CN218413186U - projection system - Google Patents

Abstract

The application provides a projection system, comprising an illumination assembly, a light splitting assembly and a modulation assembly, wherein the illumination assembly is used for providing white light; the light splitting assembly is arranged on an emergent light path of the lighting assembly and is used for splitting the white light into first color light, second color light and third color light; the modulation component comprises a first spatial light modulator, a second spatial light modulator, a third spatial light modulator and a pre-modulation spatial light modulator; the light splitting component is also used for guiding the first color light to the first spatial light modulator, guiding the second color light to the second spatial light modulator and guiding the third color light to the pre-modulation spatial light modulator for pre-modulation; the light path of the first color light and the light path of the second color light are conjugated; the premodulation spatial light modulator is used for premodulating the third chromatic light according to the facula homogeneity of first chromatic light or second chromatic light for the facula homogeneity of first chromatic light, second chromatic light and third chromatic light is unanimous, and then makes the display brightness of projecting image more even, avoids appearing "colored face" phenomenon.

Description

projection system

technical field

The present application relates to the technical field of optical systems, in particular to a projection system.

Background technique

3DLP (Digital Light Processing, digital light processing) projection system is a common projection system. The basic principle of 3DLP projection system is to separate the white light emitted by the lighting source into red, green and blue three-color light through a dichroic mirror, and enter them separately. To the corresponding three light valves, the light valve modulates the incident light beam according to the input image signal, and then combines the light beams emitted by the three light valves into a beam of synthetic light through the light combining prism, and the synthetic light is projected to the screen through the projection lens After that, a projected image can be formed on the screen. However, in the existing 3DLP projection system, the uniformity of the red, green and blue light spots before modulation is different, which eventually leads to uneven display brightness of the projected image, and the phenomenon of "painted face" appears, which affects the projection effect.

Utility model content

The purpose of this application is to propose a projection system to solve the above problems. The present application achieves the above object through the following technical solutions.

An embodiment of the present application provides a projection system, including an illumination assembly, a light splitting assembly, and a modulation assembly. The illumination assembly is used to provide white light; The second color light and the third color light; the modulation component includes a first spatial light modulator, a second spatial light modulator, a third spatial light modulator and a pre-modulation spatial light modulator, and the pre-modulation spatial light modulator is arranged on the light splitting component and On the optical path between the third spatial light modulators; the light splitting component is also used to guide the first color light to the first spatial light modulator for modulation, guide the second color light to the second spatial light modulator for modulation, and guide the second color light to the second spatial light modulator for modulation. The three-color light is guided to the pre-modulation spatial light modulator for pre-modulation; the optical path of the first color light and the optical path of the second color light are conjugated; the pre-modulation spatial light modulator is used to adjust according to the spot uniformity of the first color light or the second color light The spot uniformity of the third color light is pre-modulated and then enters the third spatial light modulator.

The projection system provided in the embodiment of the present application ensures that the light spots of the first color light and the second color light have the same uniformity by setting the optical path of the first color light and the optical path of the second color light to be conjugate, and then pre-modulates the spatial light modulator according to the first color light. The spot uniformity of the first color light or the second color light pre-modulates the spot uniformity of the third color light, so that the uniformity of the light spots of the first color light, the second color light and the third color light is consistent, so that the display brightness of the projected image is higher Uniform, to avoid the phenomenon of "painted face".

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a projection system provided by an embodiment of the present application.

FIG. 2 is a schematic structural diagram of a light combining prism and a spatial light modulator in a projection system provided by an embodiment of the present application.

Fig. 3 is a block diagram of a projection system provided by an embodiment of the present application.

Fig. 4 is a schematic structural diagram of a projection system provided by another embodiment of the present application.

FIG. 5 is a schematic structural diagram of a polarization shaper in the projection system provided by the embodiment shown in FIG. 4 .

FIG. 6 is a schematic structural diagram of a projection system provided by another embodiment of the present application.

Detailed ways

Embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary, are only for explaining the present application, and should not be construed as limiting the present application.

In the existing 3DLP projection system, the uniformity of the red, green, and blue light spots before modulation is different, which eventually leads to uneven display brightness of the projected image, and the phenomenon of "painted face" appears, which affects the projection effect.

In order to solve the above technical problems, the inventor found through research that the uniformity of the light spots of the red, green, and blue lights before modulation is different because the optical paths of the red, green, and blue lights are different, and the optical paths are different. . In view of this, the inventor proposed a projection system, by setting the optical path of the first color light and the optical path conjugate of the second color light to ensure that the spot uniformity of the first color light and the second color light is the same, and then through the pre-modulation space The light modulator pre-modulates the spot uniformity of the third color light according to the spot uniformity of the first color light or the second color light, and then enters the third spatial light modulator, so that the first color light, the second color light and the third color light The uniformity of the light spot before modulation is consistent, which makes the brightness of the projected image more uniform and avoids the phenomenon of "painted face".

In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Apparently, the described embodiments are only some of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of this application.

Please refer to FIG. 1 , the projection system 100 provided by the embodiment of the present application includes an illumination assembly 110, a light splitting assembly 130, and a modulation assembly 150. The illumination assembly 110 is used to provide white light, and the light splitting assembly 130 is arranged on the outgoing light path of the illumination assembly 110 for The white light is divided into a first color light 111 , a second color light 112 and a third color light 113 . The modulation component 150 includes a first spatial light modulator 151, a second spatial light modulator 152, a third spatial light modulator 153 and a pre-modulation spatial light modulator 154, and the pre-modulation spatial light modulator 154 is arranged between the light splitting component 130 and the second On the optical path between the three spatial light modulators 153; the light splitting component 130 is also used to guide the first color light 111 to the first spatial light modulator 151 for modulation, and guide the second color light 112 to the second spatial light modulator 152 Modulation is performed, and the third color light 113 is guided to the pre-modulation spatial light modulator 154 for pre-modulation.

