CN204241753U - Projection zoom lens and projection type image display apparatus - Google Patents

Abstract

The utility model provides a kind of projection zoom lens, and it can the maximization of restraining device, realizes the good correction of wide angle, long back focal length and various aberration.Described projection zoom lens possess be configured in by Zoom Side and fix when multiple changes there is first lens combination (G1) of negative focal power, change the plural mobile lens group of compartment of terrain movement each other when multiple changes, one group in mobile lens group and the first lens combination (G1) adjacent configuration.The refractive index of the d line of i-th negative lens in the first lens combination is set to Ndn (i), and the focal length of i-th negative lens in the first lens combination is set to fn (i), and the maximum of reduced side is effectively set to as circular diameter time, the formula that satisfies condition (1).[formula 1] .

Description

Projection zoom lens and projection type image display apparatus

Technical field

The utility model relates to projection zoom lens and projection type image display apparatus, such as, relate to and being suitable for the original image enlarging projection that formed by light valve to the projection zoom lens on screen and the projection type image display apparatus being equipped with this projection zoom lens.

Background technology

At present, the projection type image display apparatus employing the light valve such as liquid crystal display cells or DMD (Digital Micromirror Device: registered trademark) is extensively popularized.In addition, in recent years, in hall or auditorium, exhibition etc., such projection type image display apparatus is also used for gradually being applicable to large picture and is shown out the image of fine.Expect that projection lens can carry out multiple and change with the size that can change the projects images on screen.

As projection zoom lens known at present, there is the projection zoom lens such as described in following patent documentation 1 ~ 3.Projection zoom lens described in following patent documentation 1 ~ 3 is all the lens combination with negative focal power be fixed when being configured with carrying out multiple change by Zoom Side.

[at first technical literature]

[patent documentation]

[patent documentation 1] Jap.P. No. 4672827 publications

[patent documentation 2] Jap.P. No. 4097957 publications

[patent documentation 3] Japanese Unexamined Patent Publication 2010-271558 publication

[problem that utility model will solve]

But, in order to tackle various setting place, expect that projection lens are the lens combination can carrying out the wide-angle of large image projection in short projection distance.In addition, in the projection type image display apparatus that above-mentioned setting place uses, use reflection type liquid crystal display element or DMD as light valve more and adopt three plate modes.Three plate modes refer to corresponding each primary colors and arrange three light valves, and the light beam color separation optical system from light source is separated into three primary colors, and three primary colors are projected via utilizing color combining optical to synthesize after each light valve.In order to configure color separation optical system, color combining optical between lens combination and light valve, require that projection lens have long back focal length.

But in the projection zoom lens described in above-mentioned patent documentation 1, the full filed angle of wide-angle side is about 60 degree so narrow.In projection zoom lens described in above-mentioned patent documentation 2,3, the full filed angle of wide-angle side has about 80 degree, but when combining with the light valve such as reflection type liquid crystal display element or DMD, more preferably expects to increase back focal length further.

Utility model content

The utility model proposes in view of the foregoing, its object is to provide a kind of can the maximization of restraining device, wide-angle and have long back focal length, can revise the projection zoom lens distorting the various aberration such as aberration, curvature of the image and the projection type image display apparatus possessing such projection zoom lens well.

The projection zoom lens that the utility model relates to possesses and is configured in by Zoom Side and first lens combination with negative focal power of fixing when multiple changes, the plural mobile lens group of compartment of terrain movement of changing each other when multiple changes, one group in mobile lens group and the adjacent configuration of the first lens combination, described projection zoom lens meets following conditional (1).

[formula 1]

$\left|\underset{i}{\mathrm{\Σ}}\{\mathrm{Ndn}\left(i\right)/\mathrm{fn}\left(i\right)\}\right|\×\mathrm{Im\φ}>3.8\·\·\·\left(1\right)$

Wherein,

The refractive index of the d line of i-th negative lens in the Ndn (i): the first lens combination,

The focal length of i-th negative lens in the fn (i): the first lens combination,

Im φ: maximum effective picture circular diameter of reduced side.

It should be noted that, conditional (1), when having the cemented lens comprising negative lens, does not calculate for cemented lens, and calculates for the negative lens monomer in cemented lens.

In projection zoom lens of the present utility model, preferably meet following conditional (1 ').

[formula 2]

$4.0<\left|\underset{i}{\mathrm{\&Sigma;}}\right\{\mathrm{Ndn}\left(i\right)/\mathrm{fn}\left(i\right)\left\}\right|\&times;\mathrm{Im\&phi;}<5.0\&CenterDot;\&CenterDot;\&CenterDot;\left(1^{,}\right)$

In addition, in projection zoom lens of the present utility model, preferably meet following conditional (2), more preferably meet following conditional (2 ').

Bf/fw＞3.0…(2)

Bf/fw＞4.0…(2’)

Wherein,

Bf: the back focal length of the whole system under air scaled distance when taking reduced side as rear side,

Fw: the focal length of the whole system of wide-angle side.

In addition, in projection zoom lens of the present utility model, preferably meet following conditional (3).

-1.0＜fw/f1＜-0.5…(3)

Wherein,

Fw: the focal length of the whole system of wide-angle side,

The focal length of the f1: the first lens.

In addition, in projection zoom lens of the present utility model, preferably meet following conditional (4), more preferably meet following conditional (4 ').

[formula 3]

$\underset{j}{\mathrm{\&Sigma;}}\mathrm{dd}\left(j\right)/\mathrm{fw}>3.0\&CenterDot;\&CenterDot;\&CenterDot;\left(4\right)$

[formula 4]

$3.5<\underset{j}{\mathrm{\&Sigma;}}\mathrm{dd}\left(j\right)/\mathrm{fw}<5.0\&CenterDot;\&CenterDot;\&CenterDot;\left(4^{,}\right)$

Wherein,

The center thickness of the jth lens in the dd (j): the first lens combination,

Fw: the focal length of the whole system of wide-angle side.

