Projection equipment

Abstract

The invention discloses projection equipment, which comprises a laser light source device, an illumination system and a projection lens, and is characterized in that the projection lens comprises a first lens group, a second lens group and a diaphragm; the second lens group is located between the first lens group and the light modulator, and the diaphragm is located between the first lens group and the second lens group; wherein the first lens group comprises an aspheric lens, and the second lens group comprises a triplet lens group and an aspheric lens. Through reasonable optical design, the projection lens can be suitable for panchromatic laser spectrums under the condition that the projection lens is kept small in size, and the chromatic aberration is smaller than 0.2 pixel.

Description

Technical Field

[0001] The present invention relates to the field of projection technology, and in particular to a projection device. Background Art

[0002] Laser projection display technology, also known as laser projection technology or laser display technology, is a display technology that uses red, green, and blue primary color lasers as light sources. It can most realistically reproduce the rich and colorful colors of the objective world and provide more shocking expressiveness.

[0003] Since the spectral range of using primary color lasers as light sources is relatively large, it has become increasingly important to achieve small color differences while ensuring imaging quality. At the same time, keeping the distortion within a small range while achieving a large-size projection screen can effectively improve the user experience. Summary of the Invention

[0004] An embodiment of the present invention provides a projection device, including:

[0005] A laser light source device for emitting primary color lasers;

[0006] An illumination system located on the light-emitting side of the laser light source device; the illumination system includes a light modulator for modulating the incident laser and then emitting it;

[0007] A projection lens located on the light-emitting side of the light modulator; the projection lens includes a first lens group, a second lens group, and a diaphragm; the second lens group is located between the first lens group and the light modulator, and the diaphragm is located between the first lens group and the second lens group;

[0008] Wherein, the first lens group includes an aspherical lens, and the second lens group includes a three-piece lens group and an aspherical lens.

[0009] In some embodiments of the present invention, the first lens group includes: a first lens, a second lens, a third lens, and a fourth lens sequentially arranged along the direction gradually approaching the second lens group;

[0010] The first lens is an aspherical lens, and the second lens, the third lens, and the fourth lens are all spherical lenses;

[0011] The optical power of the first lens is negative, the optical power of the second lens is negative, the optical power of the third lens is positive, and the optical power of the fourth lens is positive.

[0012] In some embodiments of the present invention, the second lens group includes: a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens sequentially arranged along the direction gradually away from the first lens group;

[0013] The fifth lens, the sixth lens, and the seventh lens are mutually cemented to form the triplet lens group;

[0014] The eighth lens is an aspherical lens, and the fifth lens, the sixth lens, the seventh lens, and the ninth lens are all spherical lenses;

[0015] The optical power of the fifth lens is positive, the optical power of the sixth lens is negative, the optical power of the seventh lens is positive, the optical power of the eighth lens is positive, and the optical power of the ninth lens is positive.

[0016] In some embodiments of the present invention, the first lens satisfies:

[0017] -0.5 ≤ SAG11 / SAG12 ≤ 0;

[0018] Wherein, SAG11 represents the axial distance between the intersection of the image side of the first lens and the optical axis and the vertex of the effective radius of the image side of the first lens, and SAG12 represents the axial distance between the intersection of the object side of the first lens and the optical axis and the vertex of the effective radius of the object side of the first lens.

[0019] In some embodiments of the present invention, the eighth lens satisfies:

[0020] 3 ≤ ct / et ≤ 5;

[0021] Wherein, ct represents the central thickness of the eighth lens along the optical axis direction, and et represents the edge thickness of the eighth lens along the optical axis direction.

[0022] In some embodiments of the present invention, the projection lens satisfies:

[0023] 0.2 ≤ (CT8 + CT9) / ∑CT ≤ 0.3;

[0024] Wherein, CT8 represents the central thickness of the eighth lens along the optical axis direction, CT9 represents the central thickness of the ninth lens along the optical axis direction, and ∑CT represents the sum of the central thicknesses of the nine lenses in the projection lens along the optical axis direction.

[0025] In some embodiments of the present invention, the projection lens further includes:

[0026] A lens barrel having a hollow structure;

[0027] A first adjustment component located inside the lens barrel; the first lens and the second lens are fixed in the first adjustment component;

[0028] A second adjustment component located inside the lens barrel; the third lens and the fourth lens are fixed in the second adjustment component;

[0029] A first adjusting ring is sleeved outside the lens barrel; the first adjusting ring is respectively connected to the first adjusting component and the second adjusting component;

[0030] A second adjusting ring is sleeved outside the lens barrel; the second adjusting ring is connected to the lens barrel;

[0031] A first driving device is connected to the first adjusting ring; the first driving device is used to drive the first adjusting ring to rotate so as to drive the first adjusting component and the second adjusting component to move relatively along the optical axis direction of the projection lens;

[0032] A second driving device is connected to the second adjusting ring; the second driving device is used to drive the second adjusting ring to rotate so as to drive the lens barrel to move along the optical axis direction of the projection lens;

[0033] The projection lens projects projection pictures of different sizes under the drive of the first driving device and the second driving device.

[0034] In some embodiments of the present invention, the lens barrel is provided with a first limiting hole and a second limiting hole;

[0035] The first adjusting ring is provided with a first moving groove, a second moving groove and a third moving groove;

[0036] A first adjusting shaft is fixed on the first adjusting component, a second adjusting shaft is fixed on the second adjusting component, and a third adjusting shaft is fixed on the lens barrel;

[0037] The first adjusting shaft passes through the first limiting hole and the first moving groove; the second adjusting shaft passes through the second limiting hole and the second moving groove; the third adjusting shaft passes through the third moving groove; by rotating the first adjusting ring, the first adjusting shaft, the second adjusting shaft and the third adjusting shaft move in the corresponding moving grooves to drive the first adjusting component and the second adjusting component to move along the optical axis direction of the projection lens;

[0038] Wherein, the first moving groove and the second moving groove are curve grooves, and the third moving groove is a straight groove; the trajectories of the first moving groove and the second moving groove are generated by function fitting of the relative positions satisfied by the first adjusting component and the second adjusting component when the projection lens projects projection pictures of different sizes.

