CN111948885B

CN111948885B - Projection imaging device

Info

Publication number: CN111948885B
Application number: CN202010404527.6A
Authority: CN
Inventors: 李晓平; 钟强; 阴亮
Original assignee: Qingdao Hisense Laser Display Co Ltd
Current assignee: Qingdao Hisense Laser Display Co Ltd
Priority date: 2019-05-14
Filing date: 2020-05-13
Publication date: 2022-04-15
Anticipated expiration: 2040-05-13
Also published as: WO2020228595A1; CN111948885A

Abstract

The application discloses projection imaging device belongs to the technical field of formation of image. The projection lens includes: the vibration mirror is positioned between the first mirror group and the second mirror group; the first lens group is used for receiving the image light beam emitted by the light valve and guiding the image light beam to the galvanometer; the galvanometer is used for guiding the received image light beams to the second lens group and carrying out deviation processing on the image light beams through vibration; the second lens group is used for guiding the received image light beams to the screen. This application will shake the mirror setting and set up between first mirror group and second mirror group, because shake the mirror setting in projection lens, consequently compare with the correlation technique, can shorten the distance of light valve to projection lens among the projection imaging device, and then can reduce projection imaging device's volume, simplified projection imaging device's framework, be favorable to realizing projection imaging device's miniaturization.

Description

Projection imaging device

The present application claims priority from chinese patent application No. 201910398141.6, entitled "projection lens and projection imaging system", filed on 14/5/2019, and from chinese patent application No. 202010177880.5, entitled "projection lens and projection apparatus", filed on 13/3/2020, the entire contents of which are incorporated herein by reference.

Technical Field

The application relates to the technical field of imaging, in particular to a projection imaging device.

Background

Laser televisions are widely used in the display field because of their advantages of high color purity, large color gamut, high brightness, etc.

Current laser televisions include a projection imaging device and a projection screen. The projection imaging apparatus generally includes a light valve, a galvanometer, and a projection lens arranged in this order. The light valve is used for generating an image beam when being illuminated and transmitting the image beam to the vibrating mirror; the galvanometer is used for carrying out offset processing on the received image light beam and transmitting the image light beam after the offset processing to the projection lens; the projection lens is used for projecting the image light beam to a projection screen after the image light beam is transmitted, reflected and/or refracted.

However, the arrangement of the structures in the conventional projection imaging device leads to a large volume of the projection imaging device, and miniaturization is difficult.

Disclosure of Invention

The embodiment of the application provides a projection imaging device. The technical scheme is as follows:

according to an aspect of the present application, there is provided a projection imaging apparatus including a light valve and a projection lens, the projection lens including:

the vibration mirror is positioned between the first mirror group and the second mirror group;

the first lens group is used for receiving the image light beam emitted by the light valve and guiding the image light beam to the galvanometer;

the galvanometer is used for guiding the received image light beams to the second lens group and carrying out deviation processing on the image light beams through vibration;

the second lens group is used for guiding the received image light beams to the screen.

Optionally, the galvanometer is a reflective galvanometer, or the galvanometer is a transmissive galvanometer.

Optionally, the first mirror group comprises a first refractive mirror group, and the second mirror group comprises a second refractive mirror group and a curved mirror.

Optionally, the projection lens further includes a plane mirror, and the plane mirror is located between the second refractive mirror group and the curved mirror.

Optionally, the plane mirror is located at an image plane of the refractive mirror group.

Optionally, the first mirror group is a refractive mirror group, and the second mirror group includes a curved mirror.

Optionally, the lens further comprises a plane mirror, and the plane mirror is located in the refractive mirror group.

Optionally, the reflective galvanometer is located at an imaging surface of the refractive mirror group.

Optionally, when the galvanometer is a reflective galvanometer, the reflective galvanometer includes a vibrator base, a reflector, a metal backup plate and at least one vibration assembly located on the vibrator base, and each vibration assembly includes a backup portion, a vibrator and a spring piece;

the reflector is positioned on the metal bearing plate, the metal bearing plate is connected with the spring piece, the spring piece is installed on the vibrator base and abuts against the abutting part, and the spring piece is provided with a target load;

the vibrator is connected with the metal bearing plate and used for driving the reflector to deflect according to a target angle.

Optionally, when the galvanometer is a transmission galvanometer, the galvanometer includes an optical lens and a driving assembly;

the driving component is used for driving the optical lens to swing at a specified angle according to a target frequency.

Optionally, the specified angle is inversely related to an incident angle of the image light beam on the light incident surface of the optical lens.

Optionally, the angle of incidence is less than 16 °.

Optionally, the projection imaging apparatus further comprises: a Total Internal Reflection (TIR) prism located between the light valve and the projection lens;

the TIR prism is used for reflecting the image light beam to the projection lens.

Optionally, the resolution of the light valve is 2K or 3K, and the projection lens is a 4K ultra-short-focus projection lens.

The application provides a projection imaging device, because the galvanometer sets up in projection lens, consequently compare with the correlation technique, can shorten the distance of light valve to projection lens among the projection imaging device, and then can reduce projection imaging device's volume, simplified projection imaging device's framework, be favorable to realizing projection imaging device's miniaturization.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of the displacement of a pixel in a projected image at the light valve end when the optical lens in the galvanometer is swung to different positions;

fig. 2 is a schematic structural view of a projection imaging apparatus provided in the related art;

FIG. 3 is a schematic structural diagram of a projection imaging apparatus according to an embodiment of the present disclosure;

FIG. 4 is a schematic structural diagram of a projection imaging apparatus according to an embodiment of the present disclosure;

FIG. 5 is a schematic structural diagram of another projection imaging apparatus provided in the embodiments of the present application;

FIG. 6 is a schematic structural diagram of another projection imaging apparatus provided in the embodiments of the present application;

FIG. 7 is a schematic structural diagram of another projection imaging apparatus provided in the embodiments of the present application;

FIG. 8 is a schematic structural diagram of a reflective galvanometer provided in an embodiment of the present disclosure;

FIG. 9 is a schematic perspective view of the reflective galvanometer shown in FIG. 7;

FIG. 10 is a schematic structural diagram of a projection imaging apparatus according to an embodiment of the present disclosure;

fig. 11 is a schematic structural diagram of a lens group in a projection lens according to an embodiment of the present disclosure;

fig. 12 is a schematic view of a scene in which a transmission galvanometer performs offset processing on an image beam according to an embodiment of the disclosure;

FIG. 13 is a schematic view of another exemplary embodiment of a transmission galvanometer mirror for shifting an image beam;

FIG. 14 is a schematic view of a scene in which a transmissive galvanometer is used to shift an image beam according to an embodiment of the present disclosure;

FIG. 15 is a schematic structural diagram of another projection imaging apparatus provided in an embodiment of the present application;

FIG. 16 is a schematic structural diagram of another projection imaging apparatus provided in the embodiments of the present application;

FIG. 17 is a schematic structural diagram of a projection imaging apparatus according to an embodiment of the present disclosure;

fig. 18 is a schematic structural diagram of another projection imaging apparatus provided in an embodiment of the present application.

