calculates the speckle degree of red component light, the speckle degree of green component light, and the speckle degree of blue component light.

  Specifically, as shown in FIG. 5, the speckle degree calculation unit 250 includes a hue determination unit 251, a red multiplication unit 252, a yellow multiplication unit 253, a green multiplication unit 254, a cyan multiplication unit 255, A blue multiplication unit 256, a magenta multiplication unit 257, and a speckle degree acquisition unit 258 are included.

The hue determination unit 251 acquires a video input signal including a red input signal R _in , a green input signal G _in, and a blue input signal B _in . Subsequently, the hue determination unit 251 determines the hue of each pixel included in the frame (video). Thereby, the hue determination unit 251 acquires the hue distribution included in the frame (video).

  The red multiplier 252 multiplies the ratio R in which the frame (video) includes the red hue and the red hue speckle degree. It should be noted that the red multiplication unit 252 calculates the multiplication result for each color component light.

  The yellow multiplication unit 253 multiplies a ratio Ye in which a frame (video) includes a yellow hue and a yellow hue speckle degree. It should be noted that the yellow multiplication unit 253 calculates the multiplication result for each color component light.

  The green multiplication unit 254 multiplies the ratio G in which a frame (video) includes a green hue and the green hue speckle degree. It should be noted that the green multiplication unit 254 calculates the multiplication result for each color component light.

  The cyan multiplication unit 255 multiplies the ratio Cy in which the hue of cyan is included in the frame (video) and the cyan hue speckle degree. It should be noted that the cyan multiplication unit 255 calculates the multiplication result for each color component light.

  The blue multiplication unit 256 multiplies the ratio B in which the frame (video) includes the blue hue and the blue hue speckle degree. It should be noted that the blue multiplication unit 256 calculates the multiplication result for each color component light.

  The magenta multiplication unit 257 multiplies a ratio Mg in which the magenta hue is included in the frame (video) and the magenta hue speckle degree. It should be noted that the magenta multiplication unit 257 calculates the multiplication result for each color component light.

  Note that the hue speckle degree used by the red multiplier 252 to the magenta multiplier 257 may be the hue speckle degree acquired by speckle contrast measurement (see FIG. 4A), and acquired by subjective evaluation. The hue speckle degree (see FIG. 4B) may be used.

  The speckle degree acquisition unit 258 acquires the multiplication results obtained by the red multiplication unit 252 to the magenta multiplication unit 257. The speckle degree acquisition unit 258 acquires the speckle degree by adding the multiplication results. Note that the speckle degree acquisition unit 258 acquires the speckle degree for each color component light.

  The light source control unit 260 controls the amount of color component light emitted from each light source unit 10 according to the control coefficient calculated by the light source control coefficient calculation unit 210.

Specifically, the light source control unit 260 multiplies the maximum light amount of the light source unit 10R by the control coefficient of the red input signal R _in to obtain the light amount (target light amount R) of the red component light emitted from the light source unit 10R. decide. Similarly, the light source control unit 260 multiplies the maximum light amount of the light source unit 10G and the control coefficient of the green input signal G _in to determine the light amount (target light amount G) of the green component light emitted from the light source unit 10G. . The light source control unit 260 multiplies the maximum light amount of the light source unit 10B and the control coefficient of the blue input signal B _in to determine the light amount (target light amount B) of the blue component light emitted from the light source unit 10B.

  The maximum amount of light is the amount of light emitted from the light source unit 10 when maximum power is supplied to a plurality of solid state light sources constituting the light source unit 10.

  Here, when the light source control unit 260 controls the light source unit 10 so that the light amount of the color component light emitted from the light source unit 10 becomes the target light amount, the following two control modes (the first control mode and the first control mode) 2 control mode).

  The first control mode is a control mode in which the amount of light emitted from a plurality of solid light sources constituting the light source unit 10 is reduced on average. For example, the amount of decrease in the amount of light emitted from each solid light source is a value obtained by dividing the difference between the maximum light amount and the target light amount by the number of solid light sources.

  The second control mode is a control mode that preferentially reduces the amount of color component light emitted from a solid light source having low luminous efficiency among the plurality of solid light sources constituting the light source unit 10. For example, when the light source unit 10 is configured by the solid light source shown in FIG. 2, the amount of light emitted from the solid light source 10-4 and the solid light source 10-5 is preferentially reduced.

