CN110737162B

CN110737162B - Display device and projection system

Info

Publication number: CN110737162B
Application number: CN201810791547.6A
Authority: CN
Inventors: 田梓峰; 周萌; 李屹
Original assignee: Appotronics Corp Ltd
Current assignee: Shenzhen Appotronics Corp Ltd
Priority date: 2018-07-18
Filing date: 2018-07-18
Publication date: 2021-09-28
Anticipated expiration: 2038-07-18
Also published as: WO2020015364A1; CN110737162A

Abstract

The present invention provides a display device and a projection system, comprising: a control device for obtaining a light quantity control signal and correcting image data; a light source for emitting first fluorescence, second fluorescence, third fluorescence, The fourth fluorescence and the scattered excitation light; the light modulation device is used to modulate the light emitted by the color wheel according to the corrected image data and generate the image light of the image to be displayed, so as to dynamically adjust the first fluorescence, the second fluorescence The ratio of the third fluorescence to the second fluorescence and the fourth fluorescence further dynamically adjusts the color gamut range of the image light, which also improves the light utilization rate.

Description

Display device and projection system

Technical Field

The invention relates to the technical field of display, in particular to a display device and a projection system.

Background

This section is intended to provide a background or context to the specific embodiments of the invention that are recited in the claims. The description herein is not admitted to be prior art by inclusion in this section.

Currently, light sources for projection devices are mainly classified into the following categories: the first is a light source based on red, green and blue LEDs, the second is a light source based on red, green and blue LDs, and the third is a light source based on blue LDs exciting fluorescent powder to generate red, green and fluorescent light. In the first scheme, the color reduction capability can reach more than 105% of the NTSC standard color gamut, and the main problems are that the electro-optic conversion efficiency of a green LED is low, and the brightness of a red LED, a green LED and a blue LED is also low; in the second scheme, the pure RGB laser is adopted, the color gamut range can reach BT2020, but the pure laser light source has the main problems of serious speckle, higher cost, lower efficiency of green laser and poorer temperature stability of red laser; in the third scheme, the phosphor emits a wider spectrum, and the overall color gamut is smaller, and the color reduction capability of the projection device using the scheme can reach 72% of the NTSC standard color gamut. The color gamut can be expanded by some enhancement processes, such as adding filters to remove the yellow spectrum of green and red, but the filters cause significant light loss, thereby greatly reducing the efficiency of the system.

Disclosure of Invention

In order to solve the problem that the color gamut range and the light utilization rate of a laser fluorescence scheme in the prior art cannot be obtained at the same time, the invention provides a display device with an adjustable dynamic color gamut and a projection system.

A display device, comprising:

a control device for decoding the original image data to obtain a light quantity control signal and corrected image data;

a light source for emitting, according to the light amount control signal:

a first fluorescence and a third fluorescence for modulating the image in the first color gamut range; and

the second fluorescence, the fourth fluorescence and the scattered exciting light are used for modulating the image in the second color gamut range;

wherein the second gamut range covers the first gamut range and has a portion that is outside the first gamut range; the first fluorescence and the second fluorescence are first color light, the third fluorescence and the fourth fluorescence are second color light, and the excitation light is third color light; the first fluorescence and the second fluorescence are metameric fluorescence and/or the third fluorescence and the fourth fluorescence are metameric fluorescence; and

and the light modulation device is used for modulating the light emitted by the light source according to the corrected image data and generating image light of an image to be displayed.

A projection system comprising a display device as described above.

In the display device and the projection system provided by the invention, the control device is used for sending the light quantity control signal and the correction image signal according to original image data, the light source is used for sending the first fluorescence and the third fluorescence for modulating the first color gamut range image and the second fluorescence and the fourth fluorescence for modulating the second color gamut range image according to the light quantity control signal, and the light modulation device is used for modulating the image light according to the correction image signal, so that the proportions of the first fluorescence, the third fluorescence, the second fluorescence and the fourth fluorescence are dynamically adjusted, the color gamut range of the image light is further dynamically adjusted, and the light utilization rate is also improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments/modes of the present invention, the drawings needed to be used in the description of the embodiments/modes are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments/modes of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a display device according to a preferred embodiment of the present invention.

Fig. 2 is a schematic top view of the color wheel shown in fig. 1.

Fig. 3 is a schematic diagram of narrow-spectrum fluorescence, wide-spectrum fluorescence and a common color gamut range emitted by the color wheel.

Fig. 4 shows excitation and emission spectra of the first and second regions.

Fig. 5 is an excitation and emission spectrum of the third section.

Fig. 6 is an excitation and emission spectrum of the fourth section.

Fig. 7 is a schematic top view of a color wheel according to an embodiment.

Fig. 8 is a schematic top view of a color wheel according to another embodiment.

Fig. 9 is a luminance distribution diagram of each pixel of the high gamut image.

FIG. 10 is β -sialon: eu (Eu)²⁺With LuAG: Ce³⁺Graph of relative luminous efficiency.

Fig. 11 is a curve of the electro-optical conversion efficiency of a scheme for generating narrow-spectrum green fluorescence by using blue laser excitation and a scheme for generating green laser light source according to the luminous flux of the excitation light source.

Fig. 12 is a schematic block diagram of the principle of dynamically adjusting the color gamut by the control device.

Fig. 13 is a schematic diagram of the excitation light source corresponding to the driving current of the color wheel to emit various light rays.

