TWI805221B - Optical module and display device - Google Patents

Abstract

Embodiments of the present disclosure relate to the field of augmented reality and virtual reality. It is designed to solve the problem that the efficiency of optical waveguide is reduced due to the gradual cracking of organic filter in the process of using. An optical module and a display device are provided. The optical module includes a first transparent substrate, a first coupling-in grating, a first coupling-out grating and a first filter film. The first transparent substrate is used for conducting light of a first band. The first transparent substrate includes a first surface and a second surface opposite to the first surface. The second surface includes a first light emitting region and a second light emitting region. The first filter film is arranged in the first light emitting region for filtering the light of the first band. The first filter film includes a multilayer inorganic film.

Description

Optical components and display devices

The present application relates to the field of augmented reality and virtual reality, in particular, to an optical component and a display device.

In Augmented Reality (AR), light is coupled into the glass substrate of the optical waveguide, and the light is transmitted to the front of the eye by the principle of total reflection to release image information. Among them, the red, green and blue three-color light needs to be coupled into the three-layer optical waveguide with organic color filters, so that each layer of optical waveguide is only coupled to a certain color, improving the color uniformity of the exit pupil position and reducing the rainbow effect.

The currently used organic color filters will be cracked over time due to the high light intensity of the light source, which will increase the light loss; when the organic color filter gradually cracks over time, it is necessary to use a light source with stronger light intensity to maintain the light guiding effect , resulting in increased power consumption.

The first aspect of the present application provides an optical component to solve the problem that the organic optical filter is gradually cracked during use, thereby reducing the efficiency of the optical waveguide. The optical assembly includes a first light-transmitting substrate, a first in-coupling grating, a first out-coupling grating, and a first filter film. The first light-transmitting substrate is used to transmit light in the first wavelength band. The first light-transmitting substrate includes a first surface and a second surface opposite to each other, and the second surface includes a first light-emitting area and a second light-emitting area arranged at intervals. The first in-coupling grating and the first out-coupling grating are arranged at intervals on the first surface, and the projection of the first in-coupling grating on the first light-transmitting substrate falls into the first light-out region , the projection of the first outcoupling grating on the first light-transmitting substrate falls into the second light-out region. The first filter film is arranged in the first light exit area, and is used for filtering out the light in the first wavelength band. The first filter film includes a multi-layer inorganic film. Wherein, the light of the first wavelength band incident on the first light-transmitting substrate from the first coupling grating is filtered out after being transmitted to the first filter film so that it cannot enter the first light-exit area. After being transmitted to the first outcoupling grating, it is diffracted by the first outcoupling grating and emerges in the second light out region.

Compared with the previous organic polymer filter, the first filter film is a multi-layer inorganic film, which has a higher cracking temperature (cracking temperature Td > 450°C), slower cracking speed, and more durable; by adjusting The membrane stack structure changes the filtering range, making it easier to adjust the light color; the spectral characteristics are steeper, and the light color is purer.

The second aspect of the present application provides a display device, including a light source, and the aforementioned optical assembly, the light source is arranged on one side of the optical assembly, and the light emitted by the light source reaches the observation position after passing through the optical assembly .

Compared with the previous technology, the display device improves the color purity of the outgoing light and improves the color uniformity of the observation position; the light transmittance is higher, and the average light transmittance reaches more than 95%; it has wider applicability in the AR field, and the light source can be It is a light source that organic polymer filters are not suitable for, such as micro-light emitting diode light sources, micro-organic light-emitting diode light sources and quantum dot light-emitting diodes. The light source can also be a display device for which an organic polymer filter is not suitable, such as a digital light processing projector and a silicon-based liquid crystal display panel.

The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of them.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the application. The terms used herein in the description of the application are only for the purpose of describing specific embodiments, and are not intended to limit the application.

In the augmented reality (Augmented Reality, AR) and virtual reality (Virtual Reality, VR) fields, the light emitted from the color light source is transmitted to the position observed by human eyes through optical components. Optical components conduct light based on the principle of total internal reflection, and use filter components to separate light in different wavelength bands to improve color uniformity at the observation position. Such optical components can also be applied to wearable devices, such as VR glasses and AR glasses.

In order to further explain the technical means and functions adopted by this application to achieve the intended purpose, the following detailed description of this application will be given in conjunction with the drawings and preferred implementation modes.

The present application provides an optical component, in which a multilayer inorganic film is used as a filter component, which improves the light extraction effect and prolongs the service life of the optical component.

Embodiment one

Referring to FIG. 1 , this embodiment provides an optical component 100 . The optical assembly 100 includes a first transparent substrate 110 , a second transparent substrate 120 and a third transparent substrate 130 . The first transparent substrate 110 is used to transmit the light 119 of the first wavelength band; the second transparent substrate 120 is used to transmit the light 129 of the second wavelength band; the third transparent substrate 130 is used to transmit the light of the third wavelength band 139 of the light. No two of the first wave band, the second wave band and the third wave band overlap each other. The material of the first transparent substrate 110 , the second transparent substrate 120 and the third transparent substrate 130 is, for example, glass.

The first light-transmitting substrate 110 includes a first surface 111 and a second surface 112 opposite to each other, and the second surface 112 includes a first light-emitting region 113 and a second light-emitting region 114 arranged at intervals. A first in-coupling grating 115 and a first out-coupling grating 116 are disposed at intervals on the first surface 111 . The projection of the first in-coupling grating 115 on the first transparent substrate 110 falls into the first light exit region 113 . The projection of the first outcoupling grating 116 on the first transparent substrate 110 falls into the second light out region 114 . A first filter film 117 is disposed in the first light exit area 113 for filtering out the light 119 of the first wavelength band. In this embodiment, the first light exit area 113 is an area on the second surface 112 that is slightly larger than the projection of the first in-coupling grating 115 . The second light output area 114 is an area on the second surface 112 that is slightly larger than the projection of the first output coupling grating 116 . In other embodiments, the first light exit area 113 may be a projected area of the first in-coupling grating 115 on the second surface 112 . The second light output area 114 may be a projected area of the first output coupling grating 116 on the second surface 112 .