  The light source control unit 260 changes the control ratio between the first control mode and the second control mode according to the speckle degree calculated by the speckle degree calculation unit 250. Specifically, the light source control unit 260 changes the control ratio between the first control mode and the second control mode for the light source unit 10R according to the speckle degree of the red component light. Similarly, the light source control unit 260 changes the control ratio between the first control mode and the second control mode for the light source unit 10G according to the speckle degree of the green component light. The light source control unit 260 changes the control ratio between the first control mode and the second control mode for the light source unit 10B according to the speckle degree of the blue component light.

  Hereinafter, the control ratio between the first control mode and the second control mode will be described with reference to FIGS. 6 (a) and 6 (b). In FIGS. 6A and 6B, it should be noted that the vertical axis represents the control ratio in the first control mode.

  As shown in FIG. 6A, the light source control unit 260 switches between the first control mode and the second control mode depending on whether the speckle degree exceeds a threshold Th1 (for example, 0.5). May be. That is, when the speckle degree exceeds the threshold Th1, the light source control unit 260 controls the light source unit 10 according to the first control mode. On the other hand, when the speckle degree is lower than the threshold Th1, the light source control unit 260 controls the light source unit 10 according to the second control mode.

  The light source control unit 260 may combine the first control mode and the second control mode as shown in FIG. That is, when the speckle degree exceeds a threshold Th3 (for example, 0.7), the light source control unit 260 controls the light source unit 10 according to the first control mode. On the other hand, when the speckle degree is lower than a threshold Th2 (for example, 0.3), the light source control unit 260 controls the light source unit 10 according to the second control mode.

  When the speckle degree is between the threshold value Th2 and the threshold value Th3, the light source control unit 260 controls the light source unit 10 according to the combination of the first control mode and the second control mode. It should be noted that the control ratio of the first control mode increases as the speckle degree increases.

(Control example of the light source unit 10)
Hereinafter, a control example of the light source unit 10 according to the first embodiment will be described with reference to the drawings. 7 and 8 are diagrams illustrating a control example of the light source unit 10 according to the first embodiment.

  7 and 8, it should be noted that the speckle degree of red component light is referred to in the control of each light source unit 10 in order to simplify the description. That is, the speckle degree of red component light is also referred to in the control of the light source unit 10G and the light source unit 10B.

  First, a case where there are many magenta hues in a frame (video) displayed according to a video input signal will be described with reference to FIG.

In the case where there are many magenta hues in the frame (video), as shown in FIG. 7A, the green input signal G _in is biased toward the lower luminance side than the red input signal R _in and the blue input signal B _in. Yes. The control coefficient (maximum luminance / maximum luminance) of the red input signal R _in and the blue input signal B _in is “0.9”. The control coefficient (maximum luminance / maximum luminance) of the green input signal G _in is “0.5”.

  Here, consider a case in which the light emission efficiency of the solid light sources constituting the light source unit 10R, the light source unit 10G, and the light source unit 10B is as shown in FIG. For the light source unit 10R and the light source unit 10B, it is necessary to reduce the light amount emitted from the light source unit 10R and the light source unit 10B by the difference between the maximum light amount and the target light amount (that is, the maximum light amount × (1-0.9)). There is. On the other hand, for the light source unit 10G, it is necessary to reduce the light amount emitted from the light source unit 10G by the difference between the maximum light amount and the target light amount (that is, the maximum light amount × (1-0.5)).

  By the way, in the case where there are many magenta hues in the frame (video), as is clear from the hue speckle degree shown in FIG. 4A or FIG. ).

  Accordingly, each light source unit 10 is controlled according to the first control mode. That is, as shown in FIG. 7C, the amount of light emitted from the plurality of solid light sources constituting the light source unit 10 is reduced on average.

  Next, a case where there are many yellow hues in a frame (video) displayed according to a video input signal will be described with reference to FIG.

In the case where there are many yellow hues in the frame (video), as shown in FIG. 8A, the blue input signal B _in is biased toward the lower luminance side than the red input signal R _in and the green input signal G _in. Yes. The control coefficient (maximum luminance / maximum luminance) of the red input signal R _in and the green input signal G _in is “0.9”. The control coefficient (maximum luminance / maximum luminance) of the blue input signal B _in is “0.5”.