In addition, in projection zoom lens of the present utility model, preferably the final lens group with positive focal power of fixing when multiple changes is configured with by reduced side.When projection zoom lens of the present utility model has such final lens group, final lens group is made up of the simple lens with positive focal power, preferably meet following conditional (5), more preferably meet following conditional (5 ').

0.05＜fw/fe＜0.20…(5)

0.08＜fw/fe＜0.15…(5’)

Wherein,

Fw: the focal length of the whole system of wide-angle side,

Fe: the focal length of final lens group.

In addition, in projection zoom lens of the present utility model, the lens combination of Zoom Side of leaning on most in preferred mobile lens group has positive focal power, meets following conditional (6), more preferably meets following conditional (6 ').

0.05＜fw/f2＜0.40…(6)

0.15＜fw/f2＜0.30…(6’)

Wherein,

Fw: the focal length of the whole system of wide-angle side,

F2: the focal length leaning on the lens combination of Zoom Side most in mobile lens group.

In addition, in projection zoom lens of the present utility model, preferably the first lens combination is made up of in fact the 1b lens combination of the 1a lens combination of fixing when focusing, the movement when focusing, the 1c lens combination fixing when focusing successively from Zoom Side, meets following conditional (7).

|fw/f1c|＜0.30…(7)

Wherein,

Fw: the focal length of the whole system of wide-angle side,

The focal length of the f1c: the 1c lens combination.

In addition, in projection zoom lens of the present utility model, when the first lens combination is made up of in fact above-mentioned three lens combination, preferably meets following conditional (8), more preferably meet following conditional (8 ').

0.04＜fw/f1b＜0.15…(8)

0.05＜fw/f1b＜0.10…(8’)

Wherein,

Fw: the focal length of the whole system of wide-angle side,

The focal length of the f1b: the 1b lens combination.

In addition, in projection zoom lens of the present utility model, when the first lens combination is made up of in fact above-mentioned three lens combination, preferably 1b lens combination is made up of in fact cemented lens negative lens and positive lens engaged.

Projection zoom lens of the present utility model can be made up of in fact the first lens combination, three the mobile lens groups changing compartment of terrain movement when multiple changes each other, the final lens group fixing when multiple changes successively from Zoom Side.In this case, the first lens group of the Zoom Side in preferred mobile lens group, second lens combination and final lens group have positive focal power.

Or projection zoom lens of the present utility model can be made up of in fact the first lens combination, four the mobile lens groups changing compartment of terrain movement when multiple changes each other, the final lens group fixing when multiple changes successively from Zoom Side.In this case, in preferred mobile lens group, first ~ the 3rd lens combination of Zoom Side and final lens group have positive focal power.

Projection type image display apparatus of the present utility model possesses light source, for from the light valve of the light incidence of this light source, the above-mentioned projection zoom lens of the present utility model as projection zoom lens projected by the optical imagery that the light after carrying out optical modulation by this light valve is formed on screen.

It should be noted that, above-mentioned " Zoom Side " represents by projection side (screen side), when carrying out reducing projection, also in order to for simplicity screen side is called Zoom Side.On the other hand, above-mentioned " reduced side " represents side, original image viewing area (light valve side), when carrying out reducing projection, also in order to for simplicity light valve side is called reduced side.

It should be noted that, " in fact " in above-mentioned " forming in fact " represents except the textural element exemplified, and can also comprise in fact the optical parameter etc. beyond the lens such as lens, diaphragm or the cloche without magnification.

It should be noted that, the symbol of above-mentioned lens or the focal power of lens combination is the symbol considered near axis area for having aspheric structure.

[utility model effect]

According to projection zoom lens of the present utility model, possesses plural mobile lens group, the first lens combination of Zoom Side is leaned on most to be set as the negative lens group fixing when multiple changes by being configured in, meet the conditional (1) relevant to the structure of the negative lens in this first lens combination, therefore, it is possible to realize the maximization of restraining device, be wide-angle simultaneously and there is long back focal length, the lens combination distorting the various aberration such as aberration, curvature of the image can be revised well.

In addition, projection type image display apparatus of the present utility model possesses projection zoom lens of the present utility model, therefore can not maximize, and can be wide-angle and have good projection performance.

Accompanying drawing explanation

Fig. 1 is the cut-open view of the lens arrangement of the projection zoom lens representing embodiment 1 of the present utility model.

Fig. 2 is the cut-open view of the lens arrangement of the projection zoom lens representing embodiment 2 of the present utility model.

Fig. 3 is the cut-open view of the lens arrangement of the projection zoom lens representing embodiment 3 of the present utility model.

Fig. 4 is the cut-open view of the lens arrangement of the projection zoom lens representing embodiment 4 of the present utility model.

Fig. 5 (A) ~ (L) is each aberration diagram of the projection zoom lens of embodiment 1 of the present utility model.

Fig. 6 (A) ~ (L) is each aberration diagram of the projection zoom lens of embodiment 2 of the present utility model.

Fig. 7 (A) ~ (L) is each aberration diagram of the projection zoom lens of embodiment 3 of the present utility model.

Fig. 8 (A) ~ (L) is each aberration diagram of the projection zoom lens of embodiment 4 of the present utility model.

Fig. 9 is the brief configuration figure of the projection type image display apparatus of an embodiment of the present utility model.

Figure 10 is the brief configuration figure of the projection type image display apparatus representing other embodiments of the present utility model.

Embodiment

Below, with reference to accompanying drawing, in detail embodiment of the present utility model is described.Fig. 1 ~ Fig. 4 is the cut-open view of the configuration example of the projection zoom lens representing embodiment of the present utility model, corresponds respectively to the projection zoom lens of embodiment 1 ~ 4 described later.The basic structure of the example shown in Fig. 1 ~ Fig. 4 is identical, and the graphic technique of Fig. 1 ~ Fig. 4 is also identical, and therefore, the projection zoom lens of main reference Fig. 1 to embodiment of the present utility model is described below.