The second light-transmitting substrate 120 includes a third surface 121 and a fourth surface 122 opposite to each other, and the fourth surface 122 includes a third light-emitting region 123 and a fourth light-emitting region 124 arranged at intervals. A second in-coupling grating 125 and a second out-coupling grating 126 are disposed at intervals on the third surface 121 . The projection of the second in-coupling grating 125 on the second transparent substrate 120 falls into the third light output region 123 . The projection of the second outcoupling grating 126 on the second transparent substrate 120 falls into the fourth light out region 124 . A second filter film 127 is disposed in the third light exit area 123 for filtering out the light 129 of the second wavelength band. In this embodiment, the third light exit area 123 is an area on the fourth surface 122 that is slightly larger than the projection of the second in-coupling grating 125 . The fourth light output area 124 is an area on the fourth surface 122 slightly larger than the projection of the second output coupling grating 126 . In other embodiments, the third light exit area 123 may be a projected area of the second in-coupling grating 125 on the fourth surface 122 . The fourth light output area 124 may be a projected area of the second output coupling grating 126 on the fourth surface 122 .

The third light-transmitting substrate 130 includes a fifth surface 131 and a sixth surface 132 opposite to each other, and the sixth surface 132 includes a fifth light-emitting region 133 and a sixth light-emitting region 134 arranged at intervals. A third in-coupling grating 135 and a third out-coupling grating 136 are disposed at intervals on the fifth surface 131 . The projection of the third in-coupling grating 135 on the third transparent substrate 130 falls into the fifth light-out region 133 . The projection of the third outcoupling grating 136 on the third transparent substrate 130 falls into the sixth light out region 134 . In this embodiment, the fifth light exit area 133 is an area on the sixth surface 132 that is slightly larger than the projection of the third in-coupling grating 135 . The sixth light output area 134 is an area on the sixth surface 132 that is slightly larger than the projection of the third output coupling grating 136 . In other embodiments, the fifth light output area 133 may be a projected area of the third in-coupling grating 135 on the sixth surface 132 . The sixth light output area 134 may be a projected area of the third output coupling grating 136 on the sixth surface 132 .

The light from the light source 600 is diffracted by the first coupling grating 115 , is incident on the first transparent substrate 110 , and propagates in the first transparent substrate 110 . After the light is transmitted to the first light exit region 113 , due to the blocking effect of the first filter film 117 , the light 119 of the first wavelength band is filtered and cannot exit in the first light exit region 113 . The light 119 in the first wavelength band is transmitted to the first outcoupling grating 116 , diffracted by the first outcoupling grating 116 and exits in the second light out region 114 , and then reaches the observation position 500 . The light emitted from the first light emitting region 113 is diffracted by the second in-coupling grating 125 , enters the second transparent substrate 120 , and propagates in the second transparent substrate 120 . After the light is transmitted to the third light exit area 123 , due to the blocking effect of the second filter film 127 , the light 129 of the second wavelength band is filtered and cannot exit in the third light exit area 123 . The light 129 in the second wavelength band is transmitted to the second outcoupling grating 126 , diffracted by the second outcoupling grating 126 , exits in the fourth light out region 124 , and then reaches the observation position 500 . The light emitted from the third light output region 123 is diffracted by the third in-coupling grating 135 , enters the third transparent substrate 130 , and propagates in the third transparent substrate 130 . When the light 139 of the third wavelength band is transmitted to the third outcoupling grating 136 , it is diffracted by the third outcoupling grating 136 and exits in the sixth light out region 134 to reach the observation position 500 .

The light 119 of the first waveband is blue light, the light 129 of the second waveband is green light, and the light 139 of the third waveband is red light. Preferably, the first waveband is 400nm~470nm, the second waveband is 500nm~550nm, and the third waveband is 600nm~650nm.

FIG. 1 shows a partial enlargement 101 of the first filter film 117 . The first filter film 117 includes a multi-layer inorganic film. Preferably, the first filter film 117 is a multilayer dielectric film, which is alternately arranged with high refractive index dielectric films and low refractive index dielectric films, and the film stack structure is: (0.5HL0.5H) ^m . Wherein, 0.5H represents a high refractive index layer with a thickness of 1/8 wavelength, which can be ZrO ₂ , TiO ₂ , Nb ₂ O ₅ , ZnO, ZnS, etc. L represents a low refractive index layer with a thickness of 1/4 wavelength, which can be Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , SiON, Na ₃ AlF ₆ and so on. m represents the number of cycles. In this embodiment, H is TiO ₂ , L is SiO ₂ , and m is 7. The method of disposing the first filter film 117 in the first light exit region 113 is not limited, and may be thermal evaporation, electron gun evaporation, laser evaporation, sputtering, and the like.

Please refer to FIG. 2 , the first filter film 117 is a long-wave pass filter film, through which light with a wavelength greater than the reference wavelength can pass through, and light with a wavelength smaller than the reference wavelength cannot pass through. The light transmittance of the first filter film 117 is greater than 90% for light with a wavelength > 500nm; for light with a wavelength < 450nm, the light transmittance is less than 5%. Therefore, the light in the second waveband (500nm~550nm) and the third waveband (600nm~650nm) can pass through the first filter film 117 and has a light transmittance of over 90%. The light transmittance of the light in the first wavelength band (400nm~470nm) in the first filter film 117 is less than 30%. In particular, the transmittance of light with a wavelength of 400nm-450nm in the first filter film 117 is less than 5%. In particular, the light transmittance of light with a wavelength of 400 nm to 410 nm in the first filter film 117 is almost zero. It should be noted that, in the embodiment of the present application, the first filter film 117 is used to filter out the light 119 of the first wavelength band, which means that the light 119 of the first wave band passes through the first filter film. The transmittance in 117 is less than a specific value (for example, 30%), and does not refer to strict complete impermeability.

The second filter film 127 includes a multi-layer inorganic film. Preferably, the second filter film 127 is a multilayer dielectric film, which is alternately arranged with high refractive index dielectric films and low refractive index dielectric films, and the film stack structure is: (0.5HL0.5H) ⁷ . Wherein, 0.5H represents a high refractive index layer with a thickness of 1/8 wavelength, which can be ZrO ₂ , TiO ₂ , Nb ₂ O ₅ , ZnO, ZnS, etc. L represents a low refractive index layer with a thickness of 1/4 wavelength, which can be Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , SiON, Na ₃ AlF ₆ and so on. In this embodiment, H is ZnS, L is Na ₃ AlF ₆ , and 7 is the period number. The manner in which the second filter film 127 is disposed in the third light exit area 123 is not limited, and may be thermal evaporation, electron gun evaporation, laser evaporation, sputtering, and the like.