With the above figures, there are shown specific embodiments of the present application, which will be described in more detail below. These drawings and written description are not intended to limit the scope of the inventive concepts in any manner, but rather to illustrate the inventive concepts to those skilled in the art by reference to specific embodiments.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

In recent years, with the rapid development of laser projection display technology, the resolution of the display screen of a laser display product applying the technology is higher and higher. For example, the display screen of the laser display product can achieve 4K resolution. The 4K resolution is a resolution of 3840 pixels per line in the display screen, and usually 3840 × 2160. Illustratively, the laser display product may be a laser television.

The current laser television set comprises a projection imaging device and a projection screen. In the related art, a low-resolution light valve is usually used in a projection imaging device to achieve a high-resolution display effect in cooperation with a galvanometer. For example, a light valve with 2K or 3K resolution is adopted to match with a galvanometer, so that the display effect of 4K resolution is achieved. The galvanometer generally comprises an optical lens and an electromagnetic driver, wherein the electromagnetic driver is used for driving the optical lens to swing at a specified angle, and the specified angle is a deflection angle of the optical lens in the galvanometer.

For example, fig. 1 is a schematic diagram of the displacement of the pixel in the projected image at the light valve end when the optical lens in the galvanometer is swung to different positions. As shown in fig. 1, M1 is the equivalent position of the pixel in the projected image at the light valve end when the optical lens swings to the first position, and M2 is the equivalent position of the pixel in the projected image at the light valve end when the optical lens swings to the second position. Optionally, the shift distance of the pixel of the projected image is determined according to the pixel size of the light valve. In practical applications, the shift distance m of the pixels of the projected image has a shift tolerance g, and the shift tolerance ranges from (m-g) to (m + g). For example, when the pixel size of the light valve is 5.4 μm (micrometers), the shift distance m of the pixel of the projected image may be 2.7 μm, the shift tolerance g may be 0.3 μm, and the shift tolerance range is 2.4 μm to 3.0 μm. In the imaging process of the projection imaging device, the optical lens is driven by the electromagnetic driver to rapidly swing at a specified angle, so that the vibrating mirror can shift the image beam. The offset processing means that after the light valve converts the 4K display image received by the projection imaging device into two frames of projection images, the optical lens can relatively shift the pixels of the two frames of projection images, so that the imaging pictures of the two frames of projection images on the projection screen are not completely overlapped, and the two frames of projection images can be equivalent to one frame of visual picture by means of the visual reaction of human eyes. Because the imaging pictures of the two frames of projection images on the projection screen are not completely overlapped, the resolution of the visual picture is greater than that of each frame of projection image, and the high-resolution display effect of the laser television is further realized. The visual picture refers to a picture perceived by human vision. The frequency of the light valve is the same as that of the galvanometer, and the frequency of the visual frame is half of that of the light valve. For example, the input frequency of the display image of the projection imaging device is 60Hz, the input 4K display image with the resolution of 3840 × 2160 is converted into two frames of projection images with the resolution of 2716 × 1528, the frequencies of the optical lenses in the light valve and the galvanometer are both 120Hz, the pixels of the two frames of projection images are relatively shifted by the optical lenses, so that the imaging pictures of the two frames of projection images on the projection screen are not completely overlapped, and the two frames of projection images are equivalent to one visual picture by the visual reaction of human eyes, so that the frequency of the visual picture is 60 Hz.

Fig. 2 is a schematic structural diagram of a projection imaging apparatus provided in the related art. As shown in fig. 2, the projection imaging apparatus 1 generally includes a light valve 10, a TIR prism 11, a galvanometer 12, and a projection lens 13 arranged in this order. The light valve 10 is used to generate an image beam when illuminated. For example, the light valve may be a digital micro mirror device (DMD). The TIR prism 11 is used to reflect the image beam to the galvanometer. The galvanometer 12 is configured to perform offset processing on the image beam transmitted by the light valve 10, and transmit the image beam after the offset processing to the projection lens 13. The projection lens 13 is used for reflecting and/or refracting the image beam and then projecting the image beam to a projection screen. Illustratively, the projection lens may be a 4K ultra-short focus projection lens.

However, since the galvanometer is disposed between the light valve and the projection lens, a distance (i.e., a rear working distance) between the light valve and the projection lens in the projection imaging device is large, and thus the volume of the projection imaging device is large, which is not favorable for miniaturization of the projection imaging device.

In addition, as the vibrating mirror can generate a large amount of heat energy in the working process, the space between the light valve and the projection lens is high in tightness and difficult to dissipate heat, and the temperature of the space is high. Experiments prove that the temperature of the space can reach 70 ℃ (centigrade) to 80 ℃. Excessive temperatures may affect the proper operation of the light valve, galvanometer, projection lens, etc. Therefore, when designing the projection imaging device, factors such as the rear working distance and the heat dissipation problem of the galvanometer need to be considered, and the design difficulty of the projection imaging device is increased.

In addition, the light valve generates on (on) light and off (off) light when illuminated. The on light refers to a light beam generated by the light valve and transmitted to the projection lens, i.e. an image light beam; off light refers to the light beam generated by the light valve that is not transmitted to the projection lens. Because off light needs to be prevented from entering the projection lens during transmission, the off light is usually transmitted by avoiding an optical lens in the galvanometer, and at the moment, the off light may irradiate an electromagnetic driver in the galvanometer, and an electromagnetic coil in the electromagnetic driver has high sensitivity to light and heat, so that when the off light irradiates the electromagnetic coil, the normal operation of the electromagnetic coil is affected, and the working stability of the galvanometer is poor.

