JP2008026711A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device capable of effectively controlling the quantity of light projected to a screen. <P>SOLUTION: The display unit 100 includes a light source unit 10, a light modulation element 20 that modulates light emitted by the light source unit 10 based on a video signal, and a projection lens unit 30 that projects the light emitted from the light modulation element 20 to the screen 200. The display unit 100 is provided with a light quantity sensor 50 that detects the quantity of light emitted by the light source unit 10; and a control section 160 that controls the quantity of light emitted by the light source unit 10, based on the quantity of light detected by the light quantity sensor 50. The light quantity sensor 50 is disposed inside the region, through which light emitted by the light source unit 10 passes before the light is projected to the screen 200 and which does not affect the light projected to the screen 200. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a display device including a light source, a light modulation element that modulates light emitted from the light source based on a video signal, and a projection lens unit that projects light emitted from the light modulation element onto a screen.

  Conventionally, a projection display device that projects light emitted from a light modulation element such as a CRT or a liquid crystal panel onto a screen is generally widely known. Further, since light sources such as CRT phosphors and lamps deteriorate with time, a method for calculating the light source deterioration rate by detecting the light quantity of the light source has also been proposed.

  For example, in the case where the projection display device is an overscan type that scans to an area outside the effective screen area, a projection display apparatus in which a light amount sensor is arranged outside the effective screen area has been proposed (for example, patents). Reference 1).

  Specifically, in this projection display device, the reference light of the light source is projected on the outer area of the effective screen area, and the reference light quantity of the light source is detected by the light quantity sensor. Further, the deterioration rate of the light source with time is calculated by comparing the light amount detected by the light amount sensor with the initial light amount of the light source.

  Furthermore, in the above-described projection display device, white balance is maintained by controlling the output (light quantity) of the light source based on the calculated deterioration rate of the light source with time.

In addition, since the area outside the effective screen area is invisible to the viewer, even if the reference light of the light source is projected to the area outside the effective screen area, the viewer feels uncomfortable when viewing the video. Never give.
Japanese Patent Laid-Open No. 9-37281 (Claim 1, FIG. 1, etc.)

  By the way, in general, when a viewer views an image projected on a screen, the viewer's line of sight gathers in the central portion of the screen rather than the peripheral portion of the screen. Therefore, in the control of the amount of light projected on the screen, it is preferable to use the detection result of the amount of light projected on the central portion of the screen.

  However, in the above-described projection display device, the amount of light projected onto the screen is controlled using the detection result of the amount of light projected onto the outer area of the effective screen area, and thus projected onto the screen. In some cases, the amount of light cannot be controlled effectively.

  Accordingly, the present invention has been made to solve the above-described problem, and an object thereof is to provide a display device that can effectively control the amount of light projected on a screen. .

  One feature of the present invention is that a light source (light source unit 10), a light modulation element (light modulation element 20) that modulates light emitted from the light source based on a video signal, and light emitted from the light modulation element. A display device including a projection lens unit (projection lens unit 30) that projects onto a screen (screen 200) is detected by a light amount detection unit (light amount sensor 50) that detects the amount of light emitted by the light source and the light amount detection unit. A light amount control unit (control unit 160) for controlling the light amount emitted from the light source based on the light amount, and the light amount detection unit until the light emitted from the light source is projected on the screen. The gist of the invention is that the light source is disposed in a region through which light emitted from the light source passes and does not affect the light projected on the screen.

  According to such a feature, the light quantity detection unit should be projected on the effective screen area by being disposed in the area through which the light emitted from the light source passes before the light emitted from the light source is projected on the screen. The amount of light can be detected efficiently. As a result, the amount of light projected on the screen can be controlled effectively.

  In addition, the light amount detection unit is arranged at a position that does not affect the light projected on the screen, thereby preventing the brightness of the light projected on the screen from falling and giving the viewer an uncomfortable feeling. Can do.

  One feature of the present invention is that in the above-described feature of the present invention, a reflective mirror (reflective mirror 40) having a reflective surface (reflective surface 40a) for reflecting the light emitted from the projection lens unit toward the screen is displayed. Further, the gist of the present invention is that the light amount detection unit is provided to face the back surface (back surface 40b) of the reflection mirror provided on the opposite side of the reflection surface.

  One feature of the present invention is that in the above-described feature of the present invention, the projection lens unit has a diaphragm section (diaphragm section 31) for narrowing a region through which light emitted from the light source passes, and the diaphragm section includes: The gist of the invention is that the light source is configured by a non-light transmissive member that blocks a part of the light emitted from the light source, and the light amount detection unit is provided in the diaphragm unit.