Please refer to FIG. 3 , the second filter film 127 is a long-wave pass filter film, through which light with a wavelength greater than the reference wavelength can pass through, and light with a wavelength smaller than the reference wavelength cannot pass through. The second filter film 127 has a light transmittance greater than 90% for light with a wavelength > 600nm; and a light transmittance of less than 5% for light with a wavelength < 550nm. Therefore, the light in the third wavelength band (600nm~650nm) can pass through the second filter film 127 and has a light transmittance of over 90%. The light transmittance of the light in the second wavelength band (500nm~550nm) in the second filter film 127 is less than 5%. The light transmittance of the light in the first wavelength band (400nm~470nm) in the first filter film 117 is less than 30%. In particular, the light transmittance of light with a wavelength of 420nm-500nm in the second filter film 127 is almost zero. It should be noted that, in the embodiment of the present application, the second filter film 127 is used to filter out the light 129 of the second wavelength band, which means that the light 129 of the second wave band passes through the second filter film. The transmittance in 127 is less than a specific value (eg, 5%), and does not mean strictly impermeable.

In this embodiment, the first filter film 117 reduces the blue light emitted from the first transparent substrate 110 , and reduces the interference of blue light on green light and red light. The second filter film 127 reduces the green light emitted from the second transparent substrate 120 and reduces the interference to the red light. The optical component 100 reduces the mutual interference among the three light colors and avoids the rainbow effect. Compared with organic polymer filters, the first filter film 117 and the second filter film 127 are multi-layer inorganic films with higher cracking temperature (cleavage temperature Td > 450°C) and slower cracking speed , more durable; by selecting the materials of the high-refractive-index dielectric film and the low-refractive-index dielectric film in the first filter film and/or the second filter film, the filter range can be changed, which is easier Adjust the filter light color; the spectral characteristics are steeper, and the light color is more pure.

Embodiment two

Referring to FIG. 4 , the present embodiment provides an optical assembly 200 . The optical assembly 200 includes a first transparent substrate 210 , a second transparent substrate 220 and a third transparent substrate 230 . The first light-transmitting substrate 210 includes a first surface 211 and a second surface 212 opposite to each other, and the second surface 212 includes a first light-emitting region 213 and a second light-emitting region 214 arranged at intervals. The second light-transmitting substrate 220 includes a third surface 221 and a fourth surface 222 opposite to each other, and the fourth surface 222 includes a third light-emitting region 223 and a fourth light-emitting region 224 arranged at intervals. The third light-transmitting substrate 230 includes a fifth surface 231 and a sixth surface 232 opposite to each other, and the sixth surface 232 includes a fifth light-emitting region 233 and a sixth light-emitting region 234 arranged at intervals.

The difference between the optical assembly 200 and the optical assembly 100 of Embodiment 1 is that the second light exit region 214 is provided with a third filter film 218 , and the fourth light exit region 224 is provided with a fourth filter film 228 . The third filter film 218 is used to filter out the light 229 of the second waveband and the light 239 of the third waveband, and the fourth filter film 228 is used to filter out the light 239 of the third waveband .

The light from the light source 600 is diffracted by the first coupling grating 215 , enters the first transparent substrate 210 , and propagates in the first transparent substrate 210 . After the light is transmitted to the first light exit region 213 , due to the blocking effect of the first filter film 217 , the light 219 of the first wavelength band is filtered out and cannot exit in the first light exit region 213 . The light 219 in the first wavelength band is transmitted to the first outcoupling grating 216 , diffracted by the first outcoupling grating 216 , exits in the second light out region 214 , and then reaches the observation position 500 . Due to the blocking effect of the third filter film 218 , only the light 219 of the first wavelength band exits from the second light exit region 214 . The light emitted from the first light exit region 213 is diffracted by the second in-coupling grating 225 , enters the second light-transmitting substrate 220 , and propagates in the second light-transmitting substrate 220 . After the light is transmitted to the third light exit region 223 , due to the blocking effect of the second filter film 227 , the light 229 of the second wavelength band is filtered and cannot exit in the third light exit region 223 . The light 229 of the second wavelength band is transmitted to the second outcoupling grating 226 , diffracted by the second outcoupling grating 226 and exits in the fourth light out region 224 , and then reaches the observation position 500 . Due to the blocking function of the fourth filter film 228 , only the light 219 of the first wavelength band and the light 229 of the second wavelength band are emitted from the fourth light output region 224 . The light emitted from the third light output region 223 is diffracted by the third coupling grating 235 , enters the third light-transmitting substrate 230 , and propagates in the third light-transmitting substrate 230 . When the light 239 of the third wavelength band is transmitted to the third outcoupling grating 236 , is diffracted by the third outcoupling grating 236 and exits in the sixth light out region 234 , and then reaches the observation position 500 .

The light 219 of the first waveband is blue light, the light 229 of the second waveband is green light, and the light 239 of the third waveband is red light. Preferably, the first waveband is 400nm~470nm, the second waveband is 500nm~550nm, and the third waveband is 600nm~650nm.

The third filter film 218 includes a multi-layer inorganic film. Preferably, the third filter film 218 is a multilayer dielectric film, which is alternately arranged with high refractive index dielectric films and low refractive index dielectric films, and the film stack structure is: 1.5 (0.5LH0.5L) ⁸ ×2.0(0.5LH0.5L) ⁸ ×(0.5HL0.5H) ⁸ . Wherein, 0.5L represents a low refractive index layer with a thickness of 1/8 wavelength, which may be Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , SiON, Na ₃ AlF ₆ and so on. H represents a high refractive index layer with a thickness of 1/4 wavelength, which can be ZrO ₂ , TiO ₂ , Nb ₂ O ₅ , ZnO, ZnS, etc. In this embodiment, L is Na ₃ AlF ₆ , H is TiO ₂ , 8 is the period number, and 1.5 and 2.0 are the modulation multiples. The manner in which the third filter film 218 is disposed in the second light emitting region 214 is not limited, and may be thermal evaporation, electron gun evaporation, laser evaporation, sputtering, and the like.

