TW202122863A - Optical lens and fabrication method thereof - Google Patents

Abstract

An optical lens for receiving and projecting an image beam includes a first lens group, a second lens group, a third lens group, and a fourth lens group in order from an enlarged side to a reduced side. An aperture is located between the second lens group and the fourth lens group. When the optical lens is zoomed, the first lens group, the second lens group, and the third lens group move relative to the light valve. The optical lens meets the following conditions: (1) the image beam enters the fourth lens group first, (2) the number of lenses with refractive power is between 9~16 pieces, (3) between the aperture and the lens closest to the reduction side, there are a triple cemented lenses and a double cemented lenses, and (4) the distance between the lens surfaces with refractive power on the outermost ends of the optical lenses along the optical axis of the optical lens is between 85-110mm.

Description

Optical lens and manufacturing method thereof

The invention relates to an optical lens and a manufacturing method thereof, in particular to a projection lens and a manufacturing method thereof.

Among many types of display devices, the projection device has the characteristic of projecting a large-size image screen several times the surface area of the device with a small device volume, and therefore has an advantage that it cannot be replaced in the display field. Since the projection device uses the projection lens to project the image beam converted by the light valve onto the screen, the quality of the image picture is greatly affected by the quality of the projection lens. Therefore, the projection lens is a key optical element in the projection device.

Generally speaking, the projection lens has a variable focal length function. Using the zoom function of the projection lens, the projection device can achieve the effect of zooming the image. At present, the mainstream of projection devices is toward high-brightness designs. One way to achieve high brightness is to use a large aperture design for the projection lens. However, a projection lens with a zoom function is complicated to process and is limited by strict tolerance requirements, so it is difficult to achieve the characteristics of a large aperture and high image quality at the same time.

Other objectives and advantages of the present invention can be further understood from the technical features disclosed in the embodiments of the present invention.

An embodiment of the present invention provides an optical lens for receiving and projecting an image beam, including a first lens group, a second lens group, a third lens group, and a fourth lens group sequentially arranged from the magnification side to the reduction side , And the aperture set between the second lens group and the fourth lens group. When the optical lens is zoomed, the first lens group, the second lens group and the third lens group move relative to the light valve or the imaging surface of the optical lens, and the optical lens satisfies the following Conditions: The image beam first enters the fourth lens group, the number of lenses with diopter power is between 9-16, and the aperture and the lens closest to the reduction side include a triplet lens and a doublet lens. When the optical lens is at the wide-angle end, the distance between the outermost diopter lens surfaces of the two ends of the optical lens along the optical axis of the optical lens is between 85 and 110 mm. The optical lens of this embodiment can provide a good optical imaging quality, low thermal drift, low distortion, low chromatic aberration, large aperture and short overall length characteristics, and can provide lower manufacturing costs and better imaging quality Projection lens design.

An embodiment of the present invention provides an optical lens, including a fourth lens group, a third lens group, a second lens group, and a first lens group arranged in sequence according to the traveling direction of an image beam, and the second lens group and The aperture between the fourth lens group. When the optical lens is zoomed, the first lens group, the second lens group and the third lens group move relative to the light valve or the imaging surface of the optical lens, and the optical lens meets the following conditions: the number of lenses with diopter is between 9 and 16, The diameter of the first diopter lens that the image beam penetrates is smaller than the diameter of the last diopter lens. The aperture and the first diopter lens that penetrates contains two cemented surfaces, and when the optical lens is at the wide-angle end, the optical lens The distance between the outermost diopter lens surfaces at both ends along the optical axis of the optical lens is between 85 and 110 mm. The optical lens of this embodiment can provide a good optical imaging quality, low thermal drift, low distortion, low chromatic aberration, large aperture and short overall length characteristics, and can provide lower manufacturing costs and better imaging quality Projection lens design.

Through the design of the embodiment of the present invention, it can provide a good optical imaging quality, low thermal drift, low distortion (distortion), low chromatic aberration, large aperture and short overall length characteristics, and can provide lower manufacturing costs and Projection lens design with better imaging quality. Furthermore, the optical lens of the embodiment of the present invention includes 11-13 lenses. When the optical lens is at the wide-angle end, the distance (OAL) between the outermost diopter lens surfaces at both ends of the optical lens on the optical axis is less than 110mm, which can provide a large aperture (F# greater than or equal to 1.5), high resolution, miniaturization, With the characteristics of low thermal drift and short overall length, it can provide an optical lens design with lower manufacturing cost and better imaging quality.

The other objectives and advantages of the present invention can be further understood from the technical features disclosed in the present invention. In order to make the above and other objectives, features and advantages of the present invention more comprehensible, the following specific examples are given in conjunction with the accompanying drawings, which are described in detail as follows.