In Fig. 1, the configuration illustrating each lens combination of wide-angle side and the structure of the epimere of " W " such mark are marked, mark the configuration illustrating each lens combination under intermediate focus distance state and the structure in the stage casing of " M " such record, mark the configuration illustrating each lens combination of telescope end and the structure of the hypomere of " T " such record.

This projection zoom lens is equipped on such as projection type image display apparatus, can be used as the projection lens image information that light valve demonstrates projected to screen.In FIG, the left side of figure is set to Zoom Side, right side is set to reduced side, suppose the situation being equipped on projection type image display apparatus, the hypothesis glass blocks 2 of color synthetic prisms or light filter etc. and the picture display face 1 of light valve are illustrated in the lump.

In projection type image display apparatus, the light beam that picture display face 1 has been endowed image information is incident to this projection zoom lens via glass blocks 2, and by this projection zoom lens to the upper projection of the screen (not shown) being configured in paper left direction.

It should be noted that, in the construction shown in fig. 1, show the example of the position in the face of the reduced side of glass blocks 2 and the position consistency of picture display face 1, but may not be defined in this.In addition, in FIG, in order to the simplification of accompanying drawing, and only describe a picture display face 1, but in projection type image display apparatus, also can be configured to utilize color separation optical system that the beam separation from light source is become three primary colors, corresponding each primary colors and arrange three light valves, thus can full-color image be shown.

The projection zoom lens of the example shown in Fig. 1 comprises the first lens combination G1, the second lens combination G2, the 3rd lens combination G3, the 4th lens combination G4, these five lens combination of the 5th lens combination G5 successively from Zoom Side, when carrying out multiple and changing, first lens combination G1 and the 5th lens combination G5 fixes, and the second lens combination G2, the 3rd lens combination G3, the 4th lens combination G4 change compartment of terrain each other and move.The arrow representing the second lens combination G2, the 3rd lens combination G3, the 4th lens combination G4 direction of movement when multiple changes briefly is recorded respectively between the epimere and stage casing of Fig. 1 and between stage casing and hypomere.But, with regard to projection zoom lens of the present utility model, the lens combination of the movement when multiple changes is (following, be called mobile lens group) number or the lens combination fixing when multiple changes (following, be called fixed lens group) number be not limited to the example shown in Fig. 1, and, than the second lens combination G2 by the mobile lens group of reduced side and the example be also not limited to shown in Fig. 1 that puts in order of fixed lens group.

Projection zoom lens of the present utility model possesses to be configured in and the first lens combination G1 with negative focal power fixed when multiple changes, changes the plural mobile lens group of compartment of terrain movement each other when multiple changes, one group in mobile lens group and the adjacent configuration of the first lens combination G1 by Zoom Side.

By configuring negative lens group by Zoom Side, be conducive to thus guaranteeing wide angle and long back focal length.In addition, fixing when multiple changes by lens diameter easily being become large being set as by the lens combination of Zoom Side, driving mechanism maximization can be avoided thus to cause the phenomenon of larger-scale unit.

Projection zoom lens of the present utility model meets following conditional (1).

[formula 5]

$\left|\underset{i}{\mathrm{\&Sigma;}}\{\mathrm{Ndn}\left(i\right)/\mathrm{fn}\left(i\right)\}\right|\&times;\mathrm{Im\&phi;}>3.8\&CenterDot;\&CenterDot;\&CenterDot;\left(1\right)$

Wherein,

The refractive index of the d line of i-th negative lens in the Ndn (i): the first lens combination

The focal length of i-th negative lens in the fn (i): the first lens combination

maximum effective picture circular diameter of reduced side

The mark ∑ of conditional (1) represent all negative lenses in the first lens combination are got and.In addition, above-mentioned " which " is relevant to putting in order of the lens on optical axis direction, such as to from Zoom Side towards the order of each lens on the direction of reduced side or the order from reduced side towards each lens the direction of Zoom Side relevant.

By with refractive index and the focal length of avoiding the mode become below the lower limit of conditional (1) to set the maximum negative lens effectively had as circular diameter and the first lens combination G1, be conducive to thus easily becoming the distortion aberration of problem, the good correction of curvature of the image when wide angle.

And, preferably meet following conditional (1 ').

[formula 6]

$4.0<\left|\underset{i}{\mathrm{\&Sigma;}}\right\{\mathrm{Ndn}\left(i\right)/\mathrm{fn}\left(i\right)\left\}\right|\&times;\mathrm{Im\&phi;}<5.0\&CenterDot;\&CenterDot;\&CenterDot;\left(1^{,}\right)$

By to avoid the mode become below the lower limit of conditional (1 ') to be formed, the effect relevant to above-mentioned conditional (1) can be improved further thus.By to avoid the mode become more than the upper limit of conditional (1 ') to be formed, the total length of lens combination can be suppressed thus elongated and the maximization caused.

In addition, preferably this projection zoom lens meets following conditional (2).

Bf/fw＞3.0…(2)

Wherein,

Bf: the back focal length of the whole system under air scaled distance when reduced side being set to rear side

Fw: the focal length of the whole system of wide-angle side

By to avoid the mode become below the lower limit of conditional (2) to be formed, long back focal length can being guaranteed thus, easily guaranteeing to form color separation optical system or the beam splitter of color combining optical or the space of the glass blocks such as orthogonal dichroic prism, TIR prism or other components for inserting in the reduced side of lens combination.

In order to improve the above-mentioned effect relevant to conditional (2), more preferably meet following conditional (2 ').

Bf/fw＞4.0…(2’)

In addition, preferably this projection zoom lens meets following conditional (3).

-1.0＜fw/f1＜-0.5…(3)

Wherein,

Fw: the focal length of the whole system of wide-angle side

The focal length of the f1: the first lens

By with the focal power avoiding the mode become below the lower limit of conditional (3) to suppress the first lens combination G1, be conducive to the good correction distorting aberration, curvature of the image thus.By with the focal power avoiding the mode become more than the upper limit of conditional (3) to guarantee the first lens combination G1, the increase of the lens diameter of Zoom Side can be prevented thus.