Fig. 3 is a schematic structural diagram of a projection imaging apparatus according to an embodiment of the present application. The projection imaging device 30 may include a light valve 31 and a projection lens 20, and the projection lens 20 includes:

the first lens group 21, the galvanometer 22 and the second lens group 23, wherein the galvanometer 22 is positioned between the first lens group 21 and the second lens group 23.

The first lens group 21 is used for receiving the image beam emitted from the light valve 31 and guiding the image beam to the galvanometer 22.

The galvanometer 22 is used for guiding the received image light beams to the second lens group 23 and performing deviation processing on the image light beams through vibration.

The second lens group 23 is used for guiding the received image light beams to the screen 32.

To sum up, the projection imaging device provided by the embodiment of the present application, because the galvanometer is disposed in the projection lens, compared with the related art, can shorten the distance from the light valve to the projection lens in the projection imaging device, and then can reduce the volume of the projection imaging device, simplify the architecture of the projection imaging device, and is beneficial to the miniaturization of the projection imaging device.

In addition, because the vibrating mirror is placed between the TIR prism and the projection lens in the related art, the temperature of the area where the vibrating mirror is located is high, and the vibrating mirror is a heating element component, the temperature of the rear group of the projection lens is too high, thereby affecting the analysis of the projection lens. If the galvanometer is placed in the projection lens, the heat dissipation is easier, a heat source is reduced at the rear group of the projection lens, the temperature of the rear group of the projection lens is reduced, and the analysis of the projection lens is facilitated. Compared with the prior art that the vibrating mirror is arranged between the TIR prism and the projection lens, the vibrating mirror is arranged in the projection lens, normal work of the vibrating mirror, the projection lens and the like due to temperature influence is avoided, and the design difficulty of the projection lens is reduced.

It should be noted that, because there is no off light in the projection lens, it can be avoided that off light emitted from the light valve is irradiated onto the electromagnetic driver in the galvanometer to affect the normal operation of the electromagnetic coil in the electromagnetic driver, thereby ensuring the operational stability of the galvanometer. Meanwhile, the electromagnetic coil cannot generate extra heat due to illumination, and compared with the related technology, the heat energy generated by the vibrating mirror in the working process can be reduced.

In the embodiment of the present application, the galvanometer in the projection lens may be a reflective galvanometer or a transmissive galvanometer, which will be described below.

In the first case, when the galvanometer is a reflective galvanometer, please refer to fig. 4, which shows a schematic structural diagram of another projection imaging apparatus 30 according to an embodiment of the present disclosure.

Optionally, the first lens group 21 in the projection lens 20 includes a first refractive lens group, and the second lens group 23 includes a second refractive lens group 231 and a curved mirror 232. The first refractive lens group may include a plurality of lenses, and the plurality of lenses may include a plurality of lenses having positive refractive power, a plurality of lenses having negative refractive power, a spherical lens, and an aspherical lens. The first refractive optical element receives the image beam emitted from the light valve 31, and the image beam is incident on the reflective galvanometer 22 to realize the light path turning. The reflector is an optical element that can turn the light path in a predetermined direction by using the principle of light reflection, and the reflector can be divided into a plane reflector and a curved reflector, in this embodiment, the second lens group 23 includes a curved reflector 232, and the curved reflector 232 can achieve the function of amplifying and adjusting distortion. As shown in fig. 4, the image light beam emitted from the light valve 31 enters the first refractive lens group through a tir prism (or rtir (reverse total internal reflection) prism) to form a preliminary image, the preliminary image light beam enters the reflective polarizer 22 along the optical axis length direction 50 of the first refractive lens group, the route direction of the image light beam changes through the reflection of the reflective polarizer 22, the image light beam with the changed direction enters the second refractive lens group 231, and then enters the curved reflector 232 from the second refractive lens group 231.

Fig. 5 is a schematic structural diagram of another projection imaging apparatus according to an embodiment of the present application. Fig. 5 is a view based on fig. 4 with the addition of a plane mirror.

Optionally, the lens further includes a plane mirror 24, and the plane mirror 24 is located between the second refractive mirror group 231 and the curved reflective mirror 232. When a plane mirror 24 is further added to the lens, the direction of the image beam 40 emitted to the reflective galvanometer 22 may be parallel to the direction of the image beam emitted from the plane mirror 24.

Optionally, the plane mirror 24 is located at the image plane of the refractive mirror group. When the plane mirror is located at the image plane of the second refractor set 231, the plane mirror does not affect the image formation of the second refractor set 231, and thus the image formation effect is not affected.

Fig. 6 is a schematic structural diagram of another projection imaging apparatus according to an embodiment of the present application.

Optionally, the first lens group 21 in the projection lens 20 is a refractive lens group, and the second lens group 23 includes a curved reflecting mirror 232. As shown in fig. 5, the second mirror group 23 does not include the second refractive mirror group, and the curved reflective mirror 232 is closer to the reflective galvanometer 22, so as to directly receive the light source reflected by the reflective galvanometer 22. The imaging effect of the reflective galvanometer 22 can be made better. The specific arrangement manner of the second lens group 23 may be selected according to actual requirements, and the embodiment of the present application is not limited herein.

Fig. 7 is a schematic structural diagram of another projection imaging apparatus according to an embodiment of the present application. Fig. 7 is a view based on fig. 6 with the addition of a plane mirror.

Optionally, the projection lens 20 further includes a plane mirror 24, and the plane mirror 24 is disposed in the refractive mirror group. The refractor set may further include a refractor set 211 and a refractor set 212, the plane mirror 24 is located between the refractor set 211 and the refractor set 212, and when a plane mirror 24 is added to the lens, the direction of the image beam 40 emitted to the refractor set is parallel to the direction of the image beam emitted to the reflective galvanometer 22.

Optionally, the reflective galvanometer 22 is located at the imaging surface of the refractive optical assembly. When the reflective vibrating mirror 22 is located on the image plane of the refractor set, the reflective vibrating mirror 22 will not affect the image plane of the refractor set, and thus the image forming effect will not be affected.

Fig. 8 is a schematic structural diagram of a reflective galvanometer according to an embodiment of the present disclosure.