  One feature of the present invention is that in the above-described feature of the present invention, the light modulation element has a configuration in which a plurality of micromirrors (micromirrors 22) that reflect light emitted from the light source are arranged, By individually controlling the tilt of the mirror, the on-light that is the light reflected to the projection lens unit side and the off-light that is the light that does not reflect to the projection lens unit side are switched. The gist is that it is arranged at a position where the off-light passes.

  One feature of the present invention is that in the above-described feature of the present invention, a rotating plate (color wheel 90) that is provided between the light source and the light modulation element and is rotatable about a rotating shaft is displayed. The rotating plate further includes a plurality of transmission regions (transmission region 90r, transmission region 90g, and transmission region 90b) that transmit only light having different wavelengths, and a reflection region (reflection region) that reflects the light emitted from the light source. 91), and the gist of the light amount detection unit is arranged at a position where the light reflected by the reflection region passes.

  One feature of the present invention is an estimated light amount calculation for calculating an estimated light amount to be detected by the light amount detector based on a reference light amount of light emitted from the light source and the video signal. A display unit (estimated light amount calculation unit 150), and the light amount control unit, based on a comparison result between the light amount detected by the light amount detection unit and the estimated light amount calculated by the estimated light amount calculation unit, The gist is to control the amount of light emitted by the light source.

  One feature of the present invention is that, in the above-described feature of the present invention, an estimated light amount calculation unit that calculates an estimated light amount of light emitted from the light source based on the light amount detected by the light amount detection unit and the video signal. The display device further includes an estimated light amount calculation unit 150), and the light amount control unit is configured to compare the reference light amount of the light emitted from the light source with the estimated light amount calculated by the estimated light amount calculation unit. The gist is to control the amount of light emitted.

  One feature of the present invention is that a light source (light source unit 10), a light modulation element (light modulation element 20) that modulates light emitted from the light source based on a video signal, and light emitted from the light modulation element. A display device including a projection lens unit (projection lens unit 30) that projects on a screen has a light amount detection unit (light amount sensor 50) that detects the amount of light emitted by the light source, and a light amount detected by the light amount detection unit. And a modulation amount correction unit (modulation amount control unit 120) that corrects the modulation amount of the light modulation element based on the video signal, and the light amount detection unit has the light emitted from the light source on the screen. The gist of the invention is that the light source is disposed in a position that does not affect the light projected on the screen in an effective region through which the light emitted by the light source passes before the light is projected.

  ADVANTAGE OF THE INVENTION According to this invention, the display apparatus which makes it possible to control effectively the light quantity of the light projected on a screen can be provided.

  Hereinafter, a display device 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.

  However, it should be noted that the drawings are schematic and ratios of dimensions 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 display device)
Hereinafter, the configuration of the display device according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a display device 100 according to the first embodiment of the present invention. In FIG. 1, attention is focused on a configuration for explaining the display device 100 according to the first embodiment of the present invention, and other configurations necessary for the display device 100 such as a condenser lens and a relay lens are shown. It should be noted that this is omitted.

  As shown in FIG. 1, the display device 100 includes a light source unit 10, a light modulation element 20, a projection lens unit 30, a reflection mirror 40, and a light amount sensor 50. The display device 100 projects image light on the screen 200.

  The light source unit 10 includes a light source 10a that emits white light toward the light modulation element 20 and a reflector 10b that reflects white light emitted from the light source 10a to the light modulation element 20 side. The light source unit 10 is, for example, a white UHP lamp.

  The light modulation element 20 is an element that modulates light emitted from the light source unit 10 in units of pixels, and is, for example, a liquid crystal panel.

  The projection lens unit 30 is a unit having a projection lens (not shown) that projects light emitted from the light modulation element 20, that is, light (image light) modulated by the light modulation element 20 onto the screen 200.

  The reflection mirror 40 has a reflection surface 40a that reflects light (image light) emitted from the projection lens unit 30 to the screen 200 side. Here, the reflection mirror 40 is made of a light-transmissive member, and reflects most of the light (image light) emitted from the projection lens unit 30 to the screen 200 side. On the other hand, the reflection mirror 40 transmits part of the light (image light) emitted from the projection lens unit 30. This is because it is difficult to completely align the polarization direction of the light (image light) emitted from the projection lens unit 30 in one direction.

  The light amount sensor 50 is provided to face the back surface 40b of the reflection mirror 40 provided on the opposite side of the reflection surface 40a, and detects the amount of transmitted light transmitted through the reflection mirror 40. The light amount sensor 50 is provided at a substantially central portion of the back surface 40 b of the reflection mirror 40, and light projected on a substantially central portion of the screen 200 out of the light (image light) emitted from the projection lens unit 30. The amount of transmitted light corresponding to (image light) is detected.

(Display device functions)
Hereinafter, functions of the display device according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a block diagram illustrating functions of the display device 100 according to the first embodiment of the present invention.

