Optical system and projection apparatus

Abstract

An optical system (100) and a projection apparatus (1). The optical system (100) comprises: a black-and-white liquid crystal panel (110), which has a first region (112) and a second region (114) adjacent to each other; a first-color light source (120) and a second-color light source (130), which emit light toward the first region (112); a third-color light-emitting member (140), which emits light toward the second region (114); and a light-combining assembly (150), which is used for combining the light emitted by the first-color light source (120), the second-color light source (130) and the third-color light-emitting member (140) and then sending same into a projection lens (200).

Description

Optical system and projection device

[0001] This application claims priority to Chinese patent application filed on January 15, 2024, with application number 202410058405.4 and application name “Optical system and projection device,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application belongs to the technical field of projection devices, and in particular relates to an optical system and a projection device. Background Art

[0003] Existing projection devices mainly include LCD (Liquid-Crystal Display) and DLP (Digital Light Processing) technology routes. DLP technology is relatively expensive, and although LCD projection is low in cost, its brightness and color gamut are inferior to DLP solutions. Technical issues

[0004] How to improve the light efficiency of projection devices has become an urgent problem to be solved. Technical Solutions

[0005] The embodiments of the present application provide an optical system and a projection device, which can improve the light efficiency of the projection device and reduce the impact of heat caused by waste of light energy on liquid crystal performance.

[0006] In a first aspect, an embodiment of the present application provides an optical system applied to a projection device, wherein the projection device includes a projection lens, and the optical system includes:

[0007] A black and white liquid crystal panel having a first area and a second area adjacent to each other;

[0008] A first color light source and a second color light source are both located on one side of the black and white liquid crystal panel and emit light toward the first area;

[0009] a third color light emitting element, located on the same side of the black and white liquid crystal panel as the first color light source and the second color light source, and emitting light toward the second area;

[0010] The light combining component is arranged on the side of the black and white liquid crystal panel away from the third color light emitting element. The light combining component is used to combine the light emitted by the first color light source, the second color light source and the third color light emitting element and then send the combined light into the projection lens.

[0011] Optionally, the first color light source and the second color light source emit light in a time-sharing manner.

[0012] Optionally, the light emission interval between the first color light source and the second color light source is 1 / 120 second.

[0013] Optionally, the light combining component includes:

[0014] A polarizing beam splitter is provided on a side of the black-and-white liquid crystal panel facing away from the third-color light-emitting element. The polarizing beam splitter is used to transmit the first-color light emitted by the first-color light source and the second-color light emitted by the second-color light source toward the projection lens, and reflect the third-color light emitted by the third-color light-emitting element, and combine the first-color light, the second-color light, and the third-color light and send them into the projection lens.

[0015] Optionally, the angle between the polarization beam splitter and the black and white liquid crystal panel is 45°.

[0016] Optionally, the light combining component further includes:

[0017] The first reflector is arranged on a side of the black and white liquid crystal panel away from the third color light emitting element, and is used for reflecting the first color light and the second color light to the polarization beam splitter.

[0018] Optionally, the angle between the first reflector and the black and white liquid crystal panel is 45°.

[0019] Optionally, the reflective surface of the first reflector is respectively arranged to correspond to the first color light source, the second color light source and the polarization beam splitter.

[0020] Optionally, the light combining component further includes:

[0021] The second reflector is arranged on a side of the polarization beam splitter away from the black and white liquid crystal panel, and is used for reflecting the third color light.

[0022] Optionally, the angle between the second reflector and the polarization beam splitter is 45°.

[0023] Optionally, the light combining component further includes:

[0024] A wave plate is arranged between the polarization beam splitter and the second reflector, and is used to change the third color light into linearly polarized light.

[0025] Optionally, the wave plate is attached to the polarization beam splitter.

[0026] Optionally, the wave plate is attached to the second reflector.

[0027] Optionally, the first color light, the second color light and the third color light have a first optical path, a second optical path and a third optical path respectively from the black and white liquid crystal panel to the projection lens, and the first optical path, the second optical path and the third optical path are equal.