Fig. 14 is a schematic block diagram of a dynamic adjustment of the color gamut corresponding to the color wheel shown in fig. 7.

Description of the main elements

The following detailed description will further illustrate the invention in conjunction with the above-described figures.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, a detailed description of the present invention will be given below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention, and the described embodiments are merely a subset of the embodiments of the present invention, rather than a complete embodiment. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The embodiment of the invention provides a display device with adjustable dynamic color gamut, wherein a light source of the display device is used for emitting first fluorescence and third fluorescence for modulating an image in a first color gamut range and second fluorescence and fourth fluorescence for modulating an image in a second color gamut range, wherein the second color gamut range covers the first color gamut range and has a part exceeding the first color gamut range, namely the first color gamut range is a low color gamut range, and the second color gamut range is a high color gamut range. The control device dynamically adjusts the proportion of various light rays for modulating the image light according to the original image data, thereby realizing the dynamic adjustment of the color gamut range of the image light emitted by the display equipment. The display device in the embodiment of the invention can be applied to a projection system, and three primary colors emitted by the display device keep white balance.

The detailed structure and principle of the display device and the projection system according to the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a display device 100 according to a preferred embodiment of the invention. The display apparatus 100 comprises a light source 101, a light modulation device 105 and a control device 107. Wherein, the control device 107 is used for decoding the original image data to obtain the light quantity control signal and the correction image data; the light source 101 is configured to emit light source light according to the light amount control signal, and the light modulation device 105 is configured to modulate the light source light according to the corrected image data and generate image light of an image to be displayed. The control device 107 adjusts the light ratio for modulating the image in the first color gamut range and the image in the second color gamut range, thereby dynamically adjusting the color gamut range of the image light.

Specifically, the light source 101 includes an excitation light source 110 and a color wheel 130. The excitation light source 110 is configured to emit excitation light; the color wheel 130 is provided with a wavelength conversion material for generating fluorescence under excitation of the excitation light.

Further, the excitation light source 110 includes a laser for emitting excitation light including laser light. The excitation light is a third color light, and in the embodiment of the present invention, the third color light is a blue light, and the excitation light source 110 is a blue light source. It is to be understood that the third color light is not limited to the blue light source, and the third color light may be violet light, red light, green light, or the like. In the present embodiment, the light emitter in the excitation light source 110 is a blue laser, and emits blue laser light as excitation light. It will be appreciated that the light emitter may also comprise two colour lasers, such as a blue laser and an ultraviolet laser. In this embodiment, the light emitter may include one, two or a blue laser array, and the number of the lasers may be selected according to actual needs.

The excitation light source 110 may further include a light uniformizing device to uniformize the excitation light and emit the homogenized excitation light to a subsequent device. The light homogenizing device can be a light homogenizing rod or a fly eye lens and the like.

Referring to fig. 2 in conjunction with fig. 1, fig. 2 is a schematic top view of the color wheel 130 shown in fig. 1. The excitation light is guided to enter the color wheel 130 through the light splitting and combining element 125.

As shown in fig. 2, the substrate 131 of the color wheel 130 is circular, and the substrate 131 is periodically rotated by the driving unit, so that the edge area of the substrate 131 is always located on the optical path of the excitation light. The surface of the substrate 131 includes an outer ring region 131b and an inner ring region 131 a. The outer ring region 131b and the inner ring region 131a are both annular and disposed around the edge of the substrate 131, and the inner diameter of the outer ring region 131b is greater than the inner diameter of the inner ring region 131 a. In the present embodiment, the outer ring region 131b is provided adjacent to the inner ring region 131 a. In other embodiments, the outer ring region 131b is spaced apart from the inner ring region 131 a.

Further, the color wheel 130 includes a scattering layer B, a conversion layer, and a filtering unit. In this embodiment, the scattering layer B and the conversion layer are disposed in the outer ring region 131B, and the filter unit is disposed in the inner ring region 131 a. The switching layer includes a first segment R1, a second segment R2, a third segment G1, and a fourth segment G2. The scattering layer B and the four segments of the conversion layer are disposed along the circumference of the color wheel 130, and the scattering layer B, the first segment R1, the second segment R2, the third segment G1 and the five segments above the fourth segment G2 are driven by the driving unit to be located on the light path of the excitation light in a time sequence.

Specifically, the scattering layer B is provided with a scattering material on the surface of the substrate 131 to scatter the excitation light, thereby performing coherent cancellation processing on the laser light in the excitation light.

The first section R1 has a red wavelength conversion material disposed therein for modulating an image in the first color gamut range such that when the first section R1 is on the optical path of the excitation light, the excitation light irradiates the first section R1 and generates first fluorescence for modulating the red color of the image in the first color gamut range. A red wavelength conversion material for modulating an image in the second color gamut is disposed in the second section R2 such that when the second section R2 is on the optical path of the excitation light, the excitation light irradiates the second section R2 and generates second fluorescent light for modulating the red color of the image in the second color gamut. The third segment G1 is provided therein with a green wavelength conversion material for modulating an image in the first color gamut range, so that when the third segment G1 is on the optical path of the excitation light, the excitation light irradiates the third segment G1 and generates third fluorescence for modulating green of the image in the first color gamut range. The green wavelength conversion material for modulating the image in the second color gamut is disposed in the fourth segment G2 such that when the fourth segment G2 is on the optical path of the excitation light, the excitation light irradiates the fourth segment G2 and generates fourth fluorescence for modulating the image in the second color gamut. In this embodiment, the first fluorescent light and the second fluorescent light are red light, and the second fluorescent light and the fourth fluorescent light are green light, but the first fluorescent light and the second fluorescent light may be other colors, and the invention is not limited thereto.