Please refer to FIG. 5 , the third filter film 218 is a band-pass filter film, through which light with a wavelength within a certain range can pass through, and light with a wavelength outside a certain range cannot pass through. The third filter film 218 has a transmittance of greater than 90% for light with a wavelength of 430nm-470nm, and a transmittance of less than 5% for light with a wavelength of <420nm and light with a wavelength of >500nm. Therefore, most of the light in the first wavelength band (400nm~470nm) can pass through the third filter film 218 and has a light transmittance of over 90%. The light transmittance of the light in the second waveband (500nm~550nm) and the light in the third waveband (600nm~650nm) in the third filter film 218 is close to zero. It should be noted that, in the embodiment of the present application, the third filter film 218 is used to filter out the light 229 of the second waveband and the light 239 of the third waveband, which refers to the light of the second waveband The transmittance of the light 229 and the light 239 of the third wavelength band in the third filter film 218 is less than a specific value (for example, 5%), which does not mean that it is completely impenetrable.

The fourth filter film 228 includes a multi-layer inorganic film. Preferably, the fourth filter film 228 is a multi-layer dielectric film, which is alternately arranged with high refractive index dielectric films and low refractive index dielectric films, and the film stack structure is: (0.5LH0.5L) ⁷ . Wherein, H represents a high refractive index layer with a thickness of 1/4 wavelength, which can be ZrO ₂ , TiO ₂ , Nb ₂ O ₅ , ZnO, ZnS, etc. 0.5L represents a low refractive index layer with a thickness of 1/8 wavelength, which can be Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , SiON, Na ₃ AlF ₆ and so on. In this embodiment, L is Na ₃ AlF ₆ , H is TiO ₂ , and 7 is the period number. The method of disposing the fourth filter film 228 in the fourth light emitting area 224 is not limited, and may be thermal evaporation, electron gun evaporation, laser evaporation, sputtering, and the like.

Please refer to FIG. 6 , the fourth filter film 228 is a short-pass filter film, through which light with a wavelength smaller than the reference wavelength can pass through, and light with a wavelength larger than the reference wavelength cannot pass through. The fourth filter film 228 has a transmittance of greater than 70% for light with a wavelength of <550nm; and a transmittance of less than 5% for light with a wavelength of >600nm. Therefore, the light of the first wavelength band (400nm~470nm) and the light of the second wavelength band (500nm~550nm) can pass through the fourth filter film 228 and have a light transmittance of more than 70%. The light transmittance of the light in the third wavelength band (600nm~650nm) in the fourth filter film 228 is close to zero. It should be noted that, in the embodiment of the present application, the fourth filter film 228 is used to filter out the light 239 of the third waveband, which means that the light 239 of the third waveband passes through the fourth filter film The transmittance in 228 is less than a specific value (eg, 5%), and does not mean strictly impermeable.

In this embodiment, the first filter film 217 reduces the blue light emitted from the first transparent substrate 210 and reduces the interference of blue light on green light and red light. The second filter film 227 reduces the green light emitted from the second transparent substrate 220 and reduces the interference to the red light. The third filter film 218 reduces the green light and the red light emitted from the first transparent substrate 210 , so that the color of the blue light is more pure. The fourth filter film 228 reduces the red light emitted from the second transparent substrate 220 to make the emitted green light more pure. The optical component 200 reduces the mutual interference among the three light colors, avoids the rainbow effect, increases the purity of each light color, and improves the imaging effect. In particular, when blue light with a wavelength of 450nm reaches the observation position of 500, the light transmittance reaches 92.5%; when the green light with a wavelength of 532nm reaches the observation position of 500, the light transmittance reaches 95.2%; 91.8%. Compared with the organic polymer filter, the first filter film 217, the second filter film 227, the third filter film 218 and the fourth filter film 228 are multilayer inorganic films with Higher cracking temperature (cracking temperature Td > 450°C), slower cracking speed, more durable; by selecting the first filter, the second filter, the third filter and the fourth filter The materials of high refractive index dielectric film and low refractive index dielectric film can change the filtering range, and it is easier to adjust the color of the filtered light; the spectral characteristics are steeper, and the color of the light is purer.

Embodiment three

Please refer to FIG. 7 , the present embodiment provides an optical assembly 300 including a first transparent substrate 310 , a second transparent substrate 320 and a third transparent substrate 330 . The first light-transmitting substrate 310 includes a first surface 311 and a second surface 312 opposite to each other, and the second surface 312 includes a first light-emitting region 313 and a second light-emitting region 314 arranged at intervals. A first in-coupling grating 315 and a first out-coupling grating 316 are disposed at intervals on the first surface 311 . The first light exit region 313 is provided with a first filter film 317 . The second light-transmitting substrate 320 includes a third surface 321 and a fourth surface 322 opposite to each other, and the fourth surface 322 includes a third light-emitting region 323 and a fourth light-emitting region 324 arranged at intervals. A second in-coupling grating 325 and a second out-coupling grating 326 are disposed at intervals on the third surface 321 . The third light emitting region 323 is provided with a second filter film 327 . The third light-transmitting substrate 330 includes a fifth surface 331 and a sixth surface 332 opposite to each other, and the sixth surface 332 includes a fifth light-emitting region 333 and a sixth light-emitting region 334 arranged at intervals. A third in-coupling grating 335 and a third out-coupling grating 336 are arranged at intervals on the fifth surface 331 .

The difference between the optical assembly 300 and the optical assembly 100 of the first embodiment is that, in the optical assembly 300 , the first filter film 317 and the second filter film 327 are short-wave pass filter films. The first filter film 317 is used to filter the light 319 of the first wavelength band, and the second filter film 327 is used to filter the light 329 of the second wave band. The light 319 of the first waveband is red light, the light 329 of the second waveband is green light, and the light 339 of the third waveband is blue light. Preferably, the first waveband is 600nm~650nm, the second waveband is 500nm~550nm, and the third waveband is 400nm~450nm.

