CN100590474C - Zooming projecting lens - Google Patents

Abstract

The invention discloses a zoom projection lens, which is used to make an original image which is at image source side project on an image side to form a projective image, a projective system of the zoom projection lens sequentially comprises a first lens group with negative diopter, a second lens group with positive diopter, a third lens group with positive diopter and a fourth lens group with negative diopter and a fifth lens group with positive diopter from the imaging side. When the zoom projection lens changes from the amplifying end to the shrinking end, the first lens group and the fifthlens group are firmly fixed, and the second lens group, the third lens group and the fourth lens group all move towards the imaging side; the zoom projection lens can meet special condition so as toimprove the projection quality. The zoom projection lens also comprises an automatic light ring which can move along with the fourth lens group together.

Description

Zooming-projection camera lens

[technical field]

The present invention relates to a kind of Zooming-projection camera lens, particularly relevant for a kind of applicable to projection arrangement the Projection Display optical system and the Zooming-projection camera lens in the image capture optical system of image capture unit.

[background technology]

In recent years, projector is applied in the daily life at large, more is used in further on the little image documentation equipment of volume, as laptop computer, desktop computer etc., to satisfy the user demand in the specific environment especially recently.Common projector is as the light valve imager with DMD (Digital Micro-mirror Device), its image-forming principle is by the rotation of DMD micro-mirror device (± 10 °) control reflection of light direction, the break-make of this signal of may command in this way, and then by optical lens the imaging on the DMD micro-mirror device is projected on the screen.

The type of projection lens will determine the picture quality of projector's projection.Generally speaking, single set of contact lenses can so that picture show at middle section fine, but when light and picture when the All Ranges of screen launches, need the many set of contact lenses of employing could make edge picture and middle section at screen be consistent.And, if will when narrow space obtains big picture, need select the projector that is furnished with enlarging lens for use, for obtaining bigger projected picture size at very short projector distance; And under the far situation of projector distance, during as inner projection at the cinema, seek out the picture of suitable size, just the projector that needs selection to be furnished with heart zoom lens far away so just can also can obtain appropriate screen size and quality at projector distance far away.

The design of relevant projection lens occurs in many patents, see also United States Patent (USP) the 6th, 590, shown in No. 716, it has disclosed a kind of heart Zooming-projection camera lens far away that is adapted at using in the projector, it includes one and has negative dioptric first lens combination, one has second lens combination of positive diopter, one has negative dioptric the 3rd lens combination and has the 4th lens combination of positive diopter, when this Zooming-projection camera lens during from the enlargement ratio state variation to the reduction magnification state, the first and the 4th lens combination is fixed, second and third lens combination then can suitably move, to adjust to required focal length.But, this patent only provides the conditional relationship between the part lens in first lens combination and second lens combination, the relation between the 3rd lens combination and other lens combination is not movably made announcement, and the direct image of mobile variation meeting of the 3rd lens combination is to the projection quality of this Zooming-projection camera lens.Therefore, the deficiency of design conditions will become the key factor of the projection quality that influences this Zooming-projection camera lens.

Therefore, be necessary to provide a kind of new Zooming-projection camera lens, improving the design defect that exists in the prior art, thereby can improve projection quality.

[summary of the invention]

The object of the present invention is to provide a kind of Zooming-projection camera lens, it can effectively proofread and correct various aberrations, improves image quality.

According to above-mentioned purpose of the present invention, the invention provides a kind of Zooming-projection camera lens, be projected to the imaging side in order to raw video and form the projection image an image source side, the optical projection system of this Zooming-projection camera lens is started at from the imaging side, include successively: one has negative dioptric first lens combination, one has second lens combination of positive diopter, one has the 3rd lens combination of positive diopter, one has negative dioptric the 4th lens combination and has the 5th lens combination of positive diopter, when this Zooming-projection camera lens is held when dwindling the end variation from amplifying, first lens combination and the 5th lens combination maintain static, and second to the 4th lens combination is then all towards the imaging side shifting; This Zooming-projection camera lens satisfies following condition:

$\left|\frac{\mathrm{fw}23}{\mathrm{fw}}\right|-\left|\frac{\mathrm{ft}23}{\mathrm{fw}}\right|>0.06743---1)$

$\left|\frac{\mathrm{fw}23}{\mathrm{ft}}\right|-\left|\frac{\mathrm{ft}23}{\mathrm{ft}}\right|>0.05621---2)$

In above-mentioned formula 1), 2) in, fw23 represents that this Zooming-projection camera lens is positioned at the combination diopter of second and third lens combination when amplifying end; Ft23 represents that this Zooming-projection camera lens is positioned at the combination diopter of second and third lens combination when dwindling end; Fw represents that this Zooming-projection camera lens is positioned at the system's focal length when amplifying end; And ft represents that this Zooming-projection camera lens is positioned at the system's focal length when dwindling end.

