CN108051947B

CN108051947B - Color gamut widening device

Info

Publication number: CN108051947B
Application number: CN201810017963.0A
Authority: CN
Inventors: 孙玉宝; 张弛; 马红梅
Original assignee: Hebei University of Technology
Current assignee: Hebei University of Technology
Priority date: 2018-01-09
Filing date: 2018-01-09
Publication date: 2024-04-12
Anticipated expiration: 2038-01-09
Also published as: WO2019137109A1; CN108051947A

Abstract

The invention relates to a color gamut widening device. The device comprises the following components: in the direction of the light path, a polarizing device and M groups of first basic units which are arranged in parallel are sequentially arranged; each first basic unit comprises a phase delay plate group and a polarization analyzer which are sequentially arranged, wherein M=1-5; the phase delay plate group consists of N identical phase delay plates which are arranged in parallel, wherein N=1-20, and the azimuth angle of the optical axis of each phase delay plate is as follows: (+/-) [ (2K-1). ] +m degrees; or when N is a multiple of 4 plus 1, from the first phase retarder, the azimuth angle of the optical axis of each 4 phase retarders is sequentially ±45 degrees, 90 degrees, ±45 degrees, 0 degrees, and the angle of the optical axis of the last phase retarder is ±45 degrees. The device has simple optical structure, can realize the color gamut of more than 140% NTSC, and can realize better wide color gamut effect by lower cost.

Description

Color gamut widening device

Technical Field

The invention relates to a color gamut widening device composed of a phase delay plate and a polarizing device, which can be applied to display devices and light source spectrum regulation.

Background

In recent years, a high-color-gamut light source becomes a hot spot for research, the color gamut of the light source depends on the light emission quality of the light source, including the position of the light emission peak in the spectrum and the full width at half maximum of the light emission peak, the position of the light emission peak determines the color of the color, the closer the position of the light emission peak is to the wavelength range of the three primary colors of red, green and blue, the better the color rendering property of the light source is, the full width at half maximum of the light emission peak determines the purity of the color, the narrower the full width at half maximum of the light emission peak is, the purer the color is, and the color gamut of the light source is wider.

The existing wide color gamut light source technology can be divided into two kinds, one is a light source technology represented by an electroluminescent diode technology with good monochromatic light performance, the light emitting effect of the light source technology is completely dependent on the light source, and the light source technology is high in price; another is a backlight color gamut widening method represented by a photo-quantum dot light emitting technology, and the light emitting effect thereof depends on the absorption or reflection of light of a specified wavelength by a color gamut widening device. In the backlight color gamut widening method, the existing photoinduced quantum dot light emitting technology (such as Chinese patent No.201610915843.3 with the name of quantum dot color filters and display devices comprising quantum dot color filters) which takes a quantum dot film as a color gamut widening device is included, blue light is used for exciting green and red quantum dot materials, and the emission of red, green and blue light is realized; or a technique using a color notch filter as a color gamut widening device (chinese patent No.201280041032.5 entitled "high dynamic range display with wide color gamut and energy efficiency"), the color notch filter being used to control white light of a light source so that light of a partial color cannot pass therethrough to achieve color gamut widening; or a technique using a filter as a color gamut widening device (for example, chinese patent No.200980117147.6 entitled "organic light emitting diode display encapsulated with a filter"), controlling light of a light source using an optical filter to realize color gamut control of outgoing light; or the technology of using the functional reflection polaroid as a color gamut widening device (published paper titled "Enlarging the color gamut of liquid crystal displays with a functional reflective polarizer", journal Optics Express, vol.25,102-111,2017), and using the functional reflection polaroid to realize polarized light and simultaneously totally reflect partial wavelength light, so that the emergent light lacks partial wavelength light, and a wide color gamut is realized. The technologies are all technologies for combining a color gamut widening device with a light source to generate a wide color gamut light source, and in the technologies, the light-induced quantum dot light-emitting technology is the only technology applied in practice, and can achieve the light-emitting effect of the maximum 110% NTSC color gamut standard, but the material characteristics of the light-induced quantum dot light-emitting technology still face high manufacturing cost (about 2 times of that of a common display), other technologies can theoretically further improve the color gamut of the light source to the 120% NTSC color gamut standard, but because the color gamut widening device comprises a huge number of complex structures in nano size and other electronic devices matched with the complex structures, the production difficulty and the structure complexity of the light-induced quantum dot light-emitting technology reach quite high levels, so that the light-emitting technology has not been applied practically.