In addition, preferably this projection zoom lens meets following conditional (4).By to avoid the mode become below the lower limit of conditional (4) to be formed, the increase of the lens diameter of Zoom Side can be prevented thus.

[formula 7]

$\underset{j}{\mathrm{\&Sigma;}}\mathrm{dd}\left(j\right)/\mathrm{fw}>3.0\&CenterDot;\&CenterDot;\&CenterDot;\left(4\right)$

Wherein,

The center thickness of the jth lens in the dd (j): the first lens combination

Fw: the focal length of the whole system of wide-angle side

The mark ∑ of conditional (4) represent all lens in the first lens combination are got and.In addition, above-mentioned " which " is relevant to putting in order of the lens on optical axis direction, such as to from Zoom Side towards the order of each lens on the direction of reduced side or the order from reduced side towards each lens the direction of Zoom Side relevant.

And then, preferably meet following conditional (4 ').

[formula 8]

$3.5<\underset{j}{\mathrm{\&Sigma;}}\mathrm{dd}\left(j\right)/\mathrm{fw}<5.0\&CenterDot;\&CenterDot;\&CenterDot;\left(4^{,}\right)$

By to avoid the mode become below the lower limit of conditional (4 ') to be formed, the effect relevant to above-mentioned conditional (4) can be improved further thus.By to avoid the mode become more than the upper limit of conditional (4 ') to be formed, the increase of the total length of lens combination can be suppressed thus.

In addition, in this projection zoom lens, preferably fix when multiple changes by the lens combination (following, also referred to as final lens group) of reduced side and there is positive focal power.By leaning on most the first lens combination of Zoom Side to be set as negative lens group by being configured in, leaning on the final lens group of reduced side to be set as positive lens groups most by being configured in, being conducive to thus guaranteeing wide angle and long back focal length.In addition, by final lens group being set as the fixed lens group with positive focal power, be conducive to when multiple changes, telecentricity being ensured constant thus.

When final lens group is the fixed lens group with positive focal power, preferably this final lens group is made up of the simple lens with positive focal power.In this case, lens combination can be formed compactly.

Further, when final lens group is fixed lens group and is made up of the simple lens with positive focal power, following conditional (5) is preferably met.

0.05＜fw/fe＜0.20…(5)

Wherein,

Fw: the focal length of the whole system of wide-angle side

Fe: the focal length of final lens group

By with the focal power avoiding the mode become below the lower limit of conditional (5) to guarantee final lens group, the increase of the variation of the spherical aberration caused by multiple change can be suppressed thus.By with the focal power avoiding the mode become more than the upper limit of conditional (5) to suppress final lens group, be conducive to the good correction of spherical aberration thus, good optical property is guaranteed in the distally that is particularly advantageous in being visible.

In order to improve the above-mentioned effect relevant to conditional (5), preferably meet following conditional (5 ').

0.08＜fw/fe＜0.15…(5’)

In addition, in this projection zoom lens, the lens combination of Zoom Side of leaning on most in mobile lens group has positive focal power, preferably meets following conditional (6).

0.05＜fw/f2＜0.40…(6)

Wherein,

Fw: the focal length of the whole system of wide-angle side

F2: the focal length leaning on the lens combination of Zoom Side most in mobile lens group

By with avoid the mode become below the lower limit of conditional (6) guarantee in mobile lens group by the focal power of the lens combination of Zoom Side, the increase of the increase of the total length of lens combination or the lens combination of Zoom Side can be suppressed thus.By with avoid the mode become more than the upper limit of conditional (6) suppress in mobile lens group by the focal power of the lens combination of Zoom Side, easily revise astigmatism thus.

In order to improve the above-mentioned effect relevant to conditional (6), more preferably meet following conditional (6 ').

0.15＜fw/f2＜0.30…(6’)

Projection zoom lens of the present utility model can adopt and such as be included in first lens combination with negative focal power of fixing when multiple changes, three the mobile lens groups changing compartment of terrain movement when multiple changes each other, final lens group this five group structures fixing when multiple changes from Zoom Side successively.By the number of mobile lens group is set as three, aberration when can easily suppress the maximization of whole system and multiple to change thus changes this both sides.

When adopting above-mentioned five groups of structures, the first lens group of Zoom Side in preferred mobile lens group, second lens combination and by the lens combination of reduced side, there is positive focal power.In this case, be conducive to guaranteeing wide angle and long back focal length.

Or projection zoom lens of the present utility model can also adopt and such as be included in first lens combination with negative focal power of fixing when multiple changes, four the mobile lens groups changing compartment of terrain movement when multiple changes each other, final lens group this six group structures fixing when multiple changes from Zoom Side successively.By the number of mobile lens group is set as four, thus compared with the situation number of mobile lens group being set as three, aberration variation when can more easily suppress multiple to change.

When adopting above-mentioned six groups of structures, in preferred mobile lens group Zoom Side the first ~ three lens combination and by the lens combination of reduced side, there is positive focal power.In this case, be conducive to guaranteeing wide angle and long back focal length.

In addition, this projection zoom lens also can use a part of the first lens combination G1 to focus.Specifically, the 1b lens combination G1b of the 1a lens combination G1a fixed the first lens combination G1 is included in focusing successively during from Zoom Side, the movement when focusing and the 1c lens combination G1c fixing when focusing, preferably meets following conditional (7).

|fw/f1c|＜0.30…(7)

Wherein,

Fw: the focal length of the whole system of wide-angle side

The focal length of the f1c: the 1c lens combination

Being fixed when focusing by the 1a lens combination G1a making lens diameter large, the lens combination of movement during focusing can be formed in thus compactly, the maximization of driving mechanism can be suppressed.By making the 1c lens combination G1c of the formula of satisfying condition (7) fix when focusing, and 1b lens combination G1b being moved, the change of the performance caused by focusing can be suppressed thus.

When the first lens combination G1 is made up of above-mentioned three groups, preferably meet following conditional (8).