[0028] Optionally, the light combining component further includes:

[0029] a first reflector, disposed on a side of the black-and-white liquid crystal panel away from the third-color light-emitting element, the first reflector being configured to reflect the first-color light and the second-color light to the polarization beam splitter;

[0030] A second reflector is provided on a side of the polarization beam splitter away from the black and white liquid crystal panel, the second reflector being used to reflect the third color light; and

[0031] A wave plate is arranged between the polarization beam splitter and the second reflector, and is used to change the third color light into linearly polarized light.

[0032] Optionally, the optical system further includes:

[0033] A light-shielding partition is provided on one side of the black-and-white liquid crystal panel and is used to separate the first color light source and the second color light source from the third color light-emitting element.

[0034] Optionally, the optical system further includes:

[0035] A black matrix is ​​disposed in the black and white liquid crystal panel to separate the black and white liquid crystal panel into the first area and the second area.

[0036] Optionally, the optical system includes a first color light-emitting element and a second color light-emitting element, and the first color light-emitting element and the second color light-emitting element are used to provide the first color light source and the second color light source, respectively.

[0037] Optionally, the optical system further includes a light splitting component, wherein the light splitting component and the third color light emitting element are arranged on the same side of the black and white liquid crystal panel, and the light splitting component includes:

[0038] a fourth color light emitting element, configured to provide a fourth color light source;

[0039] The color wheel is arranged between the fourth color light emitting element and the black and white liquid crystal panel to divide the fourth color light source into the first color light source and the second color light source.

[0040] In a second aspect, an embodiment of the present application further provides a projection device, comprising:

[0041] An optical system as described in any one of the above items;

[0042] The projection lens is used to receive the light emitted by the optical system. Beneficial effects

[0043] In the optical system and projection device of the embodiments of the present application, by dividing the light source into two areas, on the one hand, the difficulty of combining light can be reduced, and on the other hand, the projection light path can be realized in conjunction with the black and white liquid crystal panel and the light combining component, and the color filter in the color liquid crystal panel in the existing projection device can be eliminated, thereby improving the utilization efficiency of light energy and reducing the impact of heat caused by waste of light energy on liquid crystal performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0045] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings. In the following description, the same reference numerals represent the same parts.

[0046] FIG1 is a schematic structural diagram of a projection device provided in an embodiment of the present application.

[0047] FIG2 is a schematic diagram of the first structure of the optical system provided in an embodiment of the present application.

[0048] FIG3 is a schematic diagram of a second structure of an optical system provided in an embodiment of the present application.

[0049] FIG4 is a schematic diagram of the structure of the color wheel provided in an embodiment of the present application.

[0050] FIG5 is a schematic diagram of a third structure of an optical system provided in an embodiment of the present application.

[0051] FIG6 is a schematic diagram of the fourth structure of the optical system provided in an embodiment of the present application.

[0052] FIG7 is a fifth structural schematic diagram of the optical system provided in an embodiment of the present application. Modes for Carrying Out the Invention

[0053] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0054] Please refer to Figure 1, which is a schematic diagram of the structure of the projection device provided in an embodiment of the present application. The embodiment of the present application provides a projection device 1, which can be a projector, or a projector, which is a device that can project an image or video onto a screen. The projection device 1 can also be a head-up display system (HUD) in a car, or a head-up display system, which refers to a blind-operated, multi-functional instrument panel centered on the vehicle driver. The function of the head-up display system is to project important driving information such as speed and navigation onto the windshield in front of the driver, so that the driver can see important driving information such as speed and navigation without lowering or turning his head as much as possible.

[0055] Depending on their operating methods, projection devices come in different types, including CRT (Cathode Ray Tube), LCD, DLP, and 3LCD. DLP technology is relatively expensive, and its core components are monopolized by developers. While LCD projection is low-cost, its brightness and color gamut are inferior to DLP solutions. This is because traditional LCD solutions require the addition of color filters. Color filters are typically absorptive, allowing specific wavelengths to pass through while absorbing light from other wavelengths. The absorbed light energy is converted into heat, causing the liquid crystal temperature to overheat, which can also affect liquid crystal performance. Therefore, improving the light efficiency of LCD-type projection devices has become a pressing issue.

