Display device, display system and display method

Abstract

The present invention provides a display device, a display system and a display method, wherein the display device comprises: a control device, used for dividing a modulation period of each image to be displayed into a plurality of sub-modulation periods, and calculating a light source control signal, a first modulation data and a second modulation data; a light source system, used for sequentially emitting a first light and a third primary color light, wherein the first light is a mixed light including at least a first primary color light and a second primary color light; a first spatial light modulator, used for time-sharingly modulating the first primary color light and at least a part of the third primary color light in each sub-modulation period according to the first modulation data to obtain a first image light and a third image light; a second spatial light modulator, used for modulating the second primary color light in each sub-modulation period according to the second modulation data to obtain a second image light; and a light combining device, used for combining the first image light, the second image light and the third image light and emitting them.

Description

Technical Field

[0001] The present invention relates to the field of projection technology, and in particular to a display device, a display system and a display method. Background Art

[0002] This section is intended to provide a background or context to the detailed description of the invention as recited in the claims. No admission is made that the description herein is prior art by inclusion in this section.

[0003] Color breakup refers to the phenomenon that RGB colors do not overlap at the edge of a color image in an RGB sequential illumination projection system, also known as the rainbow effect. The reason for color breakup is that within an image frame, the three sequential color lights of RGB are modulated by a spatial light modulator to form an image, and the imaging positions of the sequentially displayed RGB subframe images on the retina of the human eye cannot overlap. This phenomenon is more obvious for color images moving on the screen. The reason for the non-overlap of RGB color subframes on the retina may be the movement of the eyeball, or it may be that there is an optical path switch (shutter, such as a swinging finger or a rotating fan) in the imaging light path from the projected image to the human eye, which allows the human eye to sample at a certain time frequency. Similar to the human eye, optical image acquisition devices, such as cameras or high-speed cameras, also have image sampling frequencies. When the sampling frequency is greater than or approximately equal to the illumination light field refresh frequency (mostly 3*60=180Hz), subframe images of different colors will be collected separately, making the time integration effect of primary color mixing worse, thus causing the color breakup phenomenon.

[0004] In summary, color breakup may involve two major types of problems. The first type is the separation of different colors at the edge of the (still or moving) image, and the second type is that the monochromatic illumination light field of the entire image is sampled separately, and the mixing effect of the primary color is split. The key to both types of problems is that the refresh frequency of the sequential monochromatic illumination light field in the projection system is low (usually 180Hz). Summary of the invention

[0005] In view of this, the present invention provides a display device that can effectively improve the refresh frequency of sequential monochromatic illumination light. The present invention also provides a display system and a display method.

[0006] A display device, comprising:

[0007] A control device, used for dividing the modulation period of each image to be displayed into a plurality of sub-modulation periods, and calculating the light source control signal, the first modulation data and the second modulation data according to the original image data of the image to be displayed;

[0008] A light source system, configured to emit a first light and a third primary color light in a time sequence in each sub-modulation period according to the light source control signal, wherein the first light is a mixed light including at least the first primary color light and the second primary color light;

[0009] A first spatial light modulator, configured to time-divisionally modulate the first primary color light and at least a portion of the third primary color light in each sub-modulation period according to the first modulation data to obtain a first image light and a third image light;

[0010] a second spatial light modulator, configured to modulate the second primary color light in each sub-modulation period according to the second modulation data to obtain a second image light;

[0011] The light combining device is used for combining the first image light, the second image light and the third image light and then emitting the combined light.

[0012] Furthermore, the light source system comprises:

[0013] A first light source, used for emitting the third primary color light;

[0014] A second light source, for emitting excitation light; and

[0015] a wavelength conversion device, configured to receive the excitation light and convert the excitation light into the first light;

[0016] The mixed light and the third primary color light are emitted from the light source system along the same optical path.

[0017] Further, the control device divides each sub-modulation period into a first sub-period and a second sub-period;

[0018] In the first sub-period of each sub-modulation period:

[0019] The light source system is used for emitting a first light obtained by mixing the first primary color light and the second primary color light according to the light source control signal;

[0020] The first spatial light modulator is used to modulate the first primary color light according to the first modulation data;

[0021] The second spatial light modulator is used for modulating the second primary color light according to the second modulation data;

[0022] In the second sub-period of each sub-modulation period:

[0023] The light source system is used to emit the third primary color light according to the light source control signal;

[0024] The first spatial light modulator is used to modulate at least a portion of the third primary color light according to the first modulation data.

[0025] Further, in the second sub-period of each sub-modulation period:

[0026] The first spatial light modulator is used to modulate part of the third primary color light according to the first modulation data;

[0027] The second spatial light modulator is used for modulating another portion of the third primary color light according to the second modulation data.

[0028] Further, the first modulation data includes first primary color modulation data and third primary color modulation data for modulating the first primary color light and the third primary color light respectively, the second modulation data includes at least second primary color modulation data for modulating the second primary color light, and the first primary color modulation data, the second primary color modulation data and the third primary color modulation data respectively include first primary color sub-modulation data, second primary color sub-modulation data and third primary color sub-modulation data corresponding to a plurality of sub-modulation time periods one by one;

[0029] In the first sub-period of each sub-modulation period:

[0030] The first spatial light modulator is used to modulate the first primary color light according to the corresponding first primary color sub-modulation data;

[0031] The second spatial light modulator is used to modulate the second primary color light according to the corresponding second primary color sub-modulation data;

[0032] In the second sub-period of each sub-modulation period:

[0033] The first spatial light modulator is used to modulate at least a portion of the third primary color light according to corresponding third primary color sub-modulation data.

[0034] Furthermore, the control device is used to calculate, according to the original image data, a first primary color modulation value, a second primary color modulation value and a third primary color modulation value, which are respectively used to modulate the first primary color light, the second primary color light and the third primary color light; the sum of all first primary color sub-modulation data in the first modulation data is the first primary color modulation value, the sum of all third primary color sub-modulation data is the third primary color modulation value, and in the second modulation data, the sum of the second primary color sub-modulation data is the second primary color modulation value.

[0035] Furthermore, each image to be displayed includes a left-eye image and a right-eye image, and the control device is used to merge the left-eye image and the right-eye image to obtain the image to be displayed.

[0036] Furthermore, each frame of image includes two images to be displayed, and the display time of each frame of image includes two modulation time periods respectively used to modulate one image to be displayed.

[0037] Furthermore, the display device also includes a splitting device located on the light output path of the light source system, for splitting the primary color light generated by the light source system into a first primary color light propagating along the first light path and a second primary color light propagating along the second light path, and guiding at least part of the third primary color light generated by the light source system to propagate along the first light path.

[0038] Furthermore, the primary color light is subjected to wavelength splitting in the light splitting device, and the first image light, the second image light and the third image light are subjected to wavelength combining in the light combining device.

[0039] Furthermore, the light splitting device comprises:

[0040] A first polarization conversion element, used for converting the primary color light emitted by the light source system into light of a first polarization state; and

[0041] a beam splitting element, for splitting the primary color light emitted by the first polarization conversion element into a first primary color light propagating along a first optical path and a second primary color light propagating along a second optical path, and for guiding at least part of the third primary color light emitted by the first polarization conversion element to propagate along the first optical path;

[0042] The light combining device comprises:

[0043] A second polarization conversion element, used for converting the second image light of the first polarization state emitted by the second spatial light modulator into a second polarization state;

[0044] a light combining element, used for combining the light emitted by the first spatial light modulator and the second polarization conversion element;

[0045] The wavelength range of the primary color light transmitted or reflected by the light combining element covers the wavelength range of the primary color light transmitted or reflected by the light splitting element.

[0046] Furthermore, the light splitting element is used to perform wavelength splitting on the incident light, and the light combining element is used to perform wavelength combining on the incident light.

[0047] Furthermore, the first spatial light modulator and the second spatial light modulator are both LCOS.

[0048] Furthermore, the light splitting element is used to perform wavelength splitting on the incident light, and the light combining element is used to perform polarization combining on the incident light.

[0049] Furthermore, the light splitting device comprises:

[0050] A first polarization conversion element, used for converting the light emitted by the light source system into light of a first polarization state;

[0051] a third polarization conversion element, configured to convert the light emitted by the first polarization conversion element into light of different polarization states according to the wavelength range of the light emitted by the first polarization conversion element; and

[0052] The light splitting element is used to split the light emitted by the third polarization conversion element.

[0053] Furthermore, the third polarization conversion element is used to convert at least one of the primary color lights emitted by the first polarization conversion element into light of a second polarization state.

[0054] Furthermore, the light splitting element is used to perform wavelength splitting on the light emitted by the third polarization conversion element, and the light combining device is used to perform wavelength combining on the incident light.

[0055] Furthermore, the beam splitting element is used to perform wavelength splitting on the light emitted by the third polarization conversion element, and the light combining device is used to perform polarization combining on the incident light.

[0056] Furthermore, the light splitting element is used to perform polarization light splitting on the light emitted by the third polarization conversion element, and the light combining device is used to perform polarization light combining on the incident light.

[0057] Furthermore, the light combining device comprises:

[0058] a light combining element, used for combining the first image light, the second image light and the third image light;

[0059] a fourth polarization conversion element, used to convert the light emitted by the light combining element into light of the same polarization state;

[0060] The dynamic polarization conversion element is used to receive the light emitted by the fourth polarization conversion element and convert the received light into light of different polarization states to be emitted alternately.

[0061] Furthermore, the dynamic polarization conversion element is used to emit circularly polarized light.

[0062] Furthermore, the spectroscopic device includes a dynamic polarization conversion element located between the first polarization conversion element and the third polarization conversion element, and the dynamic polarization conversion element is used to receive the light emitted by the first polarization conversion element and convert the received light into light of different polarization states to alternately emit to the third polarization conversion element.

[0063] Furthermore, the dynamic polarization conversion element is used to emit linearly polarized light.

[0064] Furthermore, the beam splitting element is used to perform polarization splitting on the light emitted by the second polarization element, and the light combining device is used to perform wavelength combining on the first image light and the second image light.

[0065] Furthermore, both the first spatial light modulator and the second spatial light modulator are DMDs.

[0066] A display system comprises the display device as described in any one of the above items and wavelength spectroscopic glasses.

[0067] A display system comprises a display device as described in any one of the above items and a circularly polarized light detector, wherein the circularly polarized light detector is used to receive light emitted by the display device.

[0068] A display system comprises a display device as described in any one of the above items and a linearly polarized light detector, wherein the linearly polarized light detector is used to receive light emitted by the display device.

[0069] A display method, comprising:

[0070] Dividing the modulation period of each image to be displayed into a plurality of sub-modulation periods, and calculating the light source control signal, the first modulation data and the second modulation data according to the original image data of each image to be displayed;

[0071] According to the light source control signal, the light source system is controlled to emit the first light and the third primary color light in time sequence in each sub-modulation period, wherein the first light at least includes a mixed light of the first primary color light and the second primary color light;

[0072] According to the first modulation data, controlling the first spatial light modulator to re-modulate the first primary color light and at least part of the third primary color light in each sub-modulation period to obtain a first image light and a third image light;

[0073] According to the second modulation data, controlling the second spatial light modulator to modulate the second primary color light in each sub-modulation period to obtain a second image light;

[0074] The first image light, the second image light and the third image light are combined by a light combining device and then emitted.