Disclosure of Invention

The invention provides a color gamut widening device, which aims to solve the problems of high preparation difficulty, complex structure and high cost of the existing wide color gamut light source. The polarization device, the phase retarder group and the polarization analyzer are sequentially arranged in parallel according to a certain angle to form an optical system, the phase retarders arranged according to the invention have different effects on polarized light with different wavelengths, and the final transmitted light only has high transmittance in a specific wavelength range, so that the effect of the wide color gamut light source is realized. Compared with the existing wide-color-gamut light source technology, the invention does not depend on special materials such as quantum dots and the like for realizing the wide color gamut; the common polaroid and the phase retarder are adopted for each structure, the manufacturing precision is in the micron order, and the common polaroid and the phase retarder have general performance with the materials used by the existing liquid crystal display device, so that the production difficulty required by the structure is low; the realization of the device function only depends on the optical structure, the combination with the light source is simple, and the requirement of the application environment is reduced. The invention can realize the light source effect with wide color gamut through easier manufacturing process.

The technical scheme of the invention is as follows:

a color gamut widening device, the device comprising:

in the light path direction, a polarizing device and M first basic units which are arranged in parallel are sequentially arranged; the first basic unit comprises a phase delay plate group and a polarization analyzer, wherein M=1-5;

the polarizing device is an absorption type polarizer, a polarization selector, a metal wire grid or a reflection type polarizer;

the polarization analyzer is an absorption type polarizer, a polarization selector, a metal wire grid or a reflection type polarizer;

the light transmission axis direction of the polarizer is 0 degree; under this reference:

the transmission axis angle of the polarization analyzer is 0 degree or 90 degrees, preferably 0 degree.

The phase delay plate group consists of N identical phase delay plates which are arranged in parallel, wherein N=an integer of 1-20, preferably 1-5;

in the phase delay plate group, the azimuth angle of the optical axis of each phase delay plate is as follows: (+/-) [ (2K-1). ] +m degrees; wherein K is the number of steps of the phase retarder, m= -10, preferably m=0; the angles involved are either simultaneously positive or simultaneously negative;

or when N is a multiple of 4 plus 1, from the first phase retarder in the phase retarder group, the azimuth angle of the optical axis of each 4 phase retarders is sequentially +/-45 degrees, 90 degrees, +/-45 degrees and 0 degree; the optical axis angle of the last phase delay plate is +/-45 degrees; the angles involved are either simultaneously positive or simultaneously negative;

the phase retarder is a multi-stage full wave plate for a certain single-wavelength light with the wavelength of 500-550 nanometers in the visible light range, and the wave plate number is in the range of 2-9.

In the phase retarder group, after the arrangement sequence of the phase retarders and the angle of the optical axis are determined, the phase retarder group can be arranged in the device in all forward directions or in all reverse directions.

The beneficial effects of the invention are as follows:

compared with the existing quantum dot technology, the realization of the high light source color gamut does not depend on special materials and complex microstructures, the process production difficulty is reduced, meanwhile, compared with the quantum dot technology, the quantum dot technology is little restricted by the use environment, the quantum dot technology can be applied to all existing display devices, and the materials used in the quantum dot technology can be common compensation film materials, so that the service life is unlimited; the device of the invention can be directly attached to the outside of a light source or a display for use, so that the process production is very easy. The device has simple optical structure and simple combination with the light source, can be placed at the outermost side of the display, can be placed in a backlight module of the liquid crystal display, and can also be directly placed at the front end of a light-emitting component of the LED backlight source to directly regulate and control the wave band of emitted light. Compared with other existing optical structure technologies, the invention can realize the color gamut widening effect under the existing process conditions. The device can realize the color gamut of more than 140% NTSC, which is much larger than the color gamut of 110% NTSC at the highest of the quantum dot film, and can realize better wide color gamut effect by lower cost.