[0056] In order to alleviate the above problems, the embodiment of the present application improves the optical system in the projection device 1, which will be described below with reference to the accompanying drawings.

[0057] The optical system 100 can be applied to the projection device 1, but the optical system 100 is not limited to being applied to the projection device 1. For example, it can also be applied to lighting equipment or other display devices. The embodiment of the present application is described by taking the application of the optical system 100 in the projection device 1 as an example, and should not be understood as a limitation on the projection device 1.

[0058] Exemplarily, the projection device 1 includes an optical system 100 and a projection lens 200. The optical system 100 is used to provide a modulated light source and input it into the projection lens 200. The projection lens 200 is the last link in the entire optical path and determines the core parameters of the projection device 1, such as image color, brightness, and focus clarity. In other words, it is the device that projects the image onto the screen.

[0059] It should be noted that the projection lens 200 may also be a component of the optical system 100 . For ease of description, the projection lens 200 is distinguished from the optical system 100 , which should not be construed as a limitation on the projection lens 200 and the optical system 100 .

[0060] For example, referring to FIG1 and FIG2 , FIG2 is a schematic diagram of a first structural embodiment of an optical system provided by an embodiment of the present application. Optical system 100 includes a black and white liquid crystal panel 110, a first color light source 120, a second color light source 130, a third color light emitting element 140, and a light combining assembly 150.

[0061] The black-and-white LCD panel 110 typically uses TN (Twist Nematic) liquid crystal. The operating principle of the black-and-white LCD panel 110 is as follows: Nematic liquid crystal is sandwiched between two sheets of glass. A transparent conductive film, ITO (Indium Tin Oxide), is first coated on the surface of the glass to serve as an electrode. Then, an alignment layer, PI (Polyimide), is applied to the glass with the thin-film electrodes to align the liquid crystal in a specific direction parallel to the glass surfaces. Liquid crystal naturally has a 90-degree twist. An electric field can rotate the liquid crystal molecules, causing the birefringence of the liquid crystal to change with the orientation of the liquid crystal. This results in a rotation of the polarization direction of polarized light after passing through the TN liquid crystal. By selecting the appropriate thickness to precisely shift the polarization direction of the polarized light by 90 degrees, two parallel polarizers can be used to completely block the light from passing through. A sufficiently high voltage can also align the liquid crystals parallel to the electric field, preventing the polarization direction of the light from changing, allowing it to pass through the second polarizer. This allows the brightness of the light to be controlled.

[0062] Exemplarily, the black and white liquid crystal panel 110 has adjacent first and second regions 112 and 114 for different light sources to pass through.

[0063] The first color light source 120 and the second color light source 130 are both located on one side of the black and white liquid crystal panel 110 and emit light toward the first area 112 , that is, they can emit first color light and second color light toward the first area 112 .

[0064] The third color light emitting element 140 is located on the same side of the black and white liquid crystal panel 110 as the first color light source 120 and the second color light source 130, and emits light toward the second area 114. The third color light emitting element 140 is used to emit a third color of light. The third color light emitting element 140 is also a third color light source, or a light emitting diode that can emit a third color of light. The first color, the second color, and the third color can be green, blue, and red, respectively, or the first color, the second color, and the third color can be red, green, and blue, respectively, or the first color, the second color, and the third color can be red, blue, and green, respectively. This is not specifically limited here. The first color light source 120 and the second color light source 130 in the first area 112 can be any combination of two of the three colors. The mixing of the first color light, the second color light, and the third color light can produce different grayscales, thereby showing different display effects. Setting the light source in two areas can reduce the setting of the light combining components and reduce the difficulty of light combining compared to setting the light source in three areas.