  Here, consider a case where the light emission efficiency of the solid light sources constituting the light source unit 10R, the light source unit 10G, and the light source unit 10B is as shown in FIG. For the light source unit 10R and the light source unit 10G, it is necessary to reduce the light amount emitted from the light source unit 10R and the light source unit 10G by the difference between the maximum light amount and the target light amount (that is, the maximum light amount × (1-0.9)). There is. On the other hand, for the light source unit 10B, it is necessary to reduce the light amount emitted from the light source unit 10B by the difference between the maximum light amount and the target light amount (that is, maximum light amount × (1-0.5)).

  By the way, in the case where there are many yellow hues in the frame (video), as is apparent from the hue speckle degree shown in FIG. 4A or FIG. ).

  Accordingly, each light source unit 10 is controlled according to the second control mode. That is, as shown in FIG. 8C, the light amount of the color component light emitted from the solid light source having low luminous efficiency among the plurality of solid light sources constituting the light source unit 10 is preferentially reduced.

  For example, when the light source unit 10R is taken as an example, No. 1 having a low luminous efficiency. The amount of light emitted from the solid light source 2 is “0”. Taking the light source unit 10G as an example, No. 1 having low luminous efficiency. The amount of light emitted from the solid light source 4 is “0”.

  Taking the light source unit 10B as an example, No. 1 having poor luminous efficiency. 2 and no. The amount of light emitted from the solid light source 3 is “0”. Furthermore, since it is necessary to reduce the amount of light emitted from the light source unit 10B, 1 and no. The amount of light emitted from the solid light source 4 is reduced.

(Function and effect)
In the first embodiment, the light source control unit 260 controls the first control mode that can relieve speckles and the power consumption that can be suppressed according to the degree of speckles (speckle degree) generated by each color component light in an image. The control ratio with the 2 control mode is changed. That is, when the speckle degree is high, the control ratio of the first control mode is increased, and when the speckle degree is low, the control ratio of the second control mode is increased. Therefore, speckle can be relaxed while taking into account the suppression of power consumption.

  The speckle degree calculation unit 250 calculates the speckle degree based on the multiplication result of the ratio of each hue included in the frame (video) and each hue speckle degree. Therefore, the speckle degree calculation accuracy can be increased as compared with the case where the speckle degree is simply calculated according to only the characteristics of the solid state light source constituting the light source unit 10.

(Calculation of saturation speckle degree)
Hereinafter, calculation of the speckle degree based on the saturation instead of the hue will be described with reference to the drawings. In the following, the difference between the hue speckle degree and the saturation speckle degree will be mainly described.

  The hue speckle degree is calculated according to the hue distribution included in the video (frame). On the other hand, the saturation speckle degree is calculated according to the saturation distribution included in the video (frame).

  Hereinafter, a speckle degree calculation unit based on saturation will be described with reference to the drawings. FIG. 9 is a block diagram showing the speckle degree calculation unit 250 based on the saturation.

  As illustrated in FIG. 9, the speckle degree calculation unit 250 includes a saturation determination unit 351, a first multiplication unit 352 to a sixth multiplication unit 357, and a speckle acquisition unit 358 instead of the hue determination unit 251. Have.

The saturation determination unit 351 acquires a video input signal including a red input signal R _in , a green input signal G _in, and a blue input signal B _in . Subsequently, the saturation determination unit 351 determines the saturation of each pixel included in the frame (video). Thus, the saturation determination unit 351 acquires the saturation distribution included in the frame (video).

  Here, the storage unit 240 determines the saturation speckle degree, which is the degree at which speckle is generated for each saturation (first saturation to sixth saturation) by the color component light emitted from the light source unit 10. It is assumed that it is memorized every time. Note that the first saturation to the sixth saturation are different saturations, and the saturation decreases in order from the first saturation. That is, the saturation of the first saturation is the highest and the saturation of the sixth saturation is the lowest.

  Similar to the red multiplier 252 to the magenta multiplier 257, the first multiplier 352 to the sixth multiplier 357 and the ratio of the first saturation to the sixth saturation included in the frame (video) and the first saturation, respectively. Multiply the saturation speckle degree from degree to sixth saturation.

  Similar to the speckle degree acquisition unit 258, the speckle acquisition unit 358 acquires the multiplication results obtained by the first multiplication unit 352 to the sixth multiplication unit 357. The speckle acquisition unit 358 acquires the speckle degree by adding the multiplication results.