When being installed in this Zooming-projection camera lens on the projection display equipment, the image source side is meant the imager of this projection display equipment, and the imaging side is meant that image can throw screen thereon.

Each eyeglass of first to the 5th lens combination of Zooming-projection camera lens of the present invention is to adopt global surface glass nitre material to process, Zooming-projection camera lens of the present invention also includes an auto iris, this auto iris is positioned at the imaging side of the 4th lens combination, and can move with the 4th lens combination.

Zooming-projection camera lens of the present invention also satisfies following condition:

$\left|\frac{\mathrm{fw}234}{\mathrm{fw}}\right|-\left|\frac{\mathrm{ft}234}{\mathrm{fw}}\right|>0.11256---3)$

$\left|\frac{\mathrm{fw}234}{\mathrm{ft}}\right|-\left|\frac{\mathrm{ft}234}{\mathrm{ft}}\right|>0.09383---4)$

In above-mentioned formula 3), 4) in, fw234 represents that this Zooming-projection camera lens is positioned at the combination diopter of second, third and the 4th lens combination when amplifying end; Ft234 represents that this Zooming-projection camera lens is positioned at the combination diopter of second, third and the 4th lens combination of dwindling when end; Fw represents that this Zooming-projection camera lens is positioned at the system's focal length when amplifying end; And ft represents that this Zooming-projection camera lens is positioned at the system's focal length when dwindling end.

Compared to prior art, Zooming-projection camera lens of the present invention adopts five lens combination, when focusing, first lens combination and the 5th lens combination maintain static, second to the 4th lens combination then can move, and second to the 4th lens combination also satisfies certain design conditions, and aberration can obtain good correction like this, and projection quality also can increase substantially.Each eyeglass because of each lens combination of Zooming-projection camera lens of the present invention adopts global surface glass nitre material to process again, so Zooming-projection camera lens has resistant to elevated temperatures characteristic, and temperature variation is less to its performance impact, and the processing of global face eyeglass ratio is easier to, and can reach higher yield, reduce cost.

[description of drawings]

Figure 1A is that the position that Zooming-projection camera lens of the present invention is positioned at each lens group when amplifying end concerns synoptic diagram.

Figure 1B is that the position that Zooming-projection camera lens of the present invention is positioned at each lens group of dwindling when end concerns synoptic diagram.

Fig. 2 A to Fig. 2 E is according to described numerical value embodiment, and Zooming-projection camera lens of the present invention is positioned at the curve synoptic diagram of formed longitudinal aberration, lateral chromatic aberration, filed curvature, distortion aberration and MTF characteristic when amplifying end.

Fig. 3 A to Fig. 3 E is according to described numerical value embodiment, and Zooming-projection camera lens of the present invention is positioned at the curve synoptic diagram of formed longitudinal aberration, lateral chromatic aberration, filed curvature, distortion aberration and MTF characteristic when dwindling end.

[embodiment]

Please refer to Figure 1A and Figure 1B, wherein demonstrate the position that Zooming-projection camera lens 1 of the present invention is positioned at each lens group when amplifying end (wide) and dwindling end (tele) respectively and concern synoptic diagram, Zooming-projection camera lens 1 of the present invention is applicable to the pre-projecting type projection display equipment of telecentric system, in DLP (Digital LightProcessing) projector, be used for the raw video on the DMD imager is projected to formation projection image on the screen, wherein this DMD imager is as the image source side (being object plane) of this Zooming-projection camera lens 1, right side as shown in Figure 1A, screen is then as the imaging side (being image planes) of this Zooming-projection camera lens 1, the left side as shown in Figure 1A.

Zooming-projection camera lens 1 of the present invention is projected to the imaging side in order to the raw video with an image source side and forms the projection image, the optical projection system of this Zooming-projection camera lens 1 is started at from the imaging side, comprise successively: one has negative dioptric first lens combination 10, one has second lens combination 20 of positive diopter, one has the 3rd lens combination 30 of positive diopter, one has negative dioptric the 4th lens combination 40 and has the 5th lens combination 50 of positive diopter, when this Zooming-projection camera lens 1 holds (being enlargement ratio) when dwindling end (being reduction magnification) variation from amplifying, first lens combination 10 and the 5th lens combination 50 are fixed, second to the 4th lens combination 20,30 and 40 all towards the imaging side shifting.