10a, 10b, 10c, 10d‧‧‧Optical lens

12‧‧‧Optical axis

14‧‧‧Aperture

16‧‧‧Optical Path Adjustment Mechanism

18‧‧‧稜鏡

120‧‧‧Light valve

130‧‧‧Screen

G1-G5‧‧‧lens group

L1-L13‧‧‧lens

S1-S24‧‧‧surface

OS‧‧‧Magnified side

IS‧‧‧Reduced side

P、Q‧‧‧Intersection point

D‧‧‧Lens diameter

FIG. 1 is a schematic diagram of the optical structure of a projection device 100 according to an embodiment of the present invention.

2A and 2B are respectively an optical structure diagram of an optical lens 10a at a wide-end and a tele-end according to an embodiment of the present invention.

3A and 3B are respectively a modulation transfer function curve (MTF) diagram of the optical lens 10a at the wide-end and tele-end according to an embodiment of the present invention.

FIG. 4 is an optical structure diagram of an optical lens 10b according to an embodiment of the present invention.

FIG. 5 is a diagram of the modulation transfer function (MTF) of the optical lens 10b according to an embodiment of the invention.

FIG. 6 is an optical structure diagram of an optical lens 10c according to an embodiment of the invention.

FIG. 7 is a diagram of a modulation transfer function curve (MTF) of an optical lens 10c according to an embodiment of the invention.

FIG. 8 is an optical structure diagram of an optical lens 10d according to an embodiment of the present invention.

FIG. 9 is a diagram of the modulation transfer function (MTF) of the optical lens 10d according to an embodiment of the present invention.

Fig. 10 is a schematic diagram of the light valve arranged on the reduction side of Fig. 1.

The foregoing and other technical content, features, and effects of the present invention will be clearly presented in the detailed description of multiple embodiments below with reference to the drawings. In addition, the terms "first" and "second" used in the following embodiments are used to identify the same or similar elements, and the directional terms such as "front", "rear", etc., are only for reference to the attached drawings The direction is not used to limit the elements.

FIG. 1 is a schematic diagram of the optical structure of a projection device 100 according to an embodiment of the present invention. Please refer to FIG. 1, the projection device 100 of this embodiment includes a lighting unit 110, a light valve 120, a projection lens 10 and a screen 130. The lighting unit 110 is used to provide an illuminating light beam L1. In this embodiment, the lighting unit 110 can be any The device used to irradiate the light valve 120 includes light sources such as light bulbs, lasers, or LEDs. The light valve 120 is disposed on the transmission path of the illumination light beam L1, and is used to convert the illumination light beam L1 into an image light beam L2. In this embodiment, the light valve 120 is, for example, a digital micro-mirror device (DMD), a liquid-crystal-on-silicon panel (liquid-crystal-on-silicon panel), a liquid crystal panel (LCD) or other suitable spaces. Spatial light modulator (SLM), etc.

2A and 2B are respectively schematic diagrams of the optical structure of the projection lens 10a of the first embodiment of the projection lens 10 shown in FIG. 1 at the wide-end and tele-end. 1 and 2A-2B, the projection lens 10a of this embodiment is disposed between the image magnification side OS and the image reduction side IS. In the projection device 100, the image magnification side OS corresponds to the screen 130, and the image reduction side IS Corresponding to the light valve 120, the projection lens 10a is located on the transmission path of the image light beam L2 for projecting the image light beam L2 from the light valve 120 onto the screen 130 to form an image frame (not shown) on the screen 130. The projection lens 10a includes a first lens group G1, a second lens group G2, a third lens group G3, an aperture 14, a fourth lens group G4, and a fifth lens group G5. The first lens group G1 is disposed on the screen 130 and the light valve 120, the second lens group G2 is arranged between the first lens group G1 and the light valve 120, the third lens group G3 is arranged between the second lens group G2 and the light valve 120, and the fourth lens group G4 is arranged between the third lens group Between G3 and the light valve 120, the fifth lens group G5 is configured between the fourth lens group G4 and the light valve 120, and the aperture 14 is configured between the third lens group G3 and the fourth lens group G4. The refractive powers of the first lens group G1 to the fifth lens group G5 are negative, positive, positive, positive, and positive, respectively. The F-number of the projection lens 100 of this embodiment is 1.7 at the wide-end (wide-end) and 1.78 at the tele-end (Tele-end), both of which are greater than or equal to 1.5, so it has the optical characteristics of a large aperture . In addition, a light path adjustment mechanism (SP) 16, a prism 18, and a light-transmitting protective cover (not shown in the figure), such as a cover glass, may be provided between the fifth lens group G5 and the light valve 120, To protect the light valve 120.