  As shown in FIG. 2, in addition to the light source unit 10, the light modulation element 20, and the light quantity sensor 50, the display device 100 includes a video signal input unit 110, a modulation amount control unit 120, a contribution storage unit 130, a reference The light amount storage unit 140, the estimated light amount calculation unit 150, and the control unit 160 are included.

  The video signal input unit 110 inputs video signals to the modulation amount control unit 120 and the estimated light amount calculation unit 150 in units of frames. Here, the video signal is, for example, a signal indicating the ratio of red (R), green (G), and blue (B) in units of pixels, and is a signal generated in units of frames. The video signal is, for example, a signal indicating a color tone ratio of red (R), green (G), and blue (B) within a range of 0 to 255 bits, and (R, G, B) = (128 , 128, 196).

  The modulation amount control unit 120 controls the modulation amount of the light modulation element 20 in units of pixels based on the video signal acquired from the video signal input unit 110. For example, the modulation amount control unit 120 controls the amount of light emitted from the light modulation element 20 for each color based on the video signal acquired from the video signal input unit 110.

  The contribution storage unit 130 stores the ratio (hereinafter referred to as contribution) that the light emitted from each pixel position of the light modulation element 20 reaches the light quantity sensor 50 and the pixel position in association with each other. Here, the degree of contribution is calculated based on the amount of light detected by the light amount sensor 50 with respect to light emitted from each pixel position of the light modulation element 20 when the display device 100 is shipped from the factory. Further, the contribution degree is represented by, for example, a relative ratio of the light amount corresponding to each pixel position. The contribution storage unit 130 stores the modulation amount (that is, the video signal) of the light modulation element 20 and the contribution in association with each other when the contribution is calculated.

  Here, since the distance and optical path from each pixel position to the light quantity sensor 50 differ depending on each pixel position of the light modulation element 20, the light emitted from each pixel position becomes the light quantity detected by the light quantity sensor 50. The effect is different. Therefore, the contribution degree is used to improve the accuracy of the light amount control of the light emitted from the light source unit 10.

  The contribution may be recalculated based on the light amount detected again by the light amount sensor 50 for the light emitted from the light source unit 10 when the display device 100 is maintained after the display device 100 is shipped from the factory.

  The reference light quantity storage unit 140 stores a light quantity that serves as a reference for light emitted from the light source unit 10 (hereinafter referred to as a reference light quantity). Here, the reference light amount is, for example, the light amount (initial light amount) detected by the light amount sensor 50 for the light emitted from the light source unit 10 when the display device 100 is shipped from the factory. Note that the reference light amount storage unit 140 stores the modulation amount (that is, the video signal) of the light modulation element 20 when the reference light amount is detected and the reference light amount in association with each other.

  Further, the reference light amount may be a light amount detected again by the light amount sensor 50 for light emitted from the light source unit 10 when the display device 100 is maintained after the display device 100 is shipped from the factory.

  In the first embodiment, the modulation amount (that is, the video signal) of the light modulation element 20 when the reference light amount is detected is the modulation amount (that is, the video signal) of the light modulation element 20 when the contribution is calculated. Shall be the same.

  The estimated light amount calculation unit 150 stores the video signal acquired from the video signal input unit 110 (that is, the modulation amount of the light modulation element 20), the contribution stored in the contribution storage unit 130, and the reference light storage unit 140. Based on the reference light amount thus calculated, an estimated light amount to be detected by the light amount sensor 50 is calculated.

Specifically, the estimated light amount calculation unit 150 takes a coefficient (red coefficient) for each color of the entire frame when the pixel position is (i (1 ≦ i ≦ I), j (1 ≦ j ≦ J)). (Rt), the green coefficient (Gt), and the blue coefficient (Bt)) are calculated by the following equation (1). Note that “C _{ri, j} ”, “Cg _{i, j} ”, and “Cb _{i, j} ” are contributions for each color associated with the pixel position (i, j), and “R _{i, j} ”, “G _{i, j} ” and “B _{i, j} ” are video signals (modulation amounts).

Subsequently, the estimated light amount calculation unit 150 assumes that the reference light amount stored in the reference light amount storage unit 140 is “x _s ”, and the estimated light amount is “x _p ”. x _p ) is calculated by the following equation (2).

Based on the estimated light amount calculated by the estimated light amount calculation unit 150 and the detected light amount detected by the light amount sensor 50, the control unit 160 sets the control amount of the light amount output from the light source unit 10 (output of the light source 10a). calculate. Specifically, the control unit 160 controls the light amount output from the light source unit 10 when the control amount of the light amount output from the light source unit 10 is “I” and the detected light amount is “x _d ” ( I) is calculated by the following equation (3).

