Projection optical system

Abstract

A projection optical system comprises: an image source, a lens group, an aperture, a reflective element, and an imaging screen. Through the lens group and the reflective element, a plurality of light paths are formed between the imaging screen and the image source. Each light path has a principal ray and a marginal ray. The principal ray of one light path is closer to the optical axis at the image source to form a principal ray with a near-axis image height, and the principal ray of another light path is farther from the optical axis at the image source to form a principal ray with an off-axis image height. When the image source and the imaging screen are located in the second quadrant and the reflective element is located in the fourth quadrant, the principal ray of the near-axis image height and the principal ray of the off-axis image height intersect to form a first point and a second point in sequence. The first point is located at the origin and the second point is located in the first quadrant. The principal ray of the light path and the marginal ray of the light path intersect to form a third point and a fourth point in sequence. The third point is located in the fourth quadrant and the fourth point is located in the second quadrant.

Description

Technical Field

[0001] The present invention relates to a projection optical system, in particular to an image source, a lens group, an aperture, a reflective element, an imaging screen, and a first quadrant, a second quadrant, a third quadrant and a fourth quadrant of rectangular coordinates. Background Art

[0002] Projectors are constantly innovating with the advancement of technology, from general focal length projectors to short focal length projectors, which also shows the value of projectors in the market. They are widely used, including products in the fields of multimedia information presentation systems, projection televisions, home theaters, video conferencing, etc. However, in recent years, the short-throw projector market has been applied to the education market and promoted for use in modern small-area homes.

[0003] The projection lens is for image quality. The longer the focal length of the projection lens, the smaller its field of view. On the contrary, the shorter the focal length of the projection lens, the larger its field of view. As a result, the distortion caused by the optical principle is more intense. Therefore, the short-throw projector cannot guarantee the image quality when the projection distance is shortened. However, how to take into account the image quality when the projection distance is shortened and adjust the projection configuration to the optimal level is also a problem to be solved by the present invention. Summary of the invention

[0004] The main purpose of the present invention is to provide a projection optical system, whose image source, lens group, aperture, reflective element, and imaging screen are coordinated with the first quadrant, second quadrant, third quadrant, and fourth quadrant of rectangular coordinates, thereby stabilizing the imaging screen quality while also improving the efficiency of effectively guiding the light path from the image source to the imaging screen.

[0005] Another object of the present invention is to provide a projection optical system, wherein the front lens group and the rear lens group cooperate with each other, thereby improving the efficiency of the lens group structure with a simple structure and low cost while stabilizing the image quality.

[0006] Another object of the present invention is to provide a projection optical system, which can improve the effect of a small projection ratio while stabilizing the quality of the imaging picture by coordinating the width of the imaging picture with the projection distance from the reflective element to the imaging picture.

[0007] Another object of the present invention is to provide a projection optical system with a small F value and capable of being configured with a larger aperture to enhance the brightness of the imaging screen.

[0008] To achieve the above-mentioned purpose, the technical means adopted by the present invention include: an image source; a lens group, located at the side of the image source; a reflective element, located at the side of the lens group; an imaging screen, through the lens group and the reflective element, a plurality of light paths are formed between the imaging screen and the image source, each of the light paths has a main light and a marginal light; and an aperture, which is arranged in the lens group, and the center of the aperture is an origin, the axial direction of the origin is the X-axis and the radial direction of the origin is the Y-axis, forming a rectangular coordinate system, the rectangular coordinate system has a first quadrant, a second quadrant, a third quadrant and a fourth quadrant, and the projection optical system has an optical axis, the optical axis coincides with the X-axis The optical path is combined so that the chief ray of one optical path is closer to the optical axis at the image source to form a chief ray of near-axis image height, and the chief ray of the other optical path is farther from the optical axis at the image source to form a chief ray of off-axis image height; when the image source and the imaging screen are located in the second quadrant and the reflective element is located in the fourth quadrant, the chief ray of the near-axis image height and the chief ray of the off-axis image height intersect to form a first point and a second point in sequence, the first point is located at the origin and the second point is located in the first quadrant, and the chief ray of the optical path and the edge ray of the optical path intersect to form a third point and a fourth point in sequence, the third point is located in the fourth quadrant and the fourth point is located in the second quadrant.

[0009] According to the above-mentioned features, the lens group can be divided into a front lens group and a rear lens group, the front lens group is close to the reflective element side, the rear lens group is close to the image source side, and the distance between the front lens group and the rear lens group is the longest lens distance in the lens group.

[0010] According to the aforementioned features, the front group of lenses includes at least two aspherical lenses, at least one of the two aspherical lenses is a negative lens.