In this embodiment, the first lens group G1, the second lens group G2, the third lens group G3, the aperture 14, and the fourth lens group G4 can relatively move between the light valve 120 and the screen 130 along the optical axis 12. The effective focal length (EFL) of the projection lens 10a can be changed accordingly, so that the projection device 100 can have a zoom image scale. Inch effect. In other words, through the combination of the first lens group G1, the second lens group G2, the third lens group G3, the aperture 14, and the fourth lens group G4, the projection apparatus 100 of this embodiment can have a zoom function.

2A, when the magnification of the projection device 100 of this embodiment is to be increased, the first lens group G1 and the second lens group G2 can move toward the screen (imaging surface of the projection lens) 130, and the third lens group G3 and the fourth lens group G4 can move toward the light valve 120. At this time, the variable distances between the first lens group G1 and the second lens group G2 and the light valve 120 become larger, while the distance between the third lens group G3, the diaphragm 14, and the fourth lens group G4 and the light valve 120 can be increased. As the distance becomes smaller, this is called the wide-end (wide-end). 2B, when the magnification of the projection device 100 of this embodiment is to be reduced, the first lens group G1 and the second lens group G2 can move toward the light valve 120, and the third lens group G3, the aperture 14 and The fourth lens group G4 can move toward the screen (imaging surface of the projection lens) 130. At this time, the variable distance between the first lens group G1 and the second lens group G2 and the light valve 120 becomes smaller, and the variable distance between the third lens group G3, the diaphragm 14, and the fourth lens group G4 and the light valve 120 becomes smaller. As the distance becomes larger, this is called Tele-end. In addition, when the projection distance (that is, the distance between the first lens group G1 and the screen 130) changes, the first lens group G1 can move slightly along the optical axis 12 relative to the light valve 120 to focus, so that the The image screen changes from blurry to clear. It should be noted that the distance of the fifth lens group G5 relative to the light valve 120 is constant, no matter it is zooming or focusing.

The so-called optical element in the present invention refers to an element composed of a part or all of reflective or penetrable materials, usually including glass or plastic. For example, it is a lens, a lens, or an aperture.

The object side (or image side) of a lens has a convex surface (or concave surface) located in a certain area, which means that this area is more oriented parallel to the optical axis than the area immediately outside the area in the radial direction. "Outwardly convex" (or "inwardly concave").

Hereinafter, the composition of each lens group of the projection lens 10a of this embodiment will be illustrated by an example, but it is not intended to limit the present invention. 2A, in this embodiment, the first lens group G1 includes a first lens L1 and a second lens L2. The second lens group G2 includes a third lens L3. The third lens group G3 includes the Four lens L4. The fourth lens group G4 includes a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, and a tenth lens L10. The fifth lens group G5 includes an eleventh lens L11. In this embodiment, the refractive powers of the first lens L1 to the eleventh lens L11 are negative, negative, positive, positive, negative, positive, negative, negative, positive, positive, and positive, respectively. Except for the first lens L1, all the lenses are glass spherical lenses, and the first lens L1 is a plastic aspheric lens. In other words, more than three-quarters of the lenses are glass spherical lenses. In an embodiment, the glass spherical lens can be replaced with an aspheric lens. In another embodiment, the plastic aspheric lens can be replaced by a glass ground aspheric lens. In addition, the two adjacent surfaces of the two lenses have roughly the same (the difference in radius of curvature is less than 0.005mm) or exactly the same (substantially the same) radius of curvature and form a combined lens, cemented lens, doublet or triplet. For example, the fifth lens L5, the sixth lens L6, and the seventh lens L7 of this embodiment constitute a triplet lens, and the eighth lens L8 and the ninth lens L9 constitute a doublet lens, but the embodiment of the present invention does not use this as limit. In one embodiment, the triplet lens can also be replaced by a doublet lens. Furthermore, the number of lenses, the shape and optical characteristics of the lenses in the projection lens 10a can be designed differently according to actual needs. The image magnification side OS of each embodiment of the present invention is respectively set on the left side of each figure, and the image reduction side IS is set on the right side of each figure, and the description will not be repeated.

The aperture 14 referred to in the present invention refers to an aperture stop (Aperture Stop), which is an independent element or integrated with other optical elements. In this embodiment, the aperture uses the mechanism to block the peripheral light and retain the light transmission in the middle to achieve a similar effect, and the aforementioned so-called mechanism may be adjustable. The so-called adjustable refers to the adjustment of the position, shape or transparency of the mechanical parts. Or, the aperture can also be coated with an opaque light-absorbing material on the surface of the lens, and keep the central part of the light transparent to limit the light path. In this embodiment, the aperture 14 is provided between the third lens group G3 and the fourth lens group G4. In more detail, the aperture 14 is disposed between the fourth lens L4 and the fifth lens L5 to control the amount of incident light. When the aperture of the diaphragm 14 is larger, the projection lens 10a can correspond to a smaller F-number. Furthermore, a small F-number can represent an increase in the amount of incident light to achieve high brightness. But this At the same time, the light entering the projection lens 10a and away from the optical axis 12 of the projection lens 10a also increases at the same time, thereby causing aberration problems. In this embodiment, since the aperture 14 can be arranged between the fourth lens L4 and the fifth lens L5 that are closer to the light valve 120, the aperture 14 can block part of the light far away from the optical axis 12, thereby making the projection of this embodiment The optical characteristics of the lens 10a are good.