Drawings

FIG. 1 is a block diagram of a light source or display and a color gamut widening device;

FIG. 2 is a block diagram of four types of polarizing devices; wherein, fig. 2 (a) is a structural diagram of a general polarizer, fig. 2 (b) is a structural diagram of a polarization selector, fig. 2 (c) is a structural diagram of a metal wire grid, and fig. 2 (d) is a structural diagram of a reflective polarizer;

FIG. 3 is a graph of birefringence versus wavelength for a phase retarder (polycarbonate);

FIG. 4 is a device structure diagram, transmission spectrum and color gamut diagram in example 1; wherein FIG. 4 (a) is a block diagram of a device having a phase retarder in the structure, FIG. 4 (b) is a transmission spectrum, and FIG. 4 (c) is a color gamut diagram

FIG. 5 is a device structure diagram, transmission spectrum and color gamut diagram in example 2; wherein FIG. 5 (a) is a diagram showing a second device structure with a phase retarder, FIG. 5 (b) is a transmission spectrum, and FIG. 5 (c) is a color gamut diagram

FIG. 6 is a device structure diagram, transmission spectrum and color gamut diagram in example 3; wherein FIG. 6 (a) is a block diagram of a device including two phase retarders, FIG. 6 (b) is a transmission spectrum, and FIG. 6 (c) is a color gamut diagram

FIG. 7 is a device structure diagram, transmission spectrum and color gamut diagram in example 4; wherein FIG. 7 (a) is a block diagram of a device including three phase retarders, FIG. 7 (b) is a transmission spectrum, and FIG. 7 (c) is a color gamut diagram

FIG. 8 is a device structure diagram, transmission spectrum and color gamut diagram in example 5; wherein FIG. 8 (a) is a block diagram of a device including four phase retarders, FIG. 8 (b) is a transmission spectrum, and FIG. 8 (c) is a color gamut diagram

FIG. 9 is a device structure diagram, transmission spectrum and color gamut diagram in example 6; wherein FIG. 9 (a) is a diagram of a first device having five phase retarders, FIG. 9 (b) is a transmission spectrum, and FIG. 9 (c) is a color gamut diagram

FIG. 10 is a device structure diagram, transmission spectrum and color gamut diagram in example 7; wherein FIG. 10 (a) is a diagram showing the structure of a second device having five phase retarders, FIG. 10 (b) is a transmission spectrum, and FIG. 10 (c) is a color gamut diagram

FIG. 11 is a diagram showing a device structure including 9 phase retarders according to example 8, FIG. 11 (a) shows a transmission spectrum, FIG. 11 (b) shows a color gamut diagram

FIG. 12 is a device structure diagram, transmission spectrum and color gamut diagram in example 9; wherein FIG. 12 (a) is a block diagram of a device having 3 polarizers and 14 phase retarders, FIG. 12 (b) is a transmission spectrum, and FIG. 12 (c) is a color gamut

FIG. 13 is a device structure diagram, transmission spectrum and color gamut diagram in example 10; fig. 13 (a) is a block diagram of a device including 3 polarizers and 10 retardation plates, fig. 13 (b) is a transmission spectrum, and fig. 13 (c) is a color gamut.

Detailed Description

As shown in fig. 1, the color gamut widening device can be used for various light source devices to adjust the spectral characteristics emitted by the light source and widen the color gamut of the light source; or for various display devices to widen the display gamut of a display. The color gamut widening device is arranged on a light source or a display screen, and comprises a polarizing device 1, a phase delay plate group 2, an analyzer 3 and a light transmission axis of the polarizing device 1, wherein the light transmission axis of the analyzer 3 is parallel or perpendicular to the light transmission axis of the analyzer from bottom to top. The phase retarder group 2 is composed of one or more phase retarders, and the optical axis (slow axis) of each phase retarder is parallel to the plane of each retarder, and the materials used can be various materials with double refractive indexes, generally inorganic crystal materials and organic polymer materials. The specific examples below used in this invention were polycarbonate for the birefringent materials and full spectrum light sources were used for the light sources.

Fig. 2 shows four types of polarizing devices 1 used in the present device. (a) When the natural light passes through the common polaroid 11, polarized light parallel to the transmission axis of the polaroid is transmitted, polarized light perpendicular to the transmission axis of the polaroid is absorbed, and the natural light can also be an external polaroid of the display; (b) For the polarization selector 12, polarized light perpendicular to the incident surface is reflected by polarized light parallel to the incident surface 121; (c) For the metal wire grid 13, polarized light perpendicular to the metal wires 131 is transmitted, and polarized light parallel to the metal wires is reflected; (d) The reflective polarizer 14 is composed of an optically anisotropic film layer 141 and an optically isotropic film layer 142, one of the two refractive indices of the optically anisotropic film is equal to the refractive index of the optically isotropic film, and the polarized light having the same refractive index as the transmitted polarized light is reflected in the other direction. All the reflected polarized light can be reflected back through the reflector in the light source or the display backlight module for use. The polarization analyzer is generally an absorptive polarizer. The ideal polarizer is used in the invention, and the above various polarizing devices and polarizing analyzer are the ultimate optical characteristics without considering the reuse of reflected light, namely the characteristics of the ideal polarizer: the linear polarized light in one direction is transmitted, and the linear polarized light in the other direction is absorbed.