[0039] In some embodiments of the present invention, a fourth moving groove is provided on the second adjusting ring; the lens barrel is further provided with a fourth adjusting shaft; the fourth adjusting shaft passes through the fourth moving groove; by rotating the second adjusting ring, the fourth adjusting shaft moves in the fourth moving groove to drive the lens barrel to move along the optical axis direction of the projection lens;

[0040] Wherein, the fourth moving groove is a linear groove.

[0041] In some embodiments of the present invention, the lens further includes:

[0042] A first spacer ring, located within the second adjusting assembly, disposed between the third lens and the fourth lens, for maintaining the spacing between the third lens and the fourth lens;

[0043] A second spacer ring, located within the lens barrel, disposed between the seventh lens and the eighth lens, for maintaining the spacing between the seventh lens and the eighth lens;

[0044] A third spacer ring, located within the lens barrel, disposed between the eighth lens and the ninth lens, for maintaining the spacing between the eighth lens and the ninth lens;

[0045] A first retaining ring, located within the first adjusting assembly, for fixing the first lens and the second lens in the first adjusting assembly;

[0046] A second retaining ring, located within the second adjusting assembly, for fixing the third lens and the fourth lens in the second adjusting assembly;

[0047] A third retaining ring, located within the lens barrel, for fixing the eighth lens and the ninth lens within the lens barrel;

[0048] Wherein, the inner surface of at least one spacer ring or retaining ring includes serrations or steps.

[0049] The projection device provided by the embodiments of the present invention includes: a laser light source device, an illumination system, and a projection lens. The projection lens includes a first lens group, a second lens group, and a diaphragm. The second lens group is located between the first lens group and the light modulator, and the diaphragm is located between the first lens group and the second lens group. Wherein, the first lens group includes an aspherical lens, and the second lens group includes a triplet lens group and an aspherical lens. Through reasonable optical design, it is possible to apply to the full-color laser spectrum while maintaining a small volume of the projection lens, and the chromatic aberration is less than 0.2 pixel. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a schematic diagram of the imaging principle of the projection device provided by the embodiments of the present invention;

[0051] Figure 2 Schematic diagram of the structure of the projection lens provided by the embodiment of the present invention;

[0052] Figure 3 Modulation transfer function curve of the projection lens provided by the embodiment of the present invention when projecting a 60-inch projection image;

[0053] Figure 4 Modulation transfer function curve of the projection lens provided by the embodiment of the present invention when projecting a 120-inch projection image;

[0054] Figure 5 Modulation transfer function curve of the projection lens provided by the embodiment of the present invention when projecting a 160-inch projection image;

[0055] Figure 6 Defocus curve of the projection lens provided by the embodiment of the present invention when projecting a 60-inch projection image;

[0056] Figure 7 Defocus curve of the projection lens provided by the embodiment of the present invention when projecting a 120-inch projection image;

[0057] Figure 8 Defocus curve of the projection lens provided by the embodiment of the present invention when projecting a 160-inch projection image;

[0058] Figure 9 Lateral chromatic aberration diagram of the projection lens provided by the embodiment of the present invention when projecting a 60-inch projection image;

[0059] Figure 10 Lateral chromatic aberration diagram of the projection lens provided by the embodiment of the present invention when projecting a 120-inch projection image;

[0060] Figure 11 Lateral chromatic aberration diagram of the projection lens provided by the embodiment of the present invention when projecting a 160-inch projection image;

[0061] Figure 12 Longitudinal chromatic aberration diagram of the projection lens provided by the embodiment of the present invention when projecting a 60-inch projection image;

[0062] Figure 13 Longitudinal chromatic aberration diagram of the projection lens provided by the embodiment of the present invention when projecting a 120-inch projection image;

[0063] Figure 14 Longitudinal chromatic aberration diagram of the projection lens provided by the embodiment of the present invention when projecting a 160-inch projection image;

[0064] Figure 15 Schematic diagram of the field curvature curve of the projection lens provided by the embodiment of the present invention when projecting a 60-inch projection image;

[0065] Figure 16 Schematic diagram of the field curvature curve of the projection lens provided by the embodiment of the present invention when projecting a 120-inch projection image;

[0066] Figure 17 Schematic diagram of the field curvature curve of the projection lens provided by the embodiment of the present invention when projecting a 160-inch projection image;

[0067] Figure 18 Schematic diagram of the distortion curve of the projection lens provided by the embodiment of the present invention when projecting a 60-inch projection image;

[0068] Figure 19 Schematic diagram of the distortion curve of the projection lens provided by the embodiment of the present invention when projecting a 120-inch projection image;

[0069] Figure 20 Schematic diagram of the distortion curve of the projection lens provided by the embodiment of the present invention when projecting a 160-inch projection image;

[0070] Figure 21 Schematic diagram of the relative illuminance curve provided by the embodiment of the present invention;

[0071] Figure 22 Schematic diagram of the telecentricity curve provided by the embodiment of the present invention;

[0072] Figure 23 Cross-sectional view of the projection lens provided by the embodiment of the present invention;

[0073] Figure 24 Stereoscopic cross-sectional view of the projection lens provided by the embodiment of the present invention;

[0074] Figure 25 Schematic diagram of the structure of the adjustment component provided by the embodiment of the present invention;

[0075] Figure 26 Stereoscopic structure diagram of the lens barrel provided by the embodiment of the present invention;

[0076] Figure 27 Stereoscopic structure diagram of the first adjustment ring provided by the embodiment of the present invention;

[0077] Figure 28 Stereoscopic structure diagram of the projection lens provided by the embodiment of the present invention;

[0078] Figure 29 Schematic diagram of the relative position curve of the first lens group provided by the embodiment of the present invention;

[0079] Figure 30 Schematic diagram of the relative position curve of the second lens group provided by the embodiment of the present invention. Detailed implementation manners

[0080] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described below with reference to the accompanying drawings and examples. However, the exemplary embodiments can be implemented in various forms and should not be understood as being limited to the embodiments described herein; on the contrary, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concepts of the exemplary embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and thus their repeated descriptions will be omitted. The words expressing position and direction described in the present invention are all explained using the accompanying drawings as examples, but changes can be made as needed, and the changes made are all included in the scope of protection of the present invention. The drawings of the present invention are only used to illustrate the relative position relationship and do not represent the true proportions.