The lens diameter is defined for each lens system. For example, as shown in FIG. 2A, the lens diameter refers to the distance between the mirror turning points P and Q at the two ends of the optical axis 12 in the direction perpendicular to the optical axis 12 (for example, the lens diameter D). Furthermore, in this embodiment, the diameter (D1) of the first lens L1 is 34.7 mm, and the diameter (DL) of the eleventh lens L11 is 23.0 mm.

Spherical lens means that the front and back surfaces of the lens are part of the spherical surface, and the curvature of the spherical surface is fixed. An aspheric lens means that the radius of curvature of at least one of the front and rear surfaces of the lens changes with the central axis, which can be used to correct aberrations. The lens design parameters, shape and aspheric coefficients of the optical lens 10a are shown in Table 1 and Table 2, respectively. In the following design examples of the present invention, the aspheric polynomial can be expressed by the following formula:

In the above formula (1), Z is the offset in the direction of the optical axis (sag), c is the reciprocal of the radius of the osculating sphere, that is, the reciprocal of the radius of curvature close to the optical axis, and k is the quadratic Conic, where r is the height of the aspheric surface, which is the height from the center of the lens to the edge of the lens. A-F in Table 2 represents the coefficient values of the 4th-order, 6th-order, 8th-order, 10th-order, 12th-order, and 14th-order terms of the aspheric polynomials. However, the information listed below is not intended to limit the present invention. Anyone with ordinary knowledge in the field can make appropriate changes to its parameters or settings after referring to the present invention, but it should still fall within the scope of the present invention. .

Table I

In Table 1, the radius of curvature (mm) refers to the radius of curvature of the corresponding surface, and the distance (mm) refers to the linear distance between two adjacent surfaces on the optical axis 12. For example, the distance between the surface S1 is the distance between the surface S1 and the surface S2, the distance between the surface S20 is the distance between the surface S20 and the surface S21, and the thickness, refractive index, and refractive index of each lens and each optical element in the column are For Abbe number, please refer to the corresponding value of each pitch, refractive index and Abbe number in the same column. The surfaces S1 and S2 are the two surfaces of the first lens L1. The surfaces S3 and S4 are the two surfaces of the second lens L2. The above two lenses constitute the first lens group G1. For parameter values such as the radius of curvature and spacing of each surface, please refer to Table 1, which will not be repeated here.

<Table two>

The appearance of * on the surface in the table means that the surface is aspherical, and if it is not marked, it means spherical.

The radius of curvature refers to the inverse of the curvature. When the radius of curvature is positive, the spherical center of the lens surface is in the direction of the lens's image reduction side. When the radius of curvature is negative, the spherical center of the lens surface is in the direction of the image magnification side of the lens. The convex and concave of each lens can be seen in the table above. Table 3 lists some important parameter values of the projection lens 10a at the wide-angle end and the telephoto end. Wherein, D1, D2, D3, D4, and D5 are the distances between the first lens group G1 to the fifth lens group G5 and the light valve 120, respectively. In this embodiment, D1, D2, D3, and D4 are adjustable, so as to achieve the effect of zooming. For example, when D1 is 97.0 millimeters, D2 is 83.3 millimeters, D3 is 66.4 millimeters, and D4 is 30.2 millimeters, the projection lens 10a can be at the wide-angle end (that is, with a magnification effect). When D1 is 89.4 mm, D2 is 77.5 mm, D3 is 73.7 mm, and D4 is 34.8 mm, the projection lens 10a can be at the telephoto end (that is, it has a reduction effect).

<Table three>

3A and 3B are imaging optical simulation data diagrams of the projection lens 10a of FIGS. 2A and 2B. Please refer to Figure 3A, Figure 3A is a wide-angle end of the modulation transfer function curve (modulation transfer function, MTF), the horizontal axis is the spatial frequency per cycle/mm (spatial frequency in cycles per millimeter), the vertical axis is the optical transfer function Modulus of the OTF. And Figure 3B is a graph of the modulation transfer function (MTF) of the telephoto end. Since the graphics shown in FIGS. 3A and 3B are within the standard range, it can be verified that the projection lens 10a of this embodiment can achieve a good imaging effect.

The aperture value of the present invention is represented by F/#, as indicated in the above table. In the embodiment of the present invention, F/# is greater than or equal to 1.5.

