TWI729692B - Zoom projection system - Google Patents

Abstract

A zoom projection system, the structure can be disassembled into five groups, namely the first lens group, the second lens group, the third lens group, the fourth lens group and the fifth lens group. The first lens group includes the first lens and the second lens group. Two lenses, a second lens group including a third lens, a third lens group including a double cemented lens composed of a fourth lens and a fifth lens, and a fourth lens group including a sixth lens, a seventh lens and an eighth lens The triplet lens, the ninth lens, and the fifth lens group include the tenth lens, and the coordination of each lens group makes the lens assembly structure simple and cheap, and can take into account the effect of improving the quality of projection imaging.

Description

Zoom projection system

The present invention relates to a zoom projection system, in particular to a system that uses the cooperation of various lens groups to make the lens combination structure simple and cheap, and can take into account the quality of projection imaging.

According to the fact that the technology of the projector has gradually matured, its main feature is that the image can be clearly imaged, and the technical feature of the projection is zoom or fixed focus by a plurality of lens groups. However, it is found that the focal length of each lens group and the lens combination structure of each lens group affect the quality of projection imaging. How to adjust the focal length of each lens group and match the lens combination structure of each lens group is simple and cheap, and also The ability to take into account the quality of projection imaging is the subject to be solved by the invention.

The reason is that the main purpose of the present invention is to provide a zoom projection system, which cooperates with each lens group to make the lens assembly structure simple and low cost, and can also take into account the effect of improving the quality of projection imaging.

Another object of the present invention is to provide a zoom projection system, which cooperates with each lens group so that the aperture is arranged between each lens group to increase the effect of improving the quality of projection imaging.

To achieve the above objective, the technical means adopted by the present invention include: a first lens group with negative refractive power, including at least a first lens and a second lens, the first lens is a meniscus aspheric lens with negative refractive power and The second lens is a spherical lens with negative refractive power; a second lens group with positive refractive power includes at least one third lens; a third lens group with positive refractive power includes at least one doublet lens, the doublet lens It has positive refractive power and is composed of a fourth lens and a fifth lens; a fourth lens group has positive refractive power, including at least A triplet lens and a ninth lens. The triplet has negative refractive power and is composed of a sixth lens, a seventh lens, and an eighth lens. The seventh lens is a biconcave spherical lens. The lens is a biconvex lens with positive refractive power; and a fifth lens group with positive refractive power includes at least one tenth lens.

According to the aforementioned features, the focal length of the first lens is between -25mm~-50mm; the focal length of the second lens is between -25mm~-50mm; the focal length of the doublet lens is between 25mm~80mm; the focal length of the triplet lens The focal length is between -20mm and -50mm; the focal length of the seventh lens is between -5mm and -20mm; and the focal length of the eighth lens is between 20mm and 50mm.

According to the aforementioned features, the Abbe number of the second lens is between 50 and 82.

According to the aforementioned features, the Abbe number of the seventh lens is between 20-28.

According to the features disclosed above, the first lens is made of plastic; the second lens is made of glass; the doublet lens is made of glass; the seventh lens is made of glass; the eighth lens is made of molded glass .

According to the aforementioned features, the sum of the Abbe numbers of the first lens group is between 90 and 140; the Abbe numbers of the second lens group are between 25 and 55; the Abbe numbers of the third lens group The sum total is between 50 and 90; the sum total of the Abbe number of the fourth lens group is between 200 and 260; the sum total of the Abbe number of the fifth lens group is between 10 and 20.

According to the aforementioned features, the zoom projection system satisfies the following conditions: -2.0<f1a/fw<-1.0; 7.5>f4/fw>6; 1.35<Bf/fw<1.45; where f1a is the effective value of the first lens group Focal length, f4 is the effective focal length of the fourth lens group, fw is the focal length in the wide-angle state, and Bf is the equivalent air gap of the back focal length at the wide-angle end.

According to the features of the previous disclosure, the zoom projection system can switch between the wide-angle end and the telephoto end, and set The first lens group is a focusing group, so that the first lens group and the fifth lens group do not move, and the second lens group, the third lens group, and the fourth lens group change the distance of an imaging element, When switched to the wide-angle end, the second lens group is close to the imaging element, the third lens group is close to the imaging element, and the fourth lens group is close to the imaging element, or when it is switched to the telephoto end, the second lens group is close to the imaging element. The lens group is away from the imaging element, the third lens group is away from the imaging element, and the fourth lens group is away from the imaging element.

According to the aforementioned features, the projection zoom ratio of the zoom projection system is a high zoom magnification of 1.25x.

According to the aforementioned features, it further includes an aperture, which is between 1.6 and 2.0, and is located between the third lens group and the fourth lens group.