[0081] Projection display technology is a technology that uses optical systems and projection space to magnify and display image information. The projection system is an optical imaging system that ultimately displays the image. With the continuous development of projection technology, laser projection systems have been widely used in large-screen displays, laser TVs, digital cinemas, portable projection displays, and other fields due to their unique advantages. Laser projection display can display more realistic and gorgeous dynamic images on ultra-large screens, achieving visual shock effects that other display technologies cannot achieve.

[0082] In practical applications, projection systems can be divided into front projection systems and rear projection systems, wherein the front projection system may include: a projection device and a projection screen. The projection screen is located on the light-emitting side of the projection device, the audience faces the projection screen, the projection device emits projection light, the projection light is incident on the projection screen, and is reflected to the position of the audience through the projection screen, so that the audience can see the projected image.

[0083] The projection device is provided with a projection lens, and the specifications of the projection lens will affect the size of the projection image and the projection distance. In actual applications, ultra-short-throw, short-throw or long-throw projection lenses are used according to different application scenarios.

[0084] Figure 1 A schematic diagram of the imaging principle of a projection device provided in an embodiment of the present invention.

[0085] like Figure 1 As shown, the projection device includes: a projection light source 1, an illumination system 2 and a projection lens 3. The illumination system 2 is located at the light-emitting side of the projection light source 1, and a light modulator 21 is provided in the illumination system 2. The light modulator 21 is used to modulate the incident light before emitting it, and the projection lens 3 is located at the light-emitting side of the light modulator 21.

[0086] The projection light source 1 can adopt a light emitting diode (LED) light source or a laser light source. The LED light source has the advantages of low power consumption, small size, long service life, etc., and is suitable for application scenarios such as small-sized projection. The laser light source has higher brightness and better color saturation, and can optimize the display effect of the projection image.

[0087] In the embodiment of the present invention, the projection light source 1 can adopt a laser light source device. The laser light source device can adopt a single-color laser or a laser that can emit multiple colors of laser or multiple lasers that emit different colors of laser. When the laser light source device adopts a single-color laser, a color wheel needs to be set. The color wheel is used for color conversion, and the single-color laser and the color wheel can be used to achieve the purpose of emitting primary color lights of different colors in sequence. When the laser light source device adopts a laser that can emit multiple colors of laser, it is necessary to control the laser light source to emit lasers of different colors in sequence as primary color lights. Using a three-color laser light source is beneficial to improving the color gamut of the projection image, has better color expressiveness, and can accurately reproduce the input image.

[0088] The illumination system 2 is located on the light-emitting side of the projection light source 1. On the one hand, the illumination system 2 collimates and homogenizes the emitted light of the projection light source 1, and on the other hand, it can make the emitted light of the projection light source 1 enter the light modulator 21 at an appropriate angle. The illumination system 2 can include multiple lenses or lens groups, light guide tubes, diffuser sheets, diffuser wheels and other components, which are not limited here.

[0089] The light modulator 21 is used to modulate the incident light to form an image. In specific implementation, the light modulator 21 can adopt a transmissive light modulator or a reflective light modulator. Figure 2 The shown light modulator 21 is a reflective light modulator. The light modulator 21 receives the light reflected by the beam splitter prism P, modulates the incident light, and reflects the modulated light. Since the optical path is folded back by the reflective light modulator, the volume of the projection device can be reduced.

[0090] In the embodiment of the present invention, the light modulator 21 can adopt liquid crystal on silicon (LCoS) or digital micromirror device (DMD).

[0091] LCoS is formed by laminating a complementary metal oxide semiconductor (CMOS) substrate and a glass substrate containing transparent electrodes based on semiconductor technology, and then injecting liquid crystal for encapsulation. LCoS has the characteristics of high aperture ratio and high resolution of each pixel, and can form high-resolution images.

[0092] The DMD includes a plurality of micromirrors, and each micromirror can be individually driven to deflect. By controlling the deflection angle of the DMD, the brightness of the light incident on the projection lens 3 is controlled.

[0093] The beam splitter prism P is used to separate the illumination beam and the imaging beam. Since the beam emitted by the projection light source is finally reflected by the beam splitter prism P towards the light modulator 21 after processes such as shaping and homogenization, and the light emitted after being modulated by the light modulator 21 will pass through the beam splitter prism P and be incident on the projection lens 3 for emission.

[0094] In specific implementation, an image shift component Z can also be provided on the light-emitting side of the light modulator 21. The image polarization component Z can generally adopt a flat glass, and high-frequency vibration can be used to achieve image shift so as to achieve high-resolution image display.

[0095] The surface of the light modulator 21 has a protective glass G. When conducting optical design, the influence of the protective glass G also needs to be considered.

[0096] After the light modulator 21 modulates the incident light to form an image, the light is reflected towards the projection lens 3, and the projection lens 3 performs imaging, thereby projecting the image onto a suitable size for viewing.