The first fluorescence and the second fluorescence are metameric fluorescence and/or the third fluorescence and the fourth fluorescence are metameric fluorescence. The second gamut range covers the first gamut range and has a portion exceeding the first gamut range, so the second gamut range is a high gamut range and the first gamut range is a low gamut range. The narrow-spectrum fluorescence covers a high color gamut range, and the wide-spectrum fluorescence covers a low color gamut range, so that the first fluorescence and the third fluorescence are wide-spectrum fluorescence, and the second fluorescence and the fourth fluorescence are narrow-spectrum fluorescence. Correspondingly, the first section R1 and the third section G1 are both provided with wide-spectrum phosphors, and the second section R2 and the fourth section G2 are both provided with narrow-spectrum phosphors. Generally, the half-width of the broad spectrum fluorescence is 70nm or more, and the half-width of the narrow spectrum fluorescence is less than 70 nm. In one embodiment, the first fluorescence and the second fluorescence are metameric light, i.e., the first fluorescence is broad spectrum fluorescence, the second fluorescence is narrow spectrum fluorescence, and the third fluorescence and the fourth fluorescence are metameric light. In one embodiment, the third fluorescence and the fourth fluorescence are metameric light, the third fluorescence is broad spectrum fluorescence, the fourth fluorescence is narrow spectrum fluorescence, and the first fluorescence and the second fluorescence are metameric light. By adjusting the ratio of the wide-spectrum fluorescence to the narrow-spectrum fluorescence in at least one color light, the color coordinates of the primary colors obtained after mixing can be correspondingly changed, and the color gamut can be adapted to a new color gamut.

Referring to fig. 3, fig. 3 is a schematic diagram of the narrow-spectrum fluorescence, the wide-spectrum fluorescence and the general color gamut range emitted by the color wheel 130. The color gamut range of the broad spectrum fluorescence is between the color gamut of the sRGB standard and the color gamut of the NTSC standard, and the color gamut range of the narrow spectrum fluorescence is close to the color gamut of the BT2020 standard. The narrow spectrum fluorescence has a gamut that covers the broad spectrum fluorescence and has a portion that exceeds the broad spectrum fluorescence.

In one embodiment, the second segment R2 and the fourth segment G2 are provided with quantum dots for wavelength conversion of the excitation light. In the present embodiment, the red wavelength conversion material provided in the first segment R1 is CaAlSiN₃:Eu²⁺The second segment R2 has K as the red wavelength converting material₂SiF₆:Mn⁴⁺。

Referring to fig. 4 in conjunction with fig. 3, fig. 4 shows the excitation and emission spectra of the first section R1 and the second section R2. Under the excitation of blue excitation light (445nm action), the first segment R1 emits first fluorescence with a broad spectrum (with a half-peak width of 93nm), and the color coordinate of the first fluorescence is located in the NTSC standard color gamut. The second section R2 emits a second fluorescent light with a narrow emission spectrum, a peak wavelength of 630nm and color coordinates of (0.69, 0.30), which is in a color gamut exceeding the DCI-P3 color gamut standard and approaching the BT2020 color gamut standard.

In one embodiment, the red wavelength converting material in the second segment R2 is K₂TiF₆:Mn⁴⁺(peak wavelength 630nm, color coordinates (0.69, 0.30)) or K₂GeF₆:Mn⁴⁺(peak wavelength 630nm, color coordinates: (0.69, 0.30)) color approaches the BT2020 red requirement. In one embodiment, the second section R2 may be provided with other wavelength converting materials having a narrower emission spectrum, or the second section R2 may be provided with K₂SiF₆:Mn⁴⁺、K₂TiF₆:Mn⁴⁺、K₂GeF₆:Mn⁴⁺And multiple mixed materials in quantum dots.

In the embodiment of the present invention, the green wavelength conversion material provided in the third section G1 is LuAG: Ce³⁺The fourth section G2 is provided with a wavelength converting material of gamma-AlON: Mn²⁺。

Referring further to fig. 5-6 in conjunction with fig. 3, fig. 5 shows the excitation and emission spectra of the third segment G1, and fig. 6 shows the excitation and emission spectra of the fourth segment G2. Under the excitation of blue excitation light (445nm action), the third segment G1 emits a broad spectrum (110 nm half-peak width) of third fluorescence, the color coordinate of which is located in the NTSC standard color gamut. The fourth section G2 emits fourth fluorescence with a narrow emission spectrum (44 nm of half-peak width), a peak wavelength of 515nm-520nm, a color coordinate of the 515nm fourth fluorescence of (0.19, 0.75) and a color coordinate of the 520nm fourth fluorescence of (0.22, 0.71), and the color gamut of the fourth fluorescence exceeds the DCI-P3 color gamut standard and approaches the BT2020 color gamut standard.