0.04＜fw/f1b＜0.15…(8)

Wherein,

Fw: the focal length of the whole system of wide-angle side

The focal length of the f1b: the 1b lens combination

By with the focal power avoiding the mode become below the lower limit of conditional (8) to guarantee 1b lens combination G1b, the amount of movement of the lens combination of the movement when focusing can being suppressed thus, suppressing the performance change caused by focusing.By with the focal power avoiding the mode become more than the upper limit of conditional (8) to suppress 1b lens combination G1b, easily revise astigmatism thus.

In addition, when the first lens combination G1 is made up of above-mentioned three lens combination, 1a lens combination G1a such as can be configured to four chip architectures being configured with positive lens and three negative lenses from Zoom Side successively.The 1a lens combination G1a of the example shown in Fig. 1 comprises the lens L11 of the positive meniscus shape convex surface facing Zoom Side, the lens L12 of the negative meniscus shape convex surface facing Zoom Side, the lens L13 of negative meniscus shape convex surface facing Zoom Side and the lens L14 of concave-concave shape successively from Zoom Side.

When the first lens combination G1 is made up of above-mentioned three lens combination, preferably 1b lens combination G1b is made up of the cemented lens by negative lens and positive lens being engaged.In this case, the variation of aberration when focusing can be suppressed.The 1b lens combination G1b of the example shown in Fig. 1 is made up of one group of cemented lens by being engaged successively from Zoom Side by the lens L16 of the negative lens of concave surface facing reduced side and lens L15 and biconvex shape.

When the first lens combination G1 is made up of above-mentioned three lens combination, 1c lens combination G1c such as can be configured to three chip architectures being configured with negative lens, positive lens and negative lens from Zoom Side successively.The 1c lens combination G1c of the example shown in Fig. 1 comprises the negative lens of concave surface facing reduced side and lens L17, successively convex surface facing the positive lens of reduced side and the lens L19 of lens L18 and concave-concave shape from Zoom Side.

In addition, in the example depicted in figure 1, second lens combination G2 comprises these three lens of lens L21 ~ L23 successively from Zoom Side, 3rd lens combination G3 is made up of these a slice lens of lens L31,4th lens combination G4 comprises these five lens of lens L41 ~ L45 successively from Zoom Side, the 5th lens combination G5 is made up of these a slice lens of lens L51.

The projection zoom lens of the example shown in Fig. 1 ~ Fig. 4 is all made up of spherical lens.All be set as spherical lens by lens whole system had, can production cost be suppressed thus.

In addition, it is the heart far away that the projection zoom lens of the example shown in Fig. 1 ~ Fig. 4 is configured to reduced side.It should be noted that, above-mentioned " reduced side is the heart far away " refers in the cross section of the light beam on the arbitrary point of the image planes converging at reduced side, the maximum light of upside and the bisection linea angulata of the maximum light of downside are close to the state parallel with optical axis, be not limited to the situation of the heart completely far away, namely be not limited to described bisection linea angulata relative to the completely parallel situation of optical axis, also comprise the situation that there is a little error.Here, the situation that there is a little error refers to the situation of the degree of tilt of described bisection linea angulata relative to optical axis in the scope of ± 3 °.

As the projection zoom lens of embodiment of the present utility model, preferably change in territory at whole multiple, F number is less than 3.0.In addition, as the projection zoom lens of embodiment of the present utility model, preferably change territory at whole multiple and will distort aberration (distortion) suppression within ± 2%.

It should be noted that, above-mentioned preferred structure or the item of possible structure preferably required by projection zoom lens suitably selectively adopt.

According to the projection zoom lens of embodiment of the present utility model as above, can realize can the maximization of restraining device, there is long back focal length and for wide-angle, can revise well and distort the various aberration such as aberration, curvature of the image and the lens combination with high optical property.Especially according to the projection zoom lens of embodiment of the present utility model, back focal length is being set to Bf, when the focal length of the whole system of wide-angle side is set to fw, can guarantee that Bf/fw is greater than 3.0 back focal length so grown and realizes the wide angle that full filed angle is more than 80 °.

Then, the embodiment of Fig. 9 and 10 to projection type image display apparatus of the present utility model is used to be described.Fig. 9 is the brief configuration figure of a part for the projection type image display apparatus representing an embodiment of the present utility model.Projection type image display apparatus 10 shown in this Fig. 9 possess light source 17, the reflection type display element 11a ~ 11c as light valve corresponding with each coloured light, color separated dichronic mirror 12,13, orthogonal dichroic prism 14 that color is synthesized, the completely reflecting mirror 18 of optical path-deflecting, polarized light separation prism 15a ~ 15c and embodiment of the present utility model projection zoom lens 19.

The white light L sent from light source 17 is resolved into three coloured light light beams (G light, B light, R light) by dichronic mirror 12,13.Each coloured light light beam after decomposition is carried out optical modulation via polarized light separation prism 15a ~ 15c to the reflection type display element 11a ~ 11c corresponding respectively with each coloured light light beam incidence respectively, and carry out color synthesis by orthogonal dichroic prism 14, backward projection zoom lens 19 incident.Therefore, the optical imagery that this incident light is formed is projected on screen 100 by projection zoom lens 19.

Then, Figure 10 is the brief configuration figure of a part for the projection type image display apparatus representing another embodiment of the present utility model.Projection type image display apparatus 20 shown in this Figure 10 possesses the projection zoom lens 29 of TIR (Total Internal Reflection) prism 24a ~ 24c, polarized light separation prism 25 and the embodiment of the present utility model that light source 27, the reflection type display element 21a ~ 21c as light valve corresponding with each coloured light, color separated use and color are synthesized.

The white light L sent from light source 27, via after polarized light separation prism 25, is resolved into three coloured light light beams (G light, B light, R light) by TIR prism 24a ~ 24c.Each coloured light light beam after decomposition is carried out optical modulation respectively to reflection type display element 21a ~ 21c incidence of correspondence, negative line feed and carried out color synthesis in TIR prism 24a ~ 24c again, incident to projection zoom lens 29 through polarized light separation prism 25 afterwards.Therefore, the optical imagery that this incident light is formed is projected on screen 100 by projection zoom lens 29.

