CN101995647A - Zoom projection lens - Google Patents

Abstract

The invention provides a zoom projection lens, which can be applied to a non-telecentric projection and display optical system or an image capture optical system and is composed of a first lens set with negative refraction and a second lens set with positive refraction, wherein the first lens set is disposed on the screen side, capable of moving along an optical axis and composed of at least one plastic aspheric lens; the second lens set is disposed on the image plane side, also capable of moving along the optical axis and composed of at least one glass aspheric lens. An aperture diaphragm is arranged between two adjacent lenses within the second lens set, and the aperture diaphragm can be moved together with the second lens set. The zoom projection lens provided by the invention has the advantages of short size, simple structure, low cost and good imaging quality which are carried out by using the structure comprising a negative lens set and a positive lens set and adopting an aspheric surface design and specified conditions, and the back focal length of the zoom projection lens is long.

Description

Zooming-projection camera lens

[technical field]

The present invention relates to a kind of Zooming-projection camera lens, refer to a kind of miniaturization Zooming-projection camera lens of using in non-heart Projection Display optical system far away or the image capture optical system of being suitable for especially.

[background technology]

Projector utilizes the optical projection mode that image is projected to a kind of device on the large scale screen, difference according to its inner employed photo engine (Light Engine), can be divided into LCD (Liquid CrystalDisplay) projector, DLP (Digital Light Processor) projector and LCOS (Liquid Crystalon Silicon) projector, light can see through the LCD panel when wherein LCD projector operated because of it, so belong to penetration projector, the principle video picture that LCOS, DLP then reflect by light is so be called opaque projector.And according to the difference of ray cast direction, projector can be divided into pre-projecting type (FrontProjection) and two kinds of back projection types (Rear Projection) again, pre-projecting type projector is projector and beholder same one side at screen, main frame separates with screen, and back projecting projector then is that projector and beholder are in the screen different edge.In addition, pre-projecting type or back projecting projector be according to its difference of using the light valve number, can be divided into three kinds of one chip, two-piece type and three-chip types again.

In LCD, DLP and these three kinds of projectors of LCOS, adopt the DLP projector development in recent years of non-telecentric system (Non-Telecentric System) rapid, its development trend shows for the image of reaching giant-screen, high definition, high brightness in short projector distance, and it more can obtain product performances such as volume is little, in light weight.The key element of DLP projector is DMD (Digital MicromirrorDevice) Digital Micromirror Device; DMD is the exclusive digital picture chip of grasping and developing of TIX, because its time that emerges is shorter relatively, so the patented technology of the relevant DLP projection imaging optical system that is complementary with the DMD technology is also few, and projection lens such as existing LCD, LCOS are telecentric systems owing to what adopt, thereby can't satisfy the supporting requirement of DMD digital picture chip fully.This mainly is because the miniature reflective mirror on the DMD has the upsets of 10 degree or 12 degree in when work with picture signal, being reflected into the entrance pupil of projection lens and focusing on the screen from the upset by micro-reflector of the light beam of lighting source.Based on these characteristics, projection lens such as LCD, LCOS can't fully satisfy the supporting requirement of DMD digital picture chip usually.

In addition, for reflective DLP projector or LCOS projector, for improving projection quality, need to make the input path and the increasing of the interval between the emitting light path that are incident on reflective imager such as the DMD Digital Micromirror Device to isolate to form, can avoid emitting light path to be disturbed like this by other light source.Thereby the projection lens in its Projection Display optical system need have a sufficiently long back burnt (BFL, Back FocalLength).

Existing Zooming-projection camera lens adopts the start of multigroup lens combination and each lens combination length longer more, so be not inconsistent the trend when the front projection machine miniaturization.United States Patent (USP) the 6th, 590, then disclose a kind of Zooming-projection camera lens of two groups of starts No. 716, it comprises second lens combination that has negative dioptric first lens combination, have positive diopter, has negative dioptric the 3rd lens combination and have the 4th lens combination of positive diopter, wherein the first, the 4th lens combination is to maintain static, and second, third lens combination can be carried out start.But, because this Zooming-projection camera lens is the framework that adopts the four group lens combination, nearly 12 of lens numbers cause the camera lens length overall long and increased size, cost and the weight of final projector's product, thereby are not inconsistent when front projection machine miniaturization, development trend cheaply.In addition, this Zooming-projection camera lens is only applicable to adopt LCD, the LCOS projector of telecentric system, and and be not suitable for the DLP projector that adopts non-telecentric system.