In one embodiment, the fourth section G2 may use other green wavelength conversion materials with narrow emission spectra or gamma-AlON: Mn²⁺、β-sialon:Eu²⁺(half-peak width 49nm, peak wavelength 528nm, color coordinates (0.28, 0.68), green color close to DCI-P3 standard color gamut), Ba₂LiSi₇AlN₁₂:Eu²⁺(61 nm of half-peak width, 515nm of peak wavelength (0.24, 0.61) and close to DCI-P3 green) and quantum dots.

Referring to fig. 1-2, light (including scattered excitation light, wavelength-converted broad-spectrum fluorescence and wavelength-converted narrow-spectrum fluorescence) emitted from the outer ring region 131b of the color wheel 130 is guided to the inner ring region 131a through the light splitting and combining element 125 and the light splitting and combining element 126 in sequence. The light generated by the outer ring region 131b is reflected to the light splitting and combining element 125 through the substrate 131, and the light emitted by the light splitting and combining element 126 passes through the inner ring region 131a, passes through the light homogenizing device and the TIR prism, and then enters the light modulation device 105.

The inner ring region 131a is provided with filter units B ', R1', R2', G1' and G2' for filtering the excitation light scattered by the scattering layer B, the first fluorescent light emitted by the first segment R1, the second fluorescent light emitted by the second segment R2, the third fluorescent light emitted by the third segment G1 and the fourth fluorescent light emitted by the fourth segment G2, respectively. In one embodiment, the filter units B ', R1', R2', G1' and G2' are provided with corresponding filters in each segment.

In the present embodiment, the first section R1 is circumferentially adjacent to the second section R2, and the third section G1 is circumferentially adjacent to the fourth section G2. In one embodiment, the first segment R1 is circumferentially adjacent to the third segment G1 and the second segment R2 is circumferentially adjacent to the fourth segment G2. In one embodiment, the five segments in the outer ring region 131b are arranged in other sequences, for example, sequentially emitting red-blue-green-red-green light, and accordingly, the segments of the filter unit are arranged in the sequence corresponding to the above five segments.

Fig. 7 is a schematic top view of a color wheel 230 according to an embodiment. The color wheel 230 includes a circular substrate 231, and the surface of the substrate 231 includes a first fan-shaped annular region 231c, a second fan-shaped annular region 231d and a third fan-shaped environmental region 231e arranged along the circumferential direction of the substrate 231. In the present embodiment, the first sector annular area 231c, the second sector annular area 231d and the third sector annular area 231e have the same radius, and are adjacently disposed to form an annular area. It is understood that in other embodiments, the first sector annular region 231c and the second sector annular region 231d and the third sector annular region 231e have different inner and/or outer diameters. In one embodiment, the first sector annular area 231c is spaced apart from the second sector annular area 231d and the third sector annular area 231 e.

In the embodiment of the present invention, the second sector annular region 231d includes a first region p and a second region q, and the third sector annular region 231e includes a third region s and a fourth region t. Further, the first region p, the second region q, the third region s, and the fourth region t are distributed along the circumferential direction of the substrate 231. In the present embodiment, the first region p, the second region q, the third region s, and the fourth region t are provided adjacent to each other. In one embodiment, the first region p, the second region q, the third region s, and the fourth region t are provided at intervals.

Further, the scattering layer B is disposed in the first fan-shaped region 231c, and the first section R1, the second section R2, the third section G1 and the fourth section G2 are disposed in one of the first region p, the second region q, the third region s and the fourth region t, respectively. In the present embodiment, the correspondence relationship between the first section R1, the second section R2, the third section G1, and the fourth section G2 and the first region p, the second region q, the third region s, and the fourth region t, respectively, is not limited. In the present embodiment, the first segment R1, the second segment R2, the third segment G1 and the fourth segment G2 are sequentially disposed in the first region p, the second region q, the third region s and the fourth region t, that is, the segments emitting the same color light are disposed in the same fan-shaped region, for example, the first segment R1 and the second segment R2 for emitting the first color light are disposed in the second fan-shaped region 231d, and the third segment G1 and the fourth segment G2 for emitting the second color light are disposed in the third fan-shaped region 231 e. It is understood that in other embodiments, the segments for emitting the same color light may be disposed in adjacent fan-shaped regions, such as the first segment R1 and the third segment G1 disposed in the second fan-shaped region 231d, and the second segment R2 and the fourth segment G2 disposed in the third fan-shaped region 231 e.

In the present embodiment, the boundary between the first region p and the third region s is zigzag, and the boundary between the second region q and the fourth region t is zigzag. In one embodiment, the boundary between the first region p and the second region q is an arbitrary curve, and the boundary between the third region s and the fourth region t is an arbitrary curve, which may be a wave, a straight line, or the like.

The second fan-shaped annular region 231d is provided with a wide spectrum phosphor and a narrow spectrum phosphor, and the following relationship exists between the two phosphors:

wherein r is_bAnd r_nRatio of wide-spectrum phosphor to narrow-spectrum phosphor, R₀The ratio of the two phosphors is linear with the distance from the laser spot to the geometric center of the color wheel 230, and the ratio of the two phosphors can be adjusted by adjusting the position of the laser spot, i.e., the position of the color wheel.