It should be noted that, as reflection type display element 11a ~ 11c, 21a ~ 21c, such as, can use reflection type liquid crystal display element or DMD etc.In Fig. 9 and 10, show the example using reflection type display element as light valve, but the light valve that projection type image display apparatus of the present utility model possesses is not limited thereto, and can use the transmission type display element such as transmission-type liquid crystal display element.

Then, the specific embodiment of projection zoom lens of the present utility model is described.

< embodiment 1>

The lens arrangement figure of the projection zoom lens of embodiment 1 as shown in Figure 1.About the explanation of Fig. 1 is described above, therefore omit repeat specification at this.

The projection zoom lens of embodiment 1 is configured to configure the first lens combination G1 with negative focal power, the second lens combination G2 with positive focal power successively from Zoom Side, have the 3rd lens combination G3 of positive focal power, have the 4th lens combination G4 of positive focal power and have five groups of such structures of the 5th lens combination G5 of positive focal power.The lens arrangement that each lens combination has is described above, therefore omits repeat specification at this.When multiple changes, the first lens combination G1 and the 5th lens combination G5 fixes, and the second lens combination G2, the 3rd lens combination G3 and the 4th lens combination G4 move.When focusing, form in the lens of the first lens combination G1, only lens L15 and lens L16 moves.

The basic lens data of the projection zoom lens of the embodiment 1 when projection distance is 1500 is shown in Table 1.Shown in Si mono-hurdle of basic lens data using by by the face of the Zoom Side of the textural element of Zoom Side as first along with i-th (i=1 during the face mark face numbering of the mode increased gradually towards reduced side to textural element, 2, 3, ) face numbering, the radius-of-curvature in i-th face shown in Ri mono-hurdle, the interval, face on optical axis Z in i-th face and the i-th+1 face shown in Di mono-hurdle, the textural element of Zoom Side will be leaned on most as first along with the jth increased gradually towards a reduced side (j=1 shown in Ndj mono-hurdle, 2, 3, ) refractive index about d line (wavelength 587.6nm) of textural element, the Abbe number about d line of a jth textural element shown in vdj mono-hurdle.Wherein, the symbol of radius-of-curvature is just when face shape is protruded to Zoom Side, is negative, in basic lens data, glass blocks 2 is shown in the lump when reduced side is protruded.It should be noted that, the i relevant with basic lens data uses with the implication being different from the i relevant with conditional (1).

In interval, face, the interval of the first lens combination G1 and the second lens combination G2, the interval of the second lens combination G2 and the 3rd lens combination G3, the interval of the 3rd lens combination G3 and the 4th lens combination G4 and the interval of the 4th lens combination G4 and the 5th lens combination G5 are variable the intervals changed when multiple changes, and number and are recited as DD [17], DD [22], DD [24], DD [33] respectively in the hurdle suitable with these intervals to the face that " DD " marks the Zoom Side at this interval.

It should be noted that, in the table of embodiment described later, for variable above-mentioned interval, follow the numeral after " DD " to change according to the structure in each embodiment, but the face numbering marking the Zoom Side at this interval represent this point in the table of embodiment described later too.

The wide-angle side of the projection zoom lens of embodiment 1, intermediate focus distance state, the telescope end various factors about d line separately and the value at above-mentioned variable interval are shown in table 2.In table 2, as various factors, the focal length f ' of zoom ratio, whole system is shown, back focal length Bf, the F number FNo. of whole system under air scaled distance when taking reduced side as rear side, full filed angle 2 ω (unit is degree).

It should be noted that, the numerical value shown in table 1, table 2 is the numerical value of the mode becoming 10 with the focal length of the whole system of wide-angle side when standardizing.In addition, the numerical value of each table is that the figure place specified has carried out the numerical value after rounding up.

[table 1]

The basic lens data (projection distance=1500) of embodiment 1

[table 2]

Embodiment 1 various factors and variable interval

Each aberration diagram of the spherical aberration of the projection zoom lens of the embodiment 1 of wide-angle side, astigmatism, distortion aberration (distortion), ratio chromatism, (aberration of multiplying power) is shown respectively in Fig. 5 (A) ~ Fig. 5 (D).Each aberration diagram of the spherical aberration of the projection zoom lens of the embodiment 1 under intermediate focus distance state, astigmatism, distortion aberration (distortion), ratio chromatism, (aberration of multiplying power) is shown respectively in Fig. 5 (E) ~ Fig. 5 (H).Each aberration diagram of the spherical aberration of the projection zoom lens of the embodiment 1 of telescope end, astigmatism, distortion aberration (distortion), ratio chromatism, (aberration of multiplying power) is shown respectively in Fig. 5 (I) ~ Fig. 5 (L).

Each aberration diagram of Fig. 5 (A) ~ Fig. 5 (L) obtains for benchmark with d line, but in spherical aberration diagram, also illustrate and F line (wavelength 486.1nm), aberration that C line (wavelength 656.3nm) is relevant, in ratio chromatism, figure, illustrate and F line, aberration that C line is relevant.In addition, in astigmatism figure, illustrate and radial, tangential relevant aberration with solid line, dotted line respectively.The FNo. of spherical aberration diagram represents F number, and the ω of other aberration diagram represents angle of half field-of view.It should be noted that, the figure that the aberration diagram of Fig. 5 is projection distance when being 1500.

As long as no being particularly limited to, then the mark of various data described in the explanation of the above embodiments 1, the meaning, record method, the mode becoming 10 with the focal length of the whole system of wide-angle side standardize this point etc. for following embodiment too.