[0065] The light combining component 150 is arranged on the side of the black and white liquid crystal panel 110 away from the third color light emitting element 140. The light combining component 150 is used to combine the light emitted by the first color light source 120, the second color light source 130 and the third color light emitting element 140 and send them into the projection lens 200, in the optical path display process of the projection device 1.

[0066] In the optical system 100 provided in the embodiment of the present application, by dividing the light source into two areas, on the one hand, the difficulty of light combining can be reduced, and on the other hand, the projection light path can be realized in conjunction with the black and white liquid crystal panel 110 and the light combining component 150, thereby eliminating the color filter in the color liquid crystal panel in the existing projection device, thereby improving the utilization efficiency of light energy and reducing the impact of heat caused by waste of light energy on liquid crystal performance.

[0067] Among them, the three groups of polarized light, namely the first color light, the second color light and the third color light, have the same polarization state. The three groups of light are incident from the first area 112 and the second area 114. A polarizer is also provided on the side of the black and white liquid crystal panel 110 away from the first color light source 120 and the second color light source 130, so that the modulation of the three groups of polarized light can be achieved.

[0068] It should be noted that the three-color light source, three-zone, simultaneous driving method often faces problems such as insufficient response time of the black and white LCD panel and insufficient refresh rate. Taking a projection device with a refresh rate of 60Hz as an example, using a sequential method, the refresh rate of the black and white LCD panel must reach 180Hz to ensure the three-color light source can display in a timely manner. In other words, the response period of the black and white LCD panel must reach 5.55ms. However, black and white LCD panels cannot meet such a fast response time and are prone to crosstalk and other problems.

[0069] To address the aforementioned issues, the present embodiment of the present invention time-shares the first and second color light sources 120, 130 located in the same area, namely, the first area 112, for illumination. In other words, the first and second color light sources 120, 130 are illuminated in a timed sequence. As for the third color light source in the second area 114, since there is no interference, the third color light emitting element 140 can simply remain constantly illuminated. Therefore, for a projection device 1 with a refresh rate of 60 Hz and time-shared operation of the two color light sources, the refresh rate of the black-and-white LCD panel 110 needs to reach 120 Hz to ensure that the two color light sources are displayed in a timed sequence. In other words, the response period of the black-and-white LCD panel 110, or the duration of the interval between the illumination of the first and second color light sources 120, 130, is 1 / 120 s, or 8.33 ms. This response time is typically met by the black-and-white LCD panel 110. Furthermore, since the human eye's residual vision is typically around 20 ms, the refresh rate should be greater than 50 Hz. Therefore, time-sharing operation of the two color light sources ensures the response time of the black-and-white LCD panel 110 while also ensuring a smooth viewing experience for the user. During actual image display, after the RGB image is processed by the image processing unit, the R and G colors are separated on the same side and sent to the black-and-white LCD panel 110, respectively, using the first region 112 as an example. The R and G images are then sent to the black-and-white LCD panel 110 twice for display. As a result, the B portion of the same image is displayed twice at a 120Hz frame rate. Therefore, the brightness of the third color light source can be reduced as needed to ensure white balance after combining the combined light.

[0070] There are at least two ways to form the first color light source 120 and the second color light source 130 .

[0071] In the first way, the optical system 100 includes a first color light-emitting element 120a and a second color light-emitting element 130a, and the first color light-emitting element 120a and the second color light-emitting element 130a are respectively used to provide a first color light source 120 and a second color light source 130, that is, the first color light, the second color light and the third color light are respectively provided by the first color light-emitting element 120a, the second color light-emitting element 130a and the third color light-emitting element 140, and the first color light-emitting element 120a, the second color light-emitting element 130a and the third color light-emitting element 140 can be devices such as light-emitting diodes that can emit the first color light, the second color light and the third color light.