[0011] According to the above-mentioned features, the rear group lens includes at least two cemented lenses and an aspheric lens. The aspheric lens is an independent lens with double aspheric surfaces, or one side of the aspheric lens is aspheric and the other side is spherical. The aspheric lens and a spherical lens can be bonded to form the cemented lens.

[0012] According to the above-mentioned features, the Abbe number of the last lens of the rear lens group is between 17 and 24, and is close to the image source side.

[0013] According to the above characteristics, the focal length of the reflective element is set to F1 and the focal length of the lens group is set to F2, then the projection optical system meets the 1.5 <F1 / F2<3.2。

[0014] According to the aforementioned features, the width of the imaging screen is set to W and the projection distance from the reflective element to the imaging screen is set to T, and the projection ratio condition of the projection optical system is met: T / W<0.275.

[0015] According to the aforementioned features, the F value of the projection optical system is between 1.6 and 3.2.

[0016] According to the aforementioned features, the displacement of the center point of the image source relative to the optical axis is set to d, and the short side of the image source is set to h, and meets the following condition: 2d / h>120%.

[0017] According to the above-mentioned characteristics, taking the center point of the image source as a reference, the characteristic positions of the upper point, the lower point, the left point, the right point, the upper left point, the upper right point, the lower left point and the lower right point can be obtained on the boundary of the image source, and when the image source is located above the optical axis, the main light rays of each optical path are formed at a position between the lens group and the reflective element from the midpoint to form a main light ray of a central optical path, a main light ray of an upper optical path, a main light ray of a lower optical path, a main light ray of a left optical path, a main light ray of a right optical path, a main light ray of an upper left optical path, a main light ray of an upper right optical path, a main light ray of a lower left optical path and a main light ray of a lower right optical path, and the upper and lower components of the distance from the main light ray of the central optical path to the optical axis are set to X2, and the distance from the main light ray of the upper optical path to the optical axis is set to X3. The upper and lower components are set to X3, the upper and lower components of the distance from the main light ray of the lower optical path to the optical axis are set to X1, the upper and lower components of the distance from the main light ray of the left optical path to the optical axis are set to Y2, the upper and lower components of the distance from the main light ray of the right optical path to the optical axis are set to Y2, the upper and lower components of the distance from the main light ray of the upper left optical path to the optical axis are set to Y3, the upper and lower components of the distance from the main light ray of the upper right optical path to the optical axis are set to Y3, the upper and lower components of the distance from the main light ray of the lower left optical path to the optical axis are set to Y1, and the upper and lower components of the distance from the main light ray of the lower right optical path to the optical axis are set to Y1, and meet the following conditions: 0.9*|Y1|≤|X1|≤1.2*|Y1|; |X2|>|Y2|; |X3|>|Y3|.

[0018] According to the aforementioned features, at least one optical element is further included between the reflective element and the imaging frame to deflect the light path or correct aberration.

[0019] Through the above-mentioned technical means, the present invention uses the image source, the lens group, the aperture, the reflective element, the imaging screen, the first quadrant, the second quadrant, the third quadrant and the fourth quadrant of the rectangular coordinate, and the front group lens and the rear group lens cooperate with each other, and then the width of the imaging screen and the projection distance from the reflective element to the imaging screen cooperate with each other, so as to effectively guide the light path from the image source to the imaging screen while stabilizing the imaging screen quality, the lens group structure is simple and low in cost, and the projection ratio is small. The F value of the projection optical system is small, and the aperture can be configured to be large to enhance the brightness of the imaging screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1AFIG. 1 is a schematic diagram of lens configuration according to the first embodiment of the present invention.

[0021] Figure 1B FIG. 1 is a schematic diagram of a light path according to a first embodiment of the present invention.

[0022] Figure 1C FIG. 1 is a schematic diagram of an imaging screen according to the first embodiment of the present invention.

[0023] Figure 1D for Figure 1C Magnified image shown in 1D.

[0024] Figure 1E for Figure 1C Magnified image shown in Figure 1E.

[0025] Figure 1F for Figure 1B Schematic diagram of the IMA.

[0026] Figure 1G for Figure 1B Schematic diagram of the plane of GG.

[0027] Figure 1H FIG. 1 is a schematic diagram of the optical path of the maximum image height cut into ten equal parts according to the first embodiment of the present invention.

[0028] Fig. 1I The image source of the first embodiment of the present invention presents a lateral light fan diagram with an image height of 0.5830 mm.

[0029] Figure 1J The image source of the first embodiment of the present invention presents a lateral light fan diagram with an image height of 0.8710 mm.