Fig. 3 shows the relationship between the birefringence and wavelength of a phase retarder (polycarbonate) used in the present invention, the birefringence decreasing with increasing wavelength, the thickness of the phase retarder preferably being 20 microns without specific explanation. In the case of satisfying the optical device color gamut requirement, the relationship of the birefringence of the phase retarder to the wavelength, and the thickness thereof, are not limited by the parameters herein.

The light path is sequentially provided with polarizing devices which are arranged in parallel, a phase delay plate group and a polarization analyzer. The polarization direction of polarized light that is utilized through the polarizing means is defined as 0 degrees and is used as a reference for the azimuth angle of the optical axis (transmission axis or optical axis of the retardation plate) of each optical device later. Polarizing means may be classified as a general absorptive polarizer, a polarization selector, a metal wire grid, or a reflective polarizer for generating linearly polarized light. The absorption type polaroid is used for the polarization analyzer, the light transmission axis direction of the polarization analyzer can be 0 or 90 degrees and is used for transmitting light with a required wavelength and masking light with an unnecessary wavelength, and the light transmission axis direction of the polarization analyzer is other angles, so that the light with the unnecessary wavelength cannot be completely masked, and the optimal color gamut widening cannot be achieved and is abandoned. The phase delay plate group is arranged between the polarizing device and the polarization analyzer to perform phase modulation on polarized light with different wavelengths, so that the light with the required wavelength has the maximum transmittance in the light emitted from the polarization analyzer, and the transmittance of the light with the unnecessary part of wavelengths can be reduced or the transmittance of the light with the unnecessary part of wavelengths can be blocked.

The phase retarder used in the phase retarder group is a phase retarder made of a crystal material or a polymer material, the optical axis (the direction of a special refractive index) of the phase retarder is parallel to the plane of the phase retarder, and the phase retarder is preferably a film made of the same material and having the same birefringence and thickness. The number of the phase delay plates can be one, two, three, four or five, and a plurality of phase delay plates can be used according to the requirements. The retardation of the phase retarder used exhibits the characteristics of a full wave plate in the visible range at least at 3 wavelengths, and can be expressed as: Δn×d/λ=k (k is an integer, Δn is a birefringence of the retarder, d is a thickness of the retarder), and when λ is a different value, k is also a different value. When the linearly polarized light generated by the polarizing device enters the phase retarder group, the polarization state of the full wave plate is not changed, the linear polarization characteristic can be maintained, the polarization state of the light with other wavelengths can be changed, and the change of the polarization state is controlled by controlling the angle of the optical axis of the phase retarder, so that the polarization state is perpendicular to the polarization state of the full wave plate after the light passes through the phase retarder. Therefore, under the action of the polarizing device and the polarization analyzer with parallel or perpendicular optical axes, selective wave band transmission of visible light is formed, and wave band adjustment can be performed on various known light sources, so that the effect of widening the color gamut is obtained.

When the light wave band transmitted through the device is controlled to change, the thickness of the phase delay plate can be increased to achieve the red shift of the transmission spectrum, and the thickness of the phase delay plate can be reduced to achieve the blue shift of the transmission spectrum, so that the change of the three primary colors of the spectrum is realized.

The feature of the present invention to achieve color gamut widening is further described below with reference to the drawings.