[0075] Furthermore, the step of controlling the light source system to emit the first light and the third primary color light in sequence in each sub-modulation period according to the light source control signal includes:

[0076] Dividing each sub-modulation period into a first sub-period and a second sub-period;

[0077] In the first sub-period of each sub-modulation period:

[0078] According to the light source control signal, controlling the light source system to emit a first light obtained by mixing the first primary color light and the second primary color light;

[0079] In the second sub-period of each sub-modulation period:

[0080] According to the light source control signal, controlling the light source system to emit the third primary color light;

[0081] According to the first modulation data, controlling the first spatial light modulator to re-modulate the first primary color light and at least part of the third primary color light in each sub-modulation period to obtain the first image light and the third image light; according to the second modulation data, controlling the second spatial light modulator to modulate the second primary color light in each sub-modulation period to obtain the second image light, comprises:

[0082] In the first sub-period of each sub-modulation period:

[0083] controlling the first spatial light modulator to modulate the first primary color light according to the first modulation data;

[0084] controlling the second spatial light modulator to modulate the second primary color light according to the second modulation data;

[0085] In the second sub-period of each sub-modulation period:

[0086] The first spatial light modulator is controlled to modulate at least a portion of the third primary color light according to the first modulation data.

[0087] Further, according to the first modulation data, controlling the first spatial light modulator to re-modulate the first primary color light and at least part of the third primary color light in each sub-modulation period to obtain the first image light and the third image light; according to the second modulation data, controlling the second spatial light modulator to modulate the second primary color light in each sub-modulation period to obtain the second image light, further comprising:

[0088] In the second sub-period of each sub-modulation period:

[0089] The second spatial light modulator is controlled to modulate the remaining third primary color light according to the second modulation data.

[0090] Furthermore, the step of dividing the modulation period of each image to be displayed into a plurality of sub-modulation periods, and calculating the light source control signal, the first modulation data and the second modulation data according to the original image data of each image to be displayed includes:

[0091] The first modulation data includes first primary color modulation data and third primary color modulation data for modulating the first primary color light and the third primary color light respectively, the second modulation data includes at least second primary color modulation data for modulating the second primary color light, and the first primary color modulation data, the second primary color modulation data and the third primary color modulation data respectively include first primary color sub-modulation data, second primary color sub-modulation data and third primary color sub-modulation data corresponding to a plurality of sub-modulation time periods one by one;

[0092] According to the first modulation data, controlling the first spatial light modulator to re-modulate the first primary color light and at least part of the third primary color light in each sub-modulation period to obtain the first image light and the third image light; according to the second modulation data, controlling the second spatial light modulator to modulate the second primary color light in each sub-modulation period to obtain the second image light, comprises:

[0093] In the first sub-period of each sub-modulation period:

[0094] Controlling the first spatial light modulator to modulate the first primary color light according to the corresponding first primary color sub-modulation data;

[0095] Controlling the second spatial light modulator to modulate the second primary color light according to the corresponding second primary color sub-modulation data;

[0096] In the second sub-period of each sub-modulation period:

[0097] According to the corresponding third primary color sub-modulation data, the first spatial light modulator is controlled to modulate at least a portion of the third primary color light.

[0098] Furthermore, the step of dividing the modulation period of each image to be displayed into a plurality of sub-modulation periods, and calculating the light source control signal, the first modulation data and the second modulation data according to the original image data of each image to be displayed includes:

[0099] The first primary color modulation value, the second primary color modulation value and the third primary color modulation value, which are respectively used to modulate the first primary color light, the second primary color light and the third primary color light, are calculated according to the original image data; the sum of all the first primary color sub-modulation data in the first modulation data is the first primary color modulation value, the sum of all the third primary color sub-modulation data is the third primary color modulation value; and the sum of the second primary color sub-modulation data in the second modulation data is the second primary color modulation value.

[0100] Further, dividing each sub-modulation period into a first sub-period and a second sub-period includes:

[0101] The time lengths of the first sub-period and the second sub-period are calculated according to the image refresh frequency of the image to be displayed, the emission time proportions of the primary color lights in the primary color lights, and the number of sub-modulation periods included in each modulation period.

[0102] Furthermore, the step of dividing the modulation period of each image to be displayed into a plurality of sub-modulation periods, and calculating the light source control signal, the first modulation data and the second modulation data according to the original image data, comprises:

[0103] Each image to be displayed includes a left-eye image and a right-eye image, and the image to be displayed is obtained by merging the left-eye image and the right-eye image.

[0104] Furthermore, the step of dividing the modulation period of each image to be displayed into a plurality of sub-modulation periods, and calculating the light source control signal, the first modulation data and the second modulation data according to the original image data of each image to be displayed includes:

[0105] Each frame of image includes two images to be displayed, and the display time of each frame of image includes two modulation time periods respectively used for modulating one image to be displayed.

[0106] The display device provided by the present invention realizes multiple rapid modulations of three primary colors in a picture to be displayed, and increases the refresh frequency of a traditional single color by several times, thereby facilitating the reduction of the rainbow effect occurring in the display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0107] In order to more clearly illustrate the technical solutions of the embodiments / methods of the present invention, the drawings required for use in the description of the embodiments / methods will be briefly introduced below. Obviously, the drawings described below are some embodiments / methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0108] Figure 1 This is a schematic diagram of the structure of a display device provided in the first embodiment of the present invention.

[0109] Figure 2 for Figure 1 The timing diagram of the light source system emitting light is shown.

[0110] Figure 3 is a modulation timing diagram of the first spatial light modulator 501 and the second spatial light modulator 502 .

[0111] Figure 4 This is a schematic structural diagram of a display device provided in the second embodiment of the present invention.

[0112] Figure 5 The figure is a working principle diagram of a component for realizing polarization conversion.

[0113] Figure 6 308 and the light splitting element 305.

[0114] Figure 7 308 and the light splitting element 305 .

[0115] Figure 8 This is a schematic structural diagram of a display device provided in the third embodiment of the present invention.

[0116] Fig. 9 The transmission spectra of a typical Color Select element GM44 in two typical configurations.

[0117] Fig.10 It is the green light transmission spectrum of the light combining element and the light splitting element.

[0118] Fig.11 It is the reflection spectrum of red light and blue light of the light combining element and the light splitting element.

[0119] Fig.12 This is a schematic structural diagram of a display device provided in a fourth embodiment of the present invention.

[0120] Fig.13 are the transmission and reflection spectra of the light combining element 308 .

[0121] Fig.14 This is a schematic structural diagram of a display device provided in a fifth embodiment of the present invention.

[0122] Fig.15 This is a schematic structural diagram of a display device provided in a sixth embodiment of the present invention.

[0123] Fig.16 for Fig.15 Polarization transmittance and reflectance curves of the beam splitter element are shown.

[0124] Fig.17 This is a schematic structural diagram of a display device provided in the seventh embodiment of the present invention.

[0125] Fig.18 A schematic diagram of a display system provided in accordance with an eighth embodiment of the present invention.

[0126] Fig.19 A schematic diagram of a display system provided in accordance with a ninth embodiment of the present invention.

[0127] Fig. 20 for Fig.19 Schematic diagram of the 3D module liquid crystal solution and patent solution of the dynamic polarization conversion element shown.

[0128] Fig.21for Fig.19 The timing diagram of the display device emitting an image is shown.

[0129] Fig. 22 A schematic diagram of a display system provided in accordance with a tenth embodiment of the present invention.

[0130] Fig.23 for Fig. 22 Display device timing control diagram in .

[0131] Fig.24 A schematic diagram of a display device provided in the eleventh embodiment of the present invention. DETAILED DESCRIPTION

[0132] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0133] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. The embodiments described are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0134] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0135] The display device provided in the embodiment of the present invention can be a cinema projector, an educational projector, a laser TV, a micro projector, an engineering projector, etc. In the present invention, the high modulation frequency of the laser and the diode light emitter is used to realize multiple rapid modulations of the RGB colors in an image to be displayed, and the refresh frequency of the traditional single color is increased several times, which is conducive to reducing the rainbow effect of the display device.

[0136] See also Figure 1 , is a schematic diagram of the structure of a display device provided by the first embodiment of the present invention. A display device includes: a control device, a light source system, a light splitting device, a first spatial light modulator 501, a second spatial light modulator 502 and a light combining device.

[0137] The control device includes a laser group controller 201, a laser group controller 202, a controller 601 and a controller 602. The laser group controller 201, the laser group controller 202, the controller 601 and the controller 602 may be different control units of the same controller, or may be multiple controllers. The control device is used to divide the modulation period of each image to be displayed into multiple sub-modulation periods, and to divide each sub-modulation period into a first sub-period and a second sub-period, and to calculate the light source control signal, the first modulation data and the second modulation data according to the original image data of the image to be displayed.

[0138] The light source system is used for emitting first light and third primary color light in time sequence in each sub-modulation period according to a light source control signal, wherein the first light is a mixed light including at least the first primary color light and the second primary color light.

[0139] The light source system is used to emit at least two kinds of light in time sequence in each sub-modulation period according to the light source control signal. Specifically, the light source can emit two kinds of light, three kinds of light, four kinds of light or even six kinds of light.

[0140] When the light source system emits two kinds of light, the two kinds of light may be first light formed by mixing the first primary color light and the second primary color light, and second light formed by the third primary color light alone.

[0141] When the light source system emits three kinds of light, the three kinds of light may be first primary color light, second primary color light and third primary color light; or they may be first light formed by mixing the first primary color light and the second primary color light, second light formed by the third primary color light alone, and third light formed by the fourth primary color light alone.

[0142] When the light source system emits four kinds of light, the four kinds of light may be the first primary color light, the second primary color light, the third primary color light and the fourth primary color light; or the first light formed by a mixture of the first primary color light and the second primary color light, the second light formed solely by the third primary color light, the third light formed solely by the fourth primary color light, and the fourth light formed solely by the fifth primary color light; or the first light formed by a mixture of the first primary color light and the second primary color light, the second light formed solely by the third primary color light, the third light formed by a mixture of the fourth primary color light and the fifth primary color light, and the fourth light formed solely by the sixth primary color light.

[0143] It should be understood that the primary color light mentioned in the present invention refers to the basic light that can be used to synthesize other color lights. It can be monochromatic light, such as red light, green light and blue light commonly used in the art; it can also be intermediate color light, such as magenta light, yellow light, cyan light; it can also be other mixed color light, as long as it meets the above-mentioned requirement that when a certain color of the picture is not outstanding, the desired effect can be achieved by adding the missing corresponding color and mixing.