< embodiment 2>

The lens arrangement figure of the projection zoom lens of embodiment 2 as shown in Figure 2.The projection zoom lens of embodiment 2 is configured to configure the first lens combination G1 with negative focal power, the second lens combination G2 with positive focal power successively from Zoom Side, have the 3rd lens combination G3 of positive focal power, have the 4th lens combination G4 of positive focal power and have five groups of such structures of the 5th lens combination G5 of positive focal power.First lens combination G1 comprises these nine lens of lens L11 ~ L19 successively from Zoom Side, second lens combination G2 comprises these three lens of lens L21 ~ L23 successively from Zoom Side, 3rd lens combination G3 is made up of these a slice lens of lens L31,4th lens combination G4 comprises these five lens of lens L41 ~ L45 successively from Zoom Side, the 5th lens combination G5 is made up of these a slice lens of lens L51.When multiple changes, the first lens combination G1 and the 5th lens combination G5 fixes, and the second lens combination G2, the 3rd lens combination G3, the 4th lens combination G4 move.When focusing, only lens L15 and lens L16 moves.First lens combination G1 of the projection zoom lens of embodiment 2 is different from the first lens combination G1 of the projection zoom lens of embodiment 1 on lens L17 with this point that lens L18 is engaged.

The basic lens data of the projection zoom lens of the embodiment 2 when projection distance is 1500 is shown in table 3.Various factors and variable the interval of the projection zoom lens of embodiment 2 are shown in table 4.Each aberration diagram of the projection zoom lens of the embodiment 2 when projection distance is 1500 shown in Fig. 6 (A) ~ Fig. 6 (L).

[table 3]

The basic lens data (projection distance=1500) of embodiment 2

[table 4]

Embodiment 2 various factors and variable interval

< embodiment 3>

The lens arrangement figure of the projection zoom lens of embodiment 3 as shown in Figure 3.The projection zoom lens of embodiment 3 is configured to configure the first lens combination G1 with negative focal power, the second lens combination G2 with positive focal power successively from Zoom Side, have the 3rd lens combination G3 of positive focal power, have the 4th lens combination G4 of positive focal power and have five groups of such structures of the 5th lens combination G5 of positive focal power.First lens combination G1 comprises these nine lens of lens L11 ~ L19 successively from Zoom Side, second lens combination G2 comprises these three lens of lens L21 ~ L23 successively from Zoom Side, 3rd lens combination G3 is made up of these a slice lens of lens L31,4th lens combination G4 comprises these five lens of lens L41 ~ L45 successively from Zoom Side, the 5th lens combination G5 is made up of these a slice lens of lens L51.When multiple changes, the first lens combination G1 and the 5th lens combination G5 fixes, and the second lens combination G2, the 3rd lens combination G3, the 4th lens combination G4 move.When focusing, only lens L15 and lens L16 moves.

The basic lens data of the projection zoom lens of the embodiment 3 when projection distance is 1500 is shown in table 5.The various factors of the projection zoom lens of embodiment 3 and variable interval shown in table 6.Each aberration diagram of the projection zoom lens of the embodiment 3 when projection distance is 1500 shown in Fig. 7 (A) ~ Fig. 7 (L).

[table 5]

The basic lens data (projection distance=1500) of embodiment 3

[table 6]

Embodiment 3 various factors and variable interval

< embodiment 4>

The lens arrangement figure of the projection zoom lens of embodiment 4 as shown in Figure 4.The projection zoom lens of embodiment 4 is configured to configure the first lens combination G1 with negative focal power, the second lens combination G2 with positive focal power successively from Zoom Side, have the 3rd lens combination G3 of positive focal power, have the 4th lens combination G4 of positive focal power, have the 5th lens combination G5 of positive focal power and have six groups of such structures of the 6th lens combination G6 of positive focal power.First lens combination G1 comprises these nine lens of lens L11 ~ L19 successively from Zoom Side, second lens combination G2 comprises these two panels lens of lens L21, L22 successively from Zoom Side, 3rd lens combination G3 is made up of these a slice lens of lens L31,4th lens combination G4 is made up of these a slice lens of lens L41,5th lens combination G5 comprises these five lens of lens L51 ~ L55 successively from Zoom Side, the 6th lens combination G6 is made up of these a slice lens of lens L61.When multiple changes, the first lens combination G1 and the 6th lens combination G6 fixes, and the second lens combination G2, the 3rd lens combination G3, the 4th lens combination G4, the 5th lens combination G5 move.When focusing, only lens L15 and lens L16 moves.

The basic lens data of the projection zoom lens of the embodiment 4 when projection distance is 1360 is shown in table 7.Various factors and variable the interval of the projection zoom lens of embodiment 4 are shown in table 8.Each aberration diagram of the projection zoom lens of the embodiment 4 when projection distance is 1360 shown in Fig. 8 (A) ~ Fig. 8 (L).

[table 7]

The basic lens data (projection distance=1360) of embodiment 4

[table 8]

Embodiment 4 various factors and variable interval

The respective value of above-mentioned each conditional (1) ~ (8) of above-described embodiment 1 ~ 4 shown in table 9.Shown in conditional one hurdle of table 9, the numbering of conditional and the physical quantity of correspondence, eliminate the record of the sign of inequality and ultimate value.The value associated with conditional is shown in table 10.Value shown in table 9, table 10 is the value of d line.

[table 9]

[table 10]

	Embodiment 1	Embodiment 2	Embodiment 3	Embodiment 4
					f1	-11.947	-12.903	-12.850	-11.752
f2	41.389	44.416	48.054	191.139
					fe	94.648	80.854	88.790	109.733
f1b	159494	130.570	106930	77.831
					|f1c|	59.924	71.933	57163	44.735
fn(1)	-61.783	-70.090	-66954	-61.981
					fn(2)	-60.338	-50.753	-61600	-63.238
fn(3)	-29.402	-28.857	-28335	-30.671
					fn(4)	-30.408	-21.436	-28039	-54.961
fn(5)	-45.329	-87.973	-73303	-91.315
					fn(6)	-35.343	-29.210	-40006	-36.042
Nd(1)	1.77250	1.83400	1.77250	1.80400
					Nd(2)	1.77250	1.77250	1.77250	1.80400
Nd(3)	1.84666	1.84666	1.84666	1.80518
					Nd(4)	1.61800	1.70154	1.77250	1.77250
Nd(5)	1.62299	1.72342	1.62299	1.62299
					Nd(6)	1.62299	1.61800	1.61800	1.61800
fw	10.00	10.00	10.00	10.00
					Bf	41.20	41.18	41.21	43.63
Imφ	17.08	17.07	17.09	18.1

From above data, with regard to the projection zoom lens of embodiment 1 ~ 4, back focal length ratio (Bf/fw) is more than 4, there is very long back focal length, the full filed angle of wide-angle side is more than 80 °, be configured to wide-angle, the F number of wide-angle side is about 2.5 so little, can revise various aberration well and have high optical property.