[0030] Figure 1K The image source of the first embodiment of the present invention presents a lateral light fan diagram with an image height of 1.7420 mm.

[0031] Figure 1L The image source of the first embodiment of the present invention presents a lateral light fan diagram with an image height of 2.6130 mm.

[0032] Figure 1M The image source of the first embodiment of the present invention presents a lateral light fan diagram with an image height of 3.4840 mm.

[0033] Figure 1N The image source of the first embodiment of the present invention presents a lateral light fan diagram with an image height of 4.3550 mm.

[0034] Fig.1O FIG. 4 is a field curvature diagram of the first embodiment of the present invention.

[0035] Figure 1P This is a distortion diagram of the first embodiment of the present invention.

[0036] Figure 1Q FIG. 4 is a lateral chromatic aberration diagram of the first embodiment of the present invention.

[0037] Figure 1R 2 is a longitudinal aberration diagram of the first embodiment of the present invention.

[0038] Figure 1S FIG. 1 is a schematic diagram of an optical element according to a first embodiment of the present invention.

[0039] Figure 2A FIG. 4 is a schematic diagram of lens configuration according to a second embodiment of the present invention.

[0040] Figure 2B FIG. 1 is a schematic diagram of a light path according to a second embodiment of the present invention.

[0041] Figure 2C FIG. 1 is a schematic diagram of the optical path of the maximum image height cut into ten equal parts according to the second embodiment of the present invention.

[0042] Figure 3A FIG. 4 is a schematic diagram of lens configuration according to the third embodiment of the present invention.

[0043] Figure 3B FIG. 4 is a schematic diagram of a light path according to a third embodiment of the present invention.

[0044] Figure 3C FIG. 1 is a schematic diagram of the optical path of the maximum image height cut into ten equal parts according to the third embodiment of the present invention.

[0045] Figure 4A FIG. 4 is a schematic diagram of lens configuration according to a fourth embodiment of the present invention.

[0046] Figure 4B FIG. 4 is a schematic diagram of a light path according to a fourth embodiment of the present invention.

[0047] Figure 4C FIG. 1 is a schematic diagram of the optical path of the maximum image height cut into ten equal parts according to the fourth embodiment of the present invention.

[0048] Figure 5A FIG. 4 is a schematic diagram of lens configuration according to a fifth embodiment of the present invention.

[0049] Figure 5B FIG. 4 is a schematic diagram of a light path according to a fifth embodiment of the present invention.

[0050] Figure 5C FIG. 1 is a schematic diagram of the optical path of the maximum image height cut into ten equal parts according to the fifth embodiment of the present invention.

[0051] Description of reference numerals: 10 - lens group; 20 - reflective element; 30 - imaging screen; 40 - aperture; 50 - optical element; 60A, 60B, 60C, 60D, 60E - projection optical system; 61 - optical axis; 62 - penetrating image smoothing device; 63 - prism; 64 - glass cover; IMA - image source; A - optical path; A1 - principal ray; A2 - marginal ray; B - rectangular coordinate system; B1 - first quadrant; B2 - The second quadrant; B3 to the third quadrant; B4 to the fourth quadrant; C1 to the first cemented lens; C2 to the second cemented lens; D to the distance between the lenses; E1 to the paraxial image height; E2 to the off-axis image height; G1 to the front group of lenses; G2 to the rear group of lenses; L1 to the first lens; L2 to the second lens; L3 to the third lens; L4 to the fourth lens; L5 to the fifth lens; L6 to the sixth lens; L7 to the seventh lens; L8 to the eighth lens; L9 to the ninth lens; L 10 ~10th lens; L 11 ~11th lens; O ~ origin; X ~ X-axis; Y ~ Y-axis; P1 ~ first point; P2 ~ second point; P3 ~ third point; P4 ~ fourth point; X1, Y1, X2, Y2, X3, Y3 ~ upper and lower components; T ~ projection distance; W ~ width of the image screen; d ~ displacement; e ~ boundary of the image source; h ~ short side of the image source; m1 ~ center point; m2 ~ upper point; m3 ~ lower point; m4 ~ left point; m5 ~ right point; m6 ~ upper left point; m7 ~ upper right point; m8 ~ lower left point; m9 ~ lower right point; n1 ~ Center optical path; n2~upper optical path; n3~lower optical path; n4~left optical path; n5~right optical path; n6~upper left optical path; n7~upper right optical path; n8~lower left optical path; n9~lower right optical path; λ1~first wavelength; λ2~second wavelength; λ3~third wavelength; 1R1, 1R2, 2R1, 2R2, 3R1, 3R2, 4R1, 4R2, 5R1, 6R1, 6R2, 7R1, 7R2, 8R1, 9R1, 9R2, 10R1, 10R2, 11R1, 11R2~surface. DETAILED DESCRIPTION

[0052] First, see Figure 1A to Figure 1S As shown, a first embodiment of a projection optical system 60A of the present invention includes: an image source (IMA). In this embodiment, the image source (IMA) can be combined with a transmissive smooth picture actuator 62, a prism 63 and a cover glass 64, but is not limited to this.