[0072] In the second embodiment, referring to Figures 1 and 2 in conjunction with Figures 3 and 4, Figure 3 is a schematic diagram of the second structure of the optical system provided in an embodiment of the present application, and Figure 4 is a schematic diagram of the structure of the color wheel provided in an embodiment of the present application. The optical system 100 further includes a beam splitter assembly 160, which is located on the same side of the monochrome liquid crystal panel 110 as the third-color light-emitting element 140. The beam splitter assembly 160 is used to provide a first-color light source 120 and a second-color light source 130. Exemplarily, the beam splitter assembly 160 includes a fourth-color light-emitting element 162 and a color wheel 164. The fourth-color light-emitting element 162 is used to provide a fourth-color light source. The color wheel 164 is disposed between the fourth-color light-emitting element 162 and the monochrome liquid crystal panel 110 to separate the fourth-color light source into the first-color light source 120 and the second-color light source 130. It is understood that the fourth-color light-emitting element 162 is a mixed-color light source. For example, the fourth-color light source provided by the fourth-color light-emitting element 162 can be yellow, cyan, or bright purple. The color wheel 164 can separate and filter the light source, thereby separating the desired color of light. Generally speaking, the color wheel 164 is composed of a combination of red, green, blue, and white color filters. This separates the transmitted white light into different colors and is rotated by a high-speed motor. This sequentially separates the different monochromatic lights for designated optical paths, which are then synthesized and projected through other optical components to form a full-color image. For example, a yellow light source can be separated into red and green by the color wheel 164, a cyan light source can be separated into green and blue by the color wheel 164, and a bright purple light source can be separated into red and blue by the color wheel 164. Designers can select the configuration of the first color light source 120 and the second color light source 130 as needed, and this is not specifically limited here. In the embodiment of the present application, the color wheel 164 can be divided into four regions, with two opposing regions corresponding to the same color filter film. By rotating the color wheel 164, the fourth color light source can be separated into the first color light source 120 and the second color light source 130.

[0073] When the fourth color light source is yellow, the light source can be obtained by exciting a blue light emitting diode and phosphor.

[0074] Of course, the acquisition method of the first color light source 120 and the second color light source 130 is not limited to the above two methods. For example, the first color light source 120 and the second color light source 130 can also be obtained by spectroscopic analysis of a mercury lamp.

[0075] Please refer to Figure 5, which is a schematic diagram of the third structure of the optical system provided in an embodiment of the present application. It should be noted that in order to reduce the interference between the light sources or light corresponding to the first area 112 and the second area 114, a partition can be set between the light sources. Exemplarily, the optical system 100 also includes a light-shielding partition 170, which is arranged on one side of the black and white liquid crystal panel 110, and is used to separate the first color light source 120 and the second color light source 130 from the third color light-emitting element 140, thereby reducing the crosstalk problem between the light sources. The light-shielding partition 170 can be in contact with the black and white liquid crystal panel 110, such as by being bonded to the black and white liquid crystal panel 110 by adhesive. The height of the light-shielding partition 170 can be set according to the setting height of the light source, which is not specifically limited here.

[0076] Partitions are also required in the black and white liquid crystal panel 110 to reduce crosstalk or interference of light within the black and white liquid crystal panel 110. Exemplarily, the optical system 100 further includes a black matrix 180, which is disposed within the black and white liquid crystal panel 110 to separate the black and white liquid crystal panel 110 into a first region 112 and a second region 114, thereby preventing crosstalk between different light sources within the black and white liquid crystal panel 110.

[0077] The light combining assembly 150 is used to combine the three-color light sources and then send them to the projection lens 200, and coordinate with pixel adjustment to realize image projection display. The composition of the light combining assembly 150 will be described below.

[0078] For example, please refer to Figure 6, which is a schematic diagram of the fourth structure of the optical system provided in an embodiment of the present application. The light combining assembly 150 includes a polarizing beam splitter 151, which is disposed on the side of the black-and-white liquid crystal panel 110 facing away from the third-color light emitting element 140. The polarizing beam splitter 151 is configured to transmit the first color light emitted by the first color light source 120, the second color light emitted by the second color light source 130, and the third color light emitted by the third-color light emitting element 140 toward the projection lens 200, and to combine the first color light, the second color light, and the third color light and transmit them to the projection lens 200.