With the help of the technical means of uncovering, the present invention uses the mutual cooperation of the lens groups to make the lens assembly structure simple and cheap, and can also take into account the effect of improving the quality of projection imaging, and make the arrangement of the lens groups large apertures. The effect of improving the quality of projection imaging is enhanced.

10: The first lens group

20: Second lens group

30: The third lens group

40: The fourth lens group

50: Fifth lens group

60: zoom projection system

L ₁ : the first lens

L ₂ : second lens

L ₃ : third lens

L ₄ : fourth lens

L ₅ : Fifth lens

L ₆ : sixth lens

L ₇ : seventh lens

L ₈ : Eighth lens

L ₉ : Ninth lens

L ₁₀ : Tenth lens

C ₁ : Double cemented lens

C ₂ : Triple cemented lens

S: aperture

M: imaging element

IMA: imaging surface

λ ₁ : first wavelength

λ ₂ : second wavelength

λ ₃ : third wavelength

1R ₁ , 1R ₂ , 2R ₁ , 2R ₂ , 3R ₁ , 3R ₂ , 4R ₁ , 5R ₁ , 5R ₂ , 6R ₁ , 7R ₁ , 8R ₁ , 8R ₂ , 9R ₁ , 9R ₂ , 10R ₁ , 10R ₂ :surface

D ₁ : The first moving distance

D ₂ : The second moving distance

D ₃ : The third moving distance

D ₄ : The fourth moving distance

P: 稜鏡

T: Transmissive smooth imaging device

G: Cover glass

FIG. 1A is a schematic diagram of the lens configuration of the present invention switched to the wide-angle end.

Fig. 1B is a transverse ray fan diagram with an image height of 0.0000mm on the imaging surface switched to the wide-angle end of the present invention.

Fig. 1C is a transverse ray fan diagram with an image height of 1.5610mm on the imaging surface switched to the wide-angle end of the present invention.

Fig. 1D is a horizontal ray fan diagram with an image height of 3.9010 mm on the imaging surface switched to the wide-angle end of the present invention.

Fig. 1E is a horizontal ray fan diagram of the imaging surface of the present invention switched to the wide-angle end showing an image height of 5.4620mm.

Fig. 1F is a horizontal ray fan diagram with an image height of 7.8030mm on the imaging surface switched to the wide-angle end of the present invention.

Fig. 1G is a field curve diagram of the present invention switched to the wide-angle end.

Figure 1H is a distortion diagram of the present invention switched to the wide-angle end.

2A is a schematic diagram of the lens configuration of the present invention switched to the telephoto end.

Fig. 2B is a transverse ray fan diagram with 0.0000mm image height on the imaging surface of the telephoto end switched to the present invention.

Fig. 2C is a transverse ray fan-shaped diagram with an image height of 1.5610 mm on the imaging surface of the telephoto end of the present invention switched to.

Fig. 2D is a transverse ray fan diagram with an image height of 3.9010 mm on the imaging surface of the telephoto end of the present invention switched to.

Fig. 2E is a transverse ray fan-shaped diagram with an image height of 5.4620 mm on the imaging surface at the telephoto end of the present invention switched to.

Fig. 2F is a transverse ray fan-shaped diagram with an image height of 7.8030 mm on the imaging surface of the telephoto end of the present invention switched to.

Figure 2G is a field curve diagram of the present invention switched to telephoto end.

Fig. 2H is a distortion diagram of the present invention switched to the telephoto end.

First, referring to FIGS. 1A to 1H and FIGS. 2A to 2H, a preferred embodiment of a zoom projection system 60 of the present invention includes: a first lens group 10 with negative refractive power, including at least one first lens (L ₁ ) And a second lens (L ₂ ). The first lens (L ₁ ) is a meniscus aspheric lens with negative refractive power and the second lens (L ₂ ) is a spherical lens with negative refractive power. In this embodiment Wherein, the focal length of the first lens (L ₁ ) is between -25mm and -50mm and is made of plastic; the _{focal length of the second lens (L 2} ) is between -25mm and -50mm and is made of glass, And its Abbe number is between 50 and 82, and the second lens (L ₂ ) can also be a biconcave spherical lens, but it is not limited to this.

A second lens group 20 has positive refractive power and includes at least one third lens (L ₃ ). In this embodiment, the third lens (L ₃ ) is a biconvex lens, but it is not limited thereto.