In addition, select in the lens form and the material of Zooming-projection camera lens, because the selection of the material of traditional sphere abrading glass lens is more, it is comparatively favourable for correcting aberration, so widely industry is used.When but sphere abrading glass lens were used in less and visual angle (Wide-angle) the bigger situation of aperture-coefficient (F Number), the rectification of aberrations such as spherical aberration and astigmatism is difficulty still.In order effectively to correct aberration, as mentioned above, existing Zooming-projection camera lens normally is made of a plurality of lens combination, and the camera lens overall dimensions is long, weight is big, cost is higher thereby cause.And adopt non-spherical lens to address the above problem, the barrel distortion that it can significantly improve image quality and reduce wide-angle lens, and the alternative several pieces of spherical lens aberration for compensation of a slice non-spherical lens can be simplified the optical design of camera lens quite significantly, reduce its volume and weight.

No matter be spherical lens or non-spherical lens, it is made material and mainly contains glass and plastics, and wherein the light-transmission coefficient of glass lens is bigger, and imaging effect is good, but price is higher, is mainly used in the high-order product; The light-transmission coefficient of plastic lens is less, and is cheap, is mainly used in low end.But because of plastic material is light, and glass material is more thick and heavy, so can adopt the combination of glass lens and plastic lens when lens design, learns from other's strong points to offset one's weaknesses whereby, thereby designs required lens group.If the combination of employing all-plastic lens then not only can influence the optical property of camera lens, and also can compare strictness to tolerance.

Therefore, comprehensively above-mentioned, how to design a Zooming-projection camera lens that uses in non-heart Projection Display optical system far away or the image capture optical system of being suitable for, make it have plurality of advantages such as size is short and small, simple in structure, cost is lower, image quality is good, and have the burnt characteristics in long back simultaneously, become the common demand of industry.

[summary of the invention]

Fundamental purpose of the present invention is to provide a kind of Zooming-projection camera lens, and applicable to non-heart Projection Display optical system far away or image capture optical system, it has that size is short and small, simple in structure, cost is lower and characteristics such as image quality is good.

Another object of the present invention is to provide a kind of Projection Display optical system with above-mentioned Zooming-projection camera lens.

A further object of the present invention is to provide a kind of image capture optical system with above-mentioned Zooming-projection camera lens.

According to above-mentioned purpose of the present invention, the invention provides a kind of Zooming-projection camera lens, applicable to non-heart Projection Display optical system far away or image capture optical system.This Zooming-projection camera lens has second lens combination that negative dioptric first lens combination and has positive diopter by one to be formed, and first lens combination is arranged at screen side, and first lens combination can move and includes at least one piece of plastic aspherical element lens along optical axis; Second lens combination is arranged at the picture planar side, and second lens combination also can move and includes at least one piece of glass aspheric lenses along optical axis; Second lens combination wherein be provided with an aperture diaphragm in addition between the two adjacent lens, this aperture diaphragm can move with second lens combination; This Zooming-projection camera lens formula that meets the following conditions:

$-0.75<\frac{f2}{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="H2009101686313E0000033.png,H2009101686313E0000053.png"\; state="\{\{state\}\}">f</figure-callout>}1}<-0.46;$

$-3.0<\frac{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="H2009101686313E0000033.png,H2009101686313E0000053.png"\; state="\{\{state\}\}">f</figure-callout>}1}{\mathrm{fw}}<-1.60;$ And

$1.20<\frac{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="H2009101686313E0000033.png,H2009101686313E0000053.png"\; state="\{\{state\}\}">f</figure-callout>}2}{\mathrm{fw}}<1.40,$

Wherein, f1 is the focal length of first lens combination, and f2 is the focal length of second lens combination, and fw is that this Zooming-projection camera lens is as the focal length of an integral body in wide-angle side.

According to first embodiment of the invention, to including a meniscus negative lens and a meniscus positive lens as planar side in regular turn along optical axis, wherein this meniscus positive lens is plastic aspherical element lens to this of above-mentioned Zooming-projection camera lens first lens combination from screen side.To including a meniscus positive lens, a biconcave lens and a plano-convex lens as planar side in regular turn along optical axis, wherein this biconcave lens is a glass aspheric lenses to this second lens combination from screen side.This aperture diaphragm is arranged between this meniscus positive lens and this biconcave lens of this second lens combination.

According to second embodiment of the invention, to including a meniscus negative lens and a meniscus positive lens as planar side in regular turn along optical axis, wherein this meniscus positive lens is plastic aspherical element lens to this of above-mentioned Zooming-projection camera lens first lens combination from screen side.To including one first biconvex lens, a meniscus positive lens, a biconcave lens and one second biconvex lens as planar side in regular turn along optical axis, wherein this second biconvex lens is a glass aspheric lenses to this second lens combination from screen side.This aperture diaphragm is arranged between this meniscus positive lens and this biconcave lens of this second lens combination.

According to third embodiment of the invention, this of above-mentioned Zooming-projection camera lens first lens combination extremely includes a meniscus negative lens and a compound lens as planar side along optical axis in regular turn from screen side, wherein this compound lens is to be bonded with each other by a biconcave lens and a biconvex lens to form, and this meniscus negative lens is plastic aspherical element lens.To including one first biconvex lens, a meniscus positive lens, a biconcave lens and one second biconvex lens as planar side in regular turn along optical axis, wherein this second biconvex lens is a glass aspheric lenses to this second lens combination from screen side.This aperture diaphragm is arranged between this meniscus positive lens and this biconcave lens of this second lens combination.