The light path of the first color light 111 is conjugate to the light path of the second color light 112, and the premodulation spatial light modulator 154 is used to adjust the light spot uniformity of the third color light 113 according to the light spot uniformity of the first color light 111 or the second color light 112 After being pre-modulated, it enters the third spatial light modulator 153 . Wherein, the optical path of the first color light 111 refers to the optical path of the first color light 111 from the light splitting component 130 to the first spatial light modulator 151, and the light path of the second color light 112 refers to the light path of the second color light 112 from the light splitting component 130 to the second spatial light modulator 151. The optical path of the spatial light modulator 152 .

The projection system 100 provided in the embodiment of the present application sets the optical path of the first colored light 111 and the optical path of the second colored light 112 to be conjugate, that is, the optical path of the first colored light 111 and the optical path of the second colored light 112 are mirrored along the light splitting component 130 , the optical path of the first colored light 111 is equal to the optical path of the second colored light 112, which ensures that the uniformity of the light spots of the first colored light 111 and the second colored light 112 is the same, and then through the pre-modulation spatial light modulator 154 according to the first color The light spot uniformity of the light 111 or the second color light 112 pre-modulates the light spot uniformity of the third color light 113, so that the light spot uniformity of the first color light 111, the second color light 112 and the third color light 113 are consistent, and then the projected image The brightness is more uniform, avoiding the phenomenon of "painted face". In addition, the premodulated spatial light modulator 154 can also perform local backlight adjustment (Local Dimming), that is, adjust the light spot emitted by the premodulated spatial light modulator 154 according to the brightness of each pixel corresponding to the first color light 111 or the second color light 112 , so as to improve the luminous efficiency of the system and reduce the thermal load of the pre-modulation spatial light modulator 154 .

In this embodiment, the projection system 100 further includes a light-combining prism 161 and a projection lens 162, and the light-combining prism 161 is arranged between the first spatial light modulator 151, the second spatial light modulator 152 and the third spatial light modulator 153 , for combining the light beams emitted by the first spatial light modulator 151 , the second spatial light modulator 152 and the third spatial light modulator 153 into a combined beam. The projection lens 162 is arranged on the outgoing light path of the light combining prism 161 and is used for projecting the synthesized light emitted by the light combining prism 161 onto the screen to form a projected image.

The light-combining prism 161 can be a cross dichroic prism (abbreviated as "X-cube"), the projection lens 162 can be a lens group composed of multiple lenses, and the aperture stop of the projection lens 162 can be placed outside the projection lens 162 , for example, placed at the front of the entire lens group, or placed at the rear of the entire lens group, so that the miniaturization and cost reduction of the projection lens 162 can be realized.

In some embodiments, the projection system 100 may further include a pixel shifting device 163, which is arranged on the optical path between the light combining prism 161 and the projection lens 162, and is used to combine the combined light emitted by the light combining prism 161 Translating along the direction perpendicular to the optical axis of the projection lens 162 and superimposing the synthesized light at different translation positions in time sequence can realize a small displacement of the image, thereby realizing an improvement of display resolution.

In some implementations, the pixel shifting device 163 can be a transparent flat optical device using XPR (Pixel Shift Resolution System) technology, and the transparent flat optical device can control the rotation angle through current or voltage. Specifically, when the transparent plate of the pixel shifting device 163 rotates at a certain angle, the light passing through the transparent plate is refracted twice and translated as a whole, and the transparent plate stays at the rotated position for a predetermined time, and then rotates to other positions. In an image frame period, the pixel shifting device 163 can include 2 steady states or 4 steady states, and the image is correspondingly divided into 2 subframes or 4 subframes, and the human eye uses the time integration function to analyze the captured 2 subframes Or 4 images are superimposed to form a high-resolution image in the brain. It can be understood that the pixel shifting device 163 may also include more stable states, so as to achieve higher resolution, and the present invention does not limit the multiplication number of pixels.

In some implementations, the pixel shifting device 163 can also be a liquid crystal birefringence device using E-shift (pixel expansion) technology, which controls the deflection angle of the liquid crystal molecules through a voltage, so that the light passing through the liquid crystal birefringence device Translation, so as to realize the effect of overall pixel shifting, the effect is similar to the above-mentioned mechanically rotating pixel shifting device 163, which will not be repeated here.

When the pixel shifting device 163 uses the XPR technique, there is no requirement on the polarization state of the incident light. However, when the pixel shifting device 163 adopts the E-shift technology, the light entering the pixel shifting device 163 is required to be light of the same polarization state. In the projection system 100, in order to maximize the efficiency, generally green light will pass through the light combining prism 161 in the P polarization state, and red light and blue light will pass through the light combining prism 161 in the S polarization state. The width of the highly reflective region of polarization is always less than the S polarization, so the transmission region of P polarized light in the RDM (anti-red film) and BDM (anti-blue film) of light-combining prism 161 can be made very wide, thereby realizing the spectrum Pass through the light-combining prism 161 almost losslessly.

When the pixel shifting device 163 adopts the E-shift technology, there are two ways to make the light entering the pixel shifting device 163 all be the light of the same polarization state, one of which is by clipping the spectrum, and the clipping spectrum can be specifically described in One color filter 111, the second color light 112 and the third color light 113 are respectively added to the optical path of a color filter, for example, on the optical path between the first spatial light modulator 151 and the light combining prism 161, the second spatial light modulator 152 and the light path between the light combination prism 161 and the light path between the third spatial light modulator 153 and the light combination prism 161 are respectively provided with color filters; The light filtering of the prism 161 is realized. Another way is to add a COLOR SECLECTOR (color splitter) on the optical path between the light-combining prism 161 and the pixel shifting device 163 to convert the polarization state of light of a specific wavelength, such as converting red light and blue light into P polarization state, or transform the green light into an S polarization state, so that all incident light enters the pixel shifting device 163 with the same polarization state.

In some embodiments, the first spatial light modulator 151, the second spatial light modulator 152, the third spatial light modulator 153, and the premodulation spatial light modulator 154 are all LTPS (Low Temperature Poly-Silicon, low temperature polysilicon) LCD light valve. The LTPS liquid crystal light valve is also a transmissive spatial light modulator made by LTPS technology. It realizes the modulation of the light beam by changing the orientation of the liquid crystal and combining the polarizer and the analyzer, and its cost is low, suitable for large-scale production application.