The first filter film 317 includes a multi-layer inorganic film. Preferably, the first filter film 317 is a multilayer dielectric film, which is alternately arranged with high refractive index dielectric films and low refractive index dielectric films, and the film stack structure is: (0.5LH0.5L) ⁷ . Wherein, H represents a high refractive index layer with a thickness of 1/4 wavelength, which can be ZrO ₂ , TiO ₂ , Nb ₂ O ₅ , ZnO, ZnS, etc. 0.5L represents a low refractive index layer with a thickness of 1/8 wavelength, which can be Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , SiON, Na ₃ AlF ₆ and so on. In this embodiment, L is Na ₃ AlF ₆ , H is TiO ₂ , and 7 is the period number. The method of disposing the first filter film 317 in the first light emitting region 313 is not limited, and may be thermal evaporation, electron gun evaporation, laser evaporation, sputtering, and the like.

Please refer to FIG. 8 , the first filter film 317 has a transmittance greater than 70% for light with a wavelength of <550nm; and a transmittance of less than 5% for light with a wavelength of >600nm. Therefore, the light of the third wavelength band (400nm~470nm) and the light of the second wavelength band (500nm~550nm) can pass through the first filter film 317 and have a light transmittance of more than 70%. The transmittance of light in the first wavelength band (600nm~650nm) in the first filter film 317 is close to zero. It should be noted that, in the embodiment of the present application, the first filter film 317 is used to filter out the light 319 of the first wavelength band, which means that the light 319 of the first wave band passes through the first filter film The transmittance in 317 is less than a specific value (eg, 5%), and does not mean strictly impermeable.

The second filter film 327 includes a multi-layer inorganic film. Preferably, the second filter film 327 is a multilayer dielectric film, which is alternately arranged by high refractive index dielectric films and low refractive index dielectric films, and the film stack structure is: 1.25 (0.5LH0.5L) ⁷ (0.5LH0.5L) ⁷ . Wherein, H represents a high refractive index layer with a thickness of 1/4 wavelength, which can be ZrO ₂ , TiO ₂ , Nb ₂ O ₅ , ZnO, ZnS, etc. 0.5L represents a low refractive index layer with a thickness of 1/8 wavelength, which can be Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , SiON, Na ₃ AlF ₆ and so on. In this embodiment, L is Na ₃ AlF ₆ , H is TiO ₂ , 7 is the period number, and 1.25 is the modulation factor. The manner in which the second filter film 327 is disposed in the third light exit region 323 is not limited, and may be thermal evaporation, electron gun evaporation, laser evaporation, sputtering, and the like.

Please refer to FIG. 9 , the transmittance of the second filter film 327 is greater than 90% for light with a wavelength of <460nm, and less than 5% for light with a wavelength of >475nm. Therefore, most of the light in the third wavelength band (400nm~470nm) can pass through the second filter film 327 and has a light transmittance of over 90%. The light transmittance of the light in the first waveband (600nm~650nm) and the light in the second waveband (500nm~550nm) in the second filter film 327 is close to zero. It should be noted that, in the embodiment of the present application, the second filter film 327 is used to filter out the light 329 of the second wavelength band, which means that the light 329 of the second wave band passes through the second filter film The transmittance in 327 is less than a specific value (eg, 5%), and does not mean strictly impermeable.

In this embodiment, the first filter film 317 reduces the red light emitted from the first transparent substrate 310 and reduces the interference of red light on green light and blue light. The second filter film 327 reduces the green light emitted from the second transparent substrate 320 and reduces the interference to the blue light. The optical assembly 300 reduces the mutual interference among the three light colors and avoids the rainbow effect. Compared with organic polymer filters, the first filter film 317 and the second filter film 327 are multi-layer inorganic films with higher cracking temperature (cleavage temperature Td > 450°C) and slower cracking speed , more durable; by selecting the materials of the high-refractive-index dielectric film and the low-refractive-index dielectric film in the first filter film and/or the second filter film, the filter range can be changed, which is easier Adjust the filter light color; the spectral characteristics are steeper, and the light color is more pure.

Embodiment Four

Referring to FIG. 10 , the present embodiment provides an optical assembly 400 , and the optical assembly 400 includes a first transparent substrate 410 , a second transparent substrate 420 and a third transparent substrate 430 . The first light-transmitting substrate 410 includes a first surface 411 and a second surface 412 opposite to each other, and the second surface 412 includes a first light-emitting region 413 and a second light-emitting region 414 arranged at intervals. The second light-transmitting substrate 420 includes a third surface 421 and a fourth surface 422 opposite to each other, and the fourth surface 422 includes a third light-emitting region 423 and a fourth light-emitting region 424 arranged at intervals. The third light-transmitting substrate 430 includes a fifth surface 431 and a sixth surface 432 opposite to each other, and the sixth surface 432 includes a fifth light-emitting region 433 and a sixth light-emitting region 434 arranged at intervals.

The difference between the optical assembly 400 and the optical assembly 300 of the third embodiment is that the second light exit region 414 is provided with a third filter film 418 , and the fourth light exit region 424 is provided with a fourth filter film 428 . The third filter film 418 is used to filter out the light 429 of the second waveband and the light 439 of the third waveband, and the fourth filter film 428 is used to filter out the light 439 of the third waveband .

The light from the light source 600 is diffracted by the first coupling grating 415 , enters the first transparent substrate 410 , and propagates in the first transparent substrate 410 . After the light is transmitted to the first light exit region 413 , due to the blocking effect of the first filter film 417 , the light 419 of the first wavelength band is filtered and cannot exit in the first light exit region 413 . The light 419 in the first wavelength band is transmitted to the first outcoupling grating 416 , diffracted by the first outcoupling grating 416 , exits in the second light out region 414 , and then reaches the observation position 500 . Due to the blocking effect of the third filter film 418 , only the light 419 of the first wavelength band exits from the second light exit area 414 . The light emitted from the first light exit region 413 is diffracted by the second in-coupling grating 425 , enters the second light-transmitting substrate 420 , and propagates in the second light-transmitting substrate 420 . After the light is transmitted to the third light exit region 423 , due to the blocking effect of the second filter film 427 , the light 429 of the second wavelength band is filtered and cannot exit in the third light exit region 423 . The light 229 in the second wavelength band is transmitted to the second outcoupling grating 426 , diffracted by the second outcoupling grating 426 and exits in the fourth light out region 424 , and then reaches the observation position 500 . Due to the blocking effect of the fourth filter film 428 , only the light 419 of the first wavelength band and the light 429 of the second wavelength band are emitted from the fourth light output region 424 . The light emitted from the third light emitting area 423 is diffracted by the third in-coupling grating 435 , enters the third light-transmitting substrate 430 , and propagates in the third light-transmitting substrate 430 . When the light 439 of the third wavelength band is transmitted to the third outcoupling grating 436 , is diffracted by the third outcoupling grating 436 and exits in the sixth light out region 434 , and then reaches the observation position 500 .