The Zooming-projection camera lens of three embodiment of the present invention formula that more meets the following conditions:

$0.75<\frac{\mathrm{fw}}{\mathrm{bf}}<0.84;$

$3.50<\frac{\mathrm{tt}}{\mathrm{fw}}<3.84;$

$2.79<\frac{\mathrm{tt}}{\mathrm{bf}}<2.96;$

$-1.43<\frac{\mathrm{ex}}{\mathrm{bf}}<-1.20;$ And

$0.625<\frac{\mathrm{lt}}{\mathrm{tt}}<0.663$

Wherein, fw be this Zooming-projection camera lens as the focal length of an integral body in wide-angle side, bf is the back focal length degree of this Zooming-projection camera lens, tt is the optical system length overall of this Zooming-projection camera lens, ex is the system exit pupil position of this Zooming-projection camera lens, and lt is the camera lens length overall of this Zooming-projection camera lens.

Compared to prior art, Zooming-projection camera lens of the present invention only is made up of two groups of lens combination that refractive index is respectively negative, positive, only comprises 5 to 7 lens, therefore has short and small, simple in structure, the lower-cost advantage of size; By adopting the combining and configuring of at least two pieces of non-spherical lenses and glass, plastic lens, and the satisfying of specified conditions formula, can be in reduction camera lens length overall effective various aberrations of rectification, so Zooming-projection camera lens of the present invention has preferable image quality.In addition, Zooming-projection camera lens of the present invention has long back Jiao, applicable to non-telecentric system or opaque projector DLP projector and the burnt image capture optical system that requires in long back is arranged for example.

[description of drawings]

Fig. 1 is the optical texture synoptic diagram of the Zooming-projection camera lens of first embodiment of the invention.

Longitudinal spherical aberration, lateral chromatic aberration, the curvature of field, distortion and MTF curve synoptic diagram when the Zooming-projection camera lens that Fig. 2 A to Fig. 2 E is respectively first embodiment of the invention is positioned at wide-angle side.

Longitudinal spherical aberration, lateral chromatic aberration, the curvature of field, distortion and MTF curve synoptic diagram when the Zooming-projection camera lens that Fig. 3 A to Fig. 3 E is respectively first embodiment of the invention is positioned at the intermediate angle end.

The Zooming-projection camera lens that Fig. 4 A to Fig. 4 E is respectively first embodiment of the invention is positioned at longitudinal spherical aberration, lateral chromatic aberration, the curvature of field, distortion and the MTF curve synoptic diagram when looking in the distance journey.

Fig. 5 is the optical texture synoptic diagram of the Zooming-projection camera lens of second embodiment of the invention.

Longitudinal spherical aberration, lateral chromatic aberration, the curvature of field, distortion and MTF curve synoptic diagram when the Zooming-projection camera lens that Fig. 6 A to Fig. 6 E is respectively second embodiment of the invention is positioned at wide-angle side.

Longitudinal spherical aberration, lateral chromatic aberration, the curvature of field, distortion and MTF curve synoptic diagram when the Zooming-projection camera lens that Fig. 7 A to Fig. 7 E is respectively second embodiment of the invention is positioned at the intermediate angle end.

The Zooming-projection camera lens that Fig. 8 A to Fig. 8 E is respectively second embodiment of the invention is positioned at longitudinal spherical aberration, lateral chromatic aberration, the curvature of field, distortion and the MTF curve synoptic diagram when looking in the distance journey.

Fig. 9 is the optical texture synoptic diagram of the Zooming-projection camera lens of third embodiment of the invention.

Longitudinal spherical aberration, lateral chromatic aberration, the curvature of field, distortion and MTF curve synoptic diagram when the Zooming-projection camera lens that Figure 10 A to Figure 10 E is respectively third embodiment of the invention is positioned at wide-angle side.

Longitudinal spherical aberration, lateral chromatic aberration, the curvature of field, distortion and MTF curve synoptic diagram when the Zooming-projection camera lens that Figure 11 A to Figure 11 E is respectively third embodiment of the invention is positioned at the intermediate angle end.

The Zooming-projection camera lens that Figure 12 A to Figure 12 E is respectively third embodiment of the invention is positioned at longitudinal spherical aberration, lateral chromatic aberration, the curvature of field, distortion and the MTF curve synoptic diagram when looking in the distance journey.

[embodiment]

Zooming-projection camera lens of the present invention can be applicable to for example in the display optical system of DLP projector, be used for the image on the DMD imager is projected on the screen in non-heart Projection Display optical system far away or the image capture optical system.