In this embodiment, the projection system 100 further includes a first polarizer 171, a second polarizer 172 and a third polarizer 173, and the first polarizer 171 is arranged between the light splitting assembly 130 and the first spatial light modulator 151 On the optical path, the first color light 111 is polarized by the first polarizer 171 and then enters the first spatial light modulator 151 with a single polarization state for modulation. The second polarizer 172 is arranged on the optical path between the light splitting component 130 and the second spatial light modulator 152, and the second color light 112 is polarized by the second polarizer 172 and enters the second spatial light modulator with a single polarization state. 152 for modulation. The third polarizer 173 is arranged on the optical path between the pre-modulation spatial light modulator 154 and the third spatial light modulator 153, and the third color light 113 is polarized by the third polarizer 173 and enters the first Three spatial light modulators 153 perform modulation.

The projection system 100 may also include a first polarizer (not shown in the figure), a second polarizer (not shown in the figure) and a third polarizer (not shown in the figure), the first polarizer It is arranged on the optical path between the first spatial light modulator 151 and the light-combining prism 161, and the first analyzer and the first spatial light modulator 151 can be bonded as one or separated from each other, for the first spatial light The image light emitted by the modulator 151 is polarized and purified, and the light beam meeting the polarization state requirements in the modulated light is filtered out to the light-combining prism 161 . The second analyzer is arranged on the optical path between the second spatial light modulator 152 and the light-combining prism 161, and the second analyzer and the second spatial light modulator 152 can be bonded together or arranged separately, for The modulated light emitted by the second spatial light modulator 152 is polarized and purified, and the light beam meeting the polarization state requirements in the modulated light is filtered out to the light combining prism 161 . The third polarizer is arranged on the optical path between the third spatial light modulator 153 and the light combining prism 161, and the third polarizer and the third spatial light modulator 153 can be bonded as one or separated from each other for The modulated light emitted by the third spatial light modulator 153 is polarized and purified, and the light beams meeting the polarization state requirements in the modulated light are filtered out to the light-combining prism 161 .

1 and 2, in this embodiment, the first spatial light modulator 151, the second spatial light modulator 152, and the third spatial light modulator 153 are all LTPS liquid crystal light valves, and the first spatial light modulator 151 , the second spatial light modulator 152 and the third spatial light modulator 153 are substantially rectangular plate structures, and both have a length direction and a width direction. The first spatial light modulator 151 and the third spatial light modulator 153 may be disposed opposite to the two sides of the second spatial light modulator 152 in the width direction, and the first spatial light modulator 151, the second spatial light modulator 152 and the second spatial light modulator The length directions of the three spatial light modulators 153 are consistent.

The length of the light-combining prism 161 in the light-emitting direction of the second spatial light modulator 152 is adapted to the widths of the first spatial light modulator 151 and the third spatial light modulator 153, for example, the light-combining prism 161 in the second spatial light modulator The length in the light emitting direction of the prism 152 is equal to the width of the first spatial light modulator 151 and the third spatial light modulator 153, or the length of the light combining prism 161 in the light emitting direction of the second spatial light modulator 152 is slightly smaller or slightly It is larger than the width of the first spatial light modulator 151 and the third spatial light modulator 153 . Wherein, the light emitting direction of the second spatial light modulator 152 is perpendicular to the second spatial light modulator 152 .

Therefore, the length of the light-combining prism 161 in the light-emitting direction of the second spatial light modulator 152 only needs to match the widths of the first spatial light modulator 151 and the third spatial light modulator 153, and does not need to match the width of the first spatial light modulator 152. The length of the spatial light modulator 151 and the third spatial light modulator 153 can reduce the length of the light-combining prism 161 in the light output direction of the second spatial light modulator 152 and the back intercept of the projection lens 162, so that the entire projection system 100 is more compact.

It can be understood that, in some other embodiments, the first spatial light modulator 151, the second spatial light modulator 152, the third spatial light modulator 153 and the premodulation spatial light modulator 154 can also be MEMS (Micro- Electro-Mechanical System (MEMS) reflective digital micromirror device (Digital Mirror Device, DMD) or reflective LCOS (Liquid Crystal on Silicon, liquid crystal display on silicon) device, etc.

In some embodiments, the resolution of the premodulated spatial light modulator 154 may be smaller than that of the third spatial light modulator 153, while the first spatial light modulator 151, the second spatial light modulator 152 and the third spatial light modulator 153 the same resolution. For example, the resolution of the third spatial light modulator 153 is 1920×1152 pixels, and the resolution of the pre-modulation spatial light modulator 154 is 1280×768 pixels. rate, reducing the thermal load of the pre-modulated spatial light modulator 154. It can be understood that, in some other implementation manners, the resolution of the premodulation spatial light modulator 154 may also be equal to that of the third spatial light modulator 153 .

1 and 3, in some embodiments, the projection system 100 may further include a detection unit 164 and a control unit 165, the detection unit 164 is used to detect the spot uniformity of the first color light 111 or the second color light 112 and generate Detection data; the control unit 165 is electrically connected to the detection unit 164 and the premodulation spatial light modulator 154, and is used to obtain a premodulation signal according to the detection data and send it to the premodulation spatial light modulator 154, and the premodulation spatial light modulator 154 is used for The third color light 113 is pre-modulated according to the pre-modulation signal. Thus, the entire pre-modulation process of the third color light 113 can be performed automatically without manual operation, and the pre-modulation signal can be output in real time according to the spot uniformity of the first color light 111 or the second color light 112, making the pre-modulation process more accurate.

In this embodiment, the detection unit 164 may be a CCD (Charge Coupled Device) camera, and the control unit 165 calculates the uniformity of the light spot by analyzing the image captured by the CCD camera, and obtains the premodulation signal according to the calculation of the uniformity of the light spot.