[0144] Taking the light source system emitting three kinds of light as an example, when the three kinds of light are the first primary color light, the second primary color light and the third primary color light, in one embodiment, the light source system includes a light source for emitting wide-spectrum white light and a color filter wheel having a filter for filtering specific wavelengths. Specifically, the light source can be a metal halide lamp, a high-pressure mercury lamp, or a xenon lamp. The color filter wheel is composed of three color blocks of red, green, and blue (RGB). When the white light emitted by the light source is filtered by the color filter wheel, the three primary color lights of red, green, and blue are emitted in sequence. In one embodiment, the light source system can also include a light source for emitting excitation light and a wavelength conversion device for receiving excitation light and emitting stimulated light. The wavelength conversion device preferably carries red light phosphor, green light phosphor, and blue light phosphor. When the excitation light is incident on the corresponding phosphor, it will be stimulated and emit the corresponding color light. In another embodiment, the excitation light is preferably a blue laser. At this time, the blue light phosphor area can be set as a transmission or reflection area. The red light phosphor and the green light phosphor receive the incidence of the blue laser, are stimulated, and emit red light and green light.

[0145] It should be noted that based on the three lights emitted by the above light source system, in some embodiments, the light source system is not limited to emitting three primary colors, but can also emit other primary colors, such as magenta, cyan, yellow, etc., and can add additional required colors according to the image color requirements. Specifically, it should be supplemented with the color expression of the final color picture. When a color of the picture is not outstanding, the missing corresponding color can be added. At this time, the light source system actually emits more than three lights, such as four lights.

[0146] The present invention mainly takes the light source emitting two kinds of light as an example, which can further reduce the effect of color breakup, and there is no spoke phenomenon. In some embodiments, the light source system is used to emit two kinds of light in a time sequence in each sub-modulation period according to the light source control signal. Specifically, the two kinds of light are the first light and the second light, wherein the first light is formed by mixing the first primary color light and the second primary color light, and the second light is formed by the third primary color light alone. The following is a description through specific embodiments.

[0147] The light source system includes a first light source and a second light source, wherein the first light source is used to emit a third primary color light, and the second light source is used to emit an excitation light. The laser group 101 in the first light source and the laser group 102 in the second light source respectively generate a blue laser as the third primary color light and a blue excitation light for exciting the wavelength conversion device 401 to generate yellow fluorescence, and the currents thereof are respectively regulated by the laser group controller 201 and the laser group controller 202, and the regulation frequency is preferably 1200Hz, that is, the regulated current waveform is approximately a square wave with a period of 1200Hz and a certain duty cycle, or even other waveforms that can realize current regulation. The duty cycle ratio is preferably based on the principle of achieving a higher power white light after RGB light mixing.

[0148] The surface of the wavelength conversion device 401 in the present invention is provided with yellow phosphor 402, and the yellow fluorescence generated under the excitation of the light emitted by the laser group 102 is used as the first light, wherein the yellow fluorescence includes the first primary color light and the second primary color light. In the present invention, the first primary color light is the red light in the yellow fluorescence, and the second primary color light is the green light in the yellow fluorescence. The wavelength conversion device 401 can be a color wheel or a fixed fluorescent sheet.

[0149] The first spatial light modulator 501 (DMD501) is used to time-division modulate red light and blue light, and the second spatial light modulator 502 (DMD502) is used to modulate green light.

[0150] The control device is used for dividing the modulation period of each image to be displayed into a plurality of sub-modulation periods, and calculating the light source control signal, the first modulation data and the second modulation data according to the original image data of the image to be displayed.

[0151] Specifically, a preferred control waveform may be referred to, as shown in 2, Figure 2 for Figure 1 The timing diagram of the light source system emitting light is shown. The time length of the first sub-period is equal to that of the second sub-period, both of which are t0. In other embodiments, the time length of the first sub-period may be unequal to that of the second sub-period, and the time length of the first sub-period is related to the time length of the first light and the third primary color light that need to be emitted. In the first sub-period corresponding to the time period of the red light (R: Red) and the green light (G: Green) emitted by the light source system, the laser group 101 is in the off state and the laser group 102 is in the working state. In the second sub-period corresponding to the blue light (B: Blue) and the non-luminous state (E: Empty) emitted by the light source system, the laser group 101 is in the working state and the laser group 102 is in the off state. For convenience, the first sub-period is referred to as the "yellow light segment" hereinafter, and the second sub-period is referred to as the "blue light segment" hereinafter. As Figure 1 As shown, during the yellow light period, the blue excitation light generated by the laser group 102 is incident on the yellow-transmitting blue-reflecting glass slide 301, and then is reflected and incident on the wavelength conversion device 401 whose surface is covered with a wavelength conversion material 402 to excite fluorescence. The generated yellow fluorescence is collected by the fluorescence collection lens group 302 and passes through the yellow-transmitting blue-reflecting glass slide 301, and then enters the light homogenizing element 303. The light homogenizing element 303 can be a square rod or a compound eye or other device that can achieve the light homogenizing function. The light source light emitted by the light source system then enters the relay lens group 304 and is imaged onto the light modulation device (such as DMD).

[0152] In some embodiments, in order to obtain separated primary color lights, the display device further includes a spectrometer, for example, a spectrometer is placed in the imaging light path, and the spectrometer can be either a wavelength spectrometer or a polarization spectrometer, as long as the primary color lights can be separated. The wavelength spectrometer separates the different color lights according to the different wavelengths of the different color lights; the polarization spectrometer separates the different lights according to the different polarization states designed for them.

[0153] Taking the above-mentioned light source system emitting two kinds of light as an example, in one embodiment, the spectroscopic device includes a wavelength spectroscopic prism 305, and a green-transmitting, red-and-blue-reflecting prism is preferably used, and the red light and the green light enter two independent optical paths. Specifically, the green light enters the second optical path, and the red light enters the first optical path. The wavelength spectroscopic prism 305 preferably uses a prism because it is considered that when the same components TIR prisms 305 and 306 are used, the red light and the green light have the same optical path, which can save the cost of opening molds for optical components and structural parts. The wavelength spectroscopic prism 305 can also use other wavelength spectroscopic devices that can achieve similar functions, such as a green-transmitting, red-and-blue-reflecting glass sheet. Accordingly, the compensation for the optical path difference between red light and green light should be considered, and a method of designing different TIR prism thicknesses can be used. After the red light and the green light are generated, the color can also be modified in combination with a color filter to meet the requirements of different color gamut displays. The red light, green light and blue light pass through the TIR prism groups 306 and 307 matched with the first spatial light modulator 501 and the second spatial light modulator 502 to form uniform illumination on the modulation surfaces of the first spatial light modulator 501 and the second spatial light modulator 502. After the grayscale modulation of the first spatial light modulator 501 and the second spatial light modulator 502, the corresponding first image light, second image light and third image light are emitted respectively, and then emitted to the lens 309 after being combined by the wavelength combining device 308.

[0154] Specifically, the first spatial light modulator 501 is used to time-divisionally modulate the first primary color light and the third primary color light in each sub-modulation period according to the first modulation data to obtain the first image light and the third image light respectively.

[0155] The second spatial light modulator 502 is configured to modulate the second primary color light in each sub-modulation period according to the second modulation data to obtain a second image light.

[0156] A light combining device is used for combining the first image light, the second image light and the third image light and emitting them. The light combining and emitting described in the present invention refers to guiding multiple light beams to the same optical path for emission. In the first embodiment, the first spatial light modulator 501 and the second spatial light modulator 502 are controlled by the controller 601 and the controller 602 respectively. The light combining device includes a wavelength light combining device 308, which can be a green-transmitting and red-and-blue-reflecting prism, and the wavelength light combining device 308 can also be a green-reflecting and red-and-blue-transmitting prism. The wavelength spectrometer 305 and the wavelength light combining device 308 preferably use matching reflection and transmission spectrum characteristics to achieve higher light efficiency. The light emitted by the light combining device is projected onto the screen through the lens group 309.

[0157] It can be seen that the red light and the green light are gray-scale modulated by independent spatial light modulators at the same time, so the wavelength conversion device 401 only generates yellow light and does not need to be synchronized with the control signal, which simplifies the system control and does not have the limitation of spokes (spoke area), so it is a solution that does not require synchronization and is spoke free. The spoke phenomenon refers to the situation that when a fluorescent color wheel or a color filter wheel with multiple color schemes is used, when light is irradiated at the junction of two colors, the color will be impure (for example, when the junction of red and blue is irradiated at the same time, red light and blue light will be emitted at the same time, and magenta light will be emitted). The current solution is not to emit the picture during the time period at this place, so that when the whole image is sampled, a section of the picture will be completely black. During the blue light period, the laser group 101 is in working state, and the light source system generates the third primary color light. The generated third primary color light passes through the laser speckle elimination element 310 and is reflected by the yellow-transmitting and blue-reflecting glass 301 into the light splitting and light combining optical path. The speckle elimination element 310 can be a rotating wheel with a scattering plate or other elements that can eliminate the coherence of the laser light, or multiple lasers with similar wavelengths can be selected to form the laser group 101 to achieve decoherence. And the F number of the emitted third primary color light is preferably designed to match the yellow fluorescence. The third primary color light entering the yellow light path enters the first light path after passing through the wavelength splitting element 305 that transmits green and reflects red and blue glass sheets, and after being modulated by the first spatial light modulator 501, it passes through the prism 306, the wavelength combining device 308 and the lens group 309 and is projected onto the screen.

[0158] The first modulation data includes first primary color modulation data and third primary color modulation data for modulating the first primary color light and the third primary color light respectively, the second modulation data includes second primary color modulation data, and the first primary color modulation data, the second primary color modulation data and the third primary color modulation data respectively include first primary color sub-modulation data, second primary color sub-modulation data and third primary color sub-modulation data corresponding to a plurality of sub-modulation time periods one by one;

[0159] In the first sub-period of each sub-modulation period:

[0160] The first spatial light modulator 501 is used to modulate the first primary color light according to the corresponding first primary color sub-modulation data;

[0161] The second spatial light modulator 502 is used to modulate the second primary color light according to the corresponding second primary color sub-modulation data;

[0162] In the second sub-period of each sub-modulation period:

[0163] The first spatial light modulator 501 is used to modulate the third primary color light according to the corresponding third primary color sub-modulation data.

[0164] The yellow light segment and the blue light segment work alternately, and the effect of weakening color breakup is achieved by controlling the length of the time period. The specific implementation method is described as follows. In traditional displays, the time for achieving white light mixing is generally the modulation period of an image, and the corresponding display duration is t_FRAME. In the implementation of 2D display, there are multiple frames of images within 1 second, and the continuous playback of multiple frames of images forms a dynamic picture. Each frame of the image corresponds to an image to be displayed, and each image to be displayed corresponds to a display period, and the display period is the modulation period of the image to be displayed. In other words, for a display device for 2D display, one image to be displayed corresponds to a modulation period. In the implementation of 3D display, there are multiple frames of images within 1 second, and the continuous playback of multiple frames of images forms a dynamic 3D picture, wherein each frame of 3D image corresponds to two images to be displayed, and each image to be displayed corresponds to a display period, and the display period is the modulation period of the image to be displayed. In other words, for a display device for 3D display, one frame of the image to be displayed corresponds to two consecutive modulation periods.