(Calculation of luminance speckle degree)
Hereinafter, calculation of the speckle degree based on luminance instead of hue will be described with reference to the drawings. In the following, the difference between the hue speckle degree and the luminance speckle degree will be mainly described.

  The hue speckle degree is calculated according to the hue distribution included in the video (frame). On the other hand, the luminance speckle degree is calculated according to the luminance distribution included in the video (frame).

  Hereinafter, the speckle degree calculation unit based on luminance will be described with reference to the drawings. FIG. 10 is a block diagram showing a speckle degree calculation unit 250 based on luminance.

  As illustrated in FIG. 10, the speckle degree calculation unit 250 includes a luminance determination unit 451, a first multiplication unit 452 to a sixth multiplication unit 457, and a speckle acquisition unit 458 instead of the hue determination unit 251. .

The luminance determination unit 451 acquires a video input signal including a red input signal R _in , a green input signal G _in, and a blue input signal B _in . Subsequently, the luminance determination unit 451 determines the luminance of each pixel included in the frame (video). Thereby, the luminance determination unit 451 acquires the luminance distribution included in the frame (video).

  Here, the storage unit 240 stores, for each color component light, the luminance speckle degree, which is the degree that speckle is generated for each luminance (first luminance to sixth luminance) by the color component light emitted from the light source unit 10. It shall be. Note that the first luminance to the sixth luminance are different luminances, and the luminance decreases in order from the first luminance. That is, the luminance of the first luminance is the highest and the luminance of the sixth luminance is the lowest.

  Similarly to the red multiplication unit 252 to the magenta multiplication unit 257, the first multiplication unit 452 to the sixth multiplication unit 457, respectively, the ratio of the first luminance to the sixth luminance included in the frame (video) and the first luminance to the sixth luminance. Multiply by 6 brightness speckle degree.

  Similar to the speckle degree acquisition unit 258, the speckle acquisition unit 458 acquires the multiplication results obtained by the first multiplication unit 452 to the sixth multiplication unit 457. The speckle acquisition unit 458 acquires the speckle degree by adding the multiplication results.

[Second Embodiment]
(Configuration of projection display device)
Hereinafter, the configuration of the projection display apparatus according to the second embodiment will be described with reference to the drawings. FIG. 11 is a diagram showing a configuration of a projection display apparatus 600 according to the second embodiment. In the following, differences between the first embodiment and the second embodiment will be mainly described.

  As shown in FIG. 11, the projection display apparatus 600 includes a plurality of light source units 510, a plurality of rod integrators 520, a plurality of DMDs (Digital Micromirror Devices) 530, a TIR (Total Internal Reflection) prism 540, A projection lens unit 550.

  The plurality of light source units 510 are a light source unit 510R, a light source unit 510G, and a light source unit 510B. Each light source unit 510 is a unit composed of a plurality of solid state light sources.

  The light source unit 510R includes six solid light sources that emit red component light (not shown) and six optical fibers that guide red component light from each solid light source to the incident surface of the rod integrator 520R. The light source unit 510G includes six solid light sources that emit green component light (not shown) and six optical fibers that guide the green component light from each solid light source to the incident surface of the rod integrator 520G. The light source unit 510B includes six solid light sources that emit blue component light (not shown) and six optical fibers that guide blue component light from each solid light source to the incident surface of the rod integrator 520B.

  The plurality of rod integrators 520 are a rod integrator 520R, a rod integrator 520G, and a rod integrator 520B. The rod integrator 520 is configured so that the cross-sectional area increases from the incident surface 520a toward the exit surface 520b. The rod integrator 520 makes the light emitted from each light source unit 510 uniform so that the light emitted from each light source unit 510 is irradiated on the entire surface of the DMD 530.

  The plurality of DMDs 530 are DMD 530R, DMD 530G, and DMD 530B. DMD 530R modulates red component light by reflecting the red component light. Similarly, DMD 530G and DMD 530B modulate green component light and blue component light by reflecting green component light and blue component light, respectively.

  The mirror M and the dichroic mirrors DM1 and DM2 combine the light emitted from the plurality of rod integrators 520. The lenses LS1 and LS2 are condenser lenses that collimate the light from the light source unit 510 so that each color component light is irradiated onto the DMD 530.