In the embodiment of the present invention, the total length of the optical lens is represented by OAL, as indicated in the above table. More specifically, the total length of this embodiment refers to the distance measured along the optical axis 12 between the lens surface S1 closest to the image magnification side and the lens surface S20 closest to the image reduction side of the optical lens 10a. The total length (OAL) of the optical lens is less than 110mm. In the embodiment of the present invention, the total length from the optical lens to the light valve surface S21 is represented by TTL, as indicated in the above table. More specifically, the total length of the optical lens to the light valve surface S21 in this embodiment refers to the distance measured along the optical axis 12 between the lens surface S1 of the optical lens 10a closest to the image magnification side and the light valve surface S21. The total length (TTL) of the optical lens is less than 135mm. The back focus length of the optical lens of this embodiment from the lens surface S20 closest to the image reduction side to the light valve surface S21, and the distance measured along the optical axis 12, is represented by BFL. FIG. 10 is a schematic diagram of a light valve 120 disposed on the reduction side according to an embodiment of the present invention. The viewing angle of the light valve 120 is viewed from the magnification side to the reduction side of the optical lens 10a. The light valve in this embodiment is, for example, a digital micromirror device (DMD). Taking this as an example, the distance between the optical axis 12 of the optical lens 10a and the end of the lower left corner of the light valve 120 can be defined as half of the image circle (IM) disclosed in the embodiment of the present invention. Taking the optical axis 12 as the center and IM as the radius, a circumscribed circle passing through the lower two end points of the light valve 120 can be made, and the diameter of the circumscribed circle is the image height (Image circle, IM).

The optical projection lens of an embodiment of the present invention includes five lens groups. For example, the first lens group can use two negative refractive power (Power) lenses, but it is not limited. The aperture value of the optical lens is approximately greater than or equal to 1.5. The fourth lens group includes two cemented lenses to correct chromatic aberration, and the minimum distance between the lenses of the cemented lens along the optical axis is less than or equal to 0.01 mm. Each cemented lens includes corresponding adjacent cemented surfaces with substantially the same or similar radius of curvature. The total number of optical lenses with diopter lenses is 11-13, and at least two lenses with an Abbe number greater than 70, wherein each cemented lens in the fourth lens group includes a lens with an Abbe number greater than 70, including A lens with an Abbe number less than 25.

In one embodiment, the lens of the optical lens can meet 1.2<D1/DL<1.9, in another embodiment, it can meet 1.1<D1/DL<1.95, and in yet another embodiment, it can meet 1.0<D1/DL<2.0 , Where D1 is the lens diameter of the lens L1 closest to the image magnification side, and DL is the lens diameter of the lens L11 closest to the image reduction side, so that the image light leaving the light valve is emitted substantially in parallel to achieve comparison in a limited space. Good optical effect.

In one embodiment, the optical lens can meet 110<TTL<135, in another embodiment, it can meet 105<TTL<140, and in yet another embodiment, it can meet 100<TTL<145, so as to provide a longer total length of the optical lens. Optimal design range, where TTL is the distance measured along the optical axis 12 between the lens surface S1 of the optical lens closest to the image magnification side and the light valve surface.

In one embodiment, the optical lens can meet 0.06<IM/TTL<0.082, in another embodiment, it can meet 0.058<IM/TTL<0.084, and in yet another embodiment, it can meet 0.056<IM/TTL<0.086, thereby Provides a better design range of the light valve image size corresponding to the total length of the optical lens, where TTL is the distance measured along the optical axis 12 between the lens surface S1 of the optical lens closest to the image magnification side and the light valve surface, IM (Image circle) It is twice the distance between the optical axis of the optical lens and the end of the lower left corner of the light valve, which is the image height.

The design of the projection lens 10b of the second embodiment of the projection lens 10 of the present invention will be described below. FIG. 4 is a schematic structural diagram of a projection lens 10b according to a second embodiment of the present invention. The projection lens 10b sequentially includes a first lens group G1, a second lens group G2, a third lens group G3, an aperture 14, a fourth lens group G4, and a fifth lens group G5 from the image magnifying end OS to the image reducing end IS. The refractive powers of the first lens group G1 to the fifth lens group G5 are negative, positive, positive, positive, and positive, respectively. 4, in this embodiment, the first lens group G1 includes a first lens L1 and a second lens L2. The second lens group G2 includes a third lens L3 and a fourth lens L4. The third lens group G3 includes a fifth lens L5. The fourth lens group G4 includes a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, and an eleventh lens L11. The fifth lens group G5 includes a twelfth lens L12. In this embodiment, the first lens L1 of the projection lens 10b The refractive powers of the twelfth lens L12 are negative, negative, positive, positive, positive, negative, positive, negative, negative, positive, positive, and positive. The first lens is an aspherical plastic lens, and the remaining lenses are spherical glass lenses. In one embodiment, the aspherical plastic lens can be replaced by an aspherical glass lens. The sixth lens L6, the seventh lens L7, and the eighth lens L8 of this embodiment constitute a triple cemented lens, and the ninth lens L9 and the tenth lens L10 of this embodiment constitute a double cemented lens. Furthermore, in this embodiment, the diameter (D1) of the first lens L1 is 34.6 mm, and the diameter (DL) of the twelfth lens L12 is 22.4 mm. The design parameters of the lens and peripheral components of the optical lens 10b are shown in Table 4, Table 5, and Table 6.