Still referring to FIG. 1 , in some embodiments, the light splitting assembly 130 may include a first light splitting prism 131 , a first light guide 132 , a second light guide 133 and a second light splitting prism 134 , and the first light splitting prism 131 is located on The exit light path of the lighting assembly 110 is used to divide the white light into the first color light 111 and the fourth color light 114, the first light guide 132 is arranged on the exit light path of the first color light 111, and is used to divide the first color light 111 is guided to the first spatial light modulator 151; the second light guide 133 and the second dichroic prism 134 are sequentially arranged on the outgoing light path of the fourth color light 114, and the fourth color light 114 enters the second light through the second light guide 133 The dichroic prism 134 splits light into the second color light 112 and the third color light 113 , the second color light 112 is incident to the second spatial light modulator 152 , and the third color light 113 is incident to the pre-modulated spatial light modulator 154 . Thus, the light splitting component 130 can divide the white light into the first color light 111, the second color light 112 and the third color light 113, guide the first color light 111 to the first spatial light modulator 151 for modulation, and convert the second color light 112 is guided to the second spatial light modulator 152 for modulation, and the third color light 113 is guided to the pre-modulation spatial light modulator 154 for pre-modulation.

Wherein, the second color light 112 is formed by splitting light from the fourth color light 114, and the optical path of the fourth color light 114 is equivalent to the optical path of the second color light 112, so the optical path of the fourth color light 114 and the second color light 112 partially overlap, that is The light path of the fourth color light 114 and the second color light 112 overlaps from the light splitting surface of the first dichroic prism 131 to the light splitting surface of the second dichroic prism 134, the light path of the first color light 111 and the light path of the second color light 112 referred to in the above-mentioned embodiment The optical path conjugation is the conjugation of the optical path of the first color light 111 and the total optical path of the fourth color light 114 and the second color light 112 .

In this embodiment, the first dichroic prism 131 includes a first dichroic surface 1311 and a first color light exit surface (not labeled in the figure) and a fourth color light exit surface (not labeled in the figure) that are mirror images of the first dichroic surface 1311 ), the white light emitted by the lighting assembly 110 is incident on the first dichroic surface 1311, and is split on the first dichroic surface 1311 to form the first color light 111 and the fourth color light 114, the first color light 111 exits through the first color light exit surface, The fourth color light 114 exits through the fourth color light exit surface.

The first light guide 132 includes a first light guide 1321 and an optical path deflection member 1322, the first light guide 1321 is connected between the light exit surface of the first color light and the optical path deflection member 1322, and is used to guide the first color light 111 To the light path turning member 1322, the light path turning member 1322 is used to guide the first color light 111 to the first spatial light modulator 151; the second light guiding member 133 includes a second light pipe 1331, and the second light pipe 1331 is connected to Between the light emitting surface of the fourth color light and the second dichroic prism 134 is used to guide the fourth color light 114 to the second dichroic prism 134 .

The second dichroic prism 134 includes a second dichroic surface (not labeled in the figure), and a second color light exit surface and a third color light exit surface that are mirror images of each other with respect to the second dichroic surface, and the fourth color light 114 is incident on the second dichroic surface, The second color light 112 and the third color light 113 are split on the second light splitting surface, the second color light 112 is emitted through the second color light exit surface, and the third color light 113 is emitted through the third color light exit surface.

Wherein, the first light pipe 1321 and the second light pipe 1331 are mirror images of each other with respect to the first dichroic surface 1311, and the light exit surface of the second color light and the light exit surface of the light path folding member 1322 are mirror images of each other with respect to the first dichroic surface 1311, so that the second color light The light path of the first color light 111 in the light splitting assembly 130 is conjugate to the total light path of the fourth color light 114 and the second color light 112 in the light splitting assembly 130 .

Further, the first spatial light modulator 151 and the second spatial light modulator 152 are mirror images of each other with respect to the first light splitting surface 1311, so that the optical path of the first color light 111 from the light splitting component 130 to the first spatial light modulator 151 and The fourth color light 114 and the second color light 112 are conjugated to the total optical path from the light splitting component 130 to the second spatial light modulator 152 .

In this embodiment, the first dichroic prism 131 and the second dichroic prism 134 may both be dichroic dichroic prisms, the first dichroic surface 1311 is located inside the first dichroic prism 131, and the light from the first dichroic surface 1311 and the lighting assembly 110 The axes form an included angle of 45°, and both the first colored light emitting surface and the fourth colored light emitting surface form an included angle of 45° with the first light splitting surface 1311, that is, the first colored light emitting surface and the fourth colored light emitting surface are perpendicular to each other. The second light-splitting surface is located in the second light-splitting prism 134, the second light-splitting surface is parallel to the first light-splitting surface 1311, and the second color light exit surface and the third color light exit surface form an angle of 45° with the second light separation surface, also That is, the light emitting surface of the second color light and the light emitting surface of the third color light are perpendicular to each other.

As an example, the first color light 111 is red light, the second color light 112 is green light, the third color light 113 is blue light, and the fourth color light 114 is yellow light. Specifically, the first light-splitting surface 1311 is coated with a yellow-transparent film, and the second light-splitting surface is coated with a green-transparent blue film. The white light emitted by the lighting assembly 110 enters the yellow-transparent film and splits into red light (first Color light 111) and yellow light (fourth color light 114), the yellow light is incident on the green-transparent blue film, and split to form green light (second color light 112) and blue light (third color light 113).

In this embodiment, both the first light pipe 1321 and the second light pipe 1331 can be hollow pipes, the optical path turning member 1322 is a right-angle prism, and a right-angle surface of the right-angle prism is connected to the first light pipe 1321 as a light incident surface, The other right-angled surface of the right-angled prism faces the first spatial light modulator 151 as a light-emitting surface, and the inclined surface of the right-angled prism forms an included angle of 45° with the optical axis of the first light guide 1321 for deflecting the first color light 111 by 90° Then enter the first spatial light modulator 151. The shape of the outgoing surface of the first light guide 1321 can be consistent with and coincide with the shape of the incident surface of the optical path deflector 1322 , so that an optical waveguide can be formed, and the etendue can be maintained while the optical path is folded.