About aforementioned and other technology contents, characteristics and effect of the present invention, in the following detailed description that cooperates with reference to graphic preferred embodiment, can clearly present.

First embodiment

Figure 1 shows that the optical texture synoptic diagram of the Zooming-projection camera lens of first embodiment of the invention.(right side of corresponding diagram 1 is promptly as the side of planar I P) includes along optical axis OA this Zooming-projection camera lens in regular turn from screen side (left side of corresponding diagram 1) to the picture planar side: one has the second lens combination G2 that the negative dioptric first lens combination G1 and has positive diopter.So-called screen is meant that image can throw a plane thereon, and is meant the position that is provided with of imager such as DMD Digital Micromirror Device as the plane.

The first lens combination G1 can move along optical axis OA, and it is made up of the first lens L1 and two lens of the second lens L2, and the form of the first lens L1 and the second lens L2 is respectively a meniscus negative lens and a meniscus positive lens.This meniscus negative lens L1 is made by global surface glass nitre material, and it has a convex surface R1 who is positioned at screen side and is positioned at a concave surface R2 of picture planar side.This meniscus positive lens L2 is by plastic aspherical element lens of being made by jet forming method, and it has a concave surface R3 who is positioned at screen side and is positioned at a convex surface R4 of picture planar side.Preferably, concave surface R3 and the convex surface R4 of this meniscus positive lens L2 are all aspheric surface.

The second lens combination G2 also can move along optical axis OA, and it is made up of the 3rd lens L3, the 4th lens L4 and three lens of the 5th lens L5.These lens L3, L4 and L5 are all made by global surface glass nitre material, and its form is respectively a meniscus positive lens, a biconcave lens and a plano-convex lens.Wherein, this meniscus positive lens L3 has a convex surface R5 who is positioned at screen side and is positioned at a concave surface R6 of picture planar side, this biconcave lens L4 has a concave surface R7 who is positioned at screen side and is positioned at a concave surface R8 of picture planar side, and this plano-convex lens L5 has a plane R9 who is positioned at screen side and is positioned at a convex surface R10 of picture planar side.This biconcave lens L4 is a glass aspheric lenses of making by the glass mould model method, and its concave surface R7 and R8 preferably are all aspheric surface.

Be provided with an aperture diaphragm ST between the meniscus positive lens L3 of the second lens combination G2 and the biconcave lens L4 in addition, it can move with the second lens combination G2.Between the second lens combination G2 and picture planar I P (being imager), be provided with a glass plate GP.

Each lens parameter of the Zooming-projection camera lens of first embodiment of the invention can be with reference to shown in the following table one, wherein, and the focal length of " F " representative shot; " W " represents wide-angle side; " M " represents the intermediate angle end; " T " represents the journey of looking in the distance; Aperture-coefficient of " Fno. " representative shot or F value; " surperficial sequence number " R1 to R12 represents each lens surface (ginseng Fig. 1) from screen side to the picture planar side successively; The radius-of-curvature of the corresponding lens surface of " radius of curvature R " representative; On behalf of each lens, " distance/thickness D " measure the thickness of gained along optical axis OA, or represents the spacing of two adjacent lens along optical axis OA; " refractive index Nd " reaches " Abbe coefficient Vd " and then represents each lens to d ray refraction rate and Abbe coefficient.

Table one

As mentioned above, in the Zooming-projection camera lens of first embodiment of the invention, preferably, two surperficial R7, the R8 of two surperficial R3, the R4 of the meniscus convex lens L2 of the first lens combination G1 and the biconcave lens L4 of the second lens combination G2 are all aspheric surface.These aspheric design formulas are expressed as follows:

$D=\frac{C\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="H2009101686313E0000033.png,H2009101686313E0000053.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}{1+\sqrt{1-(1+K)\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="H2009101686313E0000033.png,H2009101686313E0000053.png"\; state="\{\{state\}\}">C</figure-callout>}}^2\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="H2009101686313E0000033.png,H2009101686313E0000053.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}}+E_4\&CenterDot;{\mathrm{<figure-callout\; id="4"\; label="H"\; filenames="H2009101686313E0000033.png,H2009101686313E0000053.png"\; state="\{\{state\}\}">H</figure-callout>}}^4+E_6\&CenterDot;{\mathrm{<figure-callout\; id="6"\; label="H"\; filenames="H2009101686313E0000033.png,H2009101686313E0000053.png"\; state="\{\{state\}\}">H</figure-callout>}}^6+E_8\&CenterDot;{\mathrm{<figure-callout\; id="8"\; label="H"\; filenames="H2009101686313E0000033.png,H2009101686313E0000053.png"\; state="\{\{state\}\}">H</figure-callout>}}^8+E_{10}\&CenterDot;{\mathrm{<figure-callout\; id="10"\; label="H"\; filenames="H2009101686313E0000073.png"\; state="\{\{state\}\}">H</figure-callout>}}^{10}+E_{12}\&CenterDot;H^{12}+E_{14}\&CenterDot;H^{14}$

Wherein: D be along optical axis direction highly for the position of H with the surface vertices shift value apart from optical axis for referencial use; K is the tapering constant; C=1/R, R represents radius-of-curvature; H represents the eyeglass height; E4 represents four times asphericity coefficient; E6 represents six times asphericity coefficient; E8 represents eight times asphericity coefficient; E10 represents ten times asphericity coefficient; E12 represents the asphericity coefficient of ten secondaries; E14 represents 14 times asphericity coefficient.Table two has been expressed the correlation parameter of each non-spherical surface of the Zooming-projection camera lens of first embodiment of the invention.