Optionally, the mirror reflector 22 comprises a vibrator base 221, a mirror reflector 222, a metal bearing plate 223 and at least one vibration assembly 224 on the vibrator base 221, each vibration assembly 224 comprising an abutment 2241, a vibrator 2242 and a spring strip 2243; the mirror 222 is positioned on a metal bearing plate 223, the metal bearing plate 223 is connected with a spring strip 2243, the spring strip 2243 is mounted on the vibrator base 221 and abuts against the abutting part 2241, and the spring strip 2243 has a target load.

The vibrator 2242 may provide a power source for the reflective mirror 22, when the vibrator 2242 is turned on, the vibrator 2242 moves up and down to generate power to drive the spring strip 2243 connected to the vibrator 2242 to load the spring strip 2243, the gap between the spring strip 2243 and the vibrator base 221 sets a load by bending the spring strip 2243 in place, and since the abutting part 2241 is connected to the spring strip 2243, the load of the spring strip 2243 causes the metal bearing plate 223 to abut on the vibrator base 221, thereby forming the rotation axis abutting part 2241. Vibrator 2242 is connected to metal and holds the backup plate 223 on, provide the power that makes speculum 222 slope, consequently when support portion 2241 rotates, it rotates to drive metal and holds backup plate 223, speculum 222 takes place the skew according to the rotation of metal and holds backup plate 223, in order to realize the deflection of light source, reach the function of mirror that shakes, and speculum 222 can the reflection ray, refract away the light source from original optical axis route, thereby change the route of light source, make the second mirror group can carry out the rigidity according to the light source after the refraction, need not to set gradually along the length direction of optical axis, projection lens has been reduced at the ascending length of the optical axis length direction of first mirror group. The vibrator 2242 may include a coil, a piezoelectric ceramic, and the like, or may be another vibrator, and embodiments of the present application are not limited herein.

Fig. 9 is a schematic perspective view of the reflective galvanometer shown in fig. 8. One end of the metal backup plate 223 is connected with the vibrator base 221, the other end of the metal backup plate 223 is connected with the reflector 222, and the metal backup plate 223 can transmit the rotation driven by the abutting part 2241 to the reflector 222 while supporting and fixing the reflector 222, so that the reflector 222 can deflect according to the rotation of the abutting part 2241.

In addition, the time required for the mirror 222 to deflect once may be set according to the requirements of the projection apparatus for imaging pixels, for example, when the configuration requirement of the projection apparatus is 3K pixel resolution plus dither, the time required for the mirror to deflect once is 2 times the frame rate of the input image, and when the configuration requirement of the projection apparatus is 3K pixel resolution plus dither, the time required for the mirror to deflect once is 4 times the frame rate of the input image. The reflective galvanometer 22 is located between the first lens group 21 and the second lens group 23, and the specific position can satisfy the condition: the magnification of the subsequent light path of the reflector to the screen is kept consistent in each field of view and the angle of each field of view incident on the reflector is approximately consistent.

Optionally, the flatness of the mirror is less than 3 stripes and the irregularity is less than 1/2 stripes. Flatness refers to the deviation of the height of a macro relief of a substrate from an ideal plane. Comparing the measured actual surface with the ideal plane, wherein the line value distance between the measured actual surface and the ideal plane is the flatness error value; or by measuring the relative height difference of a plurality of points on the actual surface and then converting the flatness error value represented by a line value. The flatness error measurement method may refer to related technologies, and the embodiments of the present application are not limited herein. The mirror used in the present application has a flatness of less than 3 stripes and an irregularity of less than 1/2 stripes. Specific flatness the embodiments of the present application are not limited thereto.

Optionally, the mirror 22 comprises two vibrating assemblies, the abutting portions of which are perpendicular. Exemplarily, the rotation direction of the abutting portion of one of the vibrating assemblies is left-right rotation by taking the optical axis as the axis, the rotation direction of the abutting portion of the other vibrating assembly is up-down rotation by taking the optical axis as the axis, because the abutting portion can drive the metal backup plate 223 to rotate, the metal backup plate 223 can drive the reflector 222 to deflect, therefore, when the abutting portion is left-right rotation, the metal backup plate 223 rotates left-right, the metal backup plate 223 drives the reflector 222 to deflect left-right, when the abutting portion rotates up-down, the metal backup plate 223 drives the reflector 222 to deflect up-down, namely, when the rotation directions of the abutting portions of the two vibrating assemblies are vertical, the direction of deflection of the reflector 222 can be increased, thereby increasing the direction of pixel deflection and achieving the effect of improving the resolution.

Optionally, an included angle between the optical axis of the first lens group and the optical axis of the second lens group is between 70 degrees and 110 degrees. The angle includes two parts, a fixed turning angle and a vibration angle, the first part is the fixed turning angle to realize the turning of the light path, and the size of the angle is related to the requirement of the turning direction of the light path. The second part is vibration angle to raise the resolution of the system, and its size is related to the magnification of the second lens group and the size of pixel shift, and it features high frequency rotation, its angle is generally smaller, its rotation frequency is related to the frame frequency of the image, for one direction rotation is 2 times of the frame frequency of the image, for two directions rotation is 4 times of the frame frequency of the image. The vibration angle requirement is that two indexes of each view field incident angle on the reflection type vibrating mirror 22 and the magnification of an optical system between the reflecting mirror and a screen are matched with each other, the pixel deviation of each view field point is not more than 10% of a reference value, the requirement of the deflection tolerance of pixels at the screen end can be met, and the display effect is not influenced. In the embodiment of the present application, an included angle between an optical axis of the first lens group and an optical axis of the second lens group is 90 degrees. The specific included angle degree can be slightly adjusted according to the design of the projection lens, and the embodiment of the application is not limited herein.

Optionally, the curved surface reflector is a concave high-order aspheric surface reflector. That is, the concave surface of the curved surface reflector in the embodiment of the present application adopts a high-order aspheric surface design, and other types of curved surface reflectors may also be adopted, and the embodiment of the present application is not limited herein.

Optionally, the first lens group 21 is movable along the optical axis 50 of the first lens group. The first lens group 21 receives the light source emitted from the light valve 31 and performs optical path adjustment, the first lens group 21 can move along the light emitting direction of the light valve 31 or the direction opposite to the light emitting direction, and the image quality of the projection apparatus can be adjusted by adjusting the position of the first lens group 21 along the optical axis direction. The specific movable distance may be set according to the related art, and details are not described herein in this embodiment of the application.