In example 1, as shown in fig. 4 (a), a first color gamut device structure diagram including one phase retarder is shown, the transmission axis of the polarizing device 1 is parallel to the transmission axis of the polarizing analyzer 3 (the angle is 0 °), the preferred optical axis angle of the phase retarder 211 is positive 45 ° or negative 45 °, and the two effects are the same; the retarder is a 4-stage full wave plate for 520 nm light, i.e., a polycarbonate material, and has a thickness of 20 μm (the examples below also select such a retarder, but are not limited thereto). For natural light with the same light intensity under different wavelengths in the visible light range, the polarization direction of the transmitted light is 0 degree, the relation between the transmittance and the wavelength is shown in fig. 4 (b), the transmittance has peak values at 445, 520 and 660 nanometers, the phase retarder shows full-wave plate characteristics for the light with the wavelengths, and the polarization characteristics of the wavelengths are not changed by the phase retarder, so that the maximum transmittance is achieved; the wavelength with zero transmittance exists between peaks, the phase delay plate shows half-wave plate characteristics for the light with the wavelength, and the light polarized in the 0-degree direction can be rotated to the 90-degree direction, so that the light can be absorbed by the polarization analysis plate and can not pass through the polarization analysis plate; light with other wavelengths is changed in polarization state and polarization direction, so that the light is partially absorbed and partially transmitted by the polarization-analyzed sheet; such a spectrum can be considered as a spectrum of three primary colors red, green and blue, the chromaticity coordinates of which are shown in fig. 4 (c), the CIE1931 coordinate system, and the ratio of the color gamut area of the spectrum to the color gamut area of the NTSC standard (1953) is 116%, that is, the color gamut widening device is 16% larger than the color gamut area obtained by the conventional color gamut control method, and has a display of more than 16% of color types in terms of display colors.

In example 2, as shown in fig. 5 (a), a second color gamut device structure containing one retardation plate has a structure different from that of example 1 only in the angle of the polarization analyzer, the light transmission axis angle of the polarization analyzer 31 is 90 degrees, the preferable thickness of the retardation plate in this structure is 23.5 μm, the relation between the transmittance and the wavelength is shown in fig. 5 (b), the transmittance has peaks at 405, 450, 520 and 640 nm, the chromaticity coordinates are shown in fig. 5 (c), the ratio of the color gamut area of the spectrum to the color gamut area of the NTSC standard is 111%, and the color gamut area is slightly smaller than that obtained in example 1, but still a larger result than that obtained by the conventional color gamut control method can be obtained.

In example 3, two retarders are used, and the structure is shown in fig. 6 (a), wherein the preferred thickness of the first retarder 231 and the second retarder 232 is 20 μm, the preferred optical axis angles are 22.5 and 67.5 degrees, or-22.5 and-67.5 degrees, respectively, and the optical axis angles of the two retarders are sequentially changed back and forth, as a result, the relationship between the transmittance and the wavelength is the same, as shown in fig. 6 (b), and compared with example 1, the half-height peak width corresponding to each peak is reduced, the wavelength width of the transmittance is increased to zero, it can be said that the color of the red-green-blue three primary colors is purer, the chromaticity coordinates are shown in fig. 6 (c), and the ratio of the color gamut area of the spectrum to the standard color gamut area is 128%.

In example 4, as compared with example 3, one retarder is added, and as shown in fig. 7 (a), the preferred optical axis angles of the first retarder 241, the second retarder 242 and the third retarder 243 are respectively 15, 45 and 75 degrees, or-15, -45 and-75 degrees, respectively, and the optical axis angles of the three retarders are reversed in order, and as a result, the relationship between the transmittance and the wavelength is the same, and as shown in fig. 7 (b), the half-height peak width corresponding to each peak is smaller, and the chromaticity coordinates are as shown in fig. 7 (c), and the ratio of the color gamut area of the spectrum to the color gamut area of the NTSC standard is 137%.

In example 5, as compared with example 4, one phase retarder is added, as shown in fig. 8 (a), the preferred optical axis angles of the first phase retarder 251, the second phase retarder 252, the third phase retarder 253 and the fourth phase retarder 254 are respectively 11.25 degrees, 33.75 degrees, 56.25 degrees and 78.75 degrees, or-11.25 degrees, -33.75 degrees, -56.25 degrees and-78.75 degrees, respectively, the optical axis angles of the four phase retarders are reversed in order, and as a result, the relation between the transmittance and the wavelength is the same, as shown in fig. 8 (b), the chromaticity coordinates thereof are as shown in fig. 8 (c), and the ratio of the color gamut area of the spectrum to the color gamut area of the NTSC standard is 137%.

In example 6, as compared with example 5, one retarder is added, as shown in fig. 9 (a), the preferred optical axis angles of the first retarder 261, the second retarder 262, the third retarder 263, the fourth retarder 264 and the fifth retarder 265 are respectively 9, 27, 45, 63 and 81 degrees, or-9, -27, -45, -63 and-81 degrees, respectively, and the optical axis angles of the five retarders are reversed in order, so that the same result is obtained, the relation between the transmittance and the wavelength is shown in fig. 9 (b), the chromaticity coordinates thereof are shown in fig. 9 (c), and the ratio of the color gamut area of the spectrum to the color gamut area of the NTSC standard is 139%.