  The TIR prism 540 is made of a light transmissive member and has a surface 541a and a surface 541b. An air gap is provided between the TIR prism 540 (surface 541a) and the prism 542 (surface 543a), and the angle (incident angle) at which the light from the light source unit 510 enters the surface 541a is greater than the total reflection angle. Since it is large, the light from the light source unit 510 is reflected by the surface 541a. On the other hand, an air gap is provided between the TIR prism 540 (surface 541b) and the prism 544 (surface 545a), but the angle at which the light from the light source unit 510 enters the surface 541b is greater than the total reflection angle. Since it is small, the light reflected by the surface 541a passes through the surface 545a.

  The prism 542 is made of a translucent member and has a surface 543a.

  The prism 544 is made of a light-transmitting member and has a surface 545a and a surface 545b. An air gap is provided between the TIR prism 540 (surface 541b) and the prism 544 (surface 545a). The blue component light reflected from the surface 545b and the blue component light emitted from the DMD 530B are emitted from the blue component light reflected from the surface 545b and the DMD 530B because the angle incident on the surface 545a is larger than the total reflection angle. Blue component light is reflected by the surface 545a.

  The surface 545b is a dichroic filter surface that transmits red component light and green component light and reflects blue component light. Therefore, of the light reflected by the surface 541a, the red component light and the green component light are transmitted through the surface 545b, and the blue component light is reflected at the surface 545b. The blue component light reflected by the surface 545a is reflected by the surface 545b.

  The prism 546 is formed of a light-transmitting member and has a surface 547a and a surface 547b. An air gap is provided between the prism 544 (surface 545b) and the prism 546 (surface 547a). The red component light reflected by the surface 547b and the red component light emitted from the DMD 530R have a larger incident angle on the surface 547a than the total reflection angle. The red component light emitted from the DMD 530R is reflected by the surface 547a.

  Then, the red component light that is emitted from the DMD 530R and reflected by the surfaces 547a and 547b is transmitted through the surface 547a because the angle incident on the surface 547a is smaller than the total reflection angle.

  The surface 547b is a dichroic filter surface that transmits green component light and reflects red component light. Accordingly, of the light transmitted through the surface 545b, the green component light is transmitted through the surface 547b, and the red component light is reflected at the surface 547b. The red component light reflected by the surface 547a is reflected by the surface 547b.

  The prism 548 is made of a light transmissive member and has a surface 549a. An air gap is provided between the prism 546 (surface 547b) and the prism 548 (surface 549a). Since the angle at which the green component light emitted from the DMD 530G is incident on the surface 549a is smaller than the total reflection angle, the green component light emitted from the DMD 530G is transmitted through the surface 549a.

  The surface 549a is a dichroic filter surface that transmits green component light and reflects red component light. Therefore, the red component light reflected from the surface 547a after being emitted from the DMD 530R and the green component light emitted from the DMD 530G are combined at the surface 549a.

  The surface 547a is a dichroic filter surface that transmits red component light and green component light and reflects blue component light. Therefore, the blue component light reflected from the surface 545a after being emitted from the DMD 530B, and the red component light and the green component light combined at the surface 549a are combined at the surface 547a.

  Here, the prism 544 separates the combined light including the red component light and the green component light and the blue component light by the surface 545b. The prism 546 separates the red component light and the green component light by the surface 547b. That is, the prism 544 and the prism 546 function as a color separation element that separates each color component light.

  On the other hand, the prism 544 combines the combined light including the red component light and the green component light and the blue component light by the surface 545b. The prism 546 combines the red component light and the green component light with the surface 547b. That is, the prism 544 and the prism 546 function as color combining elements that combine the color component lights.

  Since the angles at which the red component light, the green component light, and the blue component light synthesized on the surface 547a are incident on the surface 545a and the surface 543a are smaller than the total reflection angle, they are transmitted through the TIR prism 540 and the prism 542 and synthesized. Red component light, green component light, and blue component light, that is, image light is emitted to the projection lens unit 550 side.

  The projection lens unit 550 projects the combined light (image light) emitted from the TIR prism 540 on a screen or the like.

  In the second embodiment, the light source unit 510 and the rod integrator 520 constitute an “illuminating device”. It should be noted that the illumination device does not include the DMD 530, the TIR prism 540, and the projection lens unit 550. However, the illumination device may have a configuration including another optical element (for example, a condenser lens).