[0165] Each modulation period is divided into N sub-modulation periods. _FRAME It is divided into N segments, and the time of each sub-modulation period is t_WHITE=t_FRAME / N. It can be predicted that when N>1, the frequency of white light mixing becomes N times of the original, and the color breakup phenomenon will be weakened accordingly.

[0166] See also Figure 3 , is a modulation timing diagram of the first spatial light modulator 501 and the second spatial light modulator 502. In the figure, the time corresponding to R / G is the yellow light segment, and the time corresponding to B / E is the blue light segment. The time proportion of the yellow light segment in t_WHITE is F_YELLOW, and the time proportion of the blue light segment in t_WHITE is F_BLUE.

[0167] In each yellow light segment, the spatial light modulator corresponding to R / G displays the corresponding segment of the bit stream in the grayscale image, such as Figure 3(b)(c) As shown. For a certain DMD display scheme, the modulation time required to display the smallest bit is the unit modulation time, denoted as t_LSB, t_WHITE is the length of each sub-modulation period, that is, the time required for the light source system to sequentially output the three primary colors of light, and the length of the first sub-period is t_WHITE*F_YELLOW. Assuming that within the time of a first sub-period, M (M≥1) t_LSBs can be displayed evenly or according to a certain optimization rule, then M*t_LSB≤t_ WHITE *F _YELLOW <(M+1)*t _LSB . Because at t _FRAME There are N segments in total. _WHITE , the total duration of the yellow light segment (ie R / G) is N*t _WHITE *F _YELLOW The corresponding bit depth of the modulation value that can be displayed can be obtained by 2 n -1≤t _FRAME *F _YELLOW / t _LSB ≤2 n+1 -1 is determined, that is, for any positive real number, there is always a positive integer n that satisfies the above requirements, and the corresponding n is the maximum number of grayscale bits that can be displayed. _LSB is a configurable parameter in DMD control. Considering the limitation of mechanical motion time response of DMD micromirror, t _LSB Greater than the response time of the DMD micromirror, that is, it should be greater than 10us. To ensure the grayscale level, t _LSB Generally, it is between 10us and tens of us. After the bit depth of the display is determined, the gray value of each pixel corresponds to a bit stream, corresponding to the spatial light modulator, such as the PMW (Pulse Width Modulation) modulation signal of the DMD, that is, each t _LSB The on or off state of the corresponding micro-lens during the time. _FRAME *F _YELLOW Probably slightly larger than (2 n -1)*t_ LSB , the remaining time in each frame can set the last few bits to 0, that is, the microlens is set to the off state. It should be noted that the bit position is 0 and the microlens is set to the off state. Modulation data is also required to achieve modulation. This solution can cover multiple sets of parameter combinations. The adjustable parameters include the refresh frequency of each image, or the duration of the modulation period, the single frame duration t _FRAME (corresponding to the signal source update frequency f _FRAME =1 / t _FRAME ), yellow light time ratio F _YELLOW, unit modulation period (operation time corresponding to the smallest bit) t _LSB And the number N of sub-modulation time periods (white light mixing multiples).

[0168] Common image refresh frequencies (image signal source update frequencies) include 30Hz, 60Hz, 75Hz, 140Hz, etc.; yellow light time ratio F _YELLOW In principle, it can be greater than 0 and less than 1. However, in practice, considering the maximum amount of white light output, the most efficient RGB ratio, and the most uniform RGB modulation value width bit depth distribution, the preferred F _YELLOW ∈[50%,75%],preferred F _YELLOW ≥50% is because the human eye is not as sensitive to blue light as red light / green light, so the yellow light segment is preferred in the design, and the operation time corresponding to the smallest bit is t _LSB In practice, the minimum value is limited by the response time of the mechanical movement of the DMD micromirror and the control rate of the illumination source, and the maximum value is limited by the bit depth of the RGB display. _LSB ∈[10us,30us]; the white light mixing factor N is generally greater than 1, and the maximum value that can be achieved depends on t _FRAME *F _YELLOW / t _LSB , can reach 500 or higher.

[0169] The method of determining this formula is explained as follows.

[0170] In general, the nature of the DMD device determines the time t of the least significant bit of each single color (R, G, B). _LSB The above are the same, and this solution also makes a specific description based on this actual situation.

[0171] In general, the time t of the least significant bit _LSB It is determined by the image refresh rate, the multiple N of the white light mixing frequency, the time proportion of each color, and the number of binary bits of each color grayscale image (the modulation value bit width of each color light). A feasible estimation method is:

[0172] t_ LSB =F / (f*2 n ), where f represents the image refresh rate, n represents the number of binary bits of the grayscale image, and F represents the color time ratio corresponding to the grayscale image in a frame of image. The selected value is related to the display device. It should be noted that the unit of the above formula is seconds.

[0173] Taking a monolithic spatial light modulator as an example, a color wheel with equal RGB division has an F value of 1 / 3, that is, the time proportion of the three colors R, G, and B in a frame of image is 1 / 3.

[0174] In this embodiment, a simple time control takes the value of F as 1 / 2. The reason is that this case uses a dual spatial light modulator and sets the emission time of yellow light and blue light to be the same. Then, two colors of images are output sequentially within one frame of image, namely yellow (R and G) and blue. The time proportion of the three colors (R, G, B) within one frame of image is 1 / 2.

[0175] Therefore, t of this embodiment _LSB It can also be expressed as 1 / (2*f*2 n ), that is, t_ LSB =1 / (f*2 n+1 ).

[0176] Due to t _FRAME =1 / f, so t_ LSB =t_ FREAME / 2 n+1 .

[0177] In this embodiment, since the red light and the green light are separated from the yellow light and incident on the two spatial light modulators at the same time, the modulation value bit width (binary bit number) of the red grayscale image and the green grayscale image is defined as n, and the blue light is emitted at other times besides the red light and the green light, so the binary bit number of the blue grayscale image is defined as m. Then:

[0178] (2 n -1)*t _LSB ≤t _FRMAE *F _YELLOW <(2 n+1 -1)*t _LSB ,

[0179] That is: (2 n -1) / 2 n+1 ≤F _YELLOW <(2 n+1 -1) / 2 n+1 .

[0180] (2 m -1)*t _LSB ≤t _FRMAE *F _BLUE <(2 m+1 -1)*t _LSB ,

[0181] That is: (2 m -1) / 2 m+1 ≤F _BLUE <(2m+1 -1) / 2 m+1

[0182] In fact, n and m can be equal or different, depending on the actual situation. _YELLOW =F _Blue =50%, preferably m=n. For this embodiment, since the emission time of the yellow light and the blue light is the same, that is, F _YELLOW =F _Blue =50%, so m and n in this embodiment are preferably equal.

[0183] Of course, F in this embodiment _YELLOW and F _Blue They can also be unequal, when F _YELLOW ≠F _Blue When m=n-1, it is preferred. The reason is that the proportion of green light required to produce white light is higher than that of blue light or red light, and the increase of red light proportion in projection is conducive to the expression of color, so F is preferred. _YELLOW >F _Blue At this time, the supply time of blue light will inevitably be shorter than that of yellow light (R, G). If the binary digits of the grayscale pattern of blue light are the same as those of red light and green light, the blue grayscale pattern may not be fully modulated within the supply time of blue light. At this time, it is more reasonable to select the binary digit m of the blue grayscale image to be smaller than the binary digit n of the red grayscale image and the green grayscale image. The optimal m=n-1 can achieve complete modulation of the blue light grayscale image.

[0184] The following will provide specific explanations for the cases where n and m are equal or unequal.

[0185] The control device is used for calculating, according to the original image data, first primary color light data, second primary color light data and third primary color light data respectively used for modulating the first primary color light, the second primary color light and the third primary color light.

[0186] For example, using a 60Hz signal source update frequency t _FRAME =16.67ms, yellow light time proportion F _YELLOW =50%, showing the operation time t corresponding to the smallest bit _LSB is taken as 16.025us, the white light mixing multiple N is taken as 10, and the corresponding RGB white light mixing time frequency is 600Hz, that is, in the modulation period t _WHITE =1s / 600=1.67ms, white light emission can be realized. In addition, since a single DMD only needs to process two colors, the first spatial light modulator 501 processes R (red light) and B (blue light), and the second spatial light modulator 502 processes G (green light) and E (empty light). _YELLOW=50%, the time in a frame corresponding to each color is t _FRAME *F _YELLOW =1s / (2*60)=8.33ms, if the unit modulation period corresponding to the LSB of DMD is set to t _LSB = 16.025us, the first sub-modulation period and the second sub-modulation period each contain M = (833.3us) / (16.025us) = 52 unit modulation periods, so it can be set to adjust the first / second primary color sub-modulation data composed of 52 LSBs (least data bits) in each yellow light segment and blue light segment. In the entire frame display time t _FRAME N = 10 t can be displayed _WHITE , corresponding to 520 LSBs, so the bit depth n = 9 bits (2 9 -1=511<520) The first / second primary color modulation value. The grayscale value is converted into the first primary color light data, the second primary color light data, and the third primary color light data represented by 9-bit binary using the traditional DMD PMW control method. Since a single LSB can be independently controlled in the DMD, taking the first spatial light modulator 501 as an example, it can realize the alternating display of the grayscale of red light and blue light. In the yellow light segment where the first spatial light modulator 501 works, the first spatial light modulator 501 modulates the red light according to the first primary color sub-modulation data (the first 52 LSBs of the red light grayscale), and then switches to the blue light segment where the first spatial light modulator 501 works, and the first spatial light modulator 501 modulates the blue light according to the third primary color sub-modulation data (the first 52 LSBs of the blue light grayscale). Then, the first spatial light modulator 501 displays the next 52 LSBs of the red light grayscale in the second yellow light segment, and then displays the next 52 LSBs of the blue light grayscale in the second blue light segment, ..., until finally after 10 yellow light segments, all 512 LSBs of the red light grayscale are fully displayed, and after 10 blue light segments, all 512 LSBs of the blue light grayscale are fully displayed.

[0187] This involves a problem: 10 times displaying the first / second primary color sub-modulation data composed of 52 LSBs can display the first / second primary color modulation value composed of 520 LSBs, which is slightly larger than the 512 LSBs corresponding to 9 bits. For the first problem, you can choose to put the DMDmicromirror working time period at the center of the yellow light segment and the blue light segment to avoid the delay and tailing of the laser switch; for the second problem, you can choose to set the last 8 LSBs of the 10th yellow light segment and the blue light segment to 0. The sum of the first primary color sub-modulation data is the first primary color light data, the sum of the second primary color sub-modulation data is the second primary color light data, and the sum of the third primary color sub-modulation data is the third primary color light data.