Table two

The surface sequence number

K

E 4

E 6

E 8

E 10

E 12

E 14

R3

-11.1665

8.75E-06

5.22E-08

-8.65E-10

2.93E-12

0

0

R4

2.833118

3.56E-06

-8.90E-11

-5.19E-10

1.62E-12

0

0

R7

7.546776

2.69E-07

1.78E-07

-2.20E-08

5.70E-10

0

0

R8

3.175439

7.18E-05

-4.57E-07

-1.33E-08

4.68E-10

0

0

Design according to table one and the listed parameter of table two, shown in Fig. 2 A to Fig. 2 E (each aberration performance figure of wide-angle side), Fig. 3 A to Fig. 3 E (each aberration performance figure of intermediate angle end) and Fig. 4 A to Fig. 4 E (each aberration performance figure of the journey of looking in the distance), the Zooming-projection camera lens of first embodiment of the invention all has good rectification performance in wide-angle side, intermediate angle end and the journey of looking in the distance to various aberrations.Wherein, Fig. 2 A, Fig. 3 A and Fig. 4 A show longitudinal spherical aberration (the Longitudinal Spherical Aberration) performance of the Zooming-projection camera lens of first embodiment of the invention in wide-angle side, intermediate angle end and the journey of looking in the distance respectively; Fig. 2 B, Fig. 3 B and Fig. 4 B show lateral chromatic aberration (Lateral Color) performance of the Zooming-projection camera lens of first embodiment of the invention in wide-angle side, intermediate angle end and the journey of looking in the distance respectively; Fig. 2 C, Fig. 3 C and Fig. 4 C show the curvature of field (Field Curvature) performance of the Zooming-projection camera lens of first embodiment of the invention in wide-angle side, intermediate angle end and the journey of looking in the distance respectively; Fig. 2 D, Fig. 3 D and Fig. 4 D then show the Zooming-projection camera lens of first embodiment of the invention respectively in the MTF of wide-angle side, intermediate angle end and the journey of looking in the distance (Modulation Transfer Function) modulation transfer function family curve, show that the Zooming-projection camera lens of first embodiment of the invention has good contrast characteristic and resolution energy.

Second embodiment

Please refer to second embodiment of Zooming-projection camera lens of the present invention shown in Figure 5, it is that with first embodiment difference structurally shown in Figure 1 the formation of the second lens combination G2 is different.In a second embodiment, the second lens combination G2 is made up of 4 lens, comprises the 3rd lens L3, the 4th lens L4, the 5th lens L5 and the 6th lens L6.These lens L3, L4, L5 and L6 are also all made by global surface glass nitre material, and its form is respectively one first biconvex lens, a meniscus positive lens, a biconcave lens and one second biconvex lens.Aperture diaphragm ST is arranged at meniscus positive lens L4 and also can moves with the second lens combination G2 between biconcave lens L5.

Each lens parameter of the Zooming-projection camera lens of second embodiment of the invention can be with reference to shown in the following table three.

Table three

Table four shows the correlation parameter of each non-spherical surface of the Zooming-projection camera lens of second embodiment of the invention.

Table four

As shown in Table 4, in the Zooming-projection camera lens of second embodiment of the invention, two surperficial R11, the R12 of two surperficial R3, the R4 of the meniscus convex lens L2 of the first lens combination G1 and the second biconvex lens L6 of the second lens combination G2 are all aspheric surface.Preferably, the plastic aspherical element lens of these meniscus convex lens L2 for making, the glass aspheric lenses of this biconvex lens L6 for making by the glass mould model method by jet forming method.

Design according to table three and the listed parameter of table four, shown in Fig. 6 A to Fig. 6 E (each aberration performance figure of wide-angle side), Fig. 7 A to Fig. 7 E (each aberration performance figure of intermediate angle end) and Fig. 8 A to Fig. 8 E (each aberration performance figure of the journey of looking in the distance), the Zooming-projection camera lens of second embodiment of the invention all has good rectification performance and can obtain preferable image quality various aberrations in wide-angle side, intermediate angle end and the journey of looking in the distance.