(Function of projection display device)
Hereinafter, functions of the projection display apparatus (illumination apparatus) according to the second embodiment will be described with reference to the drawings. FIG. 12 is a block diagram illustrating functions of the projection display apparatus 600 (control unit 700) according to the second embodiment.

  As in the first embodiment, the control unit 700 acquires a video input signal and controls the amount of color component light emitted from each light source unit 510 in accordance with the video input signal. Specifically, as shown in FIG. 12, the control unit 700 includes a light source control coefficient calculation unit 710, a drive signal generation unit 720, a display element control unit 730, a storage unit 740, and a speckle degree calculation unit 750. And a light source controller 760.

  In contrast to the first embodiment, the display element control unit 730 controls each DMD 530 according to a video output signal (drive signal). The storage unit 740 stores, for each color component light, the hue speckle degree, which is the degree to which speckle is generated for each hue by the color component light emitted from the light source unit 510. It should be noted that the hue speckle degree varies depending on the solid-state light source constituting the light source unit 510 (10).

(Calculation of hue speckle degree)
In the following, the degree to which speckle is generated for each hue by the component light of each color emitted from the light source unit 510 (hue speckle degrees R, G, B) will be exemplified with reference to FIGS. 13 to 15.

  The hue speckle degree R measures the degree of speckle generated for each hue while only the red component light source unit 510R of the light source unit 510 is turned on and the white light source (xenon lamp) is turned on. When the hue is R, a signal of (R, G, B) = (255, 0, 0) is output to the DMD 530. Similarly, the hue Ye is (255, 255, 0), the hue G is (0, 255, 0), the hue Cy is (0, 255, 255), the hue B is (0, 0, 255), and the hue Mg is (255, 0, 255).

  FIG. 13A is a diagram showing the hue speckle degree R acquired by speckle contrast measurement. The hue value indicating the maximum speckle contrast is “1”, and the relative speckle degree for each hue when the light source unit 510R for red component light is lit. Although the solid light sources constituting the light source unit 510R are different from the solid light sources (10-1R to 10-6R) constituting the light source unit 10R in the first embodiment, as shown in FIG. The same characteristics as those of the light source unit 10R of the embodiment are shown.

  FIG. 13B is a diagram showing the hue speckle degree R acquired by subjective evaluation. As shown in FIG. 13B, the characteristic by the main pipe evaluation also shows the same characteristic as the light source unit 10R of the first embodiment.

  FIG. 14A shows the hue speckle degree G acquired by speckle contrast measurement. The hue speckle degree G measures the degree of speckle generated for each hue while only the light source unit 510G of the green component light among the light source units 510 is turned on and the white light source (xenon lamp) is turned on. The value of the hue showing the maximum speckle contrast is “1”, and the relative speckle degree for each hue when the light source unit 510G for green component light is on is shown.

  As shown in FIG. 14A, the hue speckle degree G is the highest in the green hue G, and the hue speckle degree G is the second highest in the yellow hue Ye and the cyan hue Cy. On the other hand, the hue speckle degree G is relatively low in the red hue R, the blue hue B, and the magenta hue Mg.

  FIG. 14B is a diagram illustrating the hue speckle degree G acquired by subjective evaluation. As shown in FIG. 14B, the hue speckle degree G is the highest in the green hue G, and the hue speckle degree G is the second highest in the yellow hue Ye. On the other hand, the hue speckle degree G is relatively low in the red hue R, the blue hue B, and the magenta hue Mg.

  FIG. 15A is a diagram showing the hue speckle degree B acquired by speckle contrast measurement. The hue speckle degree B measures the degree of speckle generated for each hue while only the blue component light source unit 510B of the light source unit 510 is turned on and the white light source (xenon lamp) is turned on. The value of the hue showing the maximum speckle contrast is “1”, and the relative speckle degree for each hue when the light source unit 510B for blue component light is turned on is shown.

  As shown in FIG. 15A, the hue speckle degree B is the highest in the blue hue B, and the hue speckle degree G is the second highest in the cyan hue Cy and the magenta hue Mg. On the other hand, the hue speckle degree B is relatively low in the red hue R, the yellow hue Ye, and the green hue G.