[0188] The second example uses a 30Hz signal source update frequency, so t_FRAME =33.33ms, yellow light time proportion F _YELLOW =75%, showing the operation time t corresponding to the smallest bit _LSB The white light mixing factor N is 16, and the corresponding RGB white light mixing time frequency is 480Hz, that is, in each sub-modulation period t _WHITE =1s / 480=2.08ms, white light can be emitted. _YELLOW =75%, the time within one frame corresponding to the yellow light segment (R / G) is t _FRAME *F _YELLOW =(1s*0.75) / 30=25ms, the time within a frame corresponding to the blue light color is t _FRAME *(1-F _YELLOW )=(1s*0.25) / 30=8.33ms. The LSB corresponding time of DMD is set to t_LSB=16.276us, so in each modulation period, the yellow light segment (R / G) can achieve a bit depth of 10 bits ((2 10 -1)*t _LSB ≤t _FRMAE *F _YELLOW <(2 11 -1)*t _LSB ), the Blu-ray segment can achieve a bit depth of 9 bits ((2 9 -1)*t _LSB ≤t _FRMAE *F _BLUE <(2 9+1 -1)*t _LSB ). In each sub-modulation period, the duration of the blue light segment is t _FRAME *F _BLUE / 16 = 520.83 μs, which can achieve 32 LSBs. The duration of each yellow light segment is t _FRAME *F _YELLOW / 16=1562.5μs, 96 LSBs can be realized, each yellow light segment displays the first 64 LSBs according to the bit stream, and the remaining 32 LSBs correspond to the first sub-empty time period of the first sub-time period. In the first sub-empty time period, the first spatial light modulator 501 and the second spatial light modulator 502 are not used to modulate data, and the modulated data corresponding to the first sub-empty time period can all be set to 0, that is, corresponding to the off state of the DMD micromirror.

[0189] Regarding the second example above, it should be noted that due to F _YELLOW >F _BLUE, the time of blue light is shorter than that of yellow light, so during the modulation of blue light, the operation time corresponding to the minimum bit position that the corresponding spatial light modulator can achieve is t _LSB It is smaller than the t that can be achieved by the corresponding spatial light modulator during the modulation of yellow light (red light, green light). _LSB For this case, all t _LSB The preferred value is blue light, which can avoid the t _LSB value, the modulation amount of blue light does not meet the requirement.

[0190] The third example uses a 140Hz signal source to update the frequency t _FRAME =7.143ms, yellow light time accounts for F _YELLOW = 66.67%, showing the operation time t corresponding to the smallest bit _LSB is taken as 18.599us, the white light mixing multiple N is taken as 128, and the corresponding RGB time frequency of white light mixing is 17920Hz, that is, at t _WHITE =1s / 17920≈56us, white light emission can be achieved. When the yellow light duty cycle is F_YELLOW=66.67%, the time within a frame corresponding to the yellow light segment (R / G) is t _FRAME *F _YELLOW =(1s*0.65) / 140=4.64ms, the time within a frame corresponding to the blue light color is t _FRAME *(1-F _YELLOW )=(1s*0.35) / 140=2.5ms. The LSB corresponding time of DMD is set to t _LSB = 18us, so the yellow light segment (R / G) in each modulation period can achieve a bit depth of 8 bits ((2 8 -1)*t _LSB ≤t _FRMAE *F _YELLOW <(2 8+1 -1)*t _LSB ), the Blu-ray segment can achieve a bit depth of 7 bits ((2 7 -1)*t _LSB ≤t _FRMAE *F _BLUE <(2 7+1 -1)*t _LSB ). The duration of each blue light segment is t _FRAME *F _BLUE / 128 = 18.599us, which can achieve 1 LSB. The duration of each yellow light segment is t _FRAME *F _YELLOW / 128=37.204us, 2 LSBs can be achieved.

[0191] In addition, in addition to Figure 3 In (b) and (c), the DMD bit stream is displayed from left to right from LSB to MSB. The corresponding positions of MSB and LSB can also be swapped, or another determined bit stream mapping can be established. In addition to the time sequence of each segment displayed in the figure corresponding to the bit stream, another determined sequential mapping can also be established. In addition to the figure setting the remaining bit position of the DMD PMW sequence at the end of the frame to 0, a determined mapping can also be established to insert blank bits into the first few segments.

[0192] In the above implementation, the blue light (third primary color light) can be divided into the first spatial light modulator 501 and the second spatial light modulator 502 by the light splitting device, and the two spatial light modulators are modulated simultaneously. If each spatial light modulator can modulate 32 LSBs in the blue light segment, the two spatial light modulators can achieve 64 LSBs in total. This method can achieve the function of modulating 64 LSBs in the same second sub-period.

[0193] Based on the above examples, the method for determining the reduction of color breakup by the number of sub-modulation time periods N, the image refresh frequency f, the binary bit number of the grayscale image (the bit width of the first modulation data and the second modulation data), and the color time proportion F corresponding to the grayscale image in a frame of image is described. The color time proportion F corresponding to the grayscale image in the above-mentioned frame of image refers to the proportion of each color grayscale image constituting a frame of image to the time of a frame of image. For example, an image with a refresh frequency of 60Hz is composed of corresponding red grayscale images, green grayscale images, and blue grayscale images. It is known that the time of a frame of image is 16.67ms. If the time occupied by the above-mentioned three color grayscale images is 5.56ms, then the F values ​​of the three colors are all 1 / 3.

[0194] A display method, comprising:

[0195] S1: Divide the modulation period of each image to be displayed into a plurality of sub-modulation periods, and calculate the light source control signal, the first modulation data and the second modulation data according to the original image data of each image to be displayed.

[0196] The first modulation data includes first primary color modulation data and third primary color modulation data for modulating the first primary color light and the third primary color light respectively, the second modulation data includes at least second primary color modulation data for modulating the second primary color light, and the first primary color modulation data, the second primary color modulation data and the third primary color modulation data respectively include first primary color sub-modulation data, second primary color sub-modulation data and third primary color sub-modulation data corresponding to multiple sub-modulation time periods one by one.

[0197] The first primary color modulation value, the second primary color modulation value and the third primary color modulation value used to modulate the first primary color light, the second primary color light and the third primary color light are calculated according to the original image data. The sum of all the first primary color sub-modulation data in the first modulation data is the first primary color modulation value, the sum of all the third primary color sub-modulation data is the third primary color modulation value, and the sum of the second primary color sub-modulation data in the second modulation data is the second primary color modulation value. For example, the first primary color modulation value represents the gray value used to modulate the first primary color light, the first primary color modulation value is 64, and the modulation period includes 8 sub-modulation periods, then the sum of the first primary color sub-modulation data in the 8 sub-modulation periods is equal to 64. It can be understood that each first primary color sub-modulation data can be the same data represented by binary, that is, the first primary color modulation value can be equally divided into each first primary color sub-modulation data.

[0198] In an implementation manner of 3D display, each frame of the image to be displayed includes a left-eye image and a right-eye image, and the left-eye image and the right-eye image are combined to obtain an image to be displayed.

[0199] In another implementation of 3D display, each frame of 3D image includes two images to be displayed, and the display time of each frame of image includes two modulation time periods respectively used to modulate one image to be displayed.

[0200] Taking the case where the first light is yellow light and the third primary color light is blue light as an example, the first light output by the light source system is yellow light formed by mixing the first primary color light (red light) and the second primary color light (green light).

[0201] S11: Calculate the time lengths of the first sub-period and the second sub-period according to the image refresh frequency f of the image to be displayed, the color time proportion F corresponding to the grayscale image in a frame of the image, and the number N of sub-modulation periods included in each modulation period.

[0202] Specifically, the steps include:

[0203] S111: Determine the number (multiple) N of sub-modulation time periods, that is, determine the desired frequency multiplication number;

[0204] S112: Determine the image refresh frequency f, that is, how many frames of images are expected to be output within 1 second, and calculate the time t required for one frame of image _FRAME , where t _FRAME =1 / f;

[0205] S113: Calculate the time t of the sub-modulation period _WHITE , where t _WHITE =t _FRAME / N;

[0206] S114: Calculate the time length t of the first sub-period and the second sub-period _WHITE *F, specifically, the time length of the first sub-modulation period is t _WHITE *F _YELLOW , the time length of the second sub-modulation period is t _WHITE *F _BLUE The corresponding F value can be set as required.

[0207] The time proportion of the first primary color light and the second primary color light in the primary color light is greater than or equal to that of the third primary color light, and accordingly, the time period length of the first sub-period is greater than or equal to that of the second sub-period.

[0208] S12: Based on the time length t of the first sub-period _WHITE *F_ YELLOW , the time length of the unit modulation period t _LSB1 , calculate and obtain the number of the least significant bits that can be modulated corresponding to the first / second primary color sub-modulation data;

[0209] According to the time length t of the second sub-period _WHITE *F _BLUE , the time length of the unit modulation period t _LSB2 , calculate and obtain the least significant bit number of the modulatable data corresponding to the third primary color sub-modulation data.

[0210] According to the display device, the least significant bit time t of the spatial light modulator is calculated by the formula _LSB , the formula is t _LSB =F*t _FRAME / 2 n =F / f*2 n .t _LSB The shortest modulation time for modulating the light by the first spatial light modulator and the second spatial light modulator is the unit modulation period.

[0211] In this case, since the red light and green light are separated from the yellow light and incident on two spatial light modulators at the same time, the binary digits of the red grayscale image and the green grayscale image are defined as n, and the blue light is emitted at other times besides the red light and the green light, so the binary digits of the blue grayscale image are defined as m. In the following, the least significant bit time of the spatial light modulator corresponding to the red light and the green light is regarded as t _LSB1 , then t _LSB1 =F _YELLOW / f*2 n ; The least significant bit time t of the spatial light modulator corresponding to blue light _LSB2 =F _BLUE / f*2 n .

[0212] Due to the nature of the DMD device, the time t of the least significant bit of each single color (R, G, B) is determined _LSB are the same, and t _LSB Cannot be less than the response time of the DMD micromirror, _LSB ≥10us.

[0213] Since the image frequency f and the color time proportion F corresponding to the grayscale image in a frame of image are already given, through the above t _LSB The maximum values ​​of n and m can be calculated within 10us, that is, the binary digits m of the blue grayscale image, the binary digits n of the red grayscale image, and the binary digits n of the green grayscale image can be calculated.

[0214] Due to the aforementioned F _YELLOW Can be greater than F _BLUE , solid _LSB1 It may not be equal to t _LSB2 However, the nature of the DMD device determines the time t of the least significant bit of each single color (R, G, B) _LSB are the same, so it is necessary to _LSB1 and t _LSB2 Choose one.

[0215] As mentioned above, in order to avoid using a large t _LSB The value causes other lights to not be fully modulated, so a relatively small t _LSB In this embodiment, the blue light corresponding t _LSB Value, that is, t _LSB2 .

[0216] S13: Calculate the time t=t in one frame corresponding to each primary color light _WHITE *F. Taking this embodiment as an example, t _BLUE =t _WHITE *F _BLUE , t _RED =t _GREEN＝ t _YELLOW *F _YELLOW .