Further in accordance with

(x_b,y_b,Y_b)*r_b+(x_b,y_b,Y_b)*(1-r_b)＝(x,y,Y)，

Wherein (x)_b,y_b,Y_b) Representing the color coordinates and brightness of the broad spectrum phosphor, (x)_b,y_b,Y_b) Representing the color coordinates and brightness of the narrow-spectrum phosphor, and (x, Y) representing the color coordinates and brightness of the mixed primary light. If the ratio of the wide-spectrum fluorescent powder to the narrow-spectrum fluorescent powder changes, the color coordinates of the primary colors obtained after mixing also change correspondingly, and the color gamut can be adapted to a new color gamut. Moreover, since the light saturation of the narrow-spectrum phosphor is significantly greater than that of the wide-spectrum phosphor, the narrow-spectrum phosphor has a lower power density of the excitation light than the wide-spectrum phosphor, and the light-emitting efficiency is lower under the condition of a higher light power density, the driving current of the excitation light source 110 needs to be adjusted, that is, when the signal on the spatial light modulator 105 is a narrow-spectrum fluorescent signal, the driving current of the excitation light source 110 needs to be adjusted to be small.

The distance between the excitation light spot formed on the surface of the substrate 231 and the geometric center of the substrate 231 is adjustable, and the ratio of the first fluorescence, the second fluorescence, the third fluorescence and the fourth fluorescence in the light source light is adjusted by adjusting the distance between the excitation light spot formed on the surface of the substrate 231 and the geometric center of the substrate 231. The light proportion for modulating the first color gamut and the second color gamut image changes, so that the color coordinates of the primary colors obtained after mixing also change correspondingly, and the new color gamut can be adapted. In a preferred embodiment, the distance between the spot formed by the excitation light on the surface of the substrate 231 and the geometric center of the substrate 231 is adjusted by adjusting the position of the color wheel 230.

Fig. 8 is a schematic top view of a color wheel 330 according to another embodiment. The color wheel 330 is different from the color wheel 230 mainly in that the first region p and the second region q, and the third region s and the fourth region t are all in a fan-shaped ring shape, i.e., a boundary between the first region p and the second region q is an arc, and a boundary between the third region s and the fourth region t is an arc.

It should be noted that, within the scope of the spirit or the basic features of the present invention, each specific solution applied to the color wheel 230 may also be correspondingly applied to the color wheel 330, and for the sake of brevity and avoidance of repetition, the detailed description thereof is omitted here.

In one embodiment, the substrate 131 of the color wheel 130 is circular, and the scattering layer B, the first segment R1, the second segment R2, the third segment G1 and the fourth segment G2 are radially disposed on the substrate 131. In a preferred embodiment, the scattering layer B, the first segment R1, the second segment R2, the third segment G1, and the fourth segment G2 are at different distances from the geometric center of the substrate 131. Further, in a preferred embodiment, the scattering layer B, the first section R1, the second section R2, the third section G1, and the fourth section G2 are annular regions having different inner diameters.

The distance between the excitation light spot formed on the surface of the substrate 131 and the geometric center of the substrate 131 is adjusted to adjust the ratio of the first fluorescence, the second fluorescence, the third fluorescence and the fourth fluorescence in the light source light. The light proportion for modulating the first color gamut and the second color gamut image changes, so that the color coordinates of the primary colors obtained after mixing also change correspondingly, and the new color gamut can be adapted. In a preferred embodiment, the distance between the spot formed by the excitation light on the surface of the substrate 131 and the geometric center of the substrate 131 is adjusted by adjusting the position of the color wheel 130.

Referring further to fig. 1, in the embodiment of the present invention, the light modulation device 105 is a DMD, an LCOS, or an LCD, preferably an LCOS, or an LCD.

The control device 107 is electrically connected to the light modulation device 105 and to the excitation light source 110 through the gamma correction circuit 109. In this embodiment, the control device 107 and the gamma correction circuit 109 are independent of each other. In one embodiment, the gamma correction circuit 109 is disposed inside the control device 107. The control device 107 is used for decoding the original image data to obtain a light quantity control signal and corrected image data. The excitation light source 110 is configured to emit the excitation light according to the light amount control signal, and the light amount of the excitation light is controlled by the light amount control signal. The light modulation device 105 is configured to modulate the light emitted from the color wheel 130 according to the corrected image data and generate image light of an image to be displayed.

Further, the light quantity control signal is used for controlling the driving current intensity of the excitation light source corresponding to different sections on the excitation light path, so as to adjust the light power of the excitation light.

Please refer to fig. 9, which is a luminance distribution diagram of each pixel of the high gamut image. Researchers have found that the luminance distribution of the pixel points of the current high color gamut picture is shown in fig. 9. The high brightness of the natural picture is mainly distributed in the sRGB standard color gamut, the brightness peak outside the sRGB standard color gamut is very low, and the brightness requirement is lower than that in the sRGB standard color gamut by more than about one order of magnitude. That is, light in the sRGB standard color gamut mainly provides brightness, and light outside the sRGB standard color gamut requires much lower brightness than light in the sRGB standard color gamut.

Therefore, in the embodiment of the present invention, five segments are fabricated on the outer ring region 131B of the same color wheel 130, and the first segment R1 and the third segment G1 with wider fluorescence emission spectra are selected to provide primary color light in a lower color gamut sRGB range ([ R (0.64, 0.33) G (0.30, 0.60) B (0.15, 0.06) ]), so as to provide high-brightness pixel points in a color gamut range for an image to be displayed. The second section R2 and the fourth section G2 with narrower fluorescence emission spectrums are selected to provide primary color light close to the range of the high color gamut BT2020, and low-brightness pixel points in the range of the high color gamut are further provided for the image to be displayed.