The light 419 of the first waveband is red light, the light 429 of the second waveband is green light, and the light 439 of the third waveband is blue light. Preferably, the first waveband is 600nm~650nm, the second waveband is 500nm~550nm, and the third waveband is 400nm~450nm.

The third filter film 418 includes a multi-layer inorganic film. Preferably, the third filter film 418 is a multilayer dielectric film, which is alternately arranged by high refractive index dielectric films and low refractive index dielectric films, and the film stack structure is: 1.5 (0.5LH0.5L) ⁸ ×2.3(0.5LH0.5L) ⁸ ×(0.5HL0.5H) ⁸ . Wherein, 0.5L represents a low refractive index layer with a thickness of 1/8 wavelength, which may be Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , SiON, Na ₃ AlF ₆ and so on. H represents a high refractive index layer with a thickness of 1/4 wavelength, which can be ZrO ₂ , TiO ₂ , Nb ₂ O ₅ , ZnO, ZnS, etc. In this embodiment, L is Na ₃ AlF ₆ , H is TiO ₂ , 8 is the period number, and 1.5 and 2.3 are modulation multiples. The manner in which the third filter film 418 is disposed on the second light emitting area 414 is not limited, and may be thermal evaporation, electron gun evaporation, laser evaporation, sputtering, and the like.

Please refer to FIG. 11 , the third filter film 418 is a band-pass filter film, through which light with a wavelength within a certain range can pass through, and light with a wavelength outside a certain range cannot pass through. The third filter film 418 has a transmittance greater than 90% for light with a wavelength of 605nm-640nm, and a transmittance of less than 5% for light with a wavelength <580nm and light with a wavelength >680nm. Therefore, most of the light in the first wavelength band (600nm~650nm) can pass through the third filter film 418 and has a light transmittance of over 90%. The light transmittance of the light in the second waveband (500nm~550nm) and the light in the third waveband (400nm~450nm) in the third filter film 418 is close to zero. It should be noted that, in the embodiment of the present application, the third filter film 418 is used to filter out the light 429 of the second waveband and the light 439 of the third waveband, which refers to the light of the second waveband The transmittance of 429 and the light 439 of the third wavelength band in the third filter film 418 is less than a specific value (eg, 5%), which does not mean that it is strictly not transmitted at all.

The fourth filter film 428 includes a multi-layer inorganic film. Preferably, the fourth filter film 428 is a multilayer dielectric film, which is alternately arranged with high refractive index dielectric films and low refractive index dielectric films, and the film stack structure is: (0.5HL0.5H) ⁷ . Wherein, 0.5H represents a high refractive index layer with a thickness of 1/8 wavelength, which can be ZrO ₂ , TiO ₂ , Nb ₂ O ₅ , ZnO, ZnS, etc. L represents a low refractive index layer with a thickness of 1/4 wavelength, which can be Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , SiON, Na ₃ AlF ₆ and so on. In this embodiment, H is TiO ₂ , L is SiO ₂ , and 7 is the period number. The method of disposing the fourth filter film 428 in the fourth light output area 424 is not limited, and may be thermal evaporation, electron gun evaporation, laser evaporation, sputtering, and the like.

Please refer to FIG. 12 , the fourth filter film 428 is a long-wave pass filter film, through which light with a wavelength greater than the reference wavelength can pass through, and light with a wavelength smaller than the reference wavelength cannot pass through. The fourth filter film 428 has a light transmittance greater than 90% for light with a wavelength > 500nm; and a light transmittance of less than 5% for light with a wavelength < 450nm. Therefore, the light in the second waveband (500nm~550nm) and the first waveband (600nm~650nm) can pass through the fourth filter film 428 and has a light transmittance of over 90%. The light transmittance of the light in the third wavelength band (400nm~470nm) in the fourth filter film 428 is less than 30%. In particular, the light transmittance of light with a wavelength of 400nm-450nm in the fourth filter film 428 is less than 5%. It should be noted that, in the embodiment of the present application, the fourth filter film 428 is used to filter out the light 439 of the third wavelength band, which means that the light 439 of the third wave band passes through the fourth filter film. The transmittance in 428 is less than a specific value (for example, 30%), and does not mean strictly impermeable.

In this embodiment, the first filter film 417 reduces the red light emitted from the first transparent substrate 410 and reduces the interference of red light on green light and blue light. The second filter film 427 reduces the green light emitted from the second transparent substrate 420 and reduces the interference to the blue light. The third filter film 418 reduces the green light and blue light emitted from the first transparent substrate 410 , so that the color of the red light is more pure. The fourth filter film 428 reduces the blue light emitted from the second transparent substrate 420 , making the emitted green light more pure. The optical component 400 reduces the mutual interference among the three light colors, avoids the rainbow effect, increases the purity of each light color, and improves the imaging effect. In particular, when the blue light with a wavelength of 450nm reaches the observation position of 500, the light transmittance reaches 88.9%; when the green light with a wavelength of 532nm reaches the observation position of 500, the light transmittance reaches 95.2%; 92.5%. Compared with the organic polymer filter, the first filter film 417, the second filter film 427, the third filter film 418 and the fourth filter film 428 are multilayer inorganic films with Higher cracking temperature (cracking temperature Td > 450°C), slower cracking speed, more durable; by selecting the first filter, the second filter, the third filter and the fourth filter The materials of high refractive index dielectric film and low refractive index dielectric film can change the filtering range, and it is easier to adjust the color of the filtered light; the spectral characteristics are steeper, and the color of the light is purer.