[0097] For a projection system using a three-color laser light source as the projection light source, the spectral range becomes larger. On the premise of ensuring the imaging quality, it becomes increasingly important to achieve small chromatic aberration; at the same time, for a large-size projection image, keeping its distortion within a small range can effectively improve the viewing experience.

[0098] Figure 2 It is a schematic diagram of the architecture of the projection lens provided in this embodiment of the present invention.

[0099] As Figure 2 shown, the projection lens includes a first lens group 31, a diaphragm s, and a second lens group 32 which are coaxially arranged; among them, the second lens group 32 is located between the first lens group 31 and the light modulator 21, and the diaphragm s is located between the first lens group 31 and the second lens group 32. In the embodiment of the present invention, the first lens group 31 includes an aspherical lens, and the second lens group 32 includes a triplet lens group and an aspherical lens. Through reasonable optical design, it is applicable to the full-color laser spectrum with a small volume of the projection lens, and the chromatic aberration is less than 0.2 pixel.

[0100] Specifically, as Figure 2As shown, the first lens group 31 includes: a first lens l1, a second lens l2, a third lens l3, and a fourth lens l4 arranged in sequence along the direction gradually approaching the second lens group 32. The second lens group 32 includes: a fifth lens l5, a sixth lens l6, a seventh lens l7, an eighth lens l8, and a ninth lens l9 arranged in sequence along the direction gradually moving away from the first lens group 31.

[0101] According to the propagation direction of light, the light modulated by the light modulator 21 passes through the beam splitter prism P and then enters from the side of the ninth lens l9. After passing through the nine lenses in sequence, it exits from the side of the first lens l1. Therefore, when the projection lens is applied, the side close to the light modulator 21 is the object side, and the side close to the projection screen is the image side. When performing optical design, the final imaging position is used as the object plane, and the light exit surface of the light modulator 21 is used as the image plane to optimize the design of each lens in the projection lens, and then the property of reversible light path is used to achieve projection imaging.

[0102] Hereinafter, the surface of the lens close to the light modulator 21 is referred to as the object side surface, and the surface of the lens close to the projection screen is referred to as the image side surface.

[0103] The first lens l1 has a negative focal power. The diopter of the image side surface of the first lens l1 is negative, and the diopter of the object side surface of the first lens l1 is positive; the second lens l2 has a negative focal power. The diopter of the image side surface of the second lens l2 is negative, and the diopter of the object side surface of the second lens l2 is negative; the third lens l3 has a positive focal power. The diopter of the image side surface of the third lens l3 is positive, and the diopter of the object side surface of the third lens l3 is positive; the fourth lens l4 has a positive focal power. The diopter of the image side surface of the fourth lens l4 is positive, and the diopter of the object side surface of the fourth lens l4 is negative; the fifth lens l5 has a positive focal power. The diopter of the image side surface of the fifth lens l5 is positive, and the diopter of the object side surface of the fifth lens l5 is positive; the sixth lens l6 has a negative focal power. The diopter of the image side surface of the sixth lens l6 is negative, and the diopter of the object side surface of the sixth lens l6 is negative; the seventh lens l7 has a positive focal power. The diopter of the image side surface of the seventh lens l7 is positive, and the diopter of the object side surface of the seventh lens l7 is negative; the eighth lens l8 has a positive focal power. The diopter of the image side surface of the eighth lens l8 is positive, and the diopter of the object side surface of the eighth lens l8 is positive; the ninth lens l9 has a positive focal power. The diopter of the image side surface of the ninth lens l9 is positive, and the diopter of the object side surface of the ninth lens l9 is positive.

[0104] Among them, the first lens l1 and the eighth lens l8 are aspherical lenses, and the second lens l2, the third lens l3, the fourth lens l4, the fifth lens l5, the sixth lens l6, the seventh lens l7, and the ninth lens l9 are all spherical lenses.

[0105] The projection lens provided by the embodiment of the present invention only includes 9 lenses, only two aspherical lenses are required, and one of the two aspherical lenses is a plastic aspherical lens and the other is a glass aspherical lens. By reasonably optimizing the surface profiles of each lens, the length of the projection lens can be controlled within 80 mm, greatly reducing the volume of the optical engine. At the same time, the projection ratio of the projection lens is 1.2, and the image has a small distortion even at a large size, and projection display in the range of 60 to 160 inches can be achieved while maintaining the optical performance.

[0106] The fifth lens l5, the sixth lens l6 and the seventh lens l7 are mutually cemented to form a triplet lens group. The refractive indices of the fifth lens l5 and the seventh lens l7 are both less than that of the sixth lens l6, and the high Abbe numbers of the fifth lens l5 and the seventh lens l7 are both greater than that of the sixth lens l6. This triplet lens group is a typical old cemented lens combination, which can effectively reduce the chromatic aberration of the optical system, so that the chromatic aberration of the projection lens can be less than 1.1 μm within the projection range of 60 to 160 inches. If used with a 0.47-inch DMD, the chromatic aberration between red light and blue light, the chromatic aberration between red light and green light, and the chromatic aberration between blue light and green light can all meet the requirement of being less than or equal to 0.2 pixel. The overall optical power of this triplet lens group is positive, and the optical power of the cemented surface is negative. The overall optical power participating in the optical system is small, which can effectively correct the high-order aberrations of the system.

[0107] Among them, the first lens l1 satisfies:

[0108] -0.5 ≤ SAG11 / SAG12 ≤ 0;

[0109] Among them, SAG11 represents the axial distance between the intersection of the image side of the first lens l1 and the optical axis and the vertex of the effective radius of the image side of the first lens l1, that is, the sagittal height of the image side of the first lens l1; SAG12 represents the axial distance between the intersection of the object side of the first lens l1 and the optical axis and the vertex of the effective radius of the object side of the first lens l1, that is, the sagittal height of the object side of the first lens l1. By controlling the ratio of the sagittal heights, the image side of the first lens l1 is in an M shape, effectively improving the third-order aberration, coma and distortion of the optical system, and at the same time ensuring that the difference in the sagittal heights of the two surfaces of the first lens is not too large, ensuring the processability of the first lens.