A third lens group 30 with positive refractive power, including at least one double cemented lens (C ₁ ), the double cemented lens (C ₁ ) has positive refractive power, and consists of a fourth lens (L ₄ ) and a fifth lens ( L ₅ ), in this embodiment, the _{focal length of the doublet lens (C 1} ) is between 25 mm and 80 mm, and the fourth lens (L ₄ ) is a double convex lens, and the fifth lens (L ₅ ) is Convex-concave lenses, but not limited to this.

A fourth lens group 40 with positive refractive power, including at least one triplet lens (C ₂ ) and a ninth lens (L ₉ ). The triplet lens (C ₂ ) has negative refractive power and is composed of a sixth lens ( L ₆ ), a seventh lens (L ₇ ) and an eighth lens (L ₈ ), the seventh lens (L ₇ ) is a biconcave spherical lens, and the eighth lens (L ₈ ) has positive refractive power In this embodiment, the _{focal length of the triplet lens (C 2} ) is between -20mm and -50mm; the sixth lens (L ₆ ) is a meniscus lens; the focal length of _{the seventh lens (L 7)} It is between -5mm and -20mm and is made of glass, and its Abbe number is between 20 and 28; the _{focal length of the eighth lens (L 8} ) is between 20mm and 50mm and is made of molded glass; The ninth lens (L ₉ ) is a biconvex lens, but it is not limited to this.

A fifth lens group 50 has positive refractive power and includes at least one tenth lens (L ₁₀ ). In this embodiment, the tenth lens is a plano-convex lens, but it is not limited thereto. In addition, in this embodiment, it further includes an aperture (Stop) (S), which is between 1.6 and 2.0 and is located between the third lens group 30 and the fourth lens group 40, but it is not limited to this. .

To further illustrate, the zoom projection system 60 _{summarizes the lenses (L 1} , L ₂ , L ₃ , L ₄ , L ₅ , L ₆ , L ₇ , L ₈ , L ₉ , and L ₁₀ ) into each lens group 10 , 20, 30, 40, 50, and calculate the Abbe number of each lens group 10, 20, 30, 40, 50. In this embodiment, the Abbe number of the first lens group 10 is added to the total Between 90 and 140; the Abbe number of the second lens group 20 is between 25 and 55; the Abbe number of the third lens group 30 is between 50 and 90; the Abbe number of the fourth lens group 40 The sum of the numbers is between 200 and 260; the Abbe number of the fifth lens group 50 is between 10 and 20, and each of the lens groups 10, 20, 30, 40, and 50 cooperate with each other, and can be applied For zooming, and meet the following conditions: -2.0<f1a/fw<-1.0;7.5>f4/fw>6;1.35<Bf/fw<1.45; where f1a is the effective focal length of the first lens group 10. length,efl), f4 is the effective focal length of the fourth lens group 40, fw is the focal length in the wide-angle state, and Bf is the equivalent air gap of the back focal length at the wide-angle end. In this embodiment, f1a can be -14.059; fw can be It is 12.562; f4 can be 89.380; Bf can be 14.130, but it is not limited to this.

In conclusion, in this embodiment, the zoom projection system 60 can be used for zooming, and can also switch between the wide-angle end and the telephoto end, and set the first lens group 10 as a focusing group, so that the first lens group 10 and the The fifth lens group 50 does not move, and the second lens group 20, the third lens group 30, and the fourth lens group 40 change the distance of an imaging element (M). When switched to the wide-angle end, the second lens group 20, the third lens group 30, and the fourth lens group 40 change the distance of an imaging element (M). When the second lens group 20 is close to the imaging element (M), the third lens group 30 is close to the imaging element (M), and the fourth lens group 40 is close to the imaging element (M), or when switched to the telephoto end, the The second lens group 20 is away from the imaging element (M), the third lens group 30 is away from the imaging element (M), and the fourth lens group 40 is away from the imaging element (M), but not limited thereto.

In addition, a Transmissive Smooth Picture Actuator (T) is provided between the imaging surface (IMA) of the imaging element (M) and the tenth lens (L _{10 ).} The rotating glass flat panel device is synthesized by image shifting to increase the resolution. As a result, the resolution of 1080P can be increased to 4K2K resolution; a prism (P) is installed in the transmissive smooth image device (T ), and behind the frame (P), a cover glass (G) is arranged in sequence, so that the zoom projection system 60 forms a telecentric zoom projection system, but it is not limited to this.

As shown in Table 1, the first lens (L ₁ ), the second lens (L ₂ ), the third lens (L ₃ ), the fourth lens (L ₄ ), the fifth lens (L ₅ ), the radius of the surface of the sixth lens (L ₆ ), the seventh lens (L ₇ ), the eighth lens (L ₈ ), the ninth lens (L ₉ ), and the tenth lens (L ₁₀₎ (Radius), thickness (Thickness), refractive index (Nd) and Abbe number (Vd).