[0053] A lens group 10 is located on the side of the image source (IMA); a reflective element 20 is located on the side of the lens group 10; an imaging screen 30 is formed through the lens group 10 and the reflective element 20, so that a plurality of light paths (A) are formed between the imaging screen 30 and the image source (IMA), and each of the light paths (A) has a main light (A1) and a marginal light (A2).

[0054] As mentioned above, in the present embodiment, the lens group 10 can be divided into a front lens group (G1) and a rear lens group (G2), the front lens group (G1) is close to the reflective element 20 side, and the rear lens group (G2) is close to the image source (IMA) side. The distance between the front lens group (G1) and the rear lens group (G2) is the longest lens distance (D) in the lens group 10, but is not limited thereto.

[0055] As mentioned above, in the present embodiment, the front lens group (G1) includes at least two aspheric lenses, at least one of the two aspheric lenses is a negative lens; the rear lens group (G2) includes at least two cemented lenses and an aspheric lens, the aspheric lens is an independent lens with double aspheric surfaces, or one side of the aspheric lens is an aspheric surface and the other side is a spherical surface, and the aspheric lens and a spherical lens can be bonded to form the cemented lens; the Abbe number of the last lens of the rear lens group (G2) is between 17 and 24, and is close to the image source (IMA) side, but is not limited thereto.

[0056] like Figure 1A As shown in Table 1 and Table 2, in the first embodiment of the projection optical system 60A, the front lens group (G1) includes a first lens (L1), a second lens (L2), a third lens (L3), and a fourth lens (L4), and the first lens (L1) and the third lens (L3) are aspherical lenses (ASPH); the two cemented lenses of the rear lens group (G2) are respectively formed by bonding a fifth lens (L5) and a sixth lens (L6) to form a first cemented lens (C1), and an eighth lens (L8), a ninth lens (L9), and a tenth lens (L10). 10 ) are bonded to form a second cemented lens (C2), and a seventh lens (L7) is an aspherical lens (ASPH), and the seventh lens (L7) can be an independent lens, or the seventh lens (L7) and the sixth lens (L6) can be bonded, so that the fifth lens (L5), the sixth lens (L6), and the seventh lens (L7) are bonded to form the first cemented lens (C1); the eleventh lens (L 11 ) is the last lens, but is not limited to this.

[0057] Table 1

[0058]

[0059]

[0060] Table 2

[0061] ASPH MIRROR <![CDATA[1R1]]> <![CDATA[1R2]]> <![CDATA[3R1]]> <![CDATA[3R2]]> <![CDATA[7R1]]> <![CDATA[7R2]]> Radius 29.52 -18.35 15.54 19.18 14.91 10.00 -8.76 Conic -1.12 0.00 1.34 0.00 0.00 0.00 2.09 4TH -1.34E-06 3.14E-04 5.16E-04 1.50E-03 1.07E-03 0.00E+00 3.54E-04 6TH 2.27E-09 -2.38E-06 -6.26E-06 -2.99E-05 -2.04E-05 0.00E+00 -6.11E-06 8TH -1.74E-12 2.32E-08 -2.49E-07 5.03E-07 6.66E-07 0.00E+00 4.03E-06 10th 1.13E-15 -1.78E-10 7.85E-09 -7.50E-09 -2.16E-08 0.00E+00 -5.30E-07 12th -4.24E-19 1.02E-12 -1.05E-10 6.76E-11 3.77E-10 0.00E+00 4.14E-08 14th 7.24E-23 -3.72E-15 7.19E-13 -2.79E-13 -3.34E-12 0.00E+00 -1.64E-09 16th 0.00E+00 6.49E-18 -2.09E-15 2.69E-16 1.21E-14 0.00E+00 2.74E-11

[0062] An aperture 40 is provided within the lens group 10. Taking the center of the aperture 40 as an origin (O), the axial direction of the origin (O) is the X-axis (X), and the radial direction of the origin (O) is the Y-axis (Y), forming a rectangular coordinate system (B). The rectangular coordinate system (B) has a first quadrant (B1), a second quadrant (B2), a third quadrant (B3), and a fourth quadrant (B4). And the projection optical system 60A has an optical axis 61, which coincides with the X-axis (X), such that the chief ray (A1) of one optical path (A) is closer to the optical axis 61 at the image source (IMA), forming a chief ray (A1) with a paraxial image height (E1), and the chief ray (A1) of the other optical path (A) is farther from the optical axis 61 at the image source (IMA), forming a chief ray (A1) with an off-axis image height (E2).