[0110] The eighth lens l8 satisfies:

[0111] 3 ≤ ct / et ≤ 5;

[0112] Wherein, ct represents the central thickness of the eighth lens L8 along the optical axis direction, and et represents the edge thickness of the eighth lens L8 along the optical axis direction. The eighth lens L8 is a positive lens, which bears a relatively large optical power in the optical system. At the same time, since the eighth lens L8 is an aspherical lens, while realizing the change of the effective height of the light rays, it can effectively correct the system aberration and field curvature, and improve the overall performance of the system.

[0113] The projection lens satisfies:

[0114] 0.2 ≤ (CT8 + CT9) / ∑CT ≤ 0.3;

[0115] Wherein, CT8 represents the central thickness of the eighth lens L8 along the optical axis direction, CT9 represents the central thickness of the ninth lens L9 along the optical axis direction, and ∑CT represents the sum of the central thicknesses of the nine lenses in the projection lens along the optical axis direction. Reasonably controlling the central thicknesses of the two positive optical power lenses in the second lens group can more reasonably distribute the optical power on the second lens group, so that the curvature radii of these two lenses will not be too small to cause difficulty in lens processing, and at the same time reduce the system processing sensitivity, thereby contributing to the improvement of the overall yield of the projection lens assembly and enhancing the stability of the system structure.

[0116] By designing the surface shapes and their combination modes of the nine lenses in the projection lens according to the embodiments of the present invention, the projection ratio of the projection lens can be 1.2, the total length of the projection lens is less than 80 mm, and the chromatic aberration is less than 0.2 pixel within the range of 60 - 160-inch screen adjustment.

[0117] The surface shape parameters of each optical component in the projection lens provided by the embodiments of the present invention and the distances between the optical components are shown in the following table:

[0118]

[0119]

[0120] The aspheric coefficients of the first lens are shown in the following table:

[0121]

[0122]

[0123] The aspheric coefficients of the eighth lens are shown in the following table:

[0124]

[0125]

[0126] Based on the above parameters, the projection lens is a long - focal - length lens, with a projection ratio of 1.2, an effective focal length of 12.24 mm, an offset of 100% - 102%, a resolution ability of up to 93 lp / mm, a projectable size range of 60 - 160 inches, and a chromatic aberration less than or equal to 0.2 pixel.

[0127] In the embodiments of the present invention, the image quality evaluation of the projection lens for imaging with different sizes is also carried out based on the above - mentioned parameter optimization results.

[0128] Figure 3 、 Figure 4 、 Figure 5 respectively show the Modulation Transfer Function (MTF) curves of light with wavelengths of 647 nm, 525 nm, and 455 nm in different fields of view when the projection lens projects projection images of 60 inches, 120 inches, and 160 inches. Among them, the abscissa represents the spatial frequency, expressed as the number of cycles per millimeter in the image space, with the unit of cycles / mm, and the ordinate represents the MTF value (Modulation). MTF can characterize the resolution of the lens. It can be seen that Figures 3 - 5 the MTF values of light in different fields of view are all above 0.6 and the curves are relatively flat, indicating that the imaging gap between the edge and the center of the projection lens is small and the imaging quality is good.

[0129] Figure 6 、 Figure 7 、 Figure 8 respectively show the defocus curves of light with wavelengths of 647 nm, 525 nm, and 455 nm in different fields of view when the spatial frequency is 93.0 cycles / mm when the projection lens projects projection images of 60 inches, 120 inches, and 160 inches. Among them, the abscissa represents the defocusing position, with the unit of mm, and the ordinate represents the MTF value (Modulation). It can be seen that Figures 6 - 8 the MTF values of light in different fields of view at the optical axis are all above 0.6, and the degree of image plane offset is within a reasonable range.

[0130] Figure 9 、 Figure 10 、 Figure 11 respectively show the lateral chromatic aberration of light with wavelengths of 647 nm, 525 nm, and 455 nm in a certain field of view range when the projection lens projects projection images of 60 inches, 120 inches, and 160 inches. Among them, the abscissa represents the lateral chromatic aberration, with the unit of μm, and the ordinate is the actual imaging size, with the unit of mm.Figures 9 - 11 It can be seen that the lateral chromatic aberration of the projection lens is below 1.1 μm.

[0131] Figure 12 、 Figure 13 、 Figure 14 respectively show the axial chromatic aberrations of light rays with wavelengths of 647 nm, 525 nm, and 455 nm when the projection lens projects projection screens of 60 inches, 120 inches, and 160 inches. It can be seen from Figures 12 - 14 that the intervals between the curves corresponding to the three wavelengths are small, indicating that the axial chromatic aberration of the projection lens is small and meets the requirements.

[0132] Figure 15 、 Figure 16 、 Figure 17 respectively show the field curvature curves in the meridional direction (T) and the sagittal direction (S) when the projection lens projects projection screens of 60 inches, 120 inches, and 160 inches. The abscissa represents the field curvature magnitude, with the unit of mm, and the ordinate represents the image height (field of view). It can be seen from Figures 15 - 17 that the field curvature of the projection lens is controlled within 0.02 mm.

[0133] Figure 18 、 Figure 19 、 Figure 20 respectively show the distortion curves of the projection lens at different fields of view when the projection lens projects projection screens of 60 inches, 120 inches, and 160 inches. The abscissa represents the distortion percentage of the imaging, and the ordinate represents the image height (field of view). It can be seen from Figures 18 - 20 that the distortion of the projection lens is controlled within 0.5%.

[0134] Figure 21 This is a schematic diagram of the relative illuminance curve provided by the embodiment of the present invention.