  Further, the control unit 160 controls the amount of light output from the light source unit 10 based on the calculated control amount (I).

(Operation of display device)
Hereinafter, an operation of the display device according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a flowchart showing the operation of the display device 100 according to the first embodiment of the present invention.

  As shown in FIG. 3, in step 10, the display device 100 controls the modulation amount of the light modulation element 20 based on the video signal (for example, the color tone ratio of R, G, and B).

  In step 20, the display device 100 reads the contribution for each pixel position from the contribution storage unit 130.

  In step 30, the display device 100 reads the reference light amount from the reference light amount storage unit 140.

  In step 40, the display device 100 calculates an estimated light amount based on the modulation amount (video signal) controlled in step 10, the contribution read in step 20, and the reference light amount read in step 30. calculate.

Specifically, when the reference light amount read from the reference light amount storage unit 140 is “x _s ” and the estimated light amount is “x _p ”, the display device 100 calculates the estimated light amount (x _p ) as follows: Calculated by (2).

  In step 50, the display device 100 detects the light amount of the light whose modulation amount is controlled in step 10 by the light amount sensor 50.

  In step 60, the display device 100 calculates a control amount of the light amount of light emitted from the light source unit 10 (output of the light source 10 a) based on the estimated light amount calculated in step 40 and the detected light amount detected in step 50. calculate.

Specifically, the display device 100 controls the amount of light output from the light source unit 10 when the control amount of the light amount output from the light source unit 10 is “I” and the detected light amount is “x _d ” ( I) is calculated by the following equation (3).

  In step 70, the display device 100 controls the amount of light output from the light source unit 10 based on the control amount (I) calculated in step 60.

(Function and effect)
According to the display device 100 according to the first embodiment of the present invention, the light quantity sensor 50 is in a region through which light emitted from the light source unit 10 passes before light emitted from the light source unit 10 is projected onto the screen 200. Has been placed. Specifically, the light quantity sensor 50 is provided to face the back surface 40 b of the reflection mirror 40, and is provided at a substantially central portion of the reflection mirror 40. Therefore, the amount of light to be projected on the effective screen area of the screen 200 can be efficiently detected. As a result, the amount of light projected on the screen 200 can be effectively controlled.

  Further, since the light quantity sensor 50 is provided on the back surface 40b side of the reflection mirror 40, it does not affect the light projected on the screen 200. Therefore, it is possible to prevent the viewer from feeling uncomfortable due to the brightness of the light projected on the screen 200 being lowered.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In the following, differences between the above-described first embodiment and the second embodiment will be mainly described.

  Specifically, in the first embodiment described above, the display device 100 is a rear projection display device, and the light amount sensor 50 is provided to face the back surface 40 b of the reflection mirror 40. On the other hand, in the second embodiment, the light amount sensor 50 is provided in the diaphragm portion of the projection lens unit 30. In the second embodiment, it should be noted that the display device 100 is not limited to the rear projection display device.

(Configuration of display device)
Hereinafter, the configuration of the display device according to the second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a diagram showing a configuration of the display device 100 according to the second embodiment of the present invention. In FIG. 4, attention is focused on a configuration for explaining the display device 100 according to the second embodiment of the present invention, and other configurations necessary for the display device 100 such as a relay lens are omitted. It should be noted that.

  First, an optical system of the display device 100 according to the second embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 4A, the display device 100 includes a pair of fly-eye lenses (a fly-eye lens 61 and a fly-eye lens 62) in addition to the light source unit 10, the light modulation element 20, and the projection lens unit 30. A polarization conversion element 70 and a condenser lens 80.

  The fly-eye lens 61 has a plurality of microlenses 61a arranged in an array. Each microlens 61 a condenses light on the polarization conversion element 70.

  The fly-eye lens 62 has a plurality of microlenses 62a arranged in an array. Each microlens 62 a condenses light on the polarization conversion element 70. The light condensed on the polarization conversion element 70 by the micro lens 62 a is condensed on the entire surface of the light modulation element 20 by the condenser lens 80.

  The polarization conversion element 70 converts a polarization direction of the light emitted from the light source unit 10 into S-polarized light and outputs a polarization beam splitter (PBS) that emits only S-polarized component light to the condenser lens 80 side in the horizontal direction. And optical elements arrayed in the vertical direction. Specifically, the polarization conversion element 70 includes a PBS surface 71a, a PBS surface 71b, and a 1 / 2λ phase difference plate 72.

  The PBS surface 71a transmits P-polarized component light out of the light collected by the micro lens 61a of the fly-eye lens 61 to the 1 / 2λ phase difference plate 72 side, and transmits S-polarized component light to the PBS surface 71b. Reflect to the side. The PBS surface 71b reflects the S-polarized component light reflected by the PBS surface 71a to the condenser lens 80 side. The 1 / 2λ phase difference plate 72 converts the polarization direction of the P-polarized component light transmitted through the PBS surface 71a by 90 °, and emits the S-polarized component light to the condenser lens 80 side.