Since the brightness requirement of the current high color gamut picture is low, the excitation light power requirement for exciting the second fluorescent light (narrow spectrum red light) and the fourth fluorescent light (narrow spectrum green light) on the color wheel 130 is low, and from the brightness distribution of fig. 9, the brightness requirement of the narrow spectrum fluorescent light is 1/10 of the wide spectrum fluorescent light. Although narrow-spectrum fluorescence has a lower power density to withstand excitation light than broad-spectrum fluorescence due to its longer afterglow time, the luminous efficiency is lower under the condition of higher optical power density; however, by adjusting the optical power of the narrow-spectrum fluorescence, the efficiency of the narrow-spectrum fluorescence can still be kept high, and the optical power of the excitation light source 110 is saved, which is beneficial to reducing the power consumption of the display device 100 and improving the light utilization rate.

When the first segment R1, the second segment R2, the third segment G1, and the fourth segment G2 are located on the light path of the excitation light, the optical power of the excitation light is the first segment optical power, the second segment optical power, the third segment optical power, and the fourth segment optical power, respectively. The light quantity control signal is used for controlling the second section light power to be smaller than or equal to the first section light power and controlling the fourth section light power to be smaller than or equal to the third section light power. In one embodiment, the light amount control signal is used to control the optical power of the second segment to be equal to or less than 1/10 of the optical power of the red fluorescent region, and/or to control the optical power of the fourth segment to be equal to or less than 1/10 of the optical power of the third segment.

Please refer to fig. 10, which shows β -sialon: eu (Eu)²⁺With LuAG: Ce³⁺Graph of relative luminous efficiency. LuAG: Ce³⁺For emitting broad spectrum green fluorescence, the half width of the third fluorescence is 110 nm. Beta-sialon: eu (Eu)²⁺For emitting a narrow spectrum green fluorescence, the half-width of the fourth fluorescence emitted therefrom was 50 nm.

As shown in fig. 10, at a relative optical power density of 1, the β -sialon: eu (Eu)²⁺Luminescence efficiency of (1) and LuAG: Ce³⁺And (4) approaching. At a relative optical power density of 10, β -sialon: eu (Eu)²⁺The efficiency of (B) is LuAG to Ce³⁺Around 80%, thus in a narrow spectrum green powder β -sialon: eu (Eu)²⁺The excitation light power density is wide-spectrum green powder LuAG: Ce ³⁺1/10, β -sialon: eu (Eu)²⁺Can also maintain higher efficiency with LuAG: Ce³⁺And (4) approaching. The excitation light source 110 controls the light amount according to the light amount control signal,the driving currents are different corresponding to different sections on the exciting light path, so that primary color light with different proportions is generated to realize dynamic color gamut adjustment, higher light conversion efficiency is kept, and the light utilization rate is improved.

Further, compared with the second RGB laser scheme mentioned in the background art, specifically, the current electro-optical conversion efficiency of green laser excited fluorescence is 12%, the blue laser electro-optical conversion efficiency is 38%, and the conversion efficiency of blue laser used for generating narrow-spectrum green fluorescence is 40-60%, so the electro-optical conversion efficiency of blue laser used for generating narrow-spectrum green fluorescence is 15-23%, and the efficiency of blue laser excited for generating narrow-spectrum green fluorescence is higher than that of the current green laser scheme.

Referring to fig. 11, fig. 11 is a graph showing the variation of the photoelectric conversion efficiency of the scheme for generating the narrow-spectrum green fluorescence by using blue laser excitation and the scheme for generating the green laser source with the luminous flux of the excitation light source 110, wherein when the luminous flux of the excitation light source 110 is below 6000lm, the photoelectric conversion efficiency of the scheme for generating the narrow-spectrum green fluorescence by using blue laser excitation is higher than that of the scheme for generating the green laser source. As the luminous flux of the excitation light source 110 gradually increases, the electro-optic conversion efficiency of both schemes tends to decrease, wherein the electro-optic conversion efficiency of the scheme for generating the narrow-spectrum green fluorescence by using blue laser excitation is more attenuated than that of the green laser light source scheme.

Please refer to fig. 12, which is a schematic block diagram illustrating the color gamut dynamic adjustment performed by the control device 107. The control means 107 is configured to derive a gamut range based on which the original image data of the image to be displayed is derived from the original image data to derive the light amount control signal.

Specifically, the control device 107 may convert the original image data (e.g., r, g, b) of each pixel of the image to be displayed into CIE xyY chromaticity value data using a correlation formula, wherein the CIE xyY chromaticity value data of each pixel includes color coordinates x, Y and a luminance value Y. According to the CIE xyY chromaticity value data of each pixel, i.e., the color coordinates x, Y and the luminance value Y, the control device 107 obtains the color coordinates (i.e., the color coordinates x, Y) of each pixel of the image to be displayed, and further obtains the range defined by the color coordinates of each pixel of the image to be displayed, i.e., the color gamut range of the image to be displayed. Further, the control device 107 also obtains the luminance value Y of each pixel of the image to be displayed according to the CIE xyY chromaticity value data of each pixel, so that the control device 107 can generate the light quantity control signal according to the color coordinates x, Y and the luminance value Y of each pixel of the image to be displayed to control the luminance of the excitation light emitted by the excitation light source 110 so as to control the light power thereof.