[0063] As Figure 1B 、 Figure 1C 、 Figure 1D and as shown in FIG. 1E, when the image source (IMA) and the imaging screen 30 are located in the second quadrant (B2) and the reflecting element 20 is located in the fourth quadrant (B4), then the chief ray (A1) with the paraxial image height (E1) and the chief ray (A1) with the off-axis image height (E2) intersect, and sequentially form a first point (P1) and a second point (P2). The first point (P1) is located at the origin (O), and the second point (P2) is located in the first quadrant (B1). Also, the chief ray (A1) of the optical path (A) and the marginal ray (A2) of the optical path (A) intersect, and sequentially form a third point (P3) and a fourth point (P4). The third point (P3) is located in the fourth quadrant (B4), and the fourth point (P4) is located in the second quadrant (B2).

[0064] Continuing from the above, in this embodiment, the focal length of the reflecting element 20 is set as F1, and the focal length of the lens group 10 is set as F2. Then, the projection optical system 60A satisfies 1.5 < F1 / F2 < 3.2; the width of the imaging screen 30 is set as W, and the projection distance from the reflecting element 20 to the imaging screen 30 is set as T, and it satisfies the conditional formula of the projection ratio of the projection optical system 60A: T / W < 0.275; the F-number of the projection optical system 60A is between 1.6 and 3.2, but is not limited thereto.

[0065] Figure 1F and Figure 1G ​As shown, the displacement of the center point (m1) of the image source (IMA) relative to the optical axis 61 is set to d, and the short side of the image source (IMA) is set to h, and meets the following condition: 2d / h>120%, and taking the center point (m1) of the image source (IMA) as a reference, the characteristic positions of the upper point (m2), the lower point (m3), the left point (m4), the right point (m5), the upper left point (m6), the upper right point (m7), the lower left point (m8) and the lower right point (m9) can be obtained at the boundary (e) of the image source (IMA), and the image source (IMA) is located on the optical axis 61. When the main light (A1) of each optical path (A) is formed at a midpoint between the lens group 10 and the reflective element 20, a main light (A1) of a central optical path (n1), a main light (A1) of an upper optical path (n2), a main light (A1) of a lower optical path (n3), a main light (A1) of a left optical path (n4), a main light (A1) of a right optical path (n5), a main light (A1) of an upper left optical path (n6), a main light (A1) of an upper right optical path (n7), a main light (A1) of a lower left optical path (n8), and a main light (A1) of a lower right optical path (n9) The position distribution is as follows, and the upper and lower components of the distance from the chief light (A1) of the central optical path (n1) to the optical axis 61 are set to X2, the upper and lower components of the distance from the chief light (A1) of the upper optical path (n2) to the optical axis 61 are set to X3, the upper and lower components of the distance from the chief light (A1) of the lower optical path (n3) to the optical axis 61 are set to X1, the upper and lower components of the distance from the chief light (A1) of the left optical path (n4) to the optical axis 61 are set to Y2, the upper and lower components of the distance from the chief light (A1) of the right optical path (n5) to the optical axis 61 are set to Y2, and the upper and lower components of the distance from the chief light (A1) of the upper left optical path (n6) to the optical axis 61 are set to Y3. ) to the optical axis 61 is set to Y3, the upper and lower components of the distance from the main light (A1) of the upper right optical path (n7) to the optical axis 61 are set to Y3, the upper and lower components of the distance from the main light (A1) of the lower left optical path (n8) to the optical axis 61 are set to Y1, and the upper and lower components of the distance from the main light (A1) of the lower right optical path (n9) to the optical axis are set to Y1, and meet the following conditional formula: 0.9*|Y1|≤|X1|≤1.2*|Y1|; |X2|>|Y2|; |X3|>|Y3|, thus forming a rectangular nine-point characteristic optical path, but it is not limited to this. In addition, as Figure 1H As shown, the maximum image height cuts the optical path into ten equal parts, but is not limited to this.