[0217] S14: Calculate the minimum effective bit number of modulation that can be achieved by a single primary color light in each sub-modulation period. The calculation formula is t / t _LSB Taking this implementation as an example, in each sub-modulation period, the minimum number of effective bits that can be modulated by blue light is t _WHITE *F_ BLUE / t _LSB2 , the minimum number of effective bits that can be modulated for red and green light is t _WHITE *F_ YELLOW / t _LSB2 .

[0218] S15: Substitute the binary digits of the blue grayscale image calculated in S12 as m, and the binary digits of the red grayscale image and the green grayscale image as n into the formula to calculate the maximum number of grayscale modulations that can be achieved by a single primary color light in each sub-modulation period, that is, the theoretical number, and the formula is 2 a / N The formula for blue light is 2 m / N, the formula for red light and green light is 2 n / N.

[0219] S16: Compare the minimum number of effective bits of modulation that can be achieved with a single primary color light t / t _LSB Compared with the theoretical number 2 in S7 n / N difference, if t / t _LSB -2 a / N≥0, the grayscale bits of the image output corresponding to the primary color light remain unchanged; if t / t _LSB -2 a / N<0, the grayscale bit number of the image output corresponding to the primary color light should be reduced, preferably by 1 bit. The reason is that due to the frequency doubling scheme, the number of times each primary color light is modulated in the corresponding sub-modulation period may be less than the theoretical number, that is, t / t _LSB <2 a / N, so that the actual image grayscale level cannot reach the theoretical level. At this time, it is necessary to reduce the number of grayscale bits of the image, usually by 1 bit, that is, the number of grayscale bits of the image is n-1 to meet the requirement.

[0220] Taking this embodiment as an example, if t _WHITE *F _BLUE / t _LSB2 -2 m / N<0, then the number of grayscale bits of the blue image is m-1. If t _WHITE *F _BLUE / t _LSB2 -2 m / N≥0, the number of grayscale bits of the blue image is m; if t _WHITE *F _YELLOW / t _LSB2 -2 n / N<0, then the number of grayscale bits of the blue image is n-1. If t _WHITE *F _YELLOW / t _LSB2 -2 n / N≥0, the number of grayscale bits of the blue image is n.

[0221] Based on the above description, it can be known that the lower the grayscale bit number of the image, the easier it is to implement the frequency doubling scheme. Therefore, when calculating, after determining the number (multiple) of sub-modulation time periods N, the image refresh frequency f, and the color time proportion F corresponding to the grayscale image in a frame of image, the grayscale bit number n of the image output by the above primary color light should theoretically take the maximum value that the system can achieve, so that the grayscale performance of the image is the best.

[0222] In addition, it should be understood that the number (multiple) of sub-modulation time periods N, the image refresh frequency f, the color time proportion F corresponding to the grayscale image in a frame of image, and the number of grayscale bits n of the output image of the primary color light can all be changed, and the fourth item value can be obtained by any three of them.

[0223] S2: According to the light source control signal, control the light source system to emit the first light and the third primary color light in time sequence in each sub-modulation period, wherein the first light at least includes a mixed light of the first primary color light and the second primary color light;

[0224] The specific steps include:

[0225] S21: Divide each sub-modulation period into a first sub-period and a second sub-period;

[0226] S22: In the first sub-period of each sub-modulation period:

[0227] According to the light source control signal, controlling the light source system to emit a first light obtained by mixing the first primary color light and the second primary color light;

[0228] S23: In the second sub-period of each sub-modulation period:

[0229] According to the light source control signal, the light source system is controlled to emit the third primary color light.

[0230] The display method further comprises the following steps:

[0231] S3: according to the first modulation data, controlling the first spatial light modulator to time-divisionally modulate the first primary color light and at least a portion of the third primary color light in each sub-modulation period to obtain a first image light and a third image light;

[0232] According to the second modulation data, the second spatial light modulator is controlled to modulate the second primary color light in each sub-modulation period to obtain the second image light.

[0233] Specifically, the steps include:

[0234] S31: In the first sub-period of each sub-modulation period:

[0235] The first spatial light modulator is controlled to modulate the first primary color light according to the first modulation data; further, the first spatial light modulator is controlled to modulate the first primary color light according to the corresponding first primary color sub-modulation data.

[0236] The second spatial light modulator is controlled to modulate the second primary color light according to the second modulation data; further, the second spatial light modulator is controlled to modulate the second primary color light according to the corresponding second primary color sub-modulation data.

[0237] The portion of the first sub-period whose time length is longer than the actual modulation period of the first sub-period is the first sub-empty period, and the first spatial light modulator and the second spatial light modulator are controlled not to modulate the incident light in the first sub-empty period.

[0238] S32: In the second sub-period of each sub-modulation period:

[0239] The first spatial light modulator is controlled to modulate at least a portion of the third primary color light according to the first modulation data. Further, the first spatial light modulator is controlled to modulate at least a portion of the third primary color light according to the corresponding third primary color sub-modulation data.

[0240] The portion of the second sub-period whose time length is longer than the actual modulation period of the second sub-period is a second sub-empty period, and the first spatial light modulator is controlled not to modulate the third primary color light in the second sub-empty period.

[0241] In one implementation, the method further includes controlling the second spatial light modulator to modulate another portion of the third primary color light according to the second modulation data.

[0242] S4: Using a light combining device to combine the first image light, the second image light and the third image light and then emit the combined light.

[0243] In the present invention, a group of blue lasers is used as the excitation light of yellow fluorescence, and the wavelength is preferably 455nm; another group of blue lasers is used to generate blue illumination light, and the wavelength is preferably 465nm, so as to facilitate and better realize the REC2020 color gamut standard. Yellow fluorescence is used to generate red light and green light, and after homogenization and shaping, it is divided into two light paths through a color split glass. Each light path is modulated by a separate spatial light modulator (such as DMD). The modulated red light and green light are combined through another color split glass 305, and finally projected onto the screen through a lens 309. When yellow light is generated, one group of blue lasers for exciting fluorescence is in working state, and another group of blue lasers for blue illumination is in off state. After a period of time, the working states of the two groups of blue lasers alternate, that is, the blue laser for blue illumination is in working state, and the blue laser for laser fluorescence is in off state, and the switches are switched alternately. When the blue illumination light passes through the wavelength splitter for separating red light and green light, it is divided into the red light and green light paths according to a certain amplitude ratio, such as a semi-transparent and semi-reflective glass, which can achieve a part of transmission and a part of reflection. The preferred distribution ratio is that all the blue illumination light enters the red light path, and its two-dimensional grayscale adjustment is adjusted by the second spatial light modulator 502 that controls the red light.

[0244] See also Figure 4 , which is a schematic diagram of the structure of the display device provided by the second embodiment of the present invention. The polarization property of the excited fluorescence is close to that of natural light, and a polarization conversion element can be used to convert non-polarized light into linearly polarized light, and the laser itself is polarized light. One advantage of using polarized light illumination is that the light splitting and light combining system has a higher efficiency, and the reason is that the transmittance of different polarized lights for obliquely incident multilayer films is different, and the typical feature is that the cutoff wavelengths corresponding to different polarized lights are different.

[0245] The overall optical path of this embodiment is similar to that of the first embodiment, except that a first polarization conversion element 311 is added to the light splitting device after the light homogenizing device 303, and a second polarization conversion element 312 is added to the light combining device after the TIR prism 307. The polarization conversion element 311 is used to convert the fluorescence with polarization similar to natural light into a linear polarized light with a dominant polarization, and the conversion efficiency can reach 70% to 80% or even higher, depending on the f# of the incident light beam.

[0246] See also Figure 5, is a working principle diagram of a component for realizing polarization conversion. The component for realizing polarization conversion shown in the figure is called PCS (PS-conversion device), which is composed of a PBS array and a wide spectrum half-glass (HWP). After light with two polarization directions enters, a part of the light is directly transmitted, and the reflected light with a perpendicular polarization direction is reflected and deflected by 90° through the half-glass, and becomes light with the same polarization direction as the directly transmitted light, so that the non-polarized light is converted into polarized light. Since the laser has good linear polarization properties after being emitted, its placement direction is preferably selected in a direction that allows it to pass directly through the PCS. It is assumed that this polarization direction is s light relative to the wavelength splitter element 305, that is, the polarization direction is perpendicular to the paper surface. The linearly polarized light after passing through the first polarization conversion element 311 is incident on the wavelength splitter element 305. In the yellow light segment, the red light is reflected by 305, the green light is transmitted, and in the blue light segment, the blue light is reflected. The transmitted green light is spatially modulated and then enters another second polarization conversion element 312 , which deflects the polarization direction of the green light by 90°, so that it is p-polarized light relative to the wavelength combination element 308 .

[0247] Please refer to the figure Figure 6-Figure 7 , Figure 6 is the light transmission rate curve of the light combining element 308 and the light splitting element 305, Figure 7 is the light reflectance curve of the light combining element 308 and the light splitting element 305. The green light transmission spectrum T of the p-polarized light of the light combining element 308 c-p Compared with the s light T of the light splitting element 305 d-s Wider, can improve the green light synthesis efficiency near the cut-off wavelength. Correspondingly, the blue and red light reflection spectra R c-s Compared with the beam splitter R d-s Wider, can improve the light combining efficiency of blue light and red light near the cut-off wavelength. For convenience, the dotted lines in the figure mark the schematic diagram of the spectrum of the three primary colors. In summary, the principles of efficiency improvement are as follows: (1) The transmittance of s light or p light is steeper than the rising and falling edges of the cut-off wavelength of non-polarized light, and the wavelength space that can be operated after filtering is larger; (2) When splitting, use a polarization with a narrow transmission spectrum, and when combining, use a polarization with a wide transmission spectrum, which can ensure that the monochromatic light after splitting is completely collected; (3) The reflection band of the wavelength combining element can be designed to be wider than the band of the wavelength splitting element. In the specific implementation process, the reflection and transmission spectra of the splitting element and the combining element for different polarizations can be the same or different, depending on the selected RGB band. In addition, the polarization direction of the linear polarized light after passing through the polarization conversion element 301 can also be p light, that is, the polarization direction is in the straight plane. At this time, the transmission and reflection spectra of the s light and the p light need to be swapped accordingly.

[0248] The polarization conversion element 312 is preferably a half-wave plate (HWP). The element 312 can also be a PCS similar to the first polarization conversion element 311. Its working band at least covers the corresponding green light spectrum, that is, the band in which the second polarization conversion element 312 can play a polarization role must cover the wavelength of green light. Its position can also be in the green light path except Figure 4 Other positions between elements 305 and 308 other than the positions shown are preferably selected at positions with larger spot area and smaller beam divergence angle to achieve better polarization direction rotation. Moreover, the second polarization conversion element 312 can also be placed in the red light and blue light paths. Accordingly, the transmission spectrum T of the green light s polarization in the light combining element c-s Compared with the light emitting element T d-s Wide; the blue and red p-polarized reflection spectrum R of the light combining element c-p Than R d-s Width.

[0249] See also Figure 8 , is a schematic diagram of the structure of a display device provided in the third embodiment of the present invention.