Fig. 10 is a schematic structural diagram of a projection imaging apparatus according to an embodiment of the present application.

Optionally, an embodiment of the present application further provides a projection device 30, where the projection device 30 includes a light source 34, a light valve 31, and the projection lens 20 in the foregoing embodiment. The light source 34 is used for providing a light beam to the light valve 31, the light valve 31 can generate an image light beam according to the light beam and direct the image light beam to the projection lens 20, and the projection imaging device 30 can include the projection lens shown in fig. 4 or the projection lens shown in fig. 5. The light valve (DMD for short) is a digital micromirror device, the light valve can have 2K resolution or 3K resolution, the light valve with 2K resolution can also have 4K resolution when used in combination with the galvanometer, and the reflective galvanometer needs to rotate around two rotation axes. The light valve with the resolution of 3k can also achieve the resolution of 4k by being matched with a galvanometer, at the moment, the light valve needs to rotate around 1 rotating shaft, the light valve is controlled by a control circuit, a light source incident on the light valve is reflected into the projection lens 20 to generate an imaging light beam, and an image projected on a screen by the imaging light beam is finally imaged.

Optionally, the projection imaging device 30 further includes a total reflection prism 33, and the total reflection prism 33 is located between the light valve 31 and the first lens group 21 of the projection lens 20. The total reflection prism 33 comprises two glued total reflection prisms, the gluing gap of the two glued total reflection prisms is 3-8 microns, when the total reflection prism 33 is used for illumination, the total reflection function is realized in an illumination light path, and light incident on the prisms can be totally reflected to the light valve; when the total reflection prism 33 is used in an ultra-short focus lens system, the total reflection prism 33 can be used as plate glass, and the influence of dust on the imaging quality of the system can be well controlled. The total reflection prism reduces the use number of common reflectors and can reduce the volume of the system.

In the projection imaging device provided in the embodiment of the present application, the light valve 31 provides a light source, the total reflection prism 33 receives the light emitted from the light valve 31 and emits the light to the first lens group 21, the first lens group 21 emits the light to the reflective vibrating mirror 22, the reflective vibrating mirror 22 changes the direction of the light source path, the light emitted from the first lens group 21 to the reflective vibrating mirror 22 is reflected to the second lens group 23, the second lens group 23 emits the light emitted from the reflective vibrating mirror 22 to the second lens group 23 to the screen 32, and at this time, the second lens group 23 and the screen 32 are both located in the direction perpendicular to the optical axis length direction 50 of the first lens group, so that the length of the imaging lens in the optical axis length direction 50 of the first lens group is shortened. Meanwhile, due to the vibration components of the two abutted parts in the reflecting galvanometer 22 which are perpendicular to each other, the system resolution can be improved from 2k to 4 k.

Fig. 11 is a schematic structural diagram of lens groups in a projection lens according to an embodiment of the present disclosure, and the arrangement of the lenses in the first lens group 21, the second refractive lens group 231, and the curved reflecting mirror 232 may be as shown in fig. 9:

the first refractive optical lens group 21 includes a first lens group and a second lens group, wherein the first lens group includes 6 lenses, including 1 aspheric lens a2, 1 triple cemented lens a3, 1 double cemented lens a6, and 3 spherical lenses a1, a4, a 4. The second lens group comprises 1 spherical lens a 7. Wherein the tri-cemented lens a3 comprises lenses a31, a32 and a33, and the bi-cemented lens a6 comprises a61 and a 62. Wherein the diopters of a1, a2, a31, a4 and a5 are all positive, and the diopters of a32, a33, a61 and a62 are negative.

The a2 lens is an aspheric lens and is used for correcting astigmatism and coma of an imaging device, so that the aberration correction pressure of the subsequent lens can be relieved. The a2 lens can be made of materials with lower refractive index and low melting point, such as L-BSL7, D-K59 and L-BAL42(L-BSL7, D-K59 and L-BAL42 are models of three optical materials), and the processing and manufacturing of the non-curved surface with lower cost are realized. The specific model is selected, and the embodiment of the application is not limited herein.

The a3 lens is a tri-cemented lens for correcting the primary aberration of the system, such as spherical aberration, curvature of field, chromatic aberration, etc., and the a3 lens can control the aberration of the system to the maximum extent right after the aspheric lens a 2. The a3 lens can be selected from materials with large Abbe number phase difference, the Abbe number or dispersion coefficient Vd value of the middle lens can be less than 35, the refractive index can be a high value, usually nd is more than 1.8, the lenses at two sides can be selected from materials with small refractive index and large Abbe number, nd value is selected from about 1.45-1.60, and Abbe number or dispersion coefficient is 65-95.

The lenses a4 and a5 bear larger focal power, the diaphragm is positioned on the lens a4, the correction of aberration is facilitated, the aperture of the system is controlled, and the lens a5 is sensitive relative to the lens a 4. The a6 lens is a double-cemented lens for correcting spherical aberration and chromatic aberration, and the a6 lens can be made of glass with small abbe number difference to compensate chromatic aberration generated by the a4 and a5 lenses.

The lenses in the first refractive lens group are all glass lenses, so that the problem of poor imaging quality caused by thermal deformation can be prevented, and the focal power of the lenses in the first refractive lens group is positive. The first lens group moves along the optical axis of the first refractive lens group to compensate the tolerance of the imaging device by a first compensation mode so as to ensure the imaging quality of the system; the second lens group moves along the optical axis of the first refractive lens group and is matched with the position movement of the reflector to realize the image quality adjustment of different sizes.

The second refractive optical group 231 may include 3 lenses, the a8 lens and the a9 lens are spherical glass lenses, the a10 lens is aspheric plastic lens, the power of the a8 lens is positive, and the powers of the a9 and a10 lenses are negative. Since the a10 mirror is far from the stop and has a large field of view, the addition of aspheric surface can greatly reduce the system distortion and correct the astigmatism, so the second refractor set 231 can be matched with the reflector to correct the distortion. In addition, the curved mirror group 232 may include a curved mirror a11, and the curved mirror a11 may be a concave high-order aspheric mirror. That is, the concave surface of the curved surface mirror in the embodiment of the present application adopts a high-order aspheric surface design, and may also be a free-form surface mirror, and the embodiment of the present application is not limited herein.

The specification and arrangement of the lenses in the lens group are provided in this embodiment, and the arrangement of the lens group may be in other various manners, and the specific manner of this embodiment is not limited herein.