Fig. 13 is a schematic diagram of the driving current of the excitation light source 110 corresponding to the color wheel 130 for emitting various light rays. The light quantity control signal controls the driving current intensity of the excitation light source 110 corresponding to different sections on the excitation light path, so that the excitation light source 110 is controlled to emit excitation light with corresponding light power, the proportion of the wide-spectrum fluorescence and the narrow-spectrum fluorescence is adjusted, and the color coordinate which is adapted to the color gamut range on which the image to be displayed is based is obtained. Because the content of each image to be displayed is different, the color gamut range of each image to be displayed (such as a frame of image to be displayed) can be different, so that the light quantity control signals corresponding to each image to be displayed are different.

Specifically, as shown in fig. 1, the light quantity control signal is provided to the gamma correction circuit 109, and the gamma correction circuit 109 sends out a corresponding driving signal to a driving circuit in the excitation light source 110 according to the light quantity control signal, and the driving circuit dynamically controls the excitation light power sent out by the excitation light source 110 according to the driving signal.

Fig. 14 is a schematic block diagram illustrating the principle of dynamically adjusting the color gamut of the control device 107 corresponding to the color wheel shown in fig. 7. The present embodiment is mainly different from the above-described embodiment in the control principle: in this embodiment, the control device 107 calculates the ratio of the narrow-spectrum fluorescence to the wide-spectrum fluorescence, and the light quantity control signal output by the control device 107 controls the driving current of the excitation light source 110 and the position of the color wheel 230 at the same time, so that the control device 107 dynamically adjusts the irradiation position of the excitation light spot on the color wheel 230, thereby adjusting the ratio of the image light emitted by the light source 101 for modulating the first color gamut and the second color gamut, and further realizing the color gamut adjustment of the image to be displayed corresponding to the primary color light coordinate. It should be noted that, within the scope of the spirit or the basic features of the present invention, each specific solution applied to the above embodiments may also be correspondingly applied to the present embodiment, and for the sake of brevity and avoidance of repetition, the detailed description thereof is omitted here.

Referring to fig. 12, the control device 107 is configured to calculate a current color gamut range according to the light quantity control signal, convert the original image data of the image to be displayed into the image data of the current color gamut range through a corresponding formula by using the current color gamut range and the color gamut range based on the original image data, and use the image data of the current color gamut range as the corrected image data, and the light modulation device 105 further modulates the light emitted from the color wheel 130 according to the corrected image data to accurately restore the pixels of the image to be displayed.

The control means 107 determines the current gamut range in dependence on the based gamut range of the image to be displayed. The current color gamut is a triangular region, which covers the color gamut based on the image to be displayed, i.e., it covers the color coordinates of each pixel of the image to be displayed. Specifically, the current color gamut range may be a color gamut region that just covers the color coordinates of each pixel of the image to be displayed and has the smallest area. It can be understood that, since the content of each image to be displayed is different, the color gamut of each image to be displayed (e.g., one frame of image to be displayed) may also be different, and thus the current color gamut determined by the control device 107 according to each image to be displayed may also be different.

The control device 107 transmits the corrected image signal to the light modulation device 105. Taking the corrected image signal in the RGB encoding format as an example, the original image data is RGB signals, wherein the R signal in the original image data is used for modulating red light, the G signal is used for modulating green light, and the B signal is used for modulating blue light. The corrected image signal is an RRGGB signal, which is equivalent to the R signal and the G signal being repeated in time sequence, that is, in the time period when both R signals are present or both G signals are present, the light modulation device 105 actually processes the first fluorescence emitted from the first segment R1 and the second fluorescence emitted from the second segment R2, or the third fluorescence emitted from the third segment G1 and the fourth fluorescence emitted from the fourth segment G2, respectively.

Specifically, assuming that the R signal value is a (0. ltoreq. a. ltoreq.255), the light modulation device 105 receives aa as the corrected image signal corresponding to the first fluorescence and the second fluorescence period.

After the two time periods are mixed in time sequence, the actually emergent red light brightness value is a/255.Y_R'(Y_R' when a is 225, the luminance of red light emitted from the light modulation device 105); the color coordinates of the actually emitted red primary color light are (x, y).

Assuming that the brightness of the first fluorescence is a/255. Y_R1(Y_R1The brightness of the first fluorescent light emitted by the light modulation device 105 when all the first fluorescent light passes through the light modulation device 105, that is, the brightness of the first fluorescent light emitted by the light modulation device 105 when a is 225); the color coordinate of the first fluorescent light is (x)_R1，y_R1)。

Assuming that the brightness of the second fluorescence is a/255. Y_R2(Y_R2The color coordinate of the second fluorescent light is (x) when the light modulation device 105 emits the second fluorescent light at all the luminances of the second fluorescent light emitted from the light modulation device 105, that is, when a is 225_R2，y_R2) Then, the light modulation device 105 emits the brightness Y of the red primary color light_R' and color coordinates (x, y) satisfy:

Y_R'＝Y_R1+Y_R2

since the red primary color light is obtained by mixing the first fluorescence (broad spectrum fluorescence) and the second fluorescence (narrow spectrum fluorescence). If the ratio of the two lights changes, the red base color light obtained after mixing also changes correspondingly. The brightness of the first fluorescence and the second fluorescence is determined by the driving current of the corresponding excitation light source 110, so that the brightness corresponding to the first section R1 and the second section R2 can be changed by changing the driving current of the first section R1 and the driving current of the second section R2 through the light quantity control signal, thereby changing the color coordinate and the brightness of the finally obtained red primary color. The time sequence light combination of the green fluorescence of two different color gamuts can be obtained by the same method, and the green primary color light required by the system can be obtained by mixing. And white balance is maintained while changing the color coordinates of the red or green primary colors.