Table Four

The spacing of S1 is the distance of the surfaces S1 to S2 on the optical axis 12, and the spacing of S22 is the distance of the surfaces S22 to S23 on the optical axis 12.

Table 5 lists the aspheric coefficients and quadric coefficient values of the aspheric lens L1 surface of the projection lens 10b in the second embodiment of the present invention.

<Table 5>

Table 6 lists some important parameter values of the projection lens 10b at the wide-angle end and the telephoto end. Wherein, D1, D2, D3, D4, and D5 are the distances between the first lens group G1 to the fifth lens group G5 and the light valve 120, respectively. In this embodiment, D1, D2, D3, and D4 are adjustable, so as to achieve the effect of zooming.

<Table 6>

The design of the projection lens 10c of the third embodiment of the projection lens 10 of the present invention will be described below. FIG. 6 is a schematic structural diagram of a projection lens 10c according to a third embodiment of the present invention. The projection lens 10c sequentially includes a first lens group G1, a second lens group G2, a third lens group G3, an aperture 14, a fourth lens group G4, and a fifth lens group G5 from the image magnifying end OS to the image reducing end IS. The refractive powers of the first lens group G1 to the fifth lens group G5 are negative, positive, positive, positive, and positive, respectively. 6, in this embodiment, the first lens group G1 includes a first lens L1, a second lens L2, and a third lens L3. The second lens group G2 includes a fourth lens L4 and a fifth lens L5. The third lens group G3 includes a sixth lens L6. Fourth lens group G4 includes a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, and a twelfth lens L12. The fifth lens group G5 includes a thirteenth lens L13. In this embodiment, the refractive powers of the first lens L1 to the thirteenth lens L13 of the projection lens 10c are negative, negative, positive, negative, positive, positive, negative, positive, negative, negative, positive, positive, and positive, respectively. The first lens is an aspherical plastic lens, and the remaining lenses are spherical glass lenses. In one embodiment, the aspherical plastic lens can be replaced by an aspherical glass lens. The second lens L2 and the third lens L3 in this embodiment constitute a double cemented lens, the seventh lens L7, the eighth lens L8, and the ninth lens L9 in this embodiment constitute a triple cemented lens, and the tenth lens L10 and the ninth lens L9 in this embodiment constitute a doublet lens. The eleventh lens L11 constitutes a doublet lens. Furthermore, in this embodiment, the diameter (D1) of the first lens L1 is 35.0 mm, and the diameter (DL) of the thirteenth lens L13 is 23.95 mm. The design parameters of the lens and peripheral components of the optical lens 10c are shown in Table 7, Table 8 and Table 9.

Table Seven

The spacing of S1 is the distance of the surfaces S1 to S2 on the optical axis 12, and the spacing of S23 is the distance of the surfaces S23 to S24 on the optical axis 12.

Table 8 lists the aspheric coefficients and quadric coefficient values of the aspheric lens L1 surface of the projection lens 10c in the third embodiment of the present invention.

<Table 8>

Table 9 lists some important parameter values of the projection lens 10c at the wide-angle end and the telephoto end. Wherein, D1, D2, D3, D4, and D5 are the distances between the first lens group G1 to the fifth lens group G5 and the light valve 120, respectively. In this embodiment, D1, D2, D3, and D4 are adjustable, so as to achieve the effect of zooming.