[0250] The spectroscopic device includes:

[0251] A first polarization conversion element 311, used for converting the light emitted by the light source system into light of a first polarization state;

[0252] A third polarization conversion element 313, configured to convert the light emitted by the first polarization conversion element 311 into light of different polarization states according to the wavelength range of the light emitted by the first polarization conversion element;

[0253] The light splitting element 308 is used to split the light emitted by the third polarization conversion element 313 .

[0254] The third polarization conversion element 313 preferably uses a Color Select element, which can realize the deflection of the polarization direction of light of different wavelengths, for example, S polarization of red light and P polarization of green light. By designing the phase delay of different wavelengths, the rotation angle of the polarization direction of light of different wavelengths can be controlled. In a preferred embodiment, the third polarization conversion element 313 is used to convert the incident light into another polarization state of light of the same polarization type.

[0255] See also Fig. 9, is a transmission spectrum of a typical Color Select element GM44 in two typical configurations (polarization directions of the polarizer and analyzer are parallel or perpendicular to each other). After the incident light passes through the first polarizer (P), it becomes linearly polarized light. After phase modulation by ColorSelect (CS), the polarization directions of light of different wavelengths are deflected differently. After being analyzed by the second polarizer (P), different transmittances are shown: when the polarizer and analyzer are parallel to each other, the blue light band and the red light band have high transmittance; but when the polarizer and analyzer are perpendicular to each other, the green light band has a higher transmittance. Using ColorSelect in combination with the wavelength spectrometer 305 can separate yellow light into red light and green light in the yellow light band, and the red light and the green light have mutually perpendicular polarization states. The design of the wavelength spectrometer 305 and the wavelength combiner 308 in the second embodiment for improving light efficiency is also applicable in this embodiment. The width of the polarization conversion area in the ColorSelect transmission spectrum is about 30nm. Special processes and materials can achieve about 15nm. For the area with polarization conversion, color filters are used to filter it out first, which can also improve the saturation of the displayed color.

[0256] See also Fig.10 , is the green light transmission spectrum of the light combining element 308 and the light splitting element 305. Different from the second embodiment, the polarization directions of the green light, red light and blue light are perpendicular to each other during light splitting. The transmission spectrum of the green light in the light combining element 308 can be designed to be wider than that of the light splitting element 305; please refer to Fig.11 , are the reflection spectra of red light and blue light of the light combining element 308 and the light splitting element 305. The reflection spectra of blue light and red light can be designed to be wider.

[0257] See also Fig.12 , is a schematic diagram of the structure of a display device provided in the fourth embodiment of the present invention. Compared with the second embodiment, the light combining element 308 in this embodiment adopts polarization light combining instead of wavelength light combining.

[0258] See also Fig.13 , are the transmission and reflection spectra of the light combining element 308. The light combining element 308 preferably uses a wide spectrum PBS (Polarized Beam Splitter), which has a transmission and reflection spectrum of different polarized lights. Fig.13 shown.

[0259] See also Fig.14 , which is a schematic diagram of the structure of a display device provided in the fifth embodiment of the present invention. Similar to the case where the light combining element 308 in Example 2 is replaced with a polarized light combining element in Example 4, the light combining element 308 in Example 3 is also replaced with a polarized light combining element in Example 5, and the light combining element 308 also preferably uses a PBS.

[0260] See also Fig.15 , which is a schematic diagram of the structure of the display device provided by the sixth embodiment of the present invention. In this embodiment, the overall optical path design is similar to that of the fifth embodiment, except that the light splitting device of this embodiment adopts a polarization light splitting method, and the light splitting element 305 preferably uses PBS. One solution is to allow p light to pass through and s light to reflect, and its polarization transmittance and reflectivity curves are shown in 16. Combined with the light combining element 308 for polarization light combining, it can be achieved that in the yellow light segment, red light and green light are split and then combined.

[0261] See also Fig.17 , which is a schematic diagram of the structure of the display device provided by the seventh embodiment of the present invention. In this embodiment, the overall optical path design is similar to that of Example 6, except that in this embodiment, the light splitting device adopts polarization splitting, the light combining device adopts the wavelength light combining method, the light splitting element 305 preferably uses PBS, and the light combining element 308 preferably selects a wavelength light combining element that matches the transmittance spectrum of the polarization conversion element 313 and the possible wavelength filter. The design principle is that the transmittance spectrum of the green light segment p of the light combining element 308 is wider than the green light transmittance spectrum of the light splitting element 305 or the possible filter; and the reflectance spectrum of the blue and red light segment s is wider than the blue and red light reflection spectrum of the light splitting element 305 or the possible filter.

[0262] See also Fig.18 , which is a schematic diagram of a display system provided by the eighth embodiment of the present invention. The display system includes wavelength splitting glasses 700 and a display device, wherein the display device is used to emit 3D image pictures, and the wavelength splitting glasses 700 can be selected as 3D glasses to watch 3D pictures.

[0263] Each frame of 3D image includes a left eye image and a right eye image, and the control device is used to merge the left eye image and the right eye image to obtain an image to be displayed, and use the method of the first embodiment to display the image. That is, the two patterns are merged, and the grayscale patterns of the three primary colors of R, G, and B are parsed, and then the first spatial light modulator 501 and the second spatial light modulator 502 modulate the merged R, G, and B monochrome grayscale patterns respectively. Specifically, the display method applied to the control device in the display device provided in the first embodiment is used to display the image.

[0264] Magenta (red and blue) and green bands are used to realize left eye and right eye display respectively. Correspondingly, the first spatial light modulator 501 and the second spatial light modulator 502 should use a grayscale distribution with a 3D effect. The observer needs to use wavelength spectroscopic glasses 700 when watching the movie, and the color transmitted by the left and right eyes is preferably selected to correspond to the color processed by the optical path. The specific input signal of the first spatial light modulator 501 and the second spatial light modulator 502 is analyzed as follows. At present, the principle of 3D display is mostly a stereoscopic display constructed by using the binocular parallax characteristics of the human eye, which is generated by two related but not completely overlapping left eye images Fig1 and right eye Fig2. For each image, it corresponds to a separate RGB grayscale distribution, that is, Fig1 corresponds to Fig1R / G / B, and Fig2 corresponds to Fig2R / G / B. Therefore, it can be considered that in a frame of image, FigR is the result of the fusion of Fig1R and Fig2R, similarly, FigG is the result of the fusion of Fig1G and Fig2G, and FigB is the result of the fusion of Fig1B and Fig2B. In this embodiment, the second spatial light modulator 502 is used to complete the grayscale display of FigR and FigB according to the scheme in the first embodiment, and the first spatial light modulator 501 is used to complete the grayscale display of FigG.

[0265] In this embodiment, the following method can also be used to display 3D images. Each frame of the 3D image to be displayed includes two images to be displayed, and the display period of each frame of the image to be displayed includes two modulation periods for modulating one image to be displayed, that is, one frame of the 3D image corresponds to two modulation periods. The control device uses the display method of each image to be displayed in the first embodiment to use two control period display devices to display the 3D image screen.

[0266] Specifically, each sub-modulation period is divided into a first period t1 and a second period t2, and the first spatial light modulator 501 modulates the first image Fig1 and the second image Fig2 of A monochrome (R, B) in the first period t1 and the second period t2, respectively, or the second spatial light modulator 502 modulates Fig1 and Fig2 of another monochrome (G) in the first period t1 and the second period t2, respectively. The first period t1 and the second period t2 are used to display Fig1 and Fig2, respectively, that is, Fig1 is displayed in the first 8.33ms of each frame, and Fig2 is displayed in the last 8.33ms. The grayscale information of Fig1R is displayed by the yellow light segment corresponding to DMD501 in the first 8.33ms, the grayscale information of Fig1G is displayed by the yellow light segment corresponding to DMD502 in the first 8.33ms, and the grayscale information of Fig1B is displayed by the blue light segment corresponding to DMD501 in the first 8.33ms; the grayscale information of Fig2R is displayed by the yellow light segment corresponding to DMD501 in the last 8.33ms, the grayscale information of Fig2G is displayed by the yellow light segment corresponding to DMD502 in the last 8.33ms, and the grayscale information of Fig2B is displayed by the blue light segment corresponding to DMD501 in the last 8.33ms.

[0267] See also Fig.19 , is a schematic diagram of a display system provided by the ninth embodiment of the present invention. The display system includes a display device and a circular polarized light detector 701, and the circular polarized light detector 701 is used as 3D glasses to receive light emitted by the display device.

[0268] The light combining device includes:

[0269] A light combining element 308, configured to combine the first image light and the second image light;

[0270] A fourth polarization conversion element 314, used to convert the light emitted by the light combining element 308 into light of the same polarization state;

[0271] The dynamic polarization conversion element 315 is used to receive the light emitted by the fourth polarization conversion element and convert the received light into light of different polarization states to be emitted alternately. The dynamic polarization conversion element 315 is used to emit circularly polarized light.

[0272] The display system can also be compatible with polarized 3D display. Compared with Example 6, in this embodiment, after combining the light, another fourth polarization conversion element 314 is used to convert the three colors of RGB light into the same polarization, and an additional dynamic polarization conversion element 315 is used to achieve 3D display. The fourth polarization conversion element 314 preferably uses the Color Select corresponding to the third polarization conversion element 313 to combine RGB into the same polarization, so that the entire optical machine realizes the emission of a single polarized light to the dynamic polarization conversion element 315, and the dynamic polarization conversion element 315 changes the polarization state of the emission in a timing manner.

[0273] Among them, the 3D eye includes two circular polarization detectors. Fig.19 The circular polarization detector 701 shows the preferred left-handed and right-handed polarized light, that is, the left-handed polarized light and the right-handed polarized light are incident on the human eye through a circular polarization detector respectively, and the mutually perpendicular linear polarized light can also be realized similarly. At a certain time, the outgoing light has only one specific polarization state and can only pass through one lens in the circular polarization detector 701 (3D glasses) 701, and after the dynamic polarization conversion element 315 changes the polarization state of the outgoing light to be perpendicular to the original, the outgoing light can pass through the other lens in the 3D glasses. This dynamic left and right eye timing display and the dynamic coordination of the DMD display image can achieve a 3D effect.

[0274] See also Fig. 20 ,for Fig.19 The 3D module liquid crystal solution and patent solution schematic diagram of the dynamic polarization conversion element 315 are shown.

[0275] Specifically, the dynamic polarization conversion element 315 includes a dynamic polarization rotation element 315A and a polarization conversion element 315B, wherein 315A can be a voltage control element based on liquid crystal molecules such as Fig. 20 (a) (b) or use a phase delay slide based on dynamic rotation, such as Fig. 20 As shown in (c)(d).