To sum up, the projection lens and the projection apparatus provided in the embodiments of the present application include a first lens group, a reflective vibration mirror and a second lens group, the reflective vibration mirror is located between the first lens group and the second lens group, the first lens group receives light emitted from the light valve and directs the light to the reflective vibration mirror, the reflective vibration mirror reflects the light emitted from the first lens group to the reflective vibration mirror to the second lens group and deflects the light by vibration, and the second lens group directs the light emitted from the reflective vibration mirror to the screen. This application is through shaking the mirror setting with the reflection formula between first mirror group and second mirror group, because the reflection formula shakes the mirror and can change the light source route through the reflection for the optical axis of two mirror groups does not lie in same straight line, so just can shorten the length of projection lens along the principal optical axis direction. The problem of longer projection imaging device's length among the correlation technique is solved, reached the effect of reducing projection imaging device's length. Meanwhile, the distance from the light valve to the lens can be shortened, the light receiving requirement on the first lens of the lens is reduced, and the design difficulty of the lens is reduced.

In the second case, when the galvanometer is a transmissive galvanometer, the specified angle of the swing of the optical lens in the galvanometer is inversely related to the incident angle of the image beam on the light incident surface of the optical lens. Optionally, the angle of incidence is less than 16 °.

It should be noted that, when the image light beam incident on the galvanometer is a parallel light beam (that is, the incident angle of each light ray in the image light beam is the same), after the optical lens in the galvanometer swings from one position to another position, the shift distances of each pixel of the projection image corresponding to the image light beam are all the same, so that the offsets of each field of view in the projection lens to the projection screen are the same, which can ensure the high-resolution display of the visual picture. Wherein the offset of the field of view refers to the actual displacement distance of the field of view. In the embodiment of the application, because the galvanometer is arranged in the projection lens, the angles of the image beams incident on the galvanometer of the fields are different, and the offset of each field to the projection screen is different. The position of the vibrating mirror in the projection lens can be set, so that the incident angle of the image light beam on the light incident surface of the optical lens is smaller than the specified angle threshold, when the optical lens swings, the shift distance deviation between different pixels in the projection image corresponding to the image light beam is smaller, the offset of each view field in the projection lens is within the tolerance range, and the high-resolution display requirement of the visual picture is met.

In the embodiment of the present application, the specified angle of the swing of the optical lens of the galvanometer is also related to the magnification of the part of the projection lens between the galvanometer and the light valve, that is, the position of the galvanometer in the projection lens.

In the embodiment of the present application, the process of determining the designated angle of the swing of the optical lens in the galvanometer and the setting position of the galvanometer in the projection lens includes: arranging a galvanometer at a position where the image light beam approaches to the parallel light beam in the projection lens; calculating the swing designated angle of the optical lens in the galvanometer according to the specific light in the image light beam; calculating the predicted shift distance of the pixel of the projected image corresponding to the image light beam according to the specified angle; when the absolute value of the predicted shift distance is within the shift tolerance range of the target shift distance, determining the position may be used to set the galvanometer. The specific ray may be a chief ray of a near-center field (referring to a field of view in which the ray is transmitted along the optical axis), and the target shift distance is determined by the pixel size of the light valve.

Fig. 12 and fig. 13 are schematic views illustrating a scene in which a transmission galvanometer according to an embodiment of the present disclosure shifts an image beam. As shown in fig. 12 and 13, the prescribed angle of oscillation of the optical lens in the galvanometer is θ, and the thickness of the optical lens is D. Assuming that the refractive index of the optical lens is n, the magnification of a portion of the projection lens between the galvanometer and the projection screen is β, the magnification of the projection lens is β 0, and an included angle between the transmission direction of the specific light incident on the optical lens and the optical axis direction of the projection lens is γ, for example, a process of determining a designated angle of oscillation of the optical lens in the galvanometer and a setting position of the galvanometer in the projection lens will be described.

In the first step, the appointed swing angle of the optical lens in the galvanometer is calculated according to the specific light in the image light beam.

When the optical lens is swung to the first position (position indicated by a solid line in fig. 12), the incident angle of the specific light ray on the optical lens is γ, and the refraction angle is

The specific light ray is shifted by h 0-D × tanI0 after passing through the optical lens. When the optical lens swings to the second position (the position indicated by the broken line in fig. 12), the incident angle of the specific light ray on the optical lens is γ + θ, and the refraction angle

Accordingly, the specific light ray shifts its amount after passing through the optical lens

The shift amount of the specific light ray refers to a distance between an incident position of the specific light ray on the optical lens and an emergent position of the specific light ray on the optical lens on a plane perpendicular to an optical axis of the projection lens.

Therefore, when the optical lens swings from the first position to the second position, the specific light ray is actually shifted on the optical lens by the distances h0-h 1. Since the image beam emitted from the optical lens is amplified by β times and then enters the projection screen, the actual displacement distance of the pixel corresponding to the specific light ray in the image beam at the screen end (i.e. on the projection screen) is (h0-h1) × β. Assuming that the pixel size of the light valve is 5.4 μm and the target shift distance of the pixel of the projected image at the light valve end is 2.7 μm, the actual shift distance of the pixel at the screen end is made to satisfy the target shift distance, that is, (h0-h1) × β is made 2.7 × 10^-30mm (. beta.). The refractive index n of the optical lens in the galvanometer, the thickness D of the optical lens, and the magnification beta of a part of the projection lens between the galvanometer and the projection screen, wherein the magnification beta 0 of the projection lens is a known value, so the specified angle theta of the swing of the optical lens can be calculated according to the formula.

And secondly, calculating the predicted shift distance of the pixel of the projection image corresponding to the image beam according to the specified angle.

For example, assume that the maximum incident angle of the light ray in the image beam on the optical lens is q. When the optical lens swings to the first position (position indicated by solid line in fig. 13), the angle of refraction on the optical lens of the light ray having the largest incident angle q among the image light rays incident on the optical lens

After the light beam passes through the optical lens, the displacement h2 is D × tanQ. When the optical lens swings to the second position (the position indicated by the broken line in fig. 13), the incident angle q1 of the light ray on the optical lens is q + θ, and the refraction angle

Correspondingly, the light ray passes through the optical lens and then shifts

Therefore, when the optical lens swings from the first position to the second position, the predicted shift distance h4 of the light beam on the optical lens is h2-h3, and the image beam emitted from the optical lens is amplified by β times and then enters the projection screen, so that the predicted shift distance of the pixel corresponding to the light beam in the image beam at the screen end is h4 × β.