[0066] Therefore, the projection optical system 60A sets a first wavelength (λ1), a second wavelength (λ2) and a third wavelength (λ3) to 0.450 um, 0.540 um and 0.630 um respectively, and can simulate Fig. 1I , Figure 1J , Figure 1K , Figure 1L , Figure 1M and Figure 1N Different lateral ray fan diagrams are shown, and different image heights of 0.5830mm, 0.8710mm, 1.7420mm, 2.6130mm, 3.4840mm, and 4.3550mm are presented on the same image source (IMA), and the symbols ey, py, ex, and px represent the y-axis lateral aberration, the y-axis pupil height, the x-axis lateral aberration, and the x-axis pupil height, respectively. The y-axis lateral aberration and the x-axis lateral aberration have a maximum scale of ±20.000um, and the y-axis pupil height and the x-axis pupil height are normalized ratios; Fig.1O Field Curvature diagram and Figure 1P Distortion diagram, the maximum field of view is 4.355 mm; Figure 1Q The lateral color diagram has a maximum field of view of 4.3550 mm. Figure 1R The longitudinal aberration diagram has a pupil radius of 0.3470 mm. The above simulation curves and data also prove that the projection optical system 60A can maintain good projection imaging quality. Figure 1S As shown, at least one optical element 50 is further included between the reflective element 20 and the imaging frame 30 to deflect the light path or correct aberration, but the present invention is not limited thereto.

[0067] The first to fifth embodiments of the present invention all have the above-mentioned common features. Therefore, they are technically related to each other and belong to a broad inventive concept, complying with the principle of unity, and the only difference is that the front lens group (G1) and the rear lens group (G2) are slightly different.

[0068] like Figures 2A to 2C As shown in Table 3 and Table 4, in the second embodiment of the projection optical system 60B, the front lens group (G1) includes a first lens (L1), a second lens (L2), a third lens (L3), and a fourth lens (L4), and the first lens (L1) and the third lens (L3) are aspherical lenses (ASPH); the two cemented lenses of the rear lens group (G2) are respectively cemented by a fifth lens (L5) and a sixth lens (L6) into a first cemented lens (C1), and by a seventh lens (L7), an eighth lens (L8), and a ninth lens (L9) into a second cemented lens (C2), and the sixth lens (L6) is an aspherical lens (ASPH); the tenth lens (L 10 ) is the last lens, but is not limited to this.

[0069] Table 3

[0070]

[0071]

[0072] Table 4

[0073] ASPH MIRROR <![CDATA[1R1]]> <![CDATA[1R2]]> <![CDATA[3R1]]> <![CDATA[3R2]]> <![CDATA[6R1]]> <![CDATA[6R2]]> Radius 29.52 -18.35 15.54 19.18 14.91 9.59 -15.27 Conic -1.12 0.00 1.34 0.00 0.00 0.00 4.62 4TH -1.34E-06 3.14E-04 5.16E-04 1.50E-03 1.07E-03 0.00E+00 2.64E-04 6TH 2.27E-09 -2.38E-06 -6.26E-06 -2.99E-05 -2.04E-05 0.00E+00 -2.73E-05 8TH -1.74E-12 2.32E-08 -2.49E-07 5.03E-07 6.66E-07 0.00E+00 9.16E-06 10th 1.13E-15 -1.78E-10 7.85E-09 -7.50E-09 -2.16E-08 0.00E+00 -1.43E-06 12th -4.24E-19 1.02E-12 -1.05E-10 6.76E-11 3.77E-10 0.00E+00 1.19E-07 14th 7.24E-23 -3.72E-15 7.19E-13 -2.79E-13 -3.34E-12 0.00E+00 -5.03E-09 16th 0.00E+00 6.49E-18 -2.09E-15 2.69E-16 1.21E-14 0.00E+00 8.51E-11

[0074] like Figures 3A to 3C As shown in Table 5, Table 6 and Table 7, in the third embodiment of the projection optical system 60C, the front lens group (G1) includes a first lens (L1), a second lens (L2), a third lens (L3) and a fourth lens (L4), and the first lens (L1) and the third lens (L3) are aspherical lenses (ASPH); the two cemented lenses of the rear lens group (G2) are respectively formed by bonding a fifth lens (L5) and a sixth lens (L6) to form a first cemented lens (C1), and an eighth lens (L8), a ninth lens (L9), a tenth lens (L10) to form a first cemented lens (C1). 10 ) are bonded to form a second cemented lens (C2), and a seventh lens (L7) is an aspherical lens (ASPH), and the seventh lens (L7) can be an independent lens, or the seventh lens (L7) and the sixth lens (L6) can be bonded, so that the fifth lens (L5), the sixth lens (L6), and the seventh lens (L7) are bonded to form the first cemented lens (C1); the eleventh lens (L 11 ) is the last lens, but is not limited to this.