[0079] The polarization beam splitter 151 is also known as a polarization beam splitter (PBS). The primary function of the polarization beam splitter 151 is to reflect light perpendicular to the incident plane (S-polarized light) and pass light parallel to the incident plane (P-polarized light). In the embodiment of the present application, the polarized incident light (first, second, and third color light) has the same polarization state after being modulated by the black-and-white liquid crystal panel 110. This initial polarization state can directly pass through the polarization beam splitter 151.

[0080] Among them, the angle between the polarization beam splitter 151 and the black and white liquid crystal panel 110 is 45°, which can meet the transmission of the first color light and the second color light, and the reflection of the third color light, so as to realize the combination of the three color lights and ensure that the optical path of the three color lights is equal, thereby meeting the zoom requirements.

[0081] In order to ensure that the optical paths of the three color lights from the black and white liquid crystal panel 110 to the projection lens 200 are equal, other components are required to achieve this.

[0082] Exemplarily, the light combining assembly 150 further includes a first reflector 152 , a second reflector 153 and a wave plate 154 .

[0083] The first reflector 152 is disposed on a side of the monochrome liquid crystal panel 110 that is away from the third-color light emitting element 140. The first reflector 152 is configured to reflect the first-color light and the second-color light toward the polarizing beam splitter 151. The angle between the first reflector 152 and the monochrome liquid crystal panel 110 is 45°, and the reflective surfaces of the first reflector 152 are disposed corresponding to the first-color light source 120, the second-color light source 130, and the polarizing beam splitter 151, respectively.

[0084] The second reflector 153 is disposed on the side of the polarization beam splitter 151 facing away from the black-and-white liquid crystal panel 110. The second reflector 153 is configured to reflect the third color light. Exemplarily, the angle between the second reflector 153 and the polarization beam splitter 151 is 45°. That is, the second reflector 153 is disposed parallel to the black-and-white liquid crystal panel 110, and the reflective surface of the second reflector 153 faces the polarization beam splitter 151.

[0085] Wave plate 154 is an optical device that creates an additional optical path difference, or phase difference, between two mutually perpendicular light oscillations. Wave plate 154 is typically constructed from a birefringent wafer of precisely defined thickness, such as quartz, calcite, or mica, with its optical axis parallel to the wafer surface. Linearly polarized light is incident perpendicularly on the wafer, with its vibration direction at an angle to the wafer's optical axis. The incident light oscillation is decomposed into two components, one perpendicular to the optical axis and the other parallel to the axis, corresponding to the o- and e-light components in the wafer. Wave plates that create an additional optical path difference of λ / 4 between the o- and e-light components are called quarter-wave plates. If linearly polarized light is incident on a quarter-wave plate at a 45° angle, the light exiting wave plate 154 is circularly polarized. Conversely, circularly polarized light becomes linearly polarized after passing through the quarter-wave plate.

[0086] The wave plate 154 of the embodiment of the present application is a quarter-wave plate type. The wave plate 154 is arranged between the polarization beam splitter 151 and the second reflector 153. The wave plate 154 is used to convert the third color light into linearly polarized light. Please refer to Figure 7, which is a schematic diagram of the fifth structure of the optical system provided by the embodiment of the present application. The wave plate 154 is attached to the polarization beam splitter 151, which can be easily processed. Alternatively, please continue to refer to Figure 6, where the wave plate 154 is attached to the second reflector 153, making the wave plate 154 and the second reflector 153 cooperate more efficiently.

[0087] It should be noted that after the third color light is transmitted through the polarization beam splitter 151, it is reflected by the second reflector 153. At the same time, the light path passes through the wave plate 154 twice, so that the deflection angle is rotated by 90°. After the third color light is reflected by the second reflector 153, it is incident on the polarization beam splitter 151 and reflected by the polarization beam splitter 151, thereby completing the light combination with the first color light and the second color light transmitted by the polarization beam splitter 151. The deflection angle of the third color light after the combination is 90° different from that of the first color light and the second color light, but it does not affect the viewing effect of the human eye.