[0135] As Figure 21 shown, the abscissa of the relative illuminance curve graph represents the chief ray image height, with the unit of mm, and the ordinate represents the relative illuminance at the peripheral position when the central light quantity is 100%, with the unit of %. It can be seen from Figure 21 that the relative illuminance of the projection lens is above 70%, having a relatively large common amount.

[0136] Figure 22 This is a schematic diagram of the telecentricity curve provided by the embodiment of the present invention.

[0137] Figure 22 shows the telecentricity histogram of the light rays emitted by the DMD at different fields of view. The abscissa represents the image height, and the ordinate represents the angle of the emitted light corresponding to different fields of view, that is, the telecentricity. The specific data is shown in the following table. It can be seen that the telecentricity is less than 0.95 degrees, and the system performance is good.

[0138] In an embodiment of the present invention, the first lens L1 and the second lens L2 form a first lens group, the third lens L3 and the fourth lens L4 form a second lens group, and the distance between the ninth lens L9 and the light modulator 21 is the back focal length of the projection lens. By adjusting the relative positions of the first lens group and the second lens group and simultaneously adjusting the back focal length, a projection screen of 60 to 160 inches can be obtained.

[0139] Figure 23 It is a cross-sectional view of the projection lens provided by the embodiment of the present invention. Figure 24 It is a sectional perspective view of the projection lens provided by the embodiment of the present invention. Figure 25 It is a structural schematic diagram of the adjustment component provided by the embodiment of the present invention.

[0140] As Figure 23 shown, the projection lens includes: a lens barrel 301, a flange 302, a first adjustment component 303, a second adjustment component 304, a first adjustment ring 305, a second adjustment ring 306, a first driving device, and a second driving device.

[0141] The lens barrel 301 has a hollow structure and is fixed by the flange 302, and all the lenses are located inside the lens barrel. The first adjustment component 303 and the second adjustment component 304 are located inside the lens barrel 301; wherein, as Figure 25 shown, the first lens L1 and the second lens L2 are fixed in the first adjustment component 303; the third lens L3 and the fourth lens L4 are fixed in the second adjustment component 304.

[0142] As Figure 23As shown, the first lens l1 is an aspherical lens. The edges of the first lens l1 and the second lens l2 are in contact, and the first lens l1 and the second lens l2 are fixed in the first adjustment component 303 by the first retaining ring 310. The first retaining ring 310 can contact the edge of the first lens l1 to avoid blocking the main light rays. Due to the surface shape design of the third lens l3 and the fourth lens l4, there is a certain distance between them. Therefore, a first spacer ring 307 is provided between the third lens l3 and the fourth lens l4 to maintain the spacing between the third lens l3 and the fourth lens l4, and the third lens l3 and the fourth lens l4 are fixed in the second adjustment component 304 by the second retaining ring 311. The first spacer ring 307 is located at the edge between the third lens l3 and the fourth lens l4, and the second retaining ring 311 contacts the edge of the fourth lens l4. The fifth lens l5, the sixth lens l6, and the seventh lens l7 form a triplet lens and are fixed in the lens barrel 301. Since the diopter of the adjacent surfaces of the seventh lens l7 and the eighth lens l8 is opposite, a certain distance needs to be maintained between them. A second spacer ring 308 is provided between the seventh lens l7 and the eighth lens l8 to maintain the spacing between the seventh lens l7 and the eighth lens l8. A third spacer ring 309 is also provided between the eighth lens l8 and the ninth lens l9 to maintain the spacing between the eighth lens l8 and the ninth lens l9. Finally, by providing a third retaining ring 312 at the edge of the lens barrel, the triplet lens, the second spacer ring 308, the eighth lens l8, the third spacer ring 309, and the ninth lens l9 are brought into contact with each other to fix the second lens group in the lens barrel 301. Similarly, the second spacer ring 308, the third spacer ring 309, and the third retaining ring 312 are all provided at the edge positions of the lenses to avoid blocking the main light rays.

[0143] In the embodiment of the present invention, as Figure 23 shown, a serrated or stepped structure is provided on the inner surface of at least one spacer ring or retaining ring to eliminate stray light.

[0144] As Figure 23 shown, a first adjustment ring 305 and a second adjustment ring 306 are further provided on the outer side of the lens barrel. The first adjustment ring 305 and the second adjustment ring 306 are sleeved on the outer wall of the lens barrel 301, and the first adjustment ring 305 and the second adjustment ring 306 are spaced apart. As Figure 24 shown, a first serrated structure m1 is provided on the outer wall of the first adjustment ring 305, and a second serrated structure m2 is provided on the outer wall of the second adjustment ring 306. The first serrated structure m1 and the second serrated structure m2 can respectively engage with gears, so that the first adjustment ring 305 and the second adjustment ring 306 rotate under the drive of the gears.

[0145] The first adjusting ring 305 connects the first adjusting component 303 and the second adjusting component 304. When the first adjusting ring 305 rotates, it can drive the first adjusting component and the second adjusting component to move relatively along the optical axis direction of the projection lens. The second adjusting ring 306 is connected to the lens barrel. When the second adjusting ring 306 rotates, it can drive the lens barrel 301 to move along the optical axis direction of the projection lens, that is, change the back focal distance of the projection lens.

[0146] In specific implementation, a motor can be used to drive the first adjusting ring and the second adjusting ring to rotate, that is, both the first driving device and the second driving device can adopt a motor. Generally, if there are three components that need to move, three motors are required for driving, which will cause problems such as too large volume, increased cost, and difficult debugging; if only one motor is used for driving, the adjusting structure will be very complex, with too high processing requirements for the adjusting structure, a significant decrease in the error tolerance rate, and a decrease in the yield rate resulting in increased costs. Therefore, in the embodiment of the present invention, two driving devices are used for driving. Among them, the first driving device can perform linkage adjustment on the first adjusting component and the second adjusting component, and the second driving device can adjust the position of the lens barrel, thereby changing the overall back focus. By driving the first adjusting ring and the second adjusting ring through the first driving device and the second driving device, the projection lens can project projection pictures of different sizes.