[0075] Table 5

[0076]

[0077] Table 6

[0078]

[0079]

[0080] Table 7

[0081] ASPH MIRROR Radius 31.24 Normalized radius 1.00 Conic -1.03 1TH 0.00E+00 2TH 3.38E-04 3TH 5.83E-06 4TH -1.75E-06 5TH 1.55E-09 6TH 2.17E-09 7TH -2.05E-12 8TH -1.56E-12 9TH 1.21E-15 10TH 9.21E-16 11TH -2.52E-19 12th -3.00E-19 13th -1.50E-22 14th 4.41E-23 15th 1.14E-26 16th 1.02E-27

[0082] like Figures 4A to 4CAs shown in Tables 8 and 9, in the fourth embodiment of the projection optical system 60D, the front lens group (G1) includes a first lens (L1), a second lens (L2), a third lens (L3), and a fourth lens (L4), and the first lens (L1) and the third lens (L3) are aspherical lenses (ASPH); the two cemented lenses of the rear lens group (G2) are respectively formed by bonding a fifth lens (L5) and a sixth lens (L6) to form a first cemented lens (C1), and an eighth lens (L8), a ninth lens (L9), and a tenth lens (L10). 10 ) are bonded to form a second cemented lens (C2), and a seventh lens (L7) is an aspherical lens (ASPH), and the seventh lens (L7) can be an independent lens, or the seventh lens (L7) and the sixth lens (L6) can be bonded, so that the fifth lens (L5), the sixth lens (L6), and the seventh lens (L7) are bonded to form the first cemented lens (C1); the eleventh lens (L 11 ) is the last lens, but is not limited to this.

[0083] Table 8

[0084]

[0085] Table 9

[0086] ASPH MIRROR <![CDATA[1R1]]> <![CDATA[1R2]]> <![CDATA[3R1]]> <![CDATA[3R2]]> <![CDATA[7R1]]> <![CDATA[7R2]]> Radius 39.07 -78.23 16.32 -19.75 -178.17 9.74 -10.96 Conic -0.92 0.00 -1.94 0.00 0.00 0.00 1.92 4TH -5.86E-07 1.04E-04 -2.69E-05 2.38E-04 2.44E-04 0.00E+00 3.94E-04 6TH 1.22E-09 -5.68E-07 -8.41E-07 -1.22E-06 -3.50E-08 0.00E+00 1.16E-06 8TH -1.06E-12 3.22E-09 6.98E-09 9.13E-09 -7.08E-09 0.00E+00 1.14E-06 10th 6.42E-16 -1.16E-11 -2.64E-11 -5.01E-11 1.33E-10 0.00E+00 -2.27E-07 12th -2.02E-19 2.18E-14 5.09E-14 1.68E-13 -1.12E-12 0.00E+00 2.23E-08 14th 2.71E-23 -1.53E-17 -3.85E-17 -3.30E-16 4.17E-15 0.00E+00 -1.07E-09 16th 0.00E+00 0.00E+00 0.00E+00 3.27E-19 -5.80E-18 0.00E+00 2.01E-11

[0087] like Figures 5A to 5C As shown in Table 10 and Table 11, in the fifth embodiment of the projection optical system 60E, the front lens group (G1) includes a first lens (L1), a second lens (L2), a third lens (L3), and a fourth lens (L4), and the first lens (L1) and the third lens (L3) are aspherical lenses (ASPH); the two cemented lenses of the rear lens group (G2) are respectively formed by bonding a fifth lens (L5) and a sixth lens (L6) to form a first cemented lens (C1), and an eighth lens (L8), a ninth lens (L9), and a tenth lens (L10). 10 ) are bonded to form a second cemented lens (C2), and a seventh lens (L7) is an aspherical lens (ASPH), and the seventh lens (L7) can be an independent lens, or the seventh lens (L7) and the sixth lens (L6) can be bonded, so that the fifth lens (L5), the sixth lens (L6), and the seventh lens (L7) are bonded to form the first cemented lens (C1); the eleventh lens (L 11 ) is the last lens, but is not limited to this.

[0088] Table 10

[0089]

[0090] Table 11

[0091]

[0092]

[0093] Based on such a structure, the first to fifth embodiments of the projection optical system 60A~60E have summarized in Table 12 the focal length of the first lens (L1), the focal length of the third lens (L3), the focal length of the reflective element 20, the focal length of the lens group 10, the width (W) of the imaging screen 30, the projection distance (T), the F value of the projection optical system 60A~60E, the displacement (d), the short side (h) of the image source (IMA) and the upper and lower components (X1, Y1, X2, Y2, X3, Y3) to adjust within a certain matching range, thereby stabilizing the quality of the imaging screen 30 and improving the efficiency.