The light incident surface of the optical path turning member 1322 can be coated with a first optical multilayer interference film, the light output surface of the optical path turning member 1322 can be coated with a second optical multilayer interference film, the first optical multilayer interference film and the second optical multilayer interference film. The multi-layer interference films are used to transmit the light whose incident angle is smaller than the first angle value and meet the set wavelength range, and reflect the light whose incident angle is greater than the second angle value and meet the set wavelength range; wherein, the first angle value is less than the first angle value Two angle values, that is, the first optical multilayer interference film and the second optical multilayer interference film can realize the transmission of small-angle incident light and reflection of large-angle incident light for light with a specific spectral width, and can avoid being refracted by the optical path The large-angle light reflected by the reflective surface of the component 1322 passes through the light incident surface of the light path turning component 1322 and returns to the first light guide 1321, so as to avoid light waste caused by reverse transmission of light to the greatest extent and improve the utilization rate of light energy.

The first dichroic prism 131 may comprise a first right-angle prism and a second right-angle prism, the slopes of the first right-angle prism and the second right-angle prism are glued together to form the first beam-splitting surface 1311, and the first right-angle prism and the second right-angle prism are about the first beam splitter. Faces 1311 are mirror images of each other. The second dichroic prism 134 can comprise the 3rd rectangular prism and the 4th rectangular prism, the oblique surfaces of the 3rd rectangular prism and the 4th rectangular prism glue together to form the second dichroic surface, the 3rd rectangular prism is provided with the second color light exit surface, the 4th rectangular prism The rectangular prism is provided with a third color light emitting surface. Wherein, the third rectangular prism and the optical path deflector 1322 are mirror images of each other with respect to the first dichroic surface 1311 , so that the light exit surface of the second color light and the light exit surface of the optical path deflector 1322 are mirror images of each other with respect to the first dichroic surface 1311 .

In this embodiment, the projection system 100 may further include a first reflector 181 and a second reflector 182, the first reflector 181 and the second reflector 182 are sequentially arranged on the pre-modulated spatial light modulator 154 and the third spatial light modulator On the optical path between the optical devices 153, the light beam emitted by the pre-modulated spatial light modulator 154 is reflected by the first reflector 181 and the second reflector 182 in turn, and then enters the third spatial light modulator 153, so that the pre-modulated first The three-color light 113 is directed to a third spatial light modulator 153 .

The first reflector 181 and the second reflector 182 may both be plane reflectors, and the normal of the reflective surface of the first reflector 181 forms an included angle of 45° with the optical axis of the pre-modulated spatial light modulator 154, and the second reflector 182 and the optical axis of the third spatial light modulator 153 form an included angle of 45°, and the reflective surface normal of the first reflector 181 forms an included angle of 45° with the reflective surface normal of the second reflector 182 In this way, the cooperation of the first reflector 181 and the second reflector 182 can bend the third color light 113 by 180° and then enter the third spatial light modulator 153 .

In some embodiments, the third color light is blue light, the modulation component 150 further includes a pre-imaging lens 155, and the pre-imaging lens 155 is arranged on the optical path between the pre-modulation spatial light modulator 154 and the third spatial light modulator 153, for example It is arranged on the optical path between the first reflector 181 and the second reflector 182 for pre-imaging the light beam emitted by the pre-modulated spatial light modulator 154 .

In some other embodiments, the third color light is non-blue light, for example, the third color light is green light, at this time, the third color light can directly enter the third spatial light modulator 153 after being pre-modulated by the pre-modulation spatial light modulator 154 , without pre-imaging through the pre-imaging lens 155.

In some embodiments, the projection system 100 may further include a first relay lens 183 and a second relay lens 184, the first relay lens 183 and the second relay lens 184 are sequentially arranged on the pre-modulated spatial light modulator 154 and On the optical path between the third spatial light modulator 153, for example, the first relay lens 183 is arranged on the optical path between the pre-modulated spatial light modulator 154 and the first reflector 181, and the second relay lens 184 is arranged on the The optical path between the second reflector 182 and the third spatial light modulator 153 is used to relay the pre-modulated third color light 113 to the third spatial light modulator 153 .

In some embodiments, the projection system 100 may further include a first field lens, a second field lens and a third field lens, and the first field lens, the second field lens and the third field lens may be convex lenses or Fresnel lenses, The first field lens is arranged on the optical path between the light splitting assembly 130 and the first spatial light modulator 151, for example, between the optical path deflector 1322 and the first polarizer 171, or between the first polarizer 171 and the first polarizer 171. Between a spatial light modulator 151 , for converging the first color light 111 to the first spatial light modulator 151 . The second field lens is arranged on the optical path between the beam splitting assembly 130 and the second spatial light modulator 152, for example, between the second beam splitting prism 134 and the second polarizer 172, or on the second polarizer 172 and the second spatial light modulator 152 , for converging the second color light 112 to the second spatial light modulator 152 . The third field lens is arranged on the optical path between the light splitting assembly 130 and the third spatial light modulator 153, for example, between the second relay lens 184 and the third polarizer 173, or on the third polarizer 173 and the third spatial light modulator 153 for converging the third color light 113 to the third spatial light modulator 153 . Wherein, the first field mirror and the second field mirror can be mirror images of each other with respect to the first beam splitting surface 1311 , so as to ensure the optical path conjugation of the first color light 111 and the second color light 112 .

The projection system 100 can converge the telecentric light (parallel light) into converging light (non-telecentric light) by using the converging effect of the first field mirror, the second field mirror and the third field mirror on the light, so that the spatial light modulator Light in different fields of view has different incident angles of chief rays, especially when the incident angles of chief rays are converging, it is beneficial to reduce the volume of light-combining prism 161, shorten the overall length of projection lens 162, and reduce the size of projection lens 162. design difficulty, thereby reducing the cost of the projection lens 162 .

In some embodiments, the lighting assembly 110 includes a lighting source 115 and a collection device 116. The lighting source 115 is used to emit white light. Light splitting component 130.

In this embodiment, the collection device 116 may include a conical light homogenizing device 1161 and a lens 1162. The conical light homogenizing device 1161 and the lens 1162 are sequentially arranged on the outgoing light path of the illumination source 115. The optical device 1161 and the lens 1162 are collimated to form parallel light. Wherein, the tapered homogenizing device 1161 may be a solid tapered light guide rod or a hollow tapered reflector, and the lens 1162 may be a convex lens or a Fresnel lens.