  The condenser lens 80 condenses the light collected by the micro lens 62 a of the fly-eye lens 62 on the entire surface of the light modulation element 20. In other words, the condenser lens 80 condenses the light whose polarization direction is aligned in one polarization direction by the polarization conversion element 70 on the entire surface of the light modulation element 20.

  Next, a projection lens unit 30 according to a second embodiment of the invention will be described with reference to FIG.

  As shown in FIG. 4B, the projection lens unit 30 includes a diaphragm unit 31 and a projection lens 32.

  The diaphragm unit 31 is configured by a non-light-transmissive member that blocks a part of the light emitted from the light source unit 10, and narrows down the region through which the light emitted from the light source unit 10 passes.

  The projection lens 32 projects the light narrowed down by the diaphragm unit 31 onto the screen 200.

  The light quantity sensor 50 is provided in the diaphragm unit 31. Specifically, the light quantity sensor 50 is provided on the side surface of the diaphragm portion 31 provided on the light source unit 10 side.

(Function and effect)
According to the display device 100 according to the second embodiment of the present invention, the light amount sensor 50 is provided in the diaphragm portion 31 of the projection lens unit 30. Therefore, the amount of light to be projected on the effective screen area of the screen 200 can be efficiently detected. As a result, the amount of light projected on the screen 200 can be effectively controlled.

  Further, since the light amount sensor 50 is provided in the diaphragm portion 31 of the projection lens unit 30, it does not affect the light projected on the screen 200. Therefore, it is possible to prevent the viewer from feeling uncomfortable due to the brightness of the light projected on the screen 200 being lowered.

[Third Embodiment]
Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. In the following, differences between the above-described second embodiment and the third embodiment will be mainly described.

  Specifically, in the second embodiment described above, the light modulation element is not particularly limited. However, in the third embodiment, the light modulation element is an element in which a plurality of micromirrors are arranged (DMD (Digital Micromirror Device). ); Registered trademark). The light quantity sensor 50 is disposed at a position where off light reflected by an element in which a plurality of micromirrors are arranged passes.

(Configuration of display device)
Hereinafter, the configuration of the display device according to the third embodiment of the present invention will be described with reference to the drawings. 5 and 6 are diagrams showing a configuration of the display device 100 according to the third embodiment of the present invention.

  First, a display device 100 according to a third embodiment of the present invention will be described with reference to FIG. It should be noted that in FIG. 5A, the same reference numerals are given to the same configurations as in FIG. 4A described above.

  As shown in FIG. 5A, the display device 100 includes a light modulation element 21, and reflected light reflected by the light modulation element 21 is incident on the projection lens unit 30.

  Next, an optical modulation element 21 according to a third embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 5B, the light modulation element 21 has a configuration in which a plurality of micromirrors 22 are arranged. Here, the micro mirror 22 is provided, for example, in units of pixels, and the light modulation element 21 controls the inclination of the micro mirror 22 to reflect the on-light reflected toward the projection lens unit 30 and the projection lens unit. It switches off light that is not reflected to the 30 side.

  Finally, the arrangement position of the light quantity sensor 50 according to the third embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 6, the light modulation element 21 controls the inclination of the micromirror 22 to turn on light (L _on ) reflected to the projection lens unit 30 side and off light not reflected to the projection lens unit 30 side. (L _off ).

For example, the light modulation element 21 controls the inclinations of the micromirrors 22a to 22c and the micromirror 22f, and reflects the light toward the projection lens unit 30 with these micromirrors (ON light (L _on )). On the other hand, the light modulation element 21 controls the inclination of the micro mirror 22d and the micro mirror 22e, and reflects light in a direction different from the projection lens unit 30 side by these micro mirrors (off light (L _off )). .

The light quantity sensor 50 is arranged at a position where light (off light (L _off )) that is not reflected by the light modulation element 21 toward the projection lens unit 30 passes.

(Function and effect)
According to the display device 100 according to the third embodiment of the present invention, the light quantity sensor 50 is arranged at a position where off-light (L _off ) reflected by the micro lens 61 a of the light modulation element 21 passes. Therefore, the amount of light to be projected on the effective screen area of the screen 200 can be efficiently detected. As a result, the amount of light projected on the screen 200 can be effectively controlled.

Further, since the light quantity sensor 50 is disposed at a position where the off-light (L _off ) reflected by the minute lens 61 a of the light modulation element 21 passes, it does not affect the light projected on the screen 200. Therefore, it is possible to prevent the viewer from feeling uncomfortable due to the brightness of the light projected on the screen 200 being lowered.