[0094] Table 12

[0095]

[0096] The above-disclosed drawings and descriptions are only preferred embodiments of the present invention. Any modifications or equivalent changes made by persons skilled in the art within the spirit and scope of the present invention should still be included in the protection scope of the present invention.

Claims

1. A projection optical system, characterized in that: The projection optical system has an F value between 1.6 and 3.2, and includes: An image source; a lens group, located on the side of the image source; a reflective element located at a side of the lens group, the lens group is divided into a front lens group and a rear lens group, the front lens group is close to the reflective element side, the rear lens group is close to the image source side, the distance between the front lens group and the rear lens group is the longest lens distance in the lens group, the front lens group includes at least two aspheric lenses, at least one of the two aspheric lenses is a negative lens, and the Abbe number of the last lens of the rear lens group is between 17 and 24; An imaging screen, through the lens group and the reflective element, a plurality of light paths are formed between the imaging screen and the image source, each of the light paths has a main light and a marginal light, the width of the imaging screen is set to W and the projection distance from the reflective element to the imaging screen is set to T, and the projection ratio of the projection optical system is satisfied: T / W<0.275; and an aperture, which is arranged in the lens group, and takes the center of the aperture as an origin, the axial direction of the origin as the X-axis and the radial direction of the origin as the Y-axis, forming a rectangular coordinate system, the rectangular coordinate system has a first quadrant, a second quadrant, a third quadrant and a fourth quadrant, and the projection optical system has an optical axis, the optical axis coincides with the X-axis, so that the chief ray of one optical path is closer to the optical axis at the image source to form a chief ray with a near-axis image height, and the chief ray of the other optical path is farther from the optical axis at the image source to form a chief ray with an off-axis image height; When the image source and the imaging screen are located in the second quadrant and the reflective element is located in the fourth quadrant, the chief ray of the paraxial image height and the chief ray of the off-axis image height intersect to sequentially form a first point and a second point, the first point is located at the origin and the second point is located in the first quadrant, and the chief ray of the optical path and the marginal ray of the optical path intersect to sequentially form a third point and a fourth point, the third point is located in the fourth quadrant and the fourth point is located in the second quadrant.

2. The projection optical system according to claim 1, characterized in that: The rear lens group includes at least two cemented lenses and an aspheric lens. The aspheric lens is an independent lens with double aspheric surfaces, or one side of the aspheric lens is aspheric and the other side is spherical. The aspheric lens and a spherical lens are bonded to form the cemented lens.

3. The projection optical system according to claim 1, wherein: The focal length of the reflective element is set to F1 and the focal length of the lens group is set to F2, then the projection optical system meets 1.5 <F1 / F2<3.2。 4. The projection optical system according to claim 1, characterized in that: The displacement of the center point of the image source relative to the optical axis is set to d, and the short side of the image source is set to h, and meets the following condition: 2d / h>120%.

5. The projection optical system according to claim 1, wherein: Taking the center point of the image source as a reference, characteristic positions of the upper point, lower point, left point, right point, upper left point, upper right point, lower left point and lower right point are obtained on the boundary of the image source, and when the image source is located above the optical axis, the principal light rays of each optical path are made to form a position distribution of a principal light ray of a central optical path, a principal light ray of an upper optical path, a principal light ray of a lower optical path, a principal light ray of a left optical path, a principal light ray of a right optical path, a principal light ray of an upper left optical path, a principal light ray of an upper right optical path, a principal light ray of a lower left optical path and a principal light ray of a lower right optical path at a distance from the midpoint between the lens group and the reflective element, and the upper and lower components of the distance from the principal light ray of the central optical path to the optical axis are set to X2, and the upper and lower components of the distance from the principal light ray of the upper optical path to the optical axis are set to X3. Set to X3, the upper and lower components of the distance from the main light ray of the lower optical path to the optical axis are set to X1, the upper and lower components of the distance from the main light ray of the left optical path to the optical axis are set to Y2, the upper and lower components of the distance from the main light ray of the right optical path to the optical axis are set to Y2, the upper and lower components of the distance from the main light ray of the upper left optical path to the optical axis are set to Y3, the upper and lower components of the distance from the main light ray of the upper right optical path to the optical axis are set to Y3, the upper and lower components of the distance from the main light ray of the lower left optical path to the optical axis are set to Y1, and the upper and lower components of the distance from the main light ray of the lower right optical path to the optical axis are set to Y1, and meet the following conditions: 0.9*|Y1|≤|X1|≤1.2*|Y1|; |X2|>|Y2|; |X3|>|Y3|.

6. The projection optical system according to claim 1, wherein: At least one optical element is further included between the reflective element and the imaging frame for deflecting the light path or correcting aberration.

Images