Since the optical lens has a deflection angle tolerance when it is swung, the deflection angle tolerance causes the actual displacement distance of the light to be larger than the predicted displacement distance. Therefore, in practical applications, the influence of the tolerance of the deflection angle of the optical lens on the displacement distance of the light ray needs to be considered. Fig. 14 is a schematic view of a scene in which a galvanometer shifts an image beam according to an embodiment of the present disclosure. As shown in fig. 14, the tolerance of the deflection angle of the optical lens swing in the galvanometer is α. Illustratively, | α ≦ 0.05 °, e.g., α ≦ 0.03 °.

When the optical lens is swung to the second position (schematic position a in fig. 14) in consideration of the tolerance of the deflection angle of the optical lens, the incident angle of the light ray corresponding to the maximum incident angle in the image light beam on the optical lens is q2 ═ q + θ + α, and the refraction angle is q2 ═ q + θ + α

Correspondingly, the light ray passes through the optical lens and then shifts

Therefore, when the optical lens swings from the first position (the position indicated by the solid line in fig. 14) to the second position, the predicted shift distance h6 of the light beam on the optical lens is h3-h5, and the image beam emitted from the optical lens is enlarged by β times and then enters the projection screen, so that the predicted shift distance of the pixel corresponding to the light beam in the image beam at the screen end is h6 × β.

And thirdly, when the absolute value of the predicted shift distance is within the shift tolerance range of the target shift distance, determining the position to be used for setting the galvanometer.

After the predicted shift distance of the pixel at the screen end is calculated, the relationship between the absolute value of the predicted shift distance and the shift tolerance range of the target shift distance can be determined. When the absolute value of the predicted shift distance is within the shift tolerance range of the target shift distance, the position is determined to be available for setting the galvanometer, when the absolute value of the predicted shift distance is not within the shift tolerance range of the target shift distance, the setting position of the galvanometer is replaced, and the steps are repeatedly executed until the position available for setting the galvanometer is determined.

Illustratively, when the shift tolerance range of the target shift distance is (2.7 × 10)^-3X beta 0) -g to (2.7X 10)^-3X β 0) + g, when 2.7 × 10 in consideration of the deflection angle tolerance of the optical lens^-3×β0≤|h4×β+h6×β|≤(2.7×10^-3X β 0) + g, determining the position can be used to set the galvanometer; when 2.7 is multiplied by 10^-3×β0<| h4 × β + h6 × β |, or | h4 × β + h6 × β |, as a result of the deficiency in cells>(2.7×10^-3When x β 0) + g, the position of the galvanometer is changed, and the above steps are repeated.

In the embodiment of the present application, after the position available for setting the galvanometer is determined, other positions where the galvanometer may be set may be further determined by the above method, a difference between the predicted shift distance corresponding to all the positions where the galvanometer may be set and the target shift distance is compared, and the position where the difference is the smallest is determined as the setting position of the galvanometer.

Optionally, in this embodiment of the present application, an optical lens with a certain thickness may be selected according to a position of the galvanometer in the projection lens. The thickness D of the optical lens is less than or equal to 3 mm. The transmittance of the optical lens is more than or equal to 97 percent.

As can be seen from the above displacement distance formula, when the incident light ray of the optical lens in the galvanometer is constant, the larger the deflection angle θ is, the larger the predicted displacement distance of the light ray on the optical lens is, and the larger the displacement distance of the pixel corresponding to the light ray on the screen side is. Alternatively, the incident angle of the image beam on the light incident surface of the optical lens of the galvanometer in the projection lens may be less than 16 °. Thus, under the influence of the tolerance of the deflection angle, when the actual maximum deflection angle of the optical lens is slightly larger than the theoretical maximum deflection angle and the image beams output from the optical lens are approximately parallel, the displacement distance of the pixels at the screen end is within the tolerance range of the target displacement distance.

Alternatively, fig. 15 is a schematic structural diagram of another projection imaging apparatus 30 provided in the embodiment of the present application. As shown in fig. 15, the light valve 31 emits the image beam to the refraction system 202, and the refraction system 202 includes a first lens group 2021, a relay lens group 2022, and a second lens group 2023 sequentially arranged along the incident and transmission direction X of the image beam. The galvanometer 201 is located between the relay lens group 2022 and the second lens group 2023. The first lens group 2021 and the relay lens group 2022 may belong to a first lens group, and the second lens group 2023 and the curved mirror 203 may belong to a second lens group.

In the refractive system of the projection lens, which is designed generally, a gap is formed between the relay lens group and the second lens group, and the galvanometer is disposed in the gap, so that the relative position relationship of the lenses in the projection lens does not need to be changed, that is, the structure of the projection lens does not need to be redesigned, and the realizability is high.

Illustratively, referring to fig. 15, when the galvanometer is positioned between the relay lens group 2022 and the second lens group 2023, the prescribed angle by which the optical lens swings in the galvanometer 201 is 1 °.

It should be noted that, in the optical design of the lens, a unit composed of a plurality of lenses is usually regarded as a group, and intuitively, the unit can be moved as a whole as a unit, for example, there are 10 lenses in the lens, 5 lenses in a group, and the two groups are divided into two groups, and the two groups are respectively regarded as a small whole and can be displaced relative to each other, where the displacement may be tolerance adjustment during assembly, or may be a change in distance between the groups in accordance with the zooming of the lens to change the focal length of the lens. While the relative position between the lenses within each group does not change, each group has its own focal length parameter.

Exemplarily, the first lens group, the relay lens group, and the second lens group may be divided into three groups. According to the positions of the three groups in the projection lens, the first lens group is called a rear group, the relay lens group is called a middle group, and the second lens group is called a front group. Alternatively, the relay lens group and the second lens group may be divided into a group, and the group division manner of the lens groups is not limited in the embodiments of the present application.

Alternatively, the first lens group may include: and the lenses are sequentially arranged along the incident and transmission direction of the image light beam. For example, referring to fig. 15, the first lens group 2021 may include nine lenses sequentially arranged along the incident and transmission direction of the image beam, and respectively include: a first lens c1, a second lens c2, a third lens c3, a fourth lens c4, a fifth lens c5, a sixth lens c6, a seventh lens c7, an eighth lens c8, and a ninth lens c 9.