The 3rd embodiment

Please refer to the 3rd embodiment of Zooming-projection camera lens of the present invention shown in Figure 9, it is that with second embodiment main difference part structurally shown in Figure 5 the formation of the first lens combination G1 is different.In the 3rd embodiment, the first lens combination G1 is made up of 3 lens, comprise a meniscus negative lens L1, a biconcave lens L2 and a biconvex lens L3, wherein this biconcave lens L2 and this biconvex lens L3 are all made by global surface glass nitre material and are bonded with each other to be integral and to constitute a compound lens, and this meniscus negative lens L1 then is an aspherical plastic lens.

Each lens parameter of the Zooming-projection camera lens of third embodiment of the invention can be with reference to shown in the following table five.

Table five

Table six shows the correlation parameter of each non-spherical surface of the Zooming-projection camera lens of third embodiment of the invention.

Table six

The surface sequence number

K

E 4

E 6

E 8

E 10

E 12

E 14

R1

11.42132

1.22E-04

9.99E-06

9.78E-09

1.62E-11

8.30E-15

3.83E-17

R2

0.113487

1.04E-04

5.22E-06

2.64E-07

2.96E-09

4.19E-12

9.43E-14

R12

-12.3734

4.10E-04

9.92E-05

8.31E-07

6.93E-08

9.76E-10

0

R13

-0.13055

9.74E-03

5.54E-05

3.39E-07

6.23E-08

9.44E-10

0

As shown in Table 6, in the Zooming-projection camera lens of third embodiment of the invention, two surperficial R1, the R2 of the meniscus negative lens L1 of the first lens combination G1 and the biconvex lens of the second lens combination G2 i.e. two surperficial R12, the R13 of the 7th lens L7 are all aspheric surface.Preferably, the plastic aspherical element lens of this meniscus negative lens L1 for making, the glass aspheric lenses of this biconvex lens L7 for making by the glass mould model method by jet forming method.

Design according to table five and the listed parameter of table six, shown in Figure 10 A to Figure 10 E (each aberration performance figure of wide-angle side), Figure 11 A to Figure 11 E (each aberration performance figure of intermediate angle end) and Figure 12 A to Figure 12 E (each aberration performance figure of the journey of looking in the distance), the Zooming-projection camera lens of third embodiment of the invention all has good rectification performance and can obtain preferable image quality various aberrations in wide-angle side, intermediate angle end and the journey of looking in the distance.

Summarize as can be known by above-mentioned three embodiment, Zooming-projection camera lens of the present invention only is made of the second lens combination G2, two lens combination of negative dioptric first lens combination G1 and positive diopter, wherein the first lens combination G1 includes one piece of plastic aspherical element lens and (is respectively meniscus positive lens L2 in three embodiment, meniscus positive lens L2 and meniscus negative lens L1), the second lens combination G2 includes one piece of glass aspheric lenses and (is respectively biconcave lens L4 in three embodiment, biconvex lens L6 and biconvex lens L7) and between its two adjacent lens, be provided with an aperture diaphragm ST.Preferably, the screen side of these non-spherical lenses L1, L2, L4, L6 and L7 surface and be all aspheric surface as planar side surface.Zooming-projection camera lens of the present invention is by adopting the design of negative, positive two groups of lens group structures and aspheric surface, can significantly reduce the camera lens length overall, reduce the assembling and the manufacturing cost of camera lens and effectively correct various aberrations, thereby obtain the Zooming-projection camera lens that a size is short and small, simple in structure, cost is lower and image quality is good.

In above-mentioned three embodiment of Zooming-projection camera lens of the present invention, the first lens combination G1 only includes one piece of plastic aspherical element lens, the second lens combination G2 also only includes one piece of glass aspheric lenses, other lens are all global surface glass lens, to reach use number that significantly reduces lens and the optimum efficiency of effectively revising various aberrations simultaneously by the combination of glass lens and plastic lens.Yet the present invention is not limited thereto.The first lens combination G1 also can comprise the plastic aspherical element lens more than a piece, and the second lens combination G2 also can comprise the glass aspheric lenses more than a piece.But temperature variation to the forward and backward spacing of influence scioptics group of the optical property of plastic aspherical element lens or camera lens after Jiao compensated the phenomenon that can avoid camera lens to cause image quality to reduce like this because of temperature variation.

For effective reduction camera lens length overall and revise various aberrations and obtain preferable image quality, the Zooming-projection camera lens of above-mentioned three embodiment of the present invention formula (1)～(3) that all meet the following conditions:

$-0.75<\frac{f2}{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="H2009101686313E0000033.png,H2009101686313E0000053.png"\; state="\{\{state\}\}">f</figure-callout>}1}<-0.64---\left(1\right)$

$-3.0<\frac{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="H2009101686313E0000033.png,H2009101686313E0000053.png"\; state="\{\{state\}\}">f</figure-callout>}1}{\mathrm{fw}}<-1.60---\left(2\right)$

$1.20<\frac{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="H2009101686313E0000033.png,H2009101686313E0000053.png"\; state="\{\{state\}\}">f</figure-callout>}2}{\mathrm{fw}}<1.40---\left(3\right)$

Wherein, f1 is the focal length of the first lens combination G1, and f2 is the focal length of the second lens combination G2, and fw is that Zooming-projection camera lens of the present invention is as the focal length of an integral body in wide-angle side.