  FIG. 15B is a diagram showing the hue speckle degree B acquired by subjective evaluation. As shown in FIG. 15B, the hue speckle degree B is the highest in the cyan hue Cy, and the hue speckle degree B is the second highest in the blue hue B. On the other hand, the hue speckle degree B is relatively low in the red hue R, the yellow hue Ye, and the green hue G.

  Next, the degree to which speckle is generated for each hue by the light emitted from the light source unit 510 (hue speckle degree RGB) will be illustrated with reference to FIG.

  As shown in FIG. 16A, the hue speckle degree RGB is the highest in the green hue G, and then the hue speckle degree RGB is high in the yellow hue Ye and the cyan hue Cy. On the other hand, the hue speckle degree RGB is relatively low in the blue hue B, the red hue R, and the magenta hue Mg.

  Since the light source unit 510G for green component light has a large amount of light, the hue speckle degree RGB tends to increase in the hue affected by the light source unit 510G. In FIG. 13 to FIG. 15, the hue value indicating the maximum speckle contrast is set to “1”, but as the actual measured value, blue having a small speckle contrast has a low hue speckle degree RGB.

  FIG. 16B is a diagram illustrating hue speckle degrees RGB acquired by subjective evaluation. As shown in FIG. 16B, in the subjective evaluation, the hue speckle degree RGB is highest in the yellow hue Ye, and then the hue speckle degree RGB is high in the green hue G and the cyan hue Cy. On the other hand, the hue speckle degree RGB is relatively low in the blue hue B, the red hue R, and the magenta hue Mg.

  However, it can be said from FIGS. 13 to 16 that there is no significant difference between the hue speckle degree by measurement and the hue speckle degree by subjective evaluation. Therefore, the control unit 700 includes a sensor that measures speckle contrast, and the hue speckle degree that is calibrated when displaying an image may be stored in the storage unit 740. The hue speckle degree may be stored in the storage unit 740 as in the embodiment.

  The speckle degree calculation unit 750 calculates the speckle degree, which is the degree to which speckle is generated by the light emitted from the light source unit 510 in a frame (video) displayed according to the video input signal. That is, the speckle degree calculation unit 750 calculates the speckle degree RGB.

Specifically, the speckle degree calculation unit 750 acquires a video input signal including a red input signal R _in , a green input signal G _in, and a blue input signal B _in , and acquires a hue distribution included in a frame (video). To do. The speckle degree calculation unit 750 multiplies a ratio in which each hue is included in the frame (video) by each hue speckle degree in the speckle degree RGB.

  The light source control unit 760 controls the light amount of the color component light emitted from each light source unit 510 in accordance with the control coefficient calculated by the light source control coefficient calculation unit 710.

Specifically, the light source controller 760 multiplies the maximum light amount of the light source unit 510 by the control coefficients of the red input signal R _in , the green input signal G _in and the blue input signal B _in and emits the light from the light source unit 510. Determine the amount of light (target light amount). The maximum amount of light is the amount of light emitted from the light source unit 510 when maximum power is supplied to a plurality of solid state light sources constituting the light source unit 510.

  Here, when the light source control unit 760 controls the light source unit 510 so that the light amount of the color component light emitted from the light source unit 510 becomes the target light amount, the same two control modes (first steps) as in the first embodiment are used. 1 control mode and 2nd control mode).

[Other Embodiments]
Although the present invention has been described with reference to the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the embodiment described above, the liquid crystal panel 30 and the DMD 530 are used as the display means, but the present invention is not limited to this. As the display means, LCOS (Liquid Crystal on Silicon) or the like may be used.

  Each light source unit 10 is controlled according to the speckle degree calculated for each color component light, but is not limited to this. All the light source units 10 may be controlled according to the speckle degree common to each color component light (for example, the average value, maximum value, minimum value, etc. of the speckle degree calculated for each color component light).

  The hue speckle degree, the saturation speckle degree, and the luminance speckle degree may be combined. Specifically, the control units 200 and 700 include the speckle degree acquired based on the hue distribution and the hue speckle degree, the saturation distribution, the speckle degree acquired based on the chroma speckle degree, and the luminance distribution. In addition, the control ratio between the first control mode and the second control mode may be changed according to any combination of two or more of the speckle degrees acquired based on the brightness speckle degree.