[Fourth Embodiment]
Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. In the following, differences between the above-described third embodiment and the fourth embodiment will be mainly described.

  Specifically, although not touched in the third embodiment described above, in the fourth embodiment, the display device 100 has a color wheel, and the light amount sensor 50 is provided to face the color wheel. Yes.

(Configuration of display device)
The configuration of the display device according to the fourth embodiment of the present invention will be described below with reference to the drawings. FIG. 7 is a diagram showing a configuration of a display device 100 according to the fourth embodiment of the present invention.

  First, a display device 100 according to a fourth embodiment of the present invention will be described with reference to FIG. In FIG. 7A, it should be noted that the same components as those in FIG. 5A described above are denoted by the same reference numerals.

  As illustrated in FIG. 7A, the display device 100 includes a color wheel 90 in addition to the configuration illustrated in FIG.

  As will be described later, the color wheel 90 includes a transmission region that transmits light of different wavelengths and a reflection region that reflects light emitted from the light source unit 10.

  The light quantity sensor 50 is provided facing the surface (reflection area) of the color wheel 90 provided on the light source unit 10 side, and detects the light quantity of the light reflected by the reflection area. That is, the light amount sensor 50 is disposed at a position where light reflected by the reflection region of the color wheel 90 passes.

  Next, a color wheel 90 according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 7B shows the surface of the color wheel 90 when the color wheel 90 is viewed from the light source unit 10 side.

  As shown in FIG. 7B, the color wheel 90 includes a transmission region 90r that transmits light having a wavelength corresponding to red, a transmission region 90g that transmits light having a wavelength corresponding to green, and a wavelength corresponding to blue. And a transmission region 90b that transmits the light. Further, the color wheel 90 has a reflection area 91 that reflects light emitted from the light source unit 10. Note that the reflection region 91 is configured by, for example, a mirror surface.

(Function and effect)
According to the display device 100 according to the fourth embodiment of the present invention, the light amount sensor 50 is disposed at a position where light reflected by the reflection region 91 of the color wheel 90 passes. Therefore, the amount of light to be projected on the effective screen area of the screen 200 can be efficiently detected. As a result, the amount of light projected on the screen 200 can be effectively controlled.

  Further, since the light quantity sensor 50 is disposed at a position where light reflected by the reflection area 91 of the color wheel 90 passes, it does not affect the light projected on the screen 200. Therefore, it is possible to prevent the viewer from feeling uncomfortable due to the brightness of the light projected on the screen 200 being lowered.

[Fifth Embodiment]
Hereinafter, a fifth embodiment of the present invention will be described with reference to the drawings. In the following, differences between the above-described first embodiment and the fifth embodiment will be mainly described.

  Specifically, in the first embodiment described above, the control unit 160 controls the amount of light emitted from the light source unit 10, but in the fifth embodiment, the control unit 160 modulates the light modulation element 20. Correct the amount.

(Display device functions)
The configuration of the display apparatus according to the fifth embodiment of the present invention will be described below with reference to the drawings. FIG. 8 is a block diagram showing a configuration of the display device 100 according to the fifth embodiment of the present invention. In FIG. 8, it should be noted that the same components as those in FIG. 2 described above are denoted by the same reference numerals.

  As shown in FIG. 8, the control unit 160 is connected to the modulation amount control unit 120 instead of the light source unit 10. Further, the control unit 160 calculates the correction amount of the modulation amount of the light modulation element 20 based on the estimated light amount calculated by the estimated light amount calculation unit 150 and the reference light amount stored in the reference light amount storage unit 140.

Specifically, the control unit 160 determines that the correction amount of the modulation amount of the light modulation element 20 is “C”, the estimated light amount is “x _p ”, and the detected light amount is “x _d ”. The modulation amount correction amount “C” is calculated by the following equation (4).

  Further, the control unit 160 inputs the correction amount “C” of the modulation amount of the light modulation element 20 to the modulation amount control unit 120, and the modulation amount control unit 120 is based on the correction amount “C” acquired from the control unit 160. Thus, the modulation amount of the light modulation element 20 based on the video signal is corrected.

(Operation of display device)
The operation of the display device according to the fifth embodiment of the present invention will be described below with reference to the drawings. FIG. 9 is a flowchart showing the operation of the display device 100 according to the fifth embodiment of the present invention. In FIG. 9, the same steps as those in FIG. 3 are given the same step numbers.

  As shown in FIG. 9, in step 80, the display device 100 corrects the modulation amount of the light modulation element 20 based on the estimated light amount calculated in step 40 and the reference light amount read in step 50. Is calculated.