[0147] The following specifically describes the linkage adjustment principle of the first adjusting component and the second adjusting component. First of all, it should be noted that the lens barrel 301 is integrally cylindrical, its cross-sectional shape is circular, and the center of the circle coincides with the optical axis of the projection lens. Then, the direction parallel to the optical axis of the projection lens of the lens barrel is called the axial direction, and the direction parallel to the circular diameter in the cross-section of the lens barrel is called the radial direction. The direction of rotation along the outer wall of the lens barrel is called the circumferential direction.

[0148] Figure 26 It is a schematic three-dimensional structure diagram of the lens barrel provided by the embodiment of the present invention. Figure 27 It is a schematic three-dimensional structure diagram of the first adjusting ring provided by the embodiment of the present invention. Figure 28 It is a schematic three-dimensional structure diagram of the projection lens provided by the embodiment of the present invention.

[0149] Specifically, as Figure 26 shown, the lens barrel 301 is provided with a first limiting hole c1, a second limiting hole c2, and a screw hole h. As Figure 27 shown, the first adjusting ring 303 is provided with a first moving groove h1, a second moving groove h2, and a third moving groove h3. Combining Figure 23 and Figure 28, a first adjustment shaft 3031 is fixed on the first adjustment assembly 303, and the first adjustment shaft 3031 is fixed on the first adjustment assembly 303 by screws 3032. A second adjustment shaft 3041 is fixed on the second adjustment assembly 304, and the second adjustment shaft 3041 is fixed on the second adjustment assembly 304 by screws 3042. A third adjustment shaft 3051 is fixed on the lens barrel 301, and the third adjustment shaft 3051 is fixed on the lens barrel 301 by screws 3052. Threads are provided in the screw holes h of the lens barrel, and the screws can be screwed into the corresponding screw holes h to achieve the fixation of structural components.

[0150] The first adjustment shaft 3031 passes through the first limit hole c1 and the first moving slot h1; the second adjustment shaft 3041 passes through the second limit hole c2 and the second moving slot h2; the third adjustment shaft 3051 passes through the third moving slot h3. As can be seen from Figure 26 it, the width of the first limit hole c1 and the second limit hole c2 in the axial direction is greater than the width in the circumferential direction. This width can limit the axial movement range of the first adjustment shaft 3051 and the second adjustment shaft 3052, and this width is set according to the axial movement positions of the first adjustment assembly 303 and the second adjustment assembly 304. As can be seen from Figure 27 it, both the first moving slot h1 and the second moving slot h2 are curved slots, and the third moving slot h3 is a straight slot. Also, the first moving slot h1, the second moving slot h2, and the third moving slot h3 are all arranged in three places on the circumference of the first adjustment ring 303. Thus, it can be avoided that the first adjustment assembly and the second adjustment assembly tilt during adjustment and has a certain centering effect. When rotating the first adjustment ring 303, the lens barrel 301 always remains fixed without rotation. The first adjustment shaft 3031 will slide in the first moving slot h1, the second adjustment shaft 3041 will slide in the second moving slot h2, and the third adjustment shaft 3051 will slide in the third moving slot h3. Since the first moving slot h1 and the second moving slot h2 are curved slots, as the first adjustment ring 303 rotates, the relative positions of the first adjustment shaft 3031 and the second adjustment shaft 3041 in the first moving slot h1 and the second moving slot h2 change, driving the first adjustment shaft 3031 and the second adjustment shaft 3041 to move relatively axially, so that the first adjustment assembly 303 and the second adjustment assembly 304 move axially, realizing the linkage adjustment of the first adjustment assembly 303 and the second adjustment assembly with one adjustment ring.

[0151] Similarly, as shown in Figure 23 and Figure 28As shown, a fourth moving groove h4 is provided on the second adjusting ring 306. Correspondingly, the lens barrel 301 is further provided with a fourth adjusting shaft 3061. The fourth adjusting shaft 3061 passes through the fourth moving groove h4 of the second adjusting ring 306 and is fixed to the lens barrel 301 by a screw 3062. The fourth moving groove h4 is a straight groove, and this straight groove is not completely arranged along the circumferential direction of the lens barrel 301, but is an inclined line on the side wall of the lens barrel. In this way, when the second adjusting ring 306 is rotated, the second adjusting shaft 3061 can slide in the fourth moving groove h4, thereby driving the lens barrel to move axially and changing the back focal distance of the projection lens.

[0152] Among them, the curved trajectories of the first moving groove h1 and the second moving groove h2 can be generated by fitting the function of the relative positions satisfied by the first adjusting assembly 303 and the second adjusting assembly 304 when the projection lens projects projection pictures of different sizes.

[0153] Taking the projection lens provided in the embodiment of the present invention as an example, the positions of the first lens group composed of the first lens l1 and the second lens l2 and the second lens group composed of the third lens l4 and the fourth lens l4 when projecting projection pictures of different sizes are as follows:

[0154]

[0155]

[0156] According to the above table, the curve of the relative position of the first lens group (as shown in Figure 29 ) and the curve of the relative position of the second lens group (as shown in Figure 30 ) can be obtained. According to the above table, the trajectories of the first moving groove h1 and the second moving groove h2 can be determined by fitting.

[0157] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concepts. Therefore, the appended claims are intended to be interpreted to include the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0158] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. In this way, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A projection device, characterized in that, Comprising: A laser light source device for emitting three primary color lasers; An illumination system located on the light-emitting side of the laser light source device; The illumination system includes a light modulator for modulating incident laser light and then emitting it; A projection lens located on the light-emitting side of the light modulator; the projection lens includes a first lens group, a second lens group, and a diaphragm; The second lens group is located between the first lens group and the light modulator, and the diaphragm is located between the first lens group and the second lens group; Wherein, the first lens group includes an aspherical lens, and the second lens group includes a triplet lens group and an aspherical lens.