In the display device 100 and the projection system provided by the invention, the control device 107 is configured to send out a light quantity control signal and a corrected image signal according to original image data, the light source 101 is configured to send out first fluorescence and third fluorescence for modulating the first color gamut image and second fluorescence and fourth fluorescence for modulating the second color gamut image according to the light quantity control signal, and the light modulation device 105 is configured to modulate image light according to the corrected image signal, so as to dynamically adjust a ratio of wide-spectrum fluorescence to narrow-spectrum fluorescence in the image light, thereby dynamically adjusting a color gamut range of the image light, and further improving light utilization rate.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned. Furthermore, it is obvious that the word "comprising" does not exclude other elements or steps, and the singular does not exclude the plural. Several of the means recited in the apparatus claims may also be embodied by one and the same means or system in software or hardware. The terms first, second, etc. are used to denote names, but not any particular order.

Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A display device, comprising:

a light source for emitting, according to the light amount control signal:

2. The display device of claim 1, wherein the light source comprises:

an excitation light source for emitting the excitation light; and

a color wheel for receiving the excitation light, comprising:

a substrate;

the scattering layer is arranged on the surface of the substrate and used for scattering the exciting light to obtain scattered exciting light; and

the conversion layer is arranged on the surface of the substrate and comprises a first section, a second section, a third section and a fourth section which are provided with wavelength conversion materials and are respectively used for converting the exciting light into first fluorescence, second fluorescence, third fluorescence and fourth fluorescence;

the light quantity control signal is used for controlling the driving current intensity of the excitation light source corresponding to different sections on the excitation light optical path, so that the optical power of the excitation light is adjusted.

3. The display device according to claim 2, wherein when the first segment, the second segment, the third segment and the fourth segment are respectively located on an optical path of the excitation light, the optical power of the excitation light is respectively a first optical power, a second optical power, a third optical power and a fourth optical power;

the light quantity control signal is used for controlling the second optical power to be smaller than or equal to the first optical power and/or controlling the fourth optical power to be smaller than or equal to the third optical power.

4. The display device according to claim 3, wherein the light amount control signal is used to control 1/10 for the second optical power to be equal to or less than the first optical power, and to control 1/10 for the fourth optical power to be equal to or less than the third optical power.

5. The display device according to claim 2, wherein the wavelength converting material disposed in the first section is CaAlSiN₃:Eu²⁺。

6. The display device of claim 2, wherein the wavelength converting material disposed in the third section is LuAG Ce³⁺。

7. The display device according to claim 2, wherein the wavelength converting material provided in the second section is K₂SiF₆:Mn⁴⁺、K₂TiF₆:Mn⁴⁺、K₂GeF₆:Mn⁴⁺And any one or combination of several of the quantum dots.

8. The display device according to claim 2, wherein the wavelength converting material provided in the fourth section is γ -AlON: Mn²⁺、β-sialon:Eu²⁺、Ba₂LiSi₇AlN₁₂:Eu²⁺And any one or combination of several of the quantum dots.

9. The display device of claim 2, wherein the substrate is circular, and the scattering layer, the first section, the second section, the third section, and the fourth section are circumferentially disposed on the substrate.

10. The display device of claim 2, wherein a distance between the excitation light spot formed on the substrate surface and a geometric center of the substrate is adjustable, and the ratio of the first, second, third, and fourth fluorescent lights in the source light is adjusted by adjusting the distance between the excitation light spot formed on the substrate surface and the geometric center of the substrate.

11. The display device of claim 10, wherein the substrate is circular, the substrate surface comprises a first fan-shaped area, a second fan-shaped area and a third fan-shaped area arranged along a circumferential direction of the substrate, the second fan-shaped area comprises a first area and a second area, the third fan-shaped area comprises a third area and a fourth area, the first area and the third area are arranged adjacent to a geometric center of the substrate, and the second area and the fourth area are arranged adjacent to an edge of the substrate;

the scattering layer is disposed in the first fan-shaped area, and the first section, the second section, the third section and the fourth section are disposed in one of the first area, the second area, the third area and the fourth area, respectively.

12. The display device according to claim 11, wherein the first section, the second section, the third section, and the fourth section are sequentially disposed in the first region, the second region, the third region, and the fourth region.

13. The display device of claim 10, wherein the substrate is circular, and the scattering layer, the first section, the second section, the third section, and the fourth section are radially disposed on the substrate.

14. The display device of claim 1, wherein the light modulating device is an LCOS or an LCD.

15. The display device according to any one of claims 1 to 14,

the control device is used for obtaining a color gamut range based on original image data according to the original image data of the image to be displayed so as to obtain the light quantity control signal.

16. The display device of claim 14,

the control device is used for calculating a current color gamut range according to the light quantity control signal, converting original image data of an image to be displayed into image data of the current color gamut range by using the current color gamut range and the color gamut range based on the original image data, and taking the image data of the current color gamut range as the correction image data.

17. A projection system comprising a display device as claimed in any one of claims 1-16.