Other modifications

The first to fourth embodiments described above are described by taking the optical assembly including three laminated light-transmitting substrates as an example. In other modification examples, the number of light-transmitting substrates in the optical assembly may be one, two or more than three. For example, in other modified examples, the number of light-transmitting substrates is one, and the optical assembly may only include the first light-transmitting substrate 110 in FIG. 115 , the first outcoupling grating 116 , and the first filter film 117 on the second surface 112 . The light 119 of the first wavelength band incident on the first light-transmitting substrate 110 from the first coupling grating 115 is transmitted to the first filter film 117 and then filtered out so that it cannot exit in the first light-exit region 113 . The light 119 of the first wavelength band is transmitted to the first outcoupling grating 116 , diffracted by the first outcoupling grating 116 , exits in the second light out region 114 , and directly enters the observation position.

In yet another modified example, the number of light-transmitting substrates is two, and the optical components include the first light-transmitting substrate 110 in FIG. The first outcoupling grating 116 and the first filter film 117 on the second surface 112 . The optical assembly further includes the third light-transmitting substrate 130 in FIG. 1 , a third in-coupling grating 135 and a third out-coupling grating 136 located on the fifth surface 131 of the third light-transmitting substrate 130 . The light emitted from the first filter film 117 enters the third light-transmitting substrate 130 through the third coupling grating 135, propagates to the third output grating 136, and reaches the observation position 500 after exiting the sixth light exit region 134. The light emitted from the light exit region 114 passes through the third outcoupling grating 136 and the third light-transmitting substrate 130 , and then reaches the observation position 500 after exiting from the sixth light exit region 134 .

Please refer to FIG. 13 , an embodiment of the present application provides a display device 700, including a light source 600, and the aforementioned optical assembly 100 (200, 300, 400), the light source 600 is arranged on the optical assembly 100 (200 , 300 , 400 ), the light emitted by the light source 600 reaches the observation position 500 after passing through the optical assembly 100 . Wherein, in the display device 700 , the optical components 100 ( 200 , 300 , 400 ) can also be replaced with optical components of other modified examples.

The display device 700 improves the color purity of the outgoing light and improves the color uniformity of the observation position; the light transmittance is higher, and the average light transmittance reaches more than 95%; it has wider applicability in the field of AR/VR, and the light source 600 can be Light sources for which organic polymer filters are not suitable, such as micro light emitting diode light sources, micro organic light emitting diode light sources and quantum dot light emitting diodes. The light source 600 can also be a display device for which an organic polymer filter is not suitable, such as a digital light processing projector or a silicon-based liquid crystal display panel. The display device 700 can be applied to wearable devices, such as VR glasses and AR glasses.

The above embodiments are only used to illustrate the technical solutions of the present application without limitation. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced. Without departing from the spirit and scope of the technical solution of the present application.

100, 200, 300, 400: Optical components 110, 210, 310, 410: the first transparent substrate 120, 220, 320, 420: the second transparent substrate 130, 230, 330, 430: the third transparent substrate 111, 211, 311, 411: the first surface 112, 212, 312, 412: second surface 113, 213, 313, 413: the first light exit area 114, 214, 314, 414: the second light exit area 115, 215, 315, 415: the first coupling-in grating 116, 216, 316, 416: the first outcoupling grating 117, 217, 317, 417: the first filter film 121, 221, 321, 421: the third surface 122, 222, 322, 422: the fourth surface 123, 223, 323, 423: the third light exit area 124, 224, 324, 424: the fourth light output area 125, 225, 325, 425: the second coupling grating 126, 226, 326, 426: the second outcoupling grating 127, 227, 327, 427: the second filter film 131, 231, 331, 431: the fifth surface 132, 232, 332, 432: the sixth surface 133, 233, 333, 433: the fifth light output area 134, 234, 334, 434: the sixth light exit area 135, 235, 335, 435: the third coupling grating 136, 236, 336, 436: the third outcoupling grating 218, 418: the third filter film 228, 428: the fourth filter film 119, 219, 319, 419: light in the first band 129, 229, 329, 429: light in the second waveband 139, 239, 339, 439: light in the third waveband 101: Partial zoom-in 500: Observation position 600: light source 700: display device L: low refractive index layer H: high refractive index layer m: number of cycles

FIG. 1 is a schematic structural diagram of an optical component according to Embodiment 1 of the present application.

FIG. 2 is a characteristic diagram of light transmittance of the first filter film according to Embodiment 1 of the present application.

FIG. 3 is a characteristic diagram of light transmittance of a second filter film according to Embodiment 1 of the present application.

FIG. 4 is a schematic structural diagram of an optical assembly according to Embodiment 2 of the present application.

FIG. 5 is a characteristic diagram of light transmittance of the third filter film according to the second embodiment of the present application.

FIG. 6 is a characteristic diagram of light transmittance of the fourth filter film according to the second embodiment of the present application.

FIG. 7 is a schematic structural diagram of an optical assembly according to Embodiment 3 of the present application.

FIG. 8 is a characteristic diagram of light transmittance of the first filter film according to the third embodiment of the present application.

FIG. 9 is a characteristic diagram of light transmittance of the second filter film according to the third embodiment of the present application.

FIG. 10 is a schematic structural diagram of an optical assembly according to Embodiment 4 of the present application.

FIG. 11 is a characteristic diagram of light transmittance of the third filter film according to the fourth embodiment of the present application.

FIG. 12 is a characteristic diagram of light transmittance of a fourth filter film according to Embodiment 4 of the present application.

FIG. 13 is a schematic structural diagram of a display device according to an embodiment of the present application.