2. The projection device according to claim 1, characterized in that, The first lens group includes: a first lens, a second lens, a third lens, and a fourth lens arranged in sequence along the direction gradually approaching the second lens group; The first lens is an aspherical lens, and the second lens, the third lens, and the fourth lens are all spherical lenses; The optical power of the first lens is negative, the optical power of the second lens is negative, the optical power of the third lens is positive, and the optical power of the fourth lens is positive.

3. The projection device according to claim 2, characterized in that, The second lens group includes: a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged in sequence along the direction gradually away from the first lens group; The fifth lens, the sixth lens, and the seventh lens are mutually cemented to form the triplet lens group; The eighth lens is an aspherical lens, and the fifth lens, the sixth lens, the seventh lens, and the ninth lens are all spherical lenses; The optical power of the fifth lens is positive, the optical power of the sixth lens is negative, the optical power of the seventh lens is positive, the optical power of the eighth lens is positive, and the optical power of the ninth lens is positive.

4. The projection device according to claim 2, wherein, The first lens satisfies: -0.5 ≤ SAG11 / SAG12 ≤ 0; Wherein, SAG11 represents the axial distance between the intersection of the image side of the first lens and the optical axis and the vertex of the effective radius of the image side of the first lens, and SAG12 represents the axial distance between the intersection of the object side of the first lens and the optical axis and the vertex of the effective radius of the object side of the first lens.

5. The projection device according to claim 3, characterized in that, The eighth lens satisfies: 3 ≤ ct / et ≤ 5; Wherein, ct represents the central thickness of the eighth lens along the optical axis direction, and et represents the edge thickness of the eighth lens along the optical axis direction.

6. The projection device according to claim 3, characterized in that The projection lens satisfies: 0.2 ≤ (CT8 + CT9) / ∑CT ≤ 0.3; Wherein, CT8 represents the central thickness of the eighth lens along the optical axis direction, CT9 represents the central thickness of the ninth lens along the optical axis direction, and ∑CT represents the sum of the central thicknesses of the nine lenses in the projection lens along the optical axis direction.

7. The projection device according to any one of claims 2 to 6, characterized in that, The projection lens further includes: A lens barrel having a hollow structure; A first adjustment component located inside the lens barrel; the first lens and the second lens are fixed in the first adjustment component; A second adjustment component located inside the lens barrel; the third lens and the fourth lens are fixed in the second adjustment component; The first adjusting ring is sleeved outside the lens barrel; the first adjusting ring is respectively connected to the first adjusting component and the second adjusting component; The second adjusting ring is sleeved outside the lens barrel; the second adjusting ring is connected to the lens barrel; The first driving device is connected to the first adjusting ring; the first driving device is used to drive the first adjusting ring to rotate so as to drive the first adjusting component and the second adjusting component to move relatively along the optical axis direction of the projection lens; The second driving device is connected to the second adjusting ring; the second driving device is used to drive the second adjusting ring to rotate so as to drive the lens barrel to move along the optical axis direction of the projection lens; The projection lens projects projection pictures of different sizes under the drive of the first driving device and the second driving device.

8. The projection device according to claim 7, characterized in that, The lens barrel is provided with a first limiting hole and a second limiting hole; The first adjusting ring is provided with a first moving groove, a second moving groove and a third moving groove; A first adjusting shaft is fixed on the first adjusting component, a second adjusting shaft is fixed on the second adjusting component, and a third adjusting shaft is fixed on the lens barrel; The first adjusting shaft passes through the first limiting hole and the first moving groove; the second adjusting shaft passes through the second limiting hole and the second moving groove; the third adjusting shaft passes through the third moving groove; by rotating the first adjusting ring, the first adjusting shaft, the second adjusting shaft and the third adjusting shaft move in the corresponding moving grooves to drive the first adjusting component and the second adjusting component to move along the optical axis direction of the projection lens; Wherein, the first moving groove and the second moving groove are curved grooves, and the third moving groove is a straight groove; the trajectories of the first moving groove and the second moving groove are generated by function fitting according to the relative positions satisfied by the first adjusting component and the second adjusting component when the projection lens projects projection pictures of different sizes.

9. The projection device according to claim 7, characterized in that, The second adjusting ring is provided with a fourth moving groove; the lens barrel is further provided with a fourth adjusting shaft; the fourth adjusting shaft passes through the fourth moving groove; by rotating the second adjusting ring, the fourth adjusting shaft moves in the fourth moving groove to drive the lens barrel to move along the optical axis direction of the projection lens; Wherein, the fourth moving groove is a straight groove.

10. The projection device according to claim 7, wherein The lens further includes: The first spacer ring is located inside the second adjusting component, and is arranged between the third lens and the fourth lens, and is used to maintain the distance between the third lens and the fourth lens; The second spacer ring is located inside the lens barrel, and is arranged between the seventh lens and the eighth lens, and is used to maintain the distance between the seventh lens and the eighth lens; The third spacer ring is located inside the lens barrel, and is arranged between the eighth lens and the ninth lens, and is used to maintain the distance between the eighth lens and the ninth lens; The first retaining ring is located inside the first adjusting component, and is used to fix the first lens and the second lens in the first adjusting component; The second retaining ring, which is located within the second adjusting assembly, is used to fix the third lens and the fourth lens in the second adjusting assembly; The third retaining ring, which is located within the lens barrel, is used to fix the eighth lens and the ninth lens within the lens barrel; Wherein, the inner surface of at least one spacer ring or retaining ring includes serrations or steps.

Images