To further explain, the 1R ₁ and 1R ₂ are respectively the projection side surface and the image source side surface of the first lens (L _{1 ); the 2R 1} and 2R ₂ are respectively the projection side surface of the second lens (L _{2 ),} The image source side surface; the 3R ₁ and 3R ₂ are the projection side surface and the image source side surface of the third lens (L _{3 ) respectively; the 4R 1 is} the projection side surface of the fourth lens (L _{4 ); the 5R 1} and 5R ₂ are respectively the projection side surface and the image source side surface of the fifth lens (L _{4 ); the 6R 1 is} the projection side surface of the sixth lens (L _{6 ); the 7R 1 is} the seventh lens ( L ₇ ) the projection side surface; the 8R ₁ , 8R ₂ are the projection side surface and the image source side surface of the eighth lens (L _{8 ), respectively; the 9R 1} , 9R ₂ are the ninth lens (L ₉ ), respectively The projection side surface and the image source side surface; the 10R ₁ and 10R ₂ are the projection side surface and the image source side surface of the tenth lens (L _{10 ), respectively.}

As shown in Table 2, the aspheric lens (ASPH) lists the 1R ₁ and 1R ₂ as the projection side surface and the image source side surface of the aspheric lens respectively, and lists the Conic, 4TH, 6TH, 8TH of the aspheric lens , 10th, 12th, 14th, 16th; as shown in Table 3, the aspheric lens (ASPH) lists the 8R ₁ and 8R ₂ as the projection side surface and image source side surface of the aspheric lens, and lists the aspheric surface Conic, 4TH, 6TH, 8TH, 10th, 12th, 14th, 16th of the lens.

As shown in Table 4, the zoom projection system 60 can be switched to a wide-angle (Wide) end or a telephoto (Tele) end, and there is a first moving distance between the first lens group 10 and the second lens group 20 (D _{1 ); There is a second moving distance (D 2} ) between the second lens group 20 and the third lens group 30; There is a distance between the third lens group 30 and the fourth lens group 40 The third moving distance (D _{3 ); there is a fourth moving distance (D 4} ) between the fourth lens group 40 and the fifth lens group 50, and the projection zoom ratio of the zoom projection system 60 is high The zoom ratio is 1.25x. Therefore, the zoom projection system 60 can be adjusted between the wide-angle end and the telephoto end under a fixed projection distance.

Therefore, when the zoom projection system 60 is switched to the wide-angle end, a first wavelength (λ ₁ ), a second wavelength (λ ₂ ), and a third wavelength (λ ₃ ) are respectively 0.486um, 0.588um and 0.656um, and can simulate the different lateral light sector graphs of Figure 1B, Figure 1C, Figure 1D, Figure 1E, Figure 1F, and respectively present 0.0000mm, 1.5610mm, 3.9010mm, 5.4620mm on the same imaging surface (IMA) , 7.8030mm different image heights, and the symbols ey, py, ex, px represent the y-axis lateral aberration, y-axis pupil height, x-axis lateral aberration, x-axis pupil height, the y-axis lateral aberration, the x The axial lateral aberration, the maximum scale is ±20.000um, and the y-axis pupil height and the x-axis pupil height are normalized ratios; the Field Curvature diagram of Fig. 1G and the distortion (Distortion) of Fig. 1H Figure, the maximum field of view (Maximum Field) is 31.764 degrees, or the zoom projection system 60 is switched to the telephoto end, which uses a first wavelength (λ ₁ ), a second wavelength (λ ₂ ), and a third wavelength ( λ ₃ ) are 0.486um, 0.588um, and 0.656um, respectively, and can simulate the different lateral ray fan patterns of Figure 2B, Figure 2C, Figure 2D, Figure 2E, and Figure 2F, respectively, and present them on the same imaging plane (IMA) Different image heights of 0.0000mm, 1.5610mm, 3.9010mm, 5.4620mm, 7.8030mm, and the symbols ey, py, ex, px represent the y-axis lateral aberration, the y-axis pupil height, the x-axis lateral aberration, and the x-axis pupil respectively. The maximum scale of the y-axis lateral aberration and the x-axis lateral aberration is ±20.000um, and the y-axis pupil height and the x-axis pupil height are normalized ratios; Fig. 2G field curvature (Field The Curvature diagram and the Distortion diagram in Figure 2H, the maximum field of view (Maximum Field) is 26.317 degrees. Based on the above simulation curves and data, it is also proved that the zoom projection system 60 can be implemented with a simple lens assembly structure and low cost. Projection, still maintain good projection image quality.