Specifically, the display device 100 is configured such that the amount of correction of the modulation amount of the light modulation element 20 is “C”, the estimated light amount is “x _p ”, and the detected light amount is “x _d ”. The correction amount “C” of the modulation amount is calculated by the following equation (4).

  In step 90, the display device 100 corrects the modulation amount of the light modulation element 20 based on the correction amount (C) calculated in step 80.

(Function and effect)
According to the display device 100 according to the fifth embodiment of the present invention, the control unit 160 calculates the correction amount “C” of the modulation amount of the light modulation element 20, and the modulation amount control unit 120 acquires from the control unit 160. Based on the corrected amount “C”, the modulation amount of the light modulation element 20 based on the video signal is corrected. Therefore, even when the output of the light source unit 10 cannot be controlled, the amount of light projected on the screen 200 can be controlled.

  For example, even when the light source unit 10 is a monochromatic light source, if the light modulation element 20 is provided corresponding to each color (red, green, and blue), the display device 100 may include the light modulation element 20. The white balance can be maintained by correcting the modulation amount.

[Sixth Embodiment]
The sixth embodiment of the present invention will be described below. In the following, differences between the first embodiment and the sixth embodiment described above will be mainly described.

  Specifically, in the first embodiment described above, the estimated light amount calculation unit 150 stores the video signal acquired from the video signal input unit 110 (that is, the modulation amount of the light modulation element 20) and the contribution storage unit 130. Based on the degree of contribution made and the reference light amount stored in the reference light amount storage unit 140, an estimated light amount of light emitted from the light source unit 10 is calculated.

  On the other hand, in the sixth embodiment, the estimated light amount calculation unit 150 stores the video signal acquired from the video signal input unit 110 (that is, the modulation amount of the light modulation element 20) and the contribution storage unit 130. Based on the contribution degree and the light amount detected by the light amount sensor 50, an estimated light amount of light emitted from the light source unit 10 is calculated.

Specifically, the estimated light amount calculation unit 150 sets the estimated light amount (x) to the following equation (5) when the light amount detected by the light amount sensor 50 is “x _d ” and the estimated light amount is “x _p ”. Calculated by

The control unit 160 controls the light amount output from the light source unit 10 (output of the light source 10a) based on the estimated light amount calculated by the estimated light amount calculation unit 150 and the reference light amount stored in the reference light amount storage unit 140. Calculate the amount. Specifically, the control unit 160 controls the amount of light output from the light source unit 10 when the control amount of the light amount output from the light source unit 10 is “I” and the reference light amount is “x _s ” ( I) is calculated by the following equation (6).

  Further, the control unit 160 controls the amount of light output from the light source unit 10 based on the calculated control amount (I).

[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.

  For example, in the first to fifth embodiments described above, the case where the light source is a monochromatic light source has been described as an example. However, the present invention is not limited to this. Specifically, the display device 100 may include a plurality of light sources (for example, LEDs (Light Emitting Diode)) that emit light of each color (red, green, and blue).

  In this case, for example, the display device 100 estimates for each color (red, green, and blue) based on the modulation amount (video signal) of the light modulation element 20 corresponding to a plurality of frames (frame 1 to frame 3). The amount of light may be calculated.

Specifically, the reference light quantity stored in the reference light quantity storage unit 140 is “x _s ”, the red estimated light quantity is “x _rp ”, the green estimated light quantity is “x _gp ”, and the blue estimated light quantity is “x”. _In the case of “ _bp ”, the display device 100 can establish simultaneous equations of the following expression (7).

Subsequently, the display device 100 can calculate the estimated light _amounts (x _rp , x _gp, and x _bp ) of each color by solving the simultaneous equations described above. It should be noted that the coefficients (Rt, Gt, and Bt) for each color corresponding to a plurality of frames differ depending on the video signal.

  In the first to fifth embodiments described above, the light amount sensor 50 detects the total light amount without distinguishing light of each color, but is not limited thereto. Specifically, the light amount sensor 50 has a plurality of light receiving portions for each color, and may detect the light amount by distinguishing light of each color.

  The display device 100 may be a projector, a projection television, a CRT, a liquid crystal panel, or the like.

  Furthermore, in the first to fifth embodiments described above, the contribution degree stored in the contribution degree storage unit 130 is used in order to improve the calculation accuracy of the estimated light amount. However, the present invention is not limited to this. is not. Specifically, the display device 100 may calculate the estimated light amount based on the video signal and the detected light amount without using the contribution stored in the contribution storage unit 130.

  For example, when the light quantity sensor 50 is arranged at a position where the light modulated by the light modulation element 20 forms an image (for example, as shown in the first embodiment, substantially at the center of the back surface 40b of the reflection mirror 40). Therefore, sufficient calculation accuracy of the estimated light quantity can be obtained without using the contribution degree stored in the contribution degree storage unit 130.