[0088] To put it another way, at the wavelength of the third color light, the optical path difference between the o-light and the e-light of wave plate 154 is λ / 4. The linearly polarized third color light, incident at a 45° angle to the optical axis of wave plate 154, becomes circularly polarized light. After reflection by the second reflector 153 of the circular polarizer, it becomes linearly polarized light again when passing through wave plate 154. The polarization angle of the outgoing polarized light is rotated 90° relative to the original polarization angle of the incident light. The outgoing polarized third color light is reflected by the polarization beam splitter 151, combining with the transmitted first and second color light. It can be understood that the second reflector 153 cooperates with the wave plate 154 to rotate the polarization angle of the incident light.

[0089] It should be noted that the first color light and the second color light are incident on the first area 112, and the third color light is incident on the second area 114. Since the light path of the first area 112 does not need to pass through the wave plate 154, setting two light sources in the first area 112 can simplify the structural composition of the optical system 100.

[0090] It is understandable that the configuration of the light combining assembly 150 can make the first optical path, the second optical path and the third optical path of the first color light, the second color light and the third color light from the black and white liquid crystal panel 110 to the projection lens 200 equal.

[0091] For example, the length of the first region 112 can be a, the length of the second region 114 can also be a, and the length of the black matrix 180 portion can be b. Assuming that in the optical system 100, the same medium is used in the optical path, such as all air, or the entire optical device is made of materials with the same refractive index, if the refractive index in the optical path is n. Through calculation, it can be seen that the first optical path and the second optical path are both: (a+b+a)×n=(2a+b)×n, and the third optical path is: (a+b / 2+b / 2+a)×n=(2a+b)×n, that is, the first optical path, the second optical path, and the third optical path are equal.

[0092] The optical paths from the three color light sources to the projection lens 200 are equal. Considering the magnification ratio and size of the projection lens 200, it is generally desirable to minimize the optical path from the image to the projection lens 200. A smaller optical path results in a greater magnification ratio for the projection lens 200. Using this light-combining system, the optical path is minimized, which helps reduce the size of the projection light engine in the projection device 1.

[0093] In the optical system 100 and projection device 1 provided in the embodiments of the present application, by dividing the light source into two regions, the difficulty of light combination can be reduced. On the other hand, the projection light path can be realized in conjunction with the black and white liquid crystal panel 110 and the light combining component 150, eliminating the color filter in the color liquid crystal panel of the existing projection device, thereby improving the efficiency of light energy utilization and reducing the impact of heat caused by wasted light energy on liquid crystal performance. By designing the optical system 100 for the two-partitioning method using polarization beam splitter 151 and wave plate 154, the optical system 100 has a simple structure, low manufacturing cost, and good light combining effect.

[0094] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0095] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more features.

[0096] The optical system and projection device provided in the embodiments of the present application are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, according to the ideas of the present application, there may be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present application.

Claims

1. An optical system is applied to a projection device, and the projection device includes a projection lens, wherein, The optical system includes: A black-and-white liquid crystal panel having adjacent first and second regions; A first color light source and a second color light source, both located on one side of the black-and-white liquid crystal panel and emitting light toward the first region; A third color light-emitting component, located on the same side of the black-and-white liquid crystal panel as the first color light source and the second color light source, and emitting light toward the second region; A light combining component disposed on the side of the black-and-white liquid crystal panel facing away from the third color light-emitting component, the light combining component being configured to combine the light emitted by the first color light source, the second color light source, and the third color light-emitting component and then send the combined light into the projection lens.

2. The optical system according to claim 1, wherein, The first color light source and the second color light source emit light in a time-division manner.

3. The optical system according to claim 2, wherein, The emission interval duration between the first color light source and the second color light source is 1 / 120 second.

4. The optical system according to claim 2, wherein, The light combining component includes: A polarization beam splitter disposed on the side of the black-and-white liquid crystal panel facing away from the third color light-emitting component, the polarization beam splitter being configured to transmit the first color light emitted by the first color light source, the second color light emitted by the second color light source, and reflect the third color light emitted by the third color light-emitting component toward the projection lens, and combine the first color light, the second color light, and the third color light and then send the combined light into the projection lens.