In summary, the technical means disclosed in the present invention do have the requirements of invention patents such as "novelty", "progressiveness" and "available for industrial use". I hope that the Jun Bureau will grant patents to encourage creation without any responsibility. Sense of virtue.

However, the drawings and descriptions disclosed above are only preferred embodiments of the present invention. Anyone who is familiar with the art and makes modifications or equivalent changes based on the spirit of the case should still be included in the scope of the patent application in this case.

10: The first lens group

20: Second lens group

30: The third lens group

40: The fourth lens group

50: Fifth lens group

60: zoom projection system

L ₁ : the first lens

L ₂ : second lens

L ₃ : third lens

L ₄ : fourth lens

L ₅ : Fifth lens

L ₆ : sixth lens

L ₇ : seventh lens

L ₈ : Eighth lens

L ₉ : Ninth lens

L ₁₀ : Tenth lens

C ₁ : Double cemented lens

C ₂ : Triple cemented lens

S: aperture

M: imaging element

IMA: imaging surface

1R ₁ , 1R ₂ , 2R ₁ , 2R ₂ , 3R ₁ , 3R ₂ , 4R ₁ , 5R ₁ , 5R ₂ , 6R ₁ , 7R ₁ , 8R ₁ , 8R ₂ , 9R ₁ , 9R ₂ , 10R ₁ , 10R ₂ :surface

D ₁ : The first moving distance

D ₂ : The second moving distance

D ₃ : The third moving distance

D ₄ : The fourth moving distance

P: 稜鏡

T: Transmissive smooth imaging device

G: Glass cover

Claims (9)

A zoom projection system includes: a first lens group with negative refractive power, including at least one first lens and a second lens, the first lens is a meniscus aspheric lens with negative refractive power and the second lens has A spherical lens with negative refractive power; a second lens group with positive refractive power, including at least one third lens; a third lens group with positive refractive power, including at least one double cemented lens, the double cemented lens having positive refractive power and composed of A fourth lens and a fifth lens; a fourth lens group with positive refractive power, including at least a triplet lens and a ninth lens, the triplet lens has negative refractive power, and consists of a sixth lens, a The seventh lens is composed of a seventh lens and an eighth lens, the seventh lens is a biconcave spherical lens, the eighth lens is a biconvex lens with positive refractive power; and a fifth lens group with positive refractive power includes at least one tenth lens , And the zoom projection system meets the following conditions: -2.0<f1a/fw<-1.0; 7.5>f4/fw>6; 1.35<Bf/fw<1.45; where f1a is the effective focal length of the first lens group, f4 Is the effective focal length of the fourth lens group, fw is the focal length in the wide-angle state, and Bf is the equivalent air gap of the back focal length at the wide-angle end. The zoom projection system of claim 1, wherein the focal length of the first lens is between -25mm~-50mm; the focal length of the second lens is between -25mm~-50mm; the focal length of the doublet lens is between 25mm~ Between 80mm; the focal length of the triple cemented lens is between -20mm~-50mm; the focal length of the seventh lens is between -5mm~-20mm; the focal length of the eighth lens is between 20mm~50mm. The zoom projection system according to claim 1, wherein the Abbe number of the second lens is between 50 and 82. The zoom projection system according to claim 1, wherein the Abbe number of the seventh lens is between 20-28. The zoom projection system according to claim 1, wherein the first lens is made of plastic; the second lens is made of glass; the doublet lens is made of glass; the seventh lens is made of glass; the The eighth lens is composed of molded glass. The zoom projection system according to claim 1, wherein the sum of the Abbe numbers of the first lens group is between 90 and 140; the Abbe numbers of the second lens group are between 25 and 55; the The sum total of the Abbe number of the third lens group is between 50 and 90; the sum total of the Abbe number of the fourth lens group is between 200 and 260; the Abbe number of the fifth lens group is between 10-20 rooms. The zoom projection system according to claim 1, wherein the zoom projection system can switch the wide-angle end and the telephoto end, and set the first lens group as a focusing group so that the first lens group and the fifth lens group do not move , And the second lens group, the third lens group, and the fourth lens group change the distance of an imaging element. When switched to the wide-angle end, the second lens group is close to the imaging element and the third lens group. Close to the imaging element and the fourth lens group are close to the imaging element, or when switched to the telephoto end, the second lens group is away from the imaging element, the third lens group is away from the imaging element, and the fourth lens group is away The imaging element. The zoom projection system according to claim 1, wherein the projection zoom ratio of the zoom projection system is a high zoom magnification of 1.25x. The zoom projection system as described in claim 1, further comprising an aperture, which is between 1.6 and 2.0, and is located between the third lens group and the fourth lens group.

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