The cone-shaped homogenizing device 1161 is provided with an incident surface on the side facing the illumination source 115 and an exit surface on the side facing the lens, and the area of the incident surface is smaller than that of the exit surface. After the light beam sent by the illuminating light source 115 enters the inside of the conical light homogenizing device 1161 through the incident surface, it is reflected by the inner side wall of the conical light uniform device 1161 and emerges from the exit surface, so that the area of the outgoing light spot is larger than the area of the incident light spot, thereby The divergence angle of the beam is reduced.

In this embodiment, the illuminating light source 115 may be an LED light (yellow phosphor powder is coated on a blue LED chip), a laser fluorescent light source (blue laser excites yellow phosphor powder) or RGB three-color laser mixed light.

When the illumination light source 115 is an LED lamp or a laser fluorescent light source, the projection system 100 may also include an excitation light source, which is used to emit excitation light to the illumination light source 115, so as to excite the illumination light source 115 to generate excitation light, thereby forming an excitation light for the illumination light source 115. The double-sided excitation improves the maximum output lumens of the lighting source 115. For example, the illuminating light source 115 excites the yellow phosphor powder with blue light to generate white light, the exciting light source can be used to emit blue light, and the blue light irradiates the yellow phosphor powder of the illuminating light source 115 to form double-sided excitation of the yellow phosphor powder.

In some embodiments, the illumination light source 115 is a surface light source, which can directly emit divergent light with a wider beam diameter. At this time, the collection device 116 can be a discrete axiro-rod lens array or a discrete collection lens array. For example, the collection device 116 can include multiple According to the microlenses arranged in an array, these microlenses can correspond one-to-one to a single sub-light source or partition of the surface light source, so that discrete multi-area illumination can be formed, and the volume of the entire projection system 100 can be further reduced.

Please refer to FIG. 4 , in some embodiments, the collection device 116 may be a collection lens 1163 , and the light beam emitted by the illumination source 115 is shaped into parallel light by the collection lens 1163 . The collection lens 1163 may be a plano-convex lens or a biconvex lens, and the number of the collection lens 1163 may include one or more. For example, the number of collecting lenses 1163 is two, and the two collecting lenses 1163 are arranged sequentially along the outgoing light path of the illumination light source 115 .

In some embodiments, the projection system 100 may further include a polarizer 174, and the polarizer 174 is arranged on the optical path between the illumination assembly 110 and the beam splitter assembly 130, for example, between the collection device 116 and the first beam splitter prism 131 , used to polarize the white light emitted by the collecting device 116 to form white light with a single polarization state, and enter the light splitting component 130 , so that the fourth color light 114 can enter the pre-modulated spatial light modulator 154 with a single polarization state.

Among them, the polarizer 174, the first polarizer 171, the second polarizer 172, and the third polarizer 173 are used to polarize the light into the light of the same polarization state, which is equivalent to passing through at least two times for each color light. Polarization can improve the polarization purity of light, thereby improving the projection contrast. It can be understood that, in some other embodiments, the premodulated spatial light modulator 154 is a reflective digital micromirror device or a reflective LCOS device, and the projection system 100 may not be polarized by the polarizer 174 .

Please refer to FIG. 4 and FIG. 5 together. In some embodiments, the polarizing device 174 is a polarizing shaper 175, and the polarizing shaper 175 is used to shape the white light emitted by the collecting device 116 to form recycled light and have a predetermined The image light with a spot shape and a single polarization state is set. The image light is incident to the beam splitting component 130 , and the recovered light is reflected back to the collecting device 116 to improve the utilization rate of the light.

As an example, the light spot shape emitted by the collecting device 116 is circular, and the area to be illuminated by the first spatial light modulator 151 is rectangular, then the preset light spot shape of the image light is adapted to the first spatial light modulator 151 At this time, the rectangular light spot can be cut out from the circular light spot by the polarizer 174 to form image light with a rectangular light spot to illuminate the first spatial light modulator 151, and the recycled light that does not participate in the illumination is reflected back to the collector device 116. When the collection device 116 includes a conical light homogenizing device 1161 (see Figure 1 for details), the recycled light can be recycled directly through the conical light homogenizing device 1161; and when the collecting device 116 is a collecting lens 1163, the recycled light can be Through the collection lens 1163 and back to the illumination source 115, the illumination source 115 can reflect the recycled light back to the collection lens 1163 to continue to participate in the light cycle.

The polarization shaper 175 can be a polarization shaper film, the polarization shaper 175 is provided with a first area 1751 and a second area 1752, the first area 1751 is surrounded by the outer periphery of the second area 1752, and the shape of the second area 1752 is suitable It is configured for the illumination area of the first spatial light modulator 151 , for example, when the illumination area of the first spatial light modulator 151 is rectangular, the first area 1751 is rectangular. The first area 1751 can be coated with a reflective film, and the second area 1752 can be coated with a polarizing film. When the light beam emitted by the collecting device 116 passes through the polarization shaper 175, a part of the light passes through the polarizing film in the second area 1752 to form a single polarization state. And the rest of the image light with the preset spot shape is reflected by the reflective film in the first region 1751 to form recycled light.

Further, the polarizing film coated on the second region 1752 can be a reflective polarizing film, such as a reflective polarizing film (DBEF, Dual-BrightnessEnhanceFilm) or a metal wire grid, etc., through the reflective polarizing film, the polarization shaper 175 It can be used to split image light into first polarized light and second polarized light different from the polarization state of the first polarized light, wherein the first polarized light is incident on the light splitting component 130, and the second polarized light is reflected back to the collecting device 116, thereby realizing recycling of the second polarized light, and further improving system efficiency.

Taking the first spatial light modulator 151 as an example, the image light is split into P-polarized light and S-polarized light by a reflective polarizing film, wherein the P-polarized light is irradiated to the corresponding first spatial light modulator 151, and the S-polarized light is reflected back to the collection device 116, and can return to the illumination source 115 through the collection device 116. When the illumination source 115 is an LED lamp or laser fluorescence, the S-polarized light can be re-dispersed into natural light, and then continue to participate in the light cycle.