Shown in the lens optical structural drawing of Fig. 1 to Fig. 3, the Zooming-projection camera lens of three embodiment of the present invention all has long back Jiao, and this back Jiao is meant the distance of last lens surface of camera lens to picture planar I P.For example, among first embodiment shown in Figure 1, this back Jiao is meant that the surperficial R10 of plano-convex lens L5 is to the distance between the picture planar I P.This long back Jiao be adapted to reflective or non-telecentric system projector for example DLP projector require the interval between input path and the emitting light path to strengthen this demand.For the image capture optical system, long back Jiao can satisfy the demand of placing additional optical such as light-combining prism, infrared filter, to obtain better optical property.The Zooming-projection camera lens of three embodiment of the present invention is in back Jiao of wide-angle side formula (4)～(6) that meet the following conditions:

$0.75<\frac{\mathrm{fw}}{\mathrm{bf}}<0.84---\left(4\right)$

$3.50<\frac{\mathrm{tt}}{\mathrm{fw}}<3.84---\left(5\right)$

$2.79<\frac{\mathrm{tt}}{\mathrm{bf}}<2.96---\left(6\right)$

Wherein, fw is that Zooming-projection camera lens of the present invention is as the focal length of an integral body in wide-angle side, bf is the back focal length degree of Zooming-projection camera lens of the present invention, and tt is the optical system length overall (the screen side surface that is meant first lens is to the distance between the picture planar I P) of Zooming-projection camera lens of the present invention.Satisfy above-mentioned conditional (4)～(6) the back Jiao of Zooming-projection camera lens of the present invention under the wide-angle state is significantly elongated, and also can effectively reduce the camera lens length overall and revise various aberrations.

The Zooming-projection camera lens of three embodiment of the present invention meet the following conditions in addition formula (7) and (8):

$-1.43<\frac{\mathrm{ex}}{\mathrm{bf}}<-1.20---\left(7\right)$

$0.625<\frac{\mathrm{lt}}{\mathrm{tt}}<0.663---\left(8\right)$

Wherein, ex is the system exit pupil position of Zooming-projection camera lens of the present invention, bf is the back focal length degree of Zooming-projection camera lens of the present invention, lt is the camera lens length overall (being meant the distance of the screen side surface of first lens to the picture planar side surface of last lens) of Zooming-projection camera lens of the present invention, and tt is the optical system length overall of Zooming-projection camera lens of the present invention.Being satisfied with conditional (7) also can make the camera lens length overall of Zooming-projection camera lens of the present invention effectively reduce and increase the back focal length degree with (8).

In sum, compared with prior art, Zooming-projection camera lens of the present invention only is made up of two groups of lens group G1, G2 that refractive index is respectively negative, positive, only comprises 5 to 7 lens, therefore has short and small, simple in structure, the lower-cost advantage of size; By adopting the combination configuration of at least two pieces of non-spherical lenses and glass, plastic lens, and the satisfying of specified conditions formula, can be in reduction camera lens length overall effective various aberrations of rectification, so Zooming-projection camera lens of the present invention also has better image quality. In addition, Zooming-projection camera lens of the present invention also has long rear Jiao, applicable to non-telecentric system or opaque projector for example DLP projector and have long after the burnt image capturing optical system that requires.

Zooming-projection camera lens of the present invention is applicable to the pre-projecting type projector of non-telecentric system, and especially DLP projector not only makes this projector's miniaturization, also can improve the device performance and obtains high-quality image. In addition, Zooming-projection camera lens of the present invention also can be applicable in the image capturing optical system, with the length overall of reducing this optical system and improve its optical property. In fact, the Zooming-projection camera lens that three embodiment of the present invention disclose all consists of an inverted structure of dolly-out,ing dolly-back, wherein screen side (being image projectable plane thereon) can be used as image planes, and picture plane side (be the display unit surface, for example DMD imager) then can be used as an object plane. But when the display unit side was assessed the optical property of Zooming-projection camera lens, this screen side was to be regarded as object plane, and this Zooming-projection camera lens then is to be regarded as an epitome optical system (ROS, Reduction Optical System).