<Table 9>

The design of the projection lens 10d of the fourth embodiment of the projection lens 10 of the present invention will be described below. FIG. 8 is a schematic structural diagram of a projection lens 10d according to a fourth embodiment of the present invention. The projection lens 10d sequentially includes a first lens group G1, a second lens group G2, an aperture 14, a third lens group G3, and a fourth lens group G4 from the image magnifying end OS to the image reducing end IS. The refractive power of the first lens group G1 to the fourth lens group G4 (refractive power) are negative, positive, positive, and positive respectively. Referring to FIG. 8, in this embodiment, the first lens group G1 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5. The second lens group G2 includes a sixth lens L6. The third lens group G3 includes a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, and a twelfth lens L12. The fourth lens group G4 includes a thirteenth lens L13. In this embodiment, the refractive powers of the first lens L1 to the thirteenth lens L13 of the projection lens 10d are negative, negative, positive, negative, positive, positive, negative, positive, negative, negative, positive, positive, and positive, respectively. The first lens is an aspherical plastic lens, and the remaining lenses are spherical glass lenses. In one embodiment, the aspherical plastic lens can be replaced by an aspherical glass lens. The second lens L2 and the third lens L3 in this embodiment constitute a double cemented lens, the seventh lens L7, the eighth lens L8, and the ninth lens L9 in this embodiment constitute a triple cemented lens, and the tenth lens L10 and the ninth lens L9 in this embodiment constitute a doublet lens. The eleventh lens L11 constitutes a doublet lens. Furthermore, in this embodiment, the diameter (D1) of the first lens L1 is 35.0 mm, and the diameter (DL) of the thirteenth lens L13 is 23.6 mm. The design parameters of the lens and peripheral components of the optical lens 10d are shown in Table 10, Table 11 and Table 12.

Table 10

The spacing of S1 is the distance of the surfaces S1 to S2 on the optical axis 12, and the spacing of S23 is the distance of the surfaces S23 to S24 on the optical axis 12.

Table 11 lists the aspheric coefficients and quadric coefficient values of each order of the aspheric lens L1 surface of the projection lens 10d in the fourth embodiment of the present invention.

<Table eleven>

Table 12 lists some important parameter values of the projection lens 10d at the wide-angle end and the telephoto end. Wherein, D1, D2, D3, and D4 are the distances between the first lens group G1 to the fourth lens group G4 and the light valve 120, respectively. In this embodiment, D1, D2, and D3 are adjustable, so as to achieve the effect of zooming.

<Table 12>

5, 7 and 9 are respectively imaging optical simulation data diagrams of the projection lenses 10b, 10c, and 10d of Figs. 4, 6 and 8. Since the graphics shown in FIGS. 5, 7 and 9 are within the standard range, it can be verified that the projection lenses 10b, 10c, and 10d of this embodiment can achieve good imaging effects.

Based on the design of the embodiment of the present invention, in summary, in the projection device and projection lens of an embodiment of the present invention, the first lens group with negative refractive power and the second lens group, third lens group, and fourth lens with positive refractive power are used. The lens group and the fifth lens group can achieve zooming effect and produce F-number greater than or equal to 1.5. Moreover, by arranging an aspherical mirror in the first lens group, the projection lens can still have a good imaging quality under the characteristics of a large aperture, thereby enabling the projection device to have high brightness and excellent projection quality.

In addition, in an embodiment of the present invention, by arranging the aperture between the third lens group and the fourth lens group closer to the light valve, part of the light away from the optical axis can be filtered out, and the projection can be further improved. The projection quality of the device.

Through the design of the embodiment of the present invention, it can provide a good optical imaging quality, low thermal drift, low distortion (distortion), low chromatic aberration, large aperture and short overall length characteristics, and can provide lower manufacturing costs and Projection lens design with better imaging quality. Furthermore, the optical lens of the embodiment of the present invention includes 11-13 lenses. When the optical lens is at the wide-angle end, the distance (OAL) between the outermost diopter lens surfaces at both ends of the optical lens on the optical axis is less than 110mm, which can provide a large aperture (F# greater than or equal to 1.5), high resolution, miniaturization, With the characteristics of low thermal drift and short overall length, it can provide an optical lens design with lower manufacturing cost and better imaging quality.

Although the present invention has been disclosed as above in the preferred embodiment, it is not intended to limit the present invention. Anyone familiar with the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be subject to the scope of the attached patent application. In addition, any embodiment of the present invention or the scope of the patent application does not have to achieve all the objectives or advantages disclosed in the present invention or Features. In addition, the abstract part and title are only used to assist in searching for patent documents, and are not used to limit the scope of the present invention.

10a‧‧‧Optical lens

12‧‧‧Optical axis

14‧‧‧Aperture

16‧‧‧Optical Path Adjustment Mechanism

18‧‧‧稜鏡

120‧‧‧Light valve

130‧‧‧Screen

G1-G5‧‧‧lens group

L1-L11‧‧‧lens

S1-S21‧‧‧surface

OS‧‧‧Magnified side

IS‧‧‧Reduced side

P、Q‧‧‧Intersection point

D‧‧‧Lens diameter

Claims (10)