1 is a diagram illustrating a configuration of a projection display apparatus 100 according to a first embodiment. It is a figure which shows an example of the luminous efficiency of the some solid light source which comprises the light source unit 10 which concerns on 1st Embodiment. It is a block diagram which shows the function of the projection type video display apparatus 100 concerning 1st Embodiment. It is a figure which shows an example of the hue speckle degree which concerns on 1st Embodiment. It is a block diagram which shows the speckle degree calculation part 250 which concerns on 1st Embodiment. It is a figure which shows an example of the control ratio of the 1st control mode and 2nd control mode which concern on 1st Embodiment. It is a figure which shows the example of control of the light source unit 10 which concerns on 1st Embodiment. It is a figure which shows the example of control of the light source unit 10 which concerns on 1st Embodiment. It is a block diagram which shows the speckle degree calculation part 250 which concerns on 1st Embodiment. It is a block diagram which shows the speckle degree calculation part 250 which concerns on 1st Embodiment. It is a figure which shows the structure of the projection type video display apparatus 600 concerning 2nd Embodiment. It is a block diagram which shows the function of the projection type video display apparatus 600 concerning 2nd Embodiment. It is a figure which shows an example of the hue speckle degree R which concerns on 2nd Embodiment. It is a figure which shows an example of the hue speckle degree G which concerns on 2nd Embodiment. It is a figure which shows an example of the hue speckle degree B which concerns on 2nd Embodiment. It is a figure which shows an example of hue speckle degree RGB which concern on 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Light source unit, 20 ... Fly eye lens unit, 30 ... Liquid crystal panel, 40 ... Cross dichroic prism, 50 ... Projection lens unit, 100 ... Projection type video display apparatus, 200 ... Control unit, 210 ... Light source control coefficient calculation unit, 220 ... Drive signal generation unit, 230 ... Display element control unit, 240 ... Storage unit, 250 ... Speckle degree calculation unit 251 ... Hue determination unit, 252 to 257 ... Multiplication unit, 258 ... Speckle degree acquisition unit, 260 ... Light source control unit, 351 ... Saturation determination unit, 352-357 ... Multiplication unit, 358... Speckle acquisition unit, 451... Luminance determination unit, 452 to 457... Multiplication unit, 458 .. speckle acquisition unit, 510. Rod inte 530 ... DMD, 540 ... TIR prism, 542-548 ... prism, 550 ... projection lens unit, 600 ... projection display apparatus, 700 ... control unit, 710 ..Light source control coefficient calculation unit, 720... Drive signal generation unit, 730... Display element control unit, 740... Storage unit, 750. , M ... mirror, DM (DM1, DM2) ... dichroic mirror, LS (LS1, LS2) ... lens

Claims (6)

A lighting device including a light source unit having a plurality of solid-state light sources that emit the same color component light,
A light source control unit that controls the amount of the same color component light emitted from the plurality of solid-state light sources according to a video input signal;
An acquisition unit that acquires a speckle degree that is a degree that speckle is generated by the same color component light in the video according to the video input signal;
The light source controller is
A first control mode in which the amount of the same-color component light emitted from the plurality of solid-state light sources is decreased on average; A second control mode for preferentially reducing the amount of light;
A lighting device, wherein a control ratio between the first control mode and the second control mode is changed according to the speckle degree acquired by the acquisition unit. A storage unit that stores a hue speckle degree that is a degree that speckles are generated for each hue by the same color component light;
The acquisition unit acquires a hue distribution included in the video according to the video input signal, and acquires the speckle degree based on the hue distribution and the hue speckle degree. The lighting device described in 1. A storage unit that stores the saturation speckle degree, which is the degree that speckle is generated every saturation by the same color component light;
The acquisition unit acquires a saturation distribution included in the video according to the video input signal, and acquires the speckle degree based on the saturation distribution and the saturation speckle degree. The lighting device according to claim 1. A storage unit that stores a luminance speckle degree that is a degree that speckle is generated for each luminance by the same color component light;
2. The acquisition unit according to claim 1, wherein the acquisition unit acquires a luminance distribution included in the video according to the video input signal, and acquires the speckle degree based on the luminance distribution and the luminance speckle degree. The lighting device described in 1.   A projection type comprising: the illumination device according to claim 1; display means for irradiating light emitted from the illumination device; and projection means for projecting light emitted from the display means. Video display device.   The projection display apparatus according to claim 5, wherein the display unit is a reflection type display unit.