Claims (19)

1. Zooming-projection camera lens, it is characterized in that: this Zooming-projection camera lens has second lens combination that negative dioptric first lens combination and has positive diopter by one and forms, first lens combination is arranged at screen side, and first lens combination can move and includes at least one piece of plastic aspherical element lens along optical axis; Second lens combination is arranged at the picture planar side, and second lens combination also can move and includes at least one piece of glass aspheric lenses along optical axis; Second lens combination wherein be provided with an aperture diaphragm in addition between the two adjacent lens, this aperture diaphragm can move with second lens combination; This Zooming-projection camera lens formula that meets the following conditions:

$-0.75<\frac{f2}{f1}<-0.64;$

$-3.0<\frac{f1}{\mathrm{fw}}<-1.60;$ And

$1.20<\frac{f2}{\mathrm{fw}}<1.40,$

Wherein, f1 is the focal length of first lens combination, and f2 is the focal length of second lens combination, and fw is that this Zooming-projection camera lens is as the focal length of an integral body in wide-angle side.

2. Zooming-projection camera lens as claimed in claim 1 is characterized in that: this first lens combination extremely includes a meniscus negative lens and a meniscus positive lens as planar side along optical axis in regular turn from screen side.

3. Zooming-projection camera lens as claimed in claim 2 is characterized in that: this meniscus positive lens of this first lens combination is plastic aspherical element lens.

4. Zooming-projection camera lens as claimed in claim 2 is characterized in that: this second lens combination extremely includes a meniscus positive lens, a biconcave lens and a plano-convex lens as planar side along optical axis in regular turn from screen side.

5. Zooming-projection camera lens as claimed in claim 4 is characterized in that: this biconcave lens of this second lens combination is a glass aspheric lenses.

6. Zooming-projection camera lens as claimed in claim 4 is characterized in that: this aperture diaphragm is arranged between this meniscus positive lens and this biconcave lens of this second lens combination.

7. Zooming-projection camera lens as claimed in claim 2 is characterized in that: this second lens combination extremely includes one first biconvex lens, a meniscus positive lens, a biconcave lens and one second biconvex lens as planar side along optical axis in regular turn from screen side.

8. Zooming-projection camera lens as claimed in claim 7 is characterized in that: this second biconvex lens of this second lens combination is a glass aspheric lenses.

9. Zooming-projection camera lens as claimed in claim 7 is characterized in that: this aperture diaphragm is arranged between this meniscus positive lens and this biconcave lens of this second lens combination.

10. Zooming-projection camera lens as claimed in claim 1, it is characterized in that: to including a meniscus negative lens and a compound lens as planar side in regular turn along optical axis, this compound lens is to be bonded with each other by a biconcave lens and a biconvex lens to form to this first lens combination from screen side.

11. Zooming-projection camera lens as claimed in claim 10 is characterized in that: this meniscus negative lens of this first lens combination is plastic aspherical element lens.

12. Zooming-projection camera lens as claimed in claim 10 is characterized in that: this second lens combination extremely includes one first biconvex lens, a meniscus positive lens, a biconcave lens and one second biconvex lens as planar side along optical axis in regular turn from screen side.

13. Zooming-projection camera lens as claimed in claim 12 is characterized in that: this second biconvex lens of this second lens combination is a glass aspheric lenses.

14. Zooming-projection camera lens as claimed in claim 12 is characterized in that: this aperture diaphragm is arranged between this meniscus positive lens and this biconcave lens of this second lens combination.

15. Zooming-projection camera lens as claimed in claim 1 is characterized in that: formula more meets the following conditions:

$0.75<\frac{\mathrm{fw}}{\mathrm{bf}}<0.84;$

Wherein, fw be this Zooming-projection camera lens as the focal length of an integral body in wide-angle side, bf is the back focal length degree of this Zooming-projection camera lens.

16. Zooming-projection camera lens as claimed in claim 1 is characterized in that: this Zooming-projection camera lens formula that more meets the following conditions:

$3.50<\frac{\mathrm{tt}}{\mathrm{fw}}<3.84$

Wherein, tt is the optical system length overall of this Zooming-projection camera lens, and fw is that this Zooming-projection camera lens is as the focal length of an integral body in wide-angle side.

17. Zooming-projection camera lens as claimed in claim 1 is characterized in that: this Zooming-projection camera lens formula that more meets the following conditions:

$2.79<\frac{\mathrm{tt}}{\mathrm{bf}}<2.96$

Wherein, tt is the optical system length overall of this Zooming-projection camera lens, and bf is the back focal length degree of this Zooming-projection camera lens.

18. Zooming-projection camera lens as claimed in claim 1 is characterized in that: this Zooming-projection camera lens formula that more meets the following conditions:

$-1.43<\frac{\mathrm{ex}}{\mathrm{bf}}<-1.20$

Wherein, ex is the system exit pupil position of this Zooming-projection camera lens, and bf is the back focal length degree of this Zooming-projection camera lens.

19. Zooming-projection camera lens as claimed in claim 1 is characterized in that: this Zooming-projection camera lens formula that more meets the following conditions:

$0.625<\frac{\mathrm{lt}}{\mathrm{tt}}<0.663$

Wherein, lt is the camera lens length overall of this Zooming-projection camera lens, and tt is the optical system length overall of this Zooming-projection camera lens.

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