An optical lens for receiving and projecting an image beam, including: A first lens group, a second lens group, a third lens group, and a fourth lens group are sequentially arranged from a magnification side to a reduction side; and An aperture set between the second lens group and the fourth lens group, Wherein, when the optical lens is zoomed, the first lens group, the second lens group, and the third lens group move relative to the imaging surface of the optical lens, and the optical lens meets the following conditions: The image beam first enters the fourth lens group. The number of lenses with diopter is between 9 and 16. The aperture and the lens closest to the reduction side include a triplet lens and a doublet lens. When the optical lens When it is the wide-angle end, the distance between the outermost diopter lens surfaces of the two ends of the optical lens along the optical axis of the optical lens is between 85 and 110 mm. An optical lens including: A fourth lens group, a third lens group, a second lens group, and a first lens group are sequentially arranged according to the traveling direction of an image beam; and An aperture set between the second lens group and the fourth lens group, Wherein, when the optical lens is zoomed, the first lens group, the second lens group, and the third lens group move relative to the imaging surface of the optical lens, and the optical lens meets the following conditions: The number of diopter lenses is between 9 and 16, the diameter of the first diopter lens that the image beam penetrates is smaller than the diameter of the last diopter lens, and there are two diopter lenses between the aperture and the first diopter lens that penetrates. When the optical lens has a wide-angle end, the distance between the outermost diopter lens surfaces of the two ends of the optical lens along the optical axis of the optical lens is between 85 and 110 mm. The optical lens according to any one of items 1 to 2 of the scope of patent application, wherein the optical lens further includes a fifth lens group, and the fifth lens group is disposed between the first lens group and the second lens group . The optical lens described in any one of items 1 to 2 of the scope of the patent application, wherein the optical lens satisfies one of the following conditions: (1) F-number is greater than or equal to 1.5, (2) more than three-quarters of the lens is Glass spherical lens, (3) the effective focal length is between 12~17mm, and (4) the distortion is less than +-2%. The optical lens described in any one of items 1 to 2 of the scope of patent application, wherein the optical lens satisfies one of the following conditions: (1) the first lens group includes two negative refractive power (Power) lenses, (2) the The third lens group contains two cemented lenses, (3) contains two lenses with an Abbe number greater than 70, and (4) each cemented lens in the third lens group contains a lens with an Abbe number greater than 70, and includes one lens with an Abbe number greater than 70. A lens with a bay number less than 25. The optical lens described in any one of items 1 to 2 of the scope of patent application, wherein the optical lens satisfies one of the following conditions: (1) the total length (OAL) of the optical lens is less than 110mm, (2) the optical lens The total length (TTL) is less than 135mm, (3) 1.0<D1/DL<2.0, where D1 is the diameter of the lens closest to the image magnification side, DL is the diameter of the lens closest to the image reduction side, (4) the total length of the optical lens ( TTL) is between 100~145mm, (5)0.056<IM/TTL<0.086, IM (Image circle) is the image height. For the optical lens described in any one of items 1 to 2 of the scope of patent application, in a direction from the first lens group to the fourth lens group, the optical lens satisfies one of the following conditions: (1) From the direction Aspheric, biconcave, biconvex, crescent, crescent, biconvex, crescent, biconcave, biconvex, biconvex, and crescent lens in order, (2) from this direction to aspheric, biconvex Concave, crescent, biconvex, plano-convex, crescent, bi-convex, crescent, bi-concave, bi-convex, bi-convex and crescent lens, (3) Aspheric, bi-concave, bi-convex in order from this direction , Crescent, Crescent, Plano-Convex, Crescent, Double-Convex, Crescent, Double-Concave, Double-Convex, Double-Convex and Crescent Lenses. For the optical lens described in any one of items 1 to 2 of the scope of patent application, in a direction from the first lens group to the fourth lens group, the optical lens satisfies one of the following conditions: (1) From the direction The refractive power of the lens is negative, negative, positive, positive, negative, positive, negative, negative, positive, positive, and positive. (2) The refractive power of the lens from this direction is negative, negative, positive, positive, Positive, negative, positive, negative, negative, positive, positive, positive, (3) The refractive power of the lens from this direction is negative, negative, positive, negative, positive, positive, negative, positive, negative, negative, positive, respectively , Positive, positive. A projection device includes: An illumination unit for providing an illumination beam; A light valve arranged on the transmission path of the illumination beam for converting the illumination beam into an image beam; and The optical lens described in any one of items 1 to 2 in the scope of the patent application. A method for manufacturing an optical lens, including: Provide a lens barrel; Arranging a first lens group, a second lens group, a third lens group and a fourth lens group on the lens barrel; and Set an aperture between the second lens group and the fourth lens group, Wherein, when the optical lens is zoomed, the first lens group, the second lens group, and the third lens group move relative to the imaging surface of the optical lens, and the optical lens meets the following conditions: An image beam enters the fourth lens group first. The number of lenses with diopter is between 9 and 16. The aperture and the lens closest to the reduction side include a triplet lens and a doublet lens. When the optical lens When it is the wide-angle end, the distance between the outermost diopter lens surfaces of the two ends of the optical lens along the optical axis of the optical lens is between 85 and 110 mm.

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