5. The optical system according to claim 4, wherein, The angle between the polarization beam splitter and the black-and-white liquid crystal panel is 45°.

6. The optical system according to claim 5, wherein, The light combining component further includes: A first reflector disposed on the side of the black-and-white liquid crystal panel facing away from the third color light-emitting component, the first reflector being configured to reflect the first color light and the second color light to the polarization beam splitter.

7. The optical system according to claim 6, wherein, The angle between the first reflector and the black-and-white liquid crystal panel is 45°.

8. The optical system according to claim 6, wherein, The reflecting surfaces of the first reflector are respectively arranged corresponding to the first color light source, the second color light source, and the polarization beam splitter.

9. The optical system according to claim 4, wherein, The light combining component further includes: A second reflector disposed on the side of the polarization beam splitter facing away from the black-and-white liquid crystal panel, the second reflector being configured to reflect the third color light.

10. The optical system according to claim 9, wherein, The angle between the second reflector and the polarization beam splitter is 45°.

11. The optical system according to claim 10, wherein, The light combining component further includes: A wave plate disposed between the polarization beam splitter and the second reflector, the wave plate being configured to change the third color light to linearly polarized light.

12. The optical system according to claim 11, wherein, The wave plate is attached to the polarization beam splitter.

13. The optical system according to claim 11, wherein, The wave plate is attached to the second reflector.

14. The optical system according to claim 11, wherein, The first color light, the second color light, and the third color light have a first optical path, a second optical path, and a third optical path respectively from the black-and-white liquid crystal panel to the projection lens, and the first optical path, the second optical path, and the third optical path are equal.

15. The optical system according to claim 5, wherein, The light combining component further includes: A first reflector disposed on the side of the black-and-white liquid crystal panel facing away from the third color light-emitting component, the first reflector being configured to reflect the first color light and the second color light to the polarization beam splitter; A second reflector disposed on the side of the polarization beam splitter facing away from the black-and-white liquid crystal panel, the second reflector being configured to reflect the third color light; and, A wave plate is disposed between the polarization beam splitter and the second mirror, and the wave plate is configured to convert the third color light into linearly polarized light.

16. The optical system according to claim 1, wherein, The optical system further includes: A light-shielding partition is disposed on one side of the black-and-white liquid crystal panel, and is configured to separate the first color light source and the second color light source from the third color light-emitting component.

17. The optical system according to claim 16, wherein, The optical system further includes: A black matrix is disposed in the black-and-white liquid crystal panel to divide the black-and-white liquid crystal panel into the first region and the second region.

18. The optical system according to claim 1, wherein, The optical system includes a first color light-emitting component and a second color light-emitting component, and the first color light-emitting component and the second color light-emitting component are respectively configured to provide the first color light source and the second color light source.

19. The optical system according to claim 1, wherein, The optical system further includes a beam splitting component. The beam splitting component and the third color light-emitting component are disposed on the same side of the black-and-white liquid crystal panel. The beam splitting component includes: A fourth color light-emitting component configured to provide a fourth color light source; A color wheel is disposed between the fourth color light-emitting component and the black-and-white liquid crystal panel to divide the fourth color light source into the first color light source and the second color light source.

20. A projection device, wherein, Comprising: An optical system, which includes a black-and-white liquid crystal panel, a first color light source, a second color light source, a third color light-emitting component, and a light combining component. The black-and-white liquid crystal panel has adjacent first and second regions; the first color light source and the second color light source are both located on one side of the black-and-white liquid crystal panel and emit light toward the first region; The third color light-emitting component is located on the same side of the black-and-white liquid crystal panel as the first color light source and the second color light source, and emits light toward the second region; the light combining component is disposed on the side of the black-and-white liquid crystal panel facing away from the third color light-emitting component, and the light combining component is configured to combine the light emitted by the first color light source, the second color light source, and the third color light-emitting component and then send the combined light into the projection lens; and A projection lens for receiving the light emitted by the optical system.

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