Please refer to FIG. 6 , in some embodiments, the beam splitting assembly 130 includes a beam splitting prism 141, a first light guide assembly 142, and a second light guide assembly 143, and the beam splitting prism 141 is arranged on the outgoing light path of the lighting assembly 110 for separating white light Divided into the first color light 111, the second color light 112 and the third color light 113, the first light guide component 142 is arranged on the outgoing light path of the first color light 111, and is used to guide the first color light 111 to the first spatial light The modulator 151; the second light guide component 143 is arranged on the outgoing light path of the second color light 112, and is used to guide the second color light 112 to the second spatial light modulator 152; the pre-modulation spatial light modulator 154 is arranged on the third color light 113 on the outgoing light path. Thus, the light splitting component 130 can divide the white light into the first color light 111, the second color light 112 and the third color light 113, and guide the first color light 111, the second color light 112 and the third color light 113 to the first space respectively. A light modulator 151 , a second spatial light modulator 152 and a premodulation spatial light modulator 154 .

As an example, the first color light 111 is red light, the second color light 112 is blue light, and the third color light 113 is green light. Specifically, the dichroic prism 141 can be a cross dichroic dichroic prism glued together by four right-angled prisms. The dichroic prism 141 is coated with a translucent green, translucent, blue and anti-red film layer and a translucent green, translucent red and anti-blue film layer. The green light directly passes through the dichroic prism 141 to reach the third spatial light modulator 153 , the blue light is reflected by the dichroic prism 141 to the second light guiding component 143 , and the red light is reflected by the dichroic prism 141 to the first light guiding component 142 .

In this embodiment, the dichroic prism 141 includes a first color light exit surface and a second color light exit surface, the first color light 111 exits through the first color light exit surface, and the second color light 112 exits through the second color light exit surface. The light emitting surface of the first color light and the light emitting surface of the second color light are mirror images of each other with respect to the symmetrical plane of the dichroic prism 141, wherein the center of the dichroic prism 141 is located on the symmetrical plane of the dichroic prism 141, and the symmetrical plane of the dichroic prism 141 is located on the first color plane. Between the light-emitting surface and the second-color light-emitting surface, and parallel to the first-color light-emitting surface and the second-color light-emitting surface.

The first light guide component 142 is connected to the light exit surface of the first color light, and the second light guide component 143 is connected to the light exit surface of the second color light. as a mirror image. Thus, the optical path of the first color light 111 in the dichroic prism 141 and the first light guide assembly 142 and the optical path of the second color light 112 in the dichroic prism 141 and the second light guide assembly 143 can be made about the symmetry plane of the dichroic prism 141 They are mirror images of each other, thereby realizing the optical path conjugation of the first color light 111 and the second color light 112 . Further, the first spatial light modulator 151 and the second spatial light modulator 152 are mirror images of each other with respect to the symmetry plane of the dichroic prism 141, so that the entire optical path of the first color light 111 before modulation and the entire optical path of the second color light 112 before modulation The entire optical path conjugate of .

In this embodiment, the first light guide assembly 142 includes a first light guide 1421, a first light path turning member 1422, a second light guide 1423, and a second light path turning member 1424 connected in sequence. The first light guide 1421 is connected to the first color light exit surface of the dichroic prism 141; the second light guide assembly 143 includes a third light guide tube 1431, a third light path deflector 1432, a fourth light guide tube 1433 and a fourth optical path deflector connected in sequence. The transfer piece 1434 and the third light pipe 1431 are connected to the light emitting surface of the second color light of the dichroic prism 141 .

Wherein, the first light guide pipe 1421 and the third light guide pipe 1431 are mirror images of each other with respect to the plane of symmetry of the dichroic prism 141, and the plane of symmetry of the first light path deflecting member 1422 and the third optical path deflecting member 1432 are mirror images of each other with respect to the plane of symmetry of the dichroic prism 141. mirror image, the second light guide pipe 1423 and the fourth light guide pipe 1433 are mirror images of each other with respect to the plane of symmetry of the dichroic prism 141, and the plane of symmetry of the second light path deflecting member 1424 and the fourth optical path deflecting member 1434 are mutually mirror images with respect to the plane of symmetry of the dichroic prism 141 mirror image.

The first optical path turning member 1422, the second optical path turning member 1424, the third optical path turning member 1432 and the fourth optical path turning member 1434 can all be rectangular prisms, and the two right-angled surfaces of the first optical path turning member 1422 are respectively Connected to the first light pipe 1421 and the second light pipe 1423 , the first color light 111 is deflected by 90° on the slope of the first light path deflector 1422 and then enters the second light pipe 1423 . One right-angled surface of the second optical path deflecting member 1424 is connected to the second light pipe 1423, and the other right-angled surface faces the first spatial light modulator 151, and the first color light 111 is deflected by 90° on the slope of the second optical path deflecting member 1424. ° and then enter the first spatial light modulator 151. The two right-angled surfaces of the third light path deflector 1432 are respectively connected to the third light guide pipe 1431 and the fourth light guide pipe 1433, and the second color light 112 is deflected by 90° on the oblique surface of the third optical path deflector 1432 and then enters the third light guide pipe 1432. Four light pipes 1433. One right-angled surface of the fourth optical path turning member 1434 is connected to the fourth light pipe 1433, and the other right-angled surface faces the second spatial light modulator 152, and the second color light 112 is reflected on the slope of the fourth optical path turning member 1434, After being deflected by 90°, it enters the second spatial light modulator 152 .