Alternatively, the relay lens group may include one or more pieces of relay lenses. The relay lens has a positive lens characteristic, i.e., has the ability to converge light. For example, the relay lens may be a positive power lens.

Alternatively, the second lens group may include: and the lenses are sequentially arranged along the incident and transmission direction of the image light beam. For example, referring to fig. 15, the second lens group 2023 may include three lenses sequentially arranged along the incident and transmission direction of the image beam, and respectively include: a tenth lens b1, an eleventh lens b2, and a twelfth lens b 3. The second lens group may be used to correct distortion of the projection lens.

Optionally, with continued reference to fig. 15, the refractive system 202 further comprises an aperture 2024, and the aperture 2024 is located in the first lens group 2021. Illustratively, the stop 2024 may be located between the fifth lens c5 and the sixth lens c 6.

Note that, by disposing the galvanometer between the relay lens group and the second lens group and disposing the stop in the first lens group, the galvanometer can be disposed away from the stop. When the incident angle of the image incident on the light incident surface of the optical lens is large, the vibrating mirror shifts the image beam, which results in large deviation of the shift distance between different pixels of the projected image corresponding to the image beam, and affects the projection imaging effect of the projection lens. The divergence angle of the image light beam near the diaphragm is usually larger, so that the galvanometer is usually arranged far away from the diaphragm, so that the displacement distance deviation between different pixels of the projection image corresponding to the image light beam after the deflection processing of the galvanometer is smaller, the projection imaging effect of the projection lens is ensured, and the high-resolution display of the visual picture is realized.

Optionally, the galvanometer may be further disposed at another position away from the stop, for example, the galvanometer 201 may be further disposed between the reflection system 203 and the refraction system 202, or fig. 16 is a schematic structural diagram of another projection lens provided in the embodiment of the present application, please refer to fig. 16, and the galvanometer 201 may be further disposed in the second lens group 2023, which is not limited in the embodiment of the present application.

To sum up, the projection lens that this application embodiment provided, because the galvanometer sets up in projection lens, consequently compare with the correlation technique, can shorten the distance of light valve to projection lens among the projection imaging device, and then can reduce projection imaging device's volume, simplified projection imaging device's framework, be favorable to realizing projection imaging device's miniaturization.

The embodiment of the application provides a projection imaging device, because a projection lens can be a telecentric design structure (that is, a light path of the projection lens is a telecentric light path) or a non-telecentric design structure (that is, a light path of the projection lens is a non-telecentric light path), the projection imaging device can be divided into a telecentric structure and a non-telecentric structure by matching with lenses with different structures. Fig. 17 is a schematic structural diagram of a projection imaging apparatus according to an embodiment of the present application. When the projection imaging apparatus is a non-telecentric configuration, as shown in fig. 17, the projection imaging apparatus 30 includes: a light valve 31 and any of the projection lenses 20 provided in the above embodiments. The light valve 21 is used for generating an image beam when being illuminated. Illustratively, the light valve may be a DMD and the projection lens is a 4K ultra-short focal projection lens.

It should be noted that, in the projection imaging apparatus according to the embodiment of the present application, the resolution of the DMD is smaller than the resolution of the image to be projected, when the resolution of the image to be projected is 4K, the resolution of the DMD is smaller than 4K, and when the resolution of the image to be projected is higher, for example, 8K, the resolution of the DMD is also smaller than 8K, so that a galvanometer is needed to display a high-definition image by image superposition, and at this time, the resolution of the ultra-short-focus projection lens can correspondingly display the image with higher resolution.

Optionally, fig. 18 is a schematic structural diagram of another projection imaging apparatus provided in the embodiment of the present application. When the projection imaging apparatus is a telecentric configuration, as shown in fig. 18, the projection imaging apparatus 2 further includes: the TIR prism 34 and the TIR prism 23 are located between the light valve 21 and the projection lens 20. The TIR prism 23 is used to reflect the image beam to the projection lens. Illustratively, the TIR prism may be a1 total reflection prism. Because in the projection lens of telecentric design structure, the image light beam that same point sent out on the light valve does not change along with the change of light valve position, avoided like this because the projection lens focusing is inaccurate or the depth of field exists the projection parallax that produces, compare in the projection lens image quality of non-telecentric design structure better, the homogeneity of projection image is higher, consequently, in the practical application, projection lens adopts telecentric design structure more, then projection imaging device also adopts telecentric framework more.

The above description is only exemplary of the present application and should not be taken as limiting, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A projection imaging apparatus, comprising a light valve and a projection lens, wherein the projection lens comprises:

the second lens group is used for guiding the received image light beams to the screen;

the galvanometer is a transmission type galvanometer;

the first lens group comprises a first refractive lens group, and the second lens group comprises a second refractive lens group and a curved surface reflector;

the first mirror group can move along the optical axis of the first refractive mirror group to compensate the tolerance of the projection imaging device;

the first refractive lens group comprises an aspheric lens, a tri-cemented lens, a bi-cemented lens and four spherical lenses, the aspheric lens is used for correcting astigmatism and coma of the projection imaging device, and the tri-cemented lens is used for correcting primary aberration;

the lenses in the first refractive lens group are all glass lenses, and the focal power of the lenses in the first refractive lens group is positive.

2. The projection imaging apparatus of claim 1, wherein the projection lens further comprises a plane mirror, the plane mirror being located between the second set of refractive mirrors and the curved mirror.

3. A projection imaging apparatus according to claim 2, wherein said plane mirror is located at an imaging plane of said set of refractors.

4. The projection imaging apparatus according to claim 1, wherein when the galvanometer is a transmissive galvanometer, the galvanometer includes an optical lens and a driving assembly;

5. The projection imaging apparatus according to claim 4, wherein the specified angle is inversely related to an incident angle of the image beam on the light incident surface of the optical lens.

6. The projection imaging apparatus of claim 5, wherein the angle of incidence is less than 16 °.

7. The projection imaging apparatus according to claim 5, further comprising: a Total Internal Reflection (TIR) prism located between the light valve and the projection lens;

8. The projection imaging apparatus according to claim 7, wherein the resolution of the light valve is 2K or 3K, and the projection lens is a 4K ultra-short focus projection lens.