[0276] A solution to achieve dynamic polarization rotation using liquid crystal is as follows Fig. 20 As shown in (a) and (b), the dynamic polarization rotator 315A uses VAN (Vertically Aligned Nematic) liquid crystal, which is vertically aligned with the electrode in the natural state. Under a certain voltage, it will deflect along the pre-tilt direction, so that the liquid crystal material exhibits optical anisotropy in the direction perpendicular to the electrode, causing birefringence and becoming a uniaxial birefringent crystal. If the slow axis direction is taken to form an angle of 45° with the polarization direction of the incident linear polarized light, as shown in FIG. Fig. 20As shown in (b), in the biased state, the polarization direction of the incident polarized light will be deflected by 90°. In the unbiased state, the liquid crystal molecules are vertically arranged in a natural state, and there is almost no optical anisotropy in the incident direction of light, so the polarization direction of the linear polarized light will not change. In this way, the two states can realize the dynamic regulation of the polarization direction of the incident linear polarized light. The polarization conversion element 315B preferably uses a quarter glass plate (QWP) to convert linear polarized light into circular polarized light, and convert linear polarized light with perpendicular polarization directions into circular polarized light with opposite rotation directions.

[0277] Another approach using a rotating phase-delay slide is Fig. 20 As shown in (c) and (d), a wide-spectrum phase-delay glass slide is mounted on a rotating wheel with controllable speed. Fig. 20 As shown in (d), half of the rotating wheel is composed of a half-wave plate (HWP), and the other half does not produce phase delay. In order to produce consistent phase delay during the rotation process, firstly, the optical axis direction of the half-wave plate is along the radial direction to ensure that the phase change of the incident light at the same point is consistent, that is, the angle of deflection of the linear polarization is consistent; secondly, the spot through the rotating wheel is as small as possible, on the one hand to maintain the uniformity of polarization modulation, and on the other hand to reduce the spokes corresponding to the transition area between the two halves. It is preferred to place the rotating wheel at the intermediate image position (conjugate plane) corresponding to the DMD surface in order to control the spot size and light angle.

[0278] See also Fig.21 ,for Fig.19 The timing diagram of the image emitted by the display device shown. In order to achieve the 3D effect, the synchronization and timing control of polarization conversion and image need to be specifically considered. In the sequential polarization 3D display scheme in this embodiment, the light of different polarizations emitted from the lens 309 is displayed in time division, and at a certain point in time, the images displayed by DMD501 (spatial light modulator 501) and DMD502 (spatial light modulator 502) are the same. If the dynamic polarization conversion element 315 can achieve a polarization conversion frequency of 120Hz, that is, two different polarizations can be rotated once in each frame, such as Fig.21 As shown, the parallax images Fig1 and Fig2 corresponding to the two polarizations occupy half of each frame. Assume that Fig1 is displayed in one polarization state for the first 8.33ms of a frame, and DMD501 and DMD502 respectively adjust the grayscale display of R / B and G; and Fig2 is displayed in another polarization state for the last 8.33ms of a frame, and DMD501 and DMD502 respectively adjust the grayscale display of R / B and G.

[0279] See also Fig. 22, is a schematic diagram of a display system provided in the tenth embodiment of the present invention. The light splitting device includes a dynamic polarization conversion element 315 located between the first polarization conversion element 311 and the third polarization conversion element 313, and the dynamic polarization conversion element 315 is used to receive the light emitted by the first polarization conversion element 311, and convert the received light into light of different polarization states and emit it alternately to the third polarization conversion element 313.

[0280] Different from the polarization 3D scheme in the ninth embodiment, in this embodiment, as shown in 22, the dynamic polarization conversion element 315 is placed before the third polarization conversion element 313. When the dynamic polarization element 315 rotates the incident light polarization by 90° and then passes through the third polarization conversion element 313 and the beam splitter 305 (PBS), the green light will be reflected by the beam splitter 305 and the red and blue light will be transmitted. Therefore, each polarization state has three colors of RGB, thereby realizing polarization 3D. The dynamic polarization element 315 in this embodiment is different from that in the ninth embodiment. The dynamic polarization element 315 in this embodiment does not include 315B for outputting linear polarized light.

[0281] In this embodiment, the linear polarized light analyzer 701 is preferably used as 3D glasses, that is, the p light and s light emitted by the display device pass through a lens of the 3D glasses respectively and enter the human eye. It can be understood that a quarter glass can also be added before the lens 309 to convert into circular polarized light.

[0282] Since two polarized image lights exist at the same time at any point in time, DMD501 and DMD502 display Fig. 1 and Fig. 2 respectively. After polarized light combination, the parallax 3D effect can be achieved directly through 3D glasses. The synchronization and timing control are as follows: Fig.23 shown.

[0283] See also Fig.24 , is a schematic diagram of a display device provided in the eleventh embodiment of the present invention.

[0284] The first spatial light modulator 501 and the second spatial light modulator 502 in the aforementioned embodiment are both DMDs, and the first spatial light modulator 501 and the second spatial light modulator 502 in this embodiment are both LCOS. The idea of ​​using a high refresh rate of a light source to reduce color breakup in a sequential color display in the present invention can also be used on other types of spatial light modulators (SLM: spatial light modulator). Based on the second embodiment, this embodiment replaces the spatial light modulators 501 and 502 from DMDs to LCoSs, and correspondingly replaces the prisms 306 and 307 with PBSs.

[0285] Since the liquid crystal itself has a slow response speed, the time it takes to mix multiple subframes to get white light is longer than that of DMD. The existing LCoS can divide one frame into 8 subframes for display. In this case, the shortest time to mix light to get white light is 1 / 4 frame. Compared with the second embodiment, only t0 needs to be set to 2.08ms. It can be imagined that for a liquid crystal-based spatial light modulator with a faster response speed, the speed of light source regulation can be faster, and the color breakup reduction effect will be more obvious.

[0286] It should be noted that within the scope of the spirit or basic features of the present invention, the specific schemes applicable to each implementation mode may also be applicable to each other. In order to save space and avoid repetition, they will not be described here.

[0287] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved. In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple devices stated in the device claim can also be implemented by the same device or system through software or hardware. The words first, second, etc. are used to indicate names, and do not indicate any particular order.

[0288] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A display device, characterized in that: include: A control device, used for dividing the modulation period of each image to be displayed into N sub-modulation periods, and calculating the light source control signal, the first modulation data and the second modulation data according to the original image data of the image to be displayed; A light source system, configured to emit a first light and a third primary color light in a time sequence in each sub-modulation period according to the light source control signal, wherein the first light is a mixed light including at least the first primary color light and the second primary color light; A first spatial light modulator, configured to time-divisionally modulate the first primary color light and at least a portion of the third primary color light in each sub-modulation period according to the first modulation data to obtain a first image light and a third image light; a second spatial light modulator, configured to modulate the second primary color light in each sub-modulation period according to the second modulation data to obtain a second image light; A light combining device, used for combining the first image light, the second image light and the third image light and emitting the combined light; The first modulated data and the second modulated data include the least significant bit of time t_ LSB , the least significant bit time t_LSB satisfies the following formula: t_ LSB =t_ FRAME ×F / 2 n , Among them, t_ FRAME is the modulation period of a frame of image, n is the number of binary bits of the grayscale image, and F is the color time proportion corresponding to the grayscale image in a frame of image.

2. The display device according to claim 1, characterized in that The first modulation data and the second modulation data also include the time length t_ WHITE , which satisfies the following formula: t_ WHITE =t_ FRAME / N。 3. The display device according to claim 2, characterized in that The control device divides each sub-modulation period into a first sub-period and a second sub-period; The time length of the first sub-period is t_ WHITE *F_ YELLOW , where F_ YELLOW The first light at t_ WHITE The proportion of time in .

4. The display device according to claim 3, characterized in that The maximum number of grayscale bits n of the first image light and / or the second image light satisfies the following formula: 2 n -1≤t_ FRAME *F_ YELLOW / t_ LSB ≤2 n+1 -1。 5. The display device according to claim 3 or 4, characterized in that: The time length of the second sub-period is t_ WHITE *F_ BLUE , where F_ BLUE The third primary color light is at t_ WHITE The proportion of time in .

6. The display device according to claim 5, characterized in that The maximum grayscale bit number m of the third image light satisfies the following formula: 2 m -1≤t_ FRAME *F_ BLUE / t_ LSB <2 m+1 -1。 7. The display device according to claim 6, characterized in that The first light is at t_ WHITE The time proportion of the third primary color light in t_ WHITE The time proportion in is equal, and the number of grayscale bits n is equal to the number of grayscale bits m.

8. The display device according to claim 6, characterized in that The first light is at t_ WHITE The time proportion of the third primary color light in t_ WHITE The time proportion in the grayscale is m=n-1.

9. A display method, characterized in that: include: Dividing the modulation period of each image to be displayed into N sub-modulation periods, and calculating the light source control signal, the first modulation data and the second modulation data according to the original image data of each image to be displayed; According to the light source control signal, the light source system is controlled to emit the first light and the third primary color light in time sequence in each sub-modulation period, wherein the first light at least includes a mixed light of the first primary color light and the second primary color light; According to the first modulation data, controlling the first spatial light modulator to time-divisionally modulate the first primary color light and at least a portion of the third primary color light in each sub-modulation period to obtain a first image light and a third image light; According to the second modulation data, controlling the second spatial light modulator to modulate the second primary color light in each sub-modulation period to obtain a second image light; Using a light combining device to combine the first image light, the second image light and the third image light and then emit the combined light; The first modulated data and the second modulated data include the least significant bit of time t_ LSB , the least significant bit time t_ LSB Satisfies the following formula: t_ LSB =t_ FRAME ×F / 2 n , Among them, t_ FRAME is the modulation period of a frame of image, n is the number of binary bits of the grayscale image, and F is the color time proportion corresponding to the grayscale image in a frame of image.

10. The display method according to claim 9, characterized in that: The first modulation data and the second modulation data also include the time length t_ WHITE , which satisfies the following formula: t_ WHITE =t_ FRAME / N。 11. The display method according to claim 10, characterized in that: According to the light source control signal, controlling the light source system to emit the first light and the third primary color light in sequence in each sub-modulation period includes: dividing each sub-modulation period into a first sub-period and a second sub-period; the time length of the first sub-period is t_ WHITE *F_ YELLOW , where F_ YELLOW The first light at t_ WHITE The proportion of time in .

12. The display method according to claim 11, characterized in that: The maximum number of grayscale bits n of the first image light and / or the second image light satisfies the following formula: 2 n -1≤t_ FRAME *F_ YELLOW / t_ LSB ≤2 n+1 -1。 13. The display method according to claim 11 or 12, characterized in that: The time length of the second sub-period is t_ WHITE *F_ BLUE , where F_ BLUE The third primary color light is at t_ WHITE The proportion of time in .

14. The display method according to claim 13, characterized in that: The maximum grayscale bit number m of the third image light satisfies the following formula: 2 m -1≤t_ FRAME *F_ BLUE / t_ LSB <2 m+1 -1。 15. The display method according to claim 14, characterized in that: When the first light is at t_ WHITE The time proportion of the third primary color light in t_ WHITE When the time proportions in are equal, the grayscale bit number n is equal to the grayscale bit number m.

16. The display method according to claim 14, characterized in that: When the first light is at t_ WHITE The time proportion of the third primary color light in t_ WHITE When the time proportion in is , the number of grayscale bits m=n-1.

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