100: Optical components

110: the first transparent substrate

120: the second transparent substrate

130: the third transparent substrate

111: first surface

112: second surface

113: The first light exit area

114: Second light exit area

115: The first coupling into the grating

116: The first outcoupling grating

117: The first filter film

121: third surface

122: The fourth surface

139: Light in the third waveband

101: Partial zoom-in

500: Observation position

123: The third light exit area

124: The fourth light output area

125: The second coupling grating

126: The second outcoupling grating

127: Second filter film

131: fifth surface

132: sixth surface

133: Fifth light area

134: The sixth light area

135: The third coupling grating

136: The third outcoupling grating

119: Light in the first band

129: Light in the second band

600: light source

L: low refractive index layer

H: high refractive index layer

m: number of cycles

Claims (15)

An optical assembly, the improvement of which comprises: The first light-transmitting substrate is used to transmit the light of the first wavelength band; the first light-transmitting substrate includes opposite first surfaces and second surfaces, and the second surface includes first light-emitting regions and second light-emitting regions arranged at intervals district; The first in-coupling grating and the first out-coupling grating are arranged at intervals on the first surface, and the projection of the first in-coupling grating on the first light-transmitting substrate falls into the first light-out region, and The projection of the first outcoupling grating on the first light-transmitting substrate falls into the second light-out region; The first filter film is arranged in the first light exit area, the first filter film includes a multi-layer inorganic film, and the first filter film is used to filter out the light in the first wavelength band; Wherein, the light of the first wavelength band incident on the first light-transmitting substrate from the first coupling grating is filtered out after being transmitted to the first filter film, so that it cannot enter the first light-exit area. After being transmitted to the first outcoupling grating, it is diffracted by the first outcoupling grating and emerges in the second light out region. The optical assembly according to claim 1, wherein the optical assembly further comprises: The second light-transmitting substrate is used to transmit the light of the second waveband, and the second waveband does not overlap with the first waveband; the second light-transmitting substrate includes a third surface and a fourth surface opposite to each other, and the first waveband does not overlap with the first waveband; The four surfaces include a third light output area and a fourth light output area arranged at intervals; The second in-coupling grating and the second out-coupling grating are arranged at intervals on the third surface, the projection of the second in-coupling grating on the second light-transmitting substrate falls into the third light-out area, and the The projection of the second outcoupling grating on the second light-transmitting substrate falls into the fourth light-out region; The second filter film is arranged in the third light exit area, the second filter film includes a multi-layer inorganic film, and the second filter film is used to filter out the light in the second wavelength band; Wherein, the light emitted from the first light exit region is incident on the light of the second wavelength band of the second light-transmitting substrate through the second in-coupling grating, and is filtered after being transmitted to the second filter film. In addition to being unable to exit in the third light exit area, it is transmitted to the second outcoupling grating, diffracted by the second outcoupling grating, and exits in the fourth light exit area. The optical assembly according to claim 2, wherein the optical assembly further comprises: A third light-transmitting substrate, the third light-transmitting substrate is used to transmit light in a third waveband, the third waveband does not overlap with the first waveband, and the third waveband does not overlap with the second waveband; The third light-transmitting substrate includes opposite fifth and sixth surfaces, and the sixth surface includes fifth and sixth light-emitting regions arranged at intervals; The third in-coupling grating and the third out-coupling grating are arranged at intervals on the fifth surface, the projection of the third in-coupling grating on the third light-transmitting substrate falls into the fifth light-out area, and the The projection of the third outcoupling grating on the third light-transmitting substrate falls into the sixth light-out region; Wherein, the light exiting from the third light output region passes through the third in-coupling grating and enters the light in the third wavelength band of the third light-transmitting substrate, and after being transmitted to the third out-coupling grating, passes through the The third outcoupling grating diffracts and emits in the sixth light out region. The optical assembly according to claim 2 or 3, wherein the optical assembly further comprises: The third filter film is arranged in the second light exit area of the first light-transmitting substrate, the third filter film includes a multi-layer inorganic film, and the third filter film is used to filter out the second the light of the wavelength band and the light of the third wavelength band; The fourth filter film is arranged in the fourth light exit region of the second light-transmitting substrate, the fourth filter film includes a multi-layer inorganic film, and the fourth filter film is used to filter out the third bands of light. The optical assembly according to claim 4, wherein the first filter film and the second filter film are long-wave pass filter films, the third filter film is a band-pass filter film, and the The fourth filter film is a short-wave pass filter film. The optical assembly according to claim 5, wherein the first filter film allows light with a wavelength > 500 nm to pass through, the second filter film allows light with a wavelength > 600 nm to pass through, and the third filter film allows light with a wavelength > 600 nm to pass through. Light with a wavelength of 440nm to 460nm passes through, and the fourth filter film allows light with a wavelength of <550nm to pass through. The optical assembly according to claim 4, wherein the first filter film and the second filter film are short-wave pass filter films, the third filter film is a band-pass filter film, and the The fourth filter film is a long-wave pass filter film. The optical assembly according to claim 7, wherein the first filter film allows light with a wavelength <550nm to pass through, the second filter film allows light with a wavelength <450nm to pass through, and the third filter film allows Light with a wavelength of 600nm to 640nm passes through, and the fourth filter film allows light with a wavelength >500nm to pass through. The optical component according to claim 4, wherein, the third filter film and the fourth filter film are multilayer dielectric films, and the multilayer dielectric films are composed of a high refractive index dielectric film and a Low refractive index dielectric films are arranged alternately, and the dielectric films are non-metal oxides or metal oxides. The optical component according to claim 9, wherein the multilayer dielectric film forms stacked symmetrical film layers by means of coating, and the coating mode is thermal evaporation, electron gun evaporation, laser evaporation, or sputtering . The optical component according to claim 2, wherein the second filter film is a multi-layer dielectric film, and the multi-layer dielectric film consists of high refractive index dielectric films and low refractive index dielectric films alternately It is provided that the dielectric film is a non-metal oxide or a metal oxide. The optical component according to claim 11, wherein the multilayer dielectric film forms a stacked symmetrical film layer by coating, and the coating method is thermal evaporation, electron gun evaporation, laser evaporation, or sputtering . The optical component according to claim 1, wherein the first filter film is a multilayer dielectric film, and the multilayer dielectric film is composed of high refractive index dielectric films and low refractive index dielectric films alternately It is provided that the dielectric film is a non-metal oxide or a metal oxide. The optical component according to claim 13, wherein the multilayer dielectric film forms stacked symmetrical film layers by means of coating, and the coating mode is thermal evaporation, or electron gun evaporation, or laser evaporation, or sputtering . A display device, which is improved in that it includes a light source, and the optical assembly described in any one of claims 1 to 14, the light source is arranged on one side of the optical assembly, and the light emitted by the light source passes through the optical assembly After reaching the observation position.

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