In example 7, the number of phase retarders is the same as that of example 6, and as shown in fig. 10 (a), the difference is that the preferable optical axis angles of the first phase retarder 271, the second phase retarder 272, the third phase retarder 273, the fourth phase retarder 274 and the fifth phase retarder 275 are 45, 90, 45, 0 and 45 degrees, or-45, 90, -45, 0 and-45 degrees, respectively, and the optical axis angles of the second and fourth phase retarders are interchanged, and as a result, the relation between the transmittance and the wavelength is the same as that shown in fig. 10 (b), the chromaticity coordinates are as shown in fig. 10 (c), the ratio of the color gamut area of the spectrum to the color gamut area of the NTSC standard is 136%, and the color gamut area is slightly smaller than that of example 6.

In example 8, the color gamut widening effect is achieved by using 9 retardation plates, as shown in fig. 11 (a), the preferred optical axis angle order of the first retardation plate 281 to the ninth retardation plate 289 is (2 k-1) x 5 degrees (k=1, 2 … 9), or- (2 k-1) x 5 degrees (i.e., specifically 1 x 90/18 degrees, 3 x 90/18 degrees, … (2 k-1) x 90/18 degrees … x 90/18 degrees, respectively), and the order is reversed, and as a result, the relationship between the transmittance and the wavelength is the same as shown in fig. 11 (b), the chromaticity coordinates thereof are as shown in fig. 11 (c), and the ratio of the color gamut area of the spectrum to the color gamut area of the NTSC standard is 142.5%.

In example 9, as shown in fig. 12 (a), a single polarizing device and two polarizing plates were used, and the structure of example 6 and the structure of example 8 share the intermediate polarizing plate 3, and the structures of the two examples are interchanged in the up-down position, as a result, the relationship between the transmittance and the wavelength is the same, as shown in fig. 12 (b), and the chromaticity coordinates are the same, as shown in fig. 12 (c), and the ratio of the color gamut area of the spectrum to the color gamut area of the NTSC standard is 148%.

In example 10, as shown in fig. 13 (a), 2 stacks of example 7 were used, one polarizing device and two polarization analyzers were used, and the structure of 2 examples shared the middle polarization analyzer 3, and the relationship between the transmittance and the wavelength was as shown in fig. 13 (b), and it was seen from the graph that the small peak between the two transmittance peaks in the results of example 7 was not present, and the chromaticity coordinates were as shown in fig. 13 (c), and the ratio of the color gamut area of the spectrum to the color gamut area of the NTSC standard was 146%, which was increased by 10% compared with 136% of example 7.

Other configurations that use other numbers of phase retarders, and combinations of two or more embodiments to achieve a widening of the color gamut, using the basic structure of the present invention, are within the scope of the present invention.

The invention is not a matter of the known technology.

Claims

1. The color gamut widening device is characterized by comprising the following components:

the polarization direction of polarized light emitted by the polarized light device is 0 degrees;

the transmission axis angle of the polarization analyzer is 0 degree or 90 degrees;

the phase delay plate group consists of N identical phase delay plates which are arranged in parallel, wherein N=an integer of 1-20;

in the phase delay plate group, the azimuth angle of the optical axis of each phase delay plate is as follows: (+/-) [ (2K-1). ] +m degrees; wherein K is the number of times of the phase delay plate, and m= -10; the angles involved are either simultaneously positive or simultaneously negative;

the phase retarder is a multi-stage full wave plate for a certain single-wavelength light with the wavelength of 500-550 nanometers in the visible light range, and the wave plate number is in the range of 2-9;

the number of the phase delay plates in the phase delay plate group is 1-5.

2. The color gamut widening device according to claim 1, wherein the phase retarder groups are all arranged in the device in a forward or reverse order after the arrangement order of the phase retarders and the angle of the optical axis are determined.

3. The color gamut widening device according to claim 1, wherein the polarization analyzing device has a transmission axis angle of 0 degrees.

4. The color gamut widening device according to claim 1, wherein m=0 in the azimuth angle of the optical axis of the phase retarder in the phase retarder group.