In this embodiment, the premodulation spatial light modulator 154 can be arranged on the optical path between the third polarizer 173 and the third spatial light modulator 153, and the third color light 113 is polarized by the third polarizer 173 to A single polarization state enters the pre-modulation spatial light modulator 154 for pre-modulation, and the pre-modulated light enters the third spatial light modulator 153 for modulation. This is because, in the architecture shown in Figure 6, the first colored light 111 and the second colored light 112 separated by the light source are mirrored in the optical path in the light guide, so there is no problem of uniformity when combining light, while the third colored light The light path of 113 has not been folded, and the uniformity of its light spot is different from that of the first color light 111 and the second color light 112. By adding a pre-modulated spatial light modulator 154, the problem of "painted face" can be solved. The specific principle is as mentioned above. , and will not be repeated here. At the same time, due to the addition of the pre-modulated spatial light modulator 154, there is no need to install a polarizing device 174 between the illumination assembly 110 and the dichroic prism 141 (see FIG. It only needs to be biased, so that the whole projection system 100 is more concise. That is, the pre-modulation spatial light modulator 154 can not only solve the non-uniformity problem of the third color light 113, but also can polarize it. Of course, in some implementations, a polarizer 174 may also be provided on the optical path between the lighting assembly 110 and the dichroic prism 141, for polarizing the white light emitted by the lighting assembly 110 and entering the dichroic prism in a single polarization state. 141. For the detailed structure of the lighting assembly 110 and the polarizing device 174 , reference may be made to the relevant records of the embodiments shown in FIG. 1 and FIG. 4 , which will not be repeated here.

The above is only a preferred embodiment of the application, and does not limit the application in any form. Although the application has been disclosed as above with the preferred embodiment, it is not used to limit the application. Anyone skilled in the art , without departing from the scope of the technical solution of the present application, when the technical content disclosed above can be used to make some changes or modifications to equivalent embodiments with equivalent changes, but as long as it does not depart from the technical solution of the present application, the technical content of the present application In essence, any modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solutions of the present application.

Claims (11)

1. A projection system, comprising:

an illumination assembly for providing white light;

the light splitting assembly is arranged on an emergent light path of the lighting assembly and is used for splitting the white light into first color light, second color light and third color light; and

the modulation assembly comprises a first spatial light modulator, a second spatial light modulator, a third spatial light modulator and a premodulation spatial light modulator, wherein the premodulation spatial light modulator is arranged on a light path between the light splitting assembly and the third spatial light modulator; the light splitting component is further used for guiding the first color light to the first spatial light modulator for modulation, guiding the second color light to the second spatial light modulator for modulation, and guiding the third color light to the pre-modulation spatial light modulator for pre-modulation;

the light path of the first colored light and the light path of the second colored light are conjugated; the pre-modulation spatial light modulator is used for pre-modulating the spot uniformity of the third color light according to the spot uniformity of the first color light or the second color light and then transmitting the modulated spot uniformity to the third spatial light modulator.

2. The projection system of claim 1, further comprising a detection unit and a control unit, the detection unit configured to detect a spot uniformity of the first color light or the second color light and generate detection data; the control unit is used for acquiring a pre-modulation signal according to the detection data and sending the pre-modulation signal to the pre-modulation spatial light modulator, and the pre-modulation spatial light modulator is used for pre-modulating the third colored light according to the pre-modulation signal.

3. The projection system of claim 1, wherein the light splitting assembly comprises a first light splitting prism, a first light guide member, a second light guide member, and a second light splitting prism, and the first light splitting prism is disposed on an exit light path of the illumination assembly and is configured to split the white light into a fourth color light and the first color light; the first light guide part is arranged on an emergent light path of the first color light and is used for guiding the first color light to the first spatial light modulator; the second light guide piece and the second light splitting prism are sequentially arranged on an emergent light path of fourth color light, the fourth color light is incident to the second light splitting prism through the second light guide piece and split to form the second color light and the third color light, the second color light is incident to the second spatial light modulator, and the third color light is incident to the pre-modulation spatial light modulator; the light path of the fourth color light is partially overlapped with the light path of the second color light.

4. The projection system of claim 3, wherein the first dichroic prism includes a first dichroic surface and a first color light emitting surface and a fourth color light emitting surface that are mirror images of each other with respect to the first dichroic surface, the white light is split into the first color light and the fourth color light at the first dichroic surface, the first color light is emitted through the first color light emitting surface, and the fourth color light is emitted through the fourth color light emitting surface;

the first light guide part comprises a first light guide pipe and a light path turning part, the first light guide pipe is connected between the first color light emitting surface and the light path turning part, and the light path turning part is used for guiding the first color light to the first spatial light modulator; the second light guide part comprises a second light guide pipe, the second light guide pipe is connected between the fourth color light emitting surface and the second light splitting prism, and the first light guide pipe and the second light guide pipe are mirror images of each other about the first light splitting surface; the second light splitting prism is provided with a second color light emitting surface, and the second color light emitting surface and the light emitting surface of the light path turning piece are mirror images relative to the first light splitting surface.

5. The projection system of claim 4, wherein the first spatial light modulator and the second spatial light modulator are mirror images of each other with respect to the first light splitting plane.

6. The projection system of claim 3, further comprising a first reflector and a second reflector, wherein the first reflector and the second reflector are sequentially disposed on an optical path between the pre-modulation spatial light modulator and the third spatial light modulator, and a light beam emitted from the pre-modulation spatial light modulator is sequentially reflected by the first reflector and the second reflector and then enters the third spatial light modulator.

7. The projection system of claim 3, wherein the modulation assembly further comprises a pre-imaging lens disposed on the optical path between the pre-modulated spatial light modulator and the third spatial light modulator for pre-imaging the light beam emitted from the pre-modulated spatial light modulator.

8. The projection system of any of claims 3-7, wherein the first color light is red light, the second color light is green light, the third color light is blue light, and the fourth color light is yellow light.

9. The projection system of claim 1, wherein the light splitting assembly comprises a light splitting prism, a first light guiding assembly and a second light guiding assembly, the light splitting prism is disposed on the light path of the illumination assembly and is configured to split the white light into a first color light, a second color light and a third color light, and the first light guiding assembly is disposed on the light path of the first color light and is configured to guide the first color light to the first spatial light modulator; the second light guide assembly is arranged on a light path of the second color light and used for guiding the second color light to the second spatial light modulator; the pre-modulation spatial light modulator is arranged on a light path of the third color light.

10. The projection system of claim 9, wherein the first color light is red, the second color light is blue, and the third color light is green.

11. The projection system of claim 1 wherein the pre-modulated spatial light modulator has a resolution less than the third spatial light modulator.

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