It is a figure which shows the structure of the display apparatus which concerns on 1st Embodiment of this invention. It is a block diagram which shows the function of the display apparatus which concerns on 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the display apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the display apparatus 100 which concerns on 2nd Embodiment of this invention. It is a figure which shows the structure of the display apparatus 100 which concerns on 3rd Embodiment of this invention (the 1). It is a figure which shows the structure of the display apparatus 100 which concerns on 3rd Embodiment of this invention (the 2). It is a figure which shows the structure of the display apparatus 100 which concerns on 4th Embodiment of this invention. It is a block diagram which shows the function of the display apparatus 100 which concerns on 5th Embodiment of this invention. It is a flowchart which shows operation | movement of the display apparatus 100 which concerns on 5th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Light source unit, 10a ... Light source, 10b ... Reflector, 20 ... Light modulation element, 21 ... Light modulation element, 22 ... Micro mirror, 30 ... Projection lens unit, DESCRIPTION OF SYMBOLS 31 ... Diaphragm part, 32 ... Projection lens, 40 ... Reflection mirror, 40a ... Reflecting surface, 40b ... Back surface, 50 ... Light quantity sensor, 61 ... Fly eye lens, 61a ... Micro lens, 62 ... Fly eye lens, 62a ... Micro lens, 70 ... Polarization conversion element, 71a ... PBS surface, 71b ... PBS surface, 72 ... 1 / 2λ Phase plate, 80 ... condenser lens, 90 ... color wheel, 90r ... transmission region, 90g ... transmission region, 90b ... transmission region, 91 ... reflection region, 100 ... Display device, 110... Video signal 120, modulation amount control unit, 130 ... contribution degree storage unit, 140 ... reference light amount storage unit, 150 ... estimated light amount calculation unit, 160 ... control unit, 200 ... screen

Claims (8)

A display device comprising: a light source; a light modulation element that modulates light emitted from the light source based on a video signal; and a projection lens unit that projects light emitted from the light modulation element onto a screen,
A light amount detector for detecting the amount of light emitted by the light source;
A light amount control unit that controls the amount of light emitted by the light source based on the light amount detected by the light amount detection unit;
The light amount detection unit is in a region through which light emitted from the light source passes before light emitted from the light source is projected on the screen, and does not affect light projected on the screen. A display device characterized by being arranged in the above. A reflection mirror having a reflection surface for reflecting the light emitted from the projection lens unit toward the screen;
The display device according to claim 1, wherein the light amount detection unit is provided to face a back surface of the reflection mirror provided on the opposite side of the reflection surface. The projection lens unit has a diaphragm portion that narrows a region through which light emitted from the light source passes,
The diaphragm portion is configured by a non-light transmissive member that blocks a part of light emitted by the light source,
The display device according to claim 1, wherein the light amount detection unit is provided in the diaphragm unit. The light modulation element is
A plurality of micromirrors that reflect light emitted from the light source are arranged;
By individually controlling the tilt of the minute mirror, switching between on-light which is light reflected to the projection lens unit side and off-light which is light not reflected to the projection lens unit side is performed.
The display device according to claim 1, wherein the light amount detection unit is disposed at a position through which the off-light passes. Provided between the light source and the light modulation element, further comprising a rotating plate rotatable about a rotation axis;
The rotating plate has a plurality of transmission regions that transmit only light having different wavelengths, and a reflection region that reflects light emitted from the light source,
The display device according to claim 1, wherein the light amount detection unit is disposed at a position where light reflected by the reflection region passes. Further comprising an estimated light amount calculation unit for calculating an estimated light amount to be detected by the light amount detection unit based on a reference light amount of light emitted from the light source and the video signal;
The light amount control unit controls a light amount emitted from the light source based on a comparison result between a light amount detected by the light amount detection unit and an estimated light amount calculated by the estimated light amount calculation unit. The display device according to 1. Based on the light amount detected by the light amount detection unit and the video signal, further includes an estimated light amount calculation unit that calculates an estimated light amount of light emitted from the light source,
The light amount control unit controls the light amount emitted from the light source based on a comparison result between a reference light amount of light emitted from the light source and an estimated light amount calculated by the estimated light amount calculation unit. The display device described in 1. A display device comprising: a light source; a light modulation element that modulates light emitted from the light source based on a video signal; and a projection lens unit that projects light emitted from the light modulation element onto a screen,
A light amount detector for detecting the amount of light emitted by the light source;
A modulation amount correction unit that corrects the modulation amount of the light modulation element based on the video signal based on the light amount detected by the light amount detection unit;
The light amount detection unit is within an effective region through which light emitted from the light source passes until light emitted from the light source is projected onto the screen, and does not affect the light projected onto the screen. A display device characterized by being arranged at a position.

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