Above, exemplify embodiment and embodiment is illustrated the utility model, but projection zoom lens of the present utility model is not limited to above-described embodiment, can various forms of change be carried out, such as, suitably can change the radius-of-curvature of each lens, interval, face, refractive index, Abbe number.

In addition, projection type image display apparatus of the present utility model is not limited to said structure, and such as, the light valve used or the optical component for beam separation or light beam synthesis are not limited to said structure, can carry out various forms of change.

Claims (21)

1. a projection zoom lens, it possesses and is configured in by Zoom Side and first lens combination with negative focal power of fixing when multiple changes, the plural mobile lens group of compartment of terrain movement of changing each other when multiple changes,

One group in described mobile lens group and the adjacent configuration of described first lens combination,

The feature of described projection zoom lens is,

Described projection zoom lens meets following conditional (1),

[formula 1]

Wherein,

Ndn (i): the refractive index of the d line of i-th negative lens in described first lens combination,

Fn (i): the focal length of i-th negative lens in described first lens combination,

Im φ: maximum effective picture circular diameter of reduced side.

2. projection zoom lens according to claim 1, is characterized in that,

Meet following conditional (2),

Bf/fw＞3.0…(2)

Wherein,

Bf: the back focal length of the whole system under air scaled distance when reduced side being set to rear side,

Fw: the focal length of the whole system of wide-angle side.

3. projection zoom lens according to claim 1 and 2, is characterized in that,

Meet following conditional (3),

-1.0＜fw/f1＜-0.5…(3)

Wherein,

Fw: the focal length of the whole system of wide-angle side,

F1: the focal length of described first lens.

4. projection zoom lens according to claim 1 and 2, is characterized in that,

Meet following conditional (4),

[formula 2]

Wherein,

Dd (j): the center thickness of the jth lens in described first lens combination,

Fw: the focal length of the whole system of wide-angle side.

5. projection zoom lens according to claim 1 and 2, is characterized in that,

Be configured with the final lens group with positive focal power of fixing when multiple changes by reduced side.

6. projection zoom lens according to claim 5, is characterized in that,

Described final lens group is made up of the simple lens with positive focal power,

Described projection zoom lens meets following conditional (5),

0.05＜fw/fe＜0.20…(5)

Wherein,

Fw: the focal length of the whole system of wide-angle side,

Fe: the focal length of described final lens group.

7. projection zoom lens according to claim 1 and 2, is characterized in that,

The lens combination of Zoom Side of leaning on most in described mobile lens group has positive focal power,

Described projection zoom lens meets following conditional (6),

0.05＜fw/f2＜0.40…(6)

Wherein,

Fw: the focal length of the whole system of wide-angle side,

F2: the focal length leaning on the lens combination of Zoom Side most in described mobile lens group.

8. projection zoom lens according to claim 1, is characterized in that,

Described first lens combination from Zoom Side successively by the 1b lens combination of the 1a lens combination of fixing when focusing, the movement when focusing and when focusing fixing 1c lens combination form,

Described projection zoom lens meets following conditional (7),

|fw/f1c|＜0.30…(7)

Wherein,

Fw: the focal length of the whole system of wide-angle side,

F1c: the focal length of described 1c lens combination.

9. projection zoom lens according to claim 8, is characterized in that,

Meet following conditional (8),

0.04＜fw/f1b＜0.15…(8)

Wherein,

Fw: the focal length of the whole system of wide-angle side,

F1b: the focal length of described 1b lens combination.

10. projection zoom lens according to claim 8 or claim 9, is characterized in that,

Described 1b lens combination is made up of cemented lens negative lens and positive lens engaged.

11. projection zoom lens according to claim 1 and 2, is characterized in that,

Be made up of described first lens combination, three the mobile lens groups changing compartment of terrain movement when multiple changes each other, the final lens group fixing when multiple changes successively from Zoom Side.

12. projection zoom lens according to claim 11, is characterized in that,

The first lens group of the Zoom Side in described mobile lens group, second lens combination and described final lens group have positive focal power.

13. projection zoom lens according to claim 1 and 2, is characterized in that,

Be made up of described first lens combination, four the mobile lens groups changing compartment of terrain movement when multiple changes each other, the final lens group fixing when multiple changes successively from Zoom Side.

14. projection zoom lens according to claim 13, is characterized in that,

First lens group, second lens combination, the 3rd lens combination and the described final lens group of the Zoom Side in described mobile lens group have positive focal power.

15. projection zoom lens according to claim 1, is characterized in that,

Meet following conditional (1 '),

[formula 3]

16. projection zoom lens according to claim 2, is characterized in that,

Meet following conditional (2 '),

Bf/fw＞4.0…(2’)。

17. projection zoom lens according to claim 4, is characterized in that,

Meet following conditional (4 '),

[formula 4]

。

18. projection zoom lens according to claim 6, is characterized in that,

Meet following conditional (5 '),

0.08＜fw/fe＜0.15…(5’)。

19. projection zoom lens according to claim 7, is characterized in that,

Meet following conditional (6 '),

0.15＜fw/f2＜0.30…(6’)。

20. projection zoom lens according to claim 9, is characterized in that,

Meet following conditional (8 '),

0.05＜fw/f1b＜0.10…(8’)。

21. 1 kinds of projection type image display apparatus, it possesses:

Light source;

For the light valve from the light incidence of this light source,

The feature of described projection type image display apparatus is,

Possess the optical imagery that the light after carrying out optical modulation by this light valve is formed projected on screen as projection zoom lens claim 1 ~ 20 according to any one of projection zoom lens.