The present invention's first lens combination 10 by just, positive and negative lens form.

The present invention's second lens combination 20 is made up of negative, positive lens, when this Zooming-projection camera lens 1 holds (being enlargement ratio) when dwindling end (being reduction magnification) variation from amplifying, this second lens combination 20 moves towards first lens combination 10 along optical axis, has the first variable spacing D1 (its concrete numerical value is as shown in following table) between the two.

The present invention's the 3rd lens combination 30 is a balsaming lens of being made up of a negative lens and a positive lens.When zoom, the 3rd lens combination 30 moves towards second lens combination 20 along optical axis, has the second variable spacing D2 (its concrete numerical value is as shown in following table) between the two.

The present invention's the 4th lens combination 40 by just, positive and negative, negative, positive, negative lens forms.When zoom, the 4th lens combination 40 moves towards the 3rd lens combination 30 along optical axis, has the 3rd variable spacing D3 (its concrete numerical value is as shown in following table) between the two.Has the 4th variable spacing D4 (its concrete numerical value is as shown in following table) between the 4th lens combination 40 and the 5th lens combination 50.

The present invention's the 5th lens combination 50 is a positive lens, and when zoom, the 5th lens combination 50 maintains static.

Zooming-projection camera lens 1 of the present invention also includes an aperture 60, and this aperture 60 is an auto iris, and it can change the control aperture according to light and change, and can obtain high contrast and high projection effect of resolving like this.This aperture 60 is positioned at the imaging side of the 4th lens combination 40, and can move with the 4th lens combination 40.

Image source side in the 5th lens combination 50 of Zooming-projection camera lens 1 of the present invention also is provided with a combined prism 70 and a parallel-plate 80, and wherein combined prism 70 can make up the image that comes from the DMD imager, so that image carries out optical projection system.Parallel-plate 80 is used for improving image effect received on the DMD imager.

Each lens of Zooming-projection camera lens 1 of the present invention adopt global surface glass nitre material to process, and for influence that temperature variation caused, this Zooming-projection camera lens 1 can be compensated by the spacing of adjusting between first lens combination 10 and second lens combination 20, can make this Zooming-projection camera lens 1 have resistant to elevated temperatures characteristic like this, and temperature variation is less to its Effect on Performance.Again because of Zooming-projection camera lens of the present invention 1 adopts global face eyeglass, its processing is than being easier to, so can reach higher yield, reduce cost.

Zooming-projection camera lens 1 of the present invention is applicable to the high-order digit camera lens, and its three groups of starts by second, third and the 4th lens combination 20,30 and 40 can reach the effect of zoom and focusing simultaneously, thereby reduce cost significantly.For obtaining good image quality, these movable lens group of Zooming-projection camera lens 1 of the present invention (be second, third and the 4th lens combination 20,30 and 40) need meet the following conditions:

$\left|\frac{\mathrm{fw}23}{\mathrm{fw}}\right|-\left|\frac{\mathrm{ft}23}{\mathrm{fw}}\right|>0.06743---1)$

$\left|\frac{\mathrm{fw}23}{\mathrm{ft}}\right|-\left|\frac{\mathrm{ft}23}{\mathrm{ft}}\right|>0.05621---2)$

$\left|\frac{\mathrm{fw}234}{\mathrm{fw}}\right|-\left|\frac{\mathrm{ft}234}{\mathrm{fw}}\right|>0.11256---3)$

$\left|\frac{\mathrm{fw}234}{\mathrm{ft}}\right|-\left|\frac{\mathrm{ft}234}{\mathrm{ft}}\right|>0.09383---4)$

In above-mentioned formula 1) to 4) in, fw23 represents that this Zooming-projection camera lens 1 is positioned at second and third lens combination 20 when amplifying end and 30 combination diopter; Ft23 represents that this Zooming-projection camera lens 1 is positioned at second and third lens combination 20 of dwindling when end and 30 combination diopter; Fw234 represents that this Zooming-projection camera lens 1 is positioned at the combination diopter of second, third and the 4th lens combination 20,30 and 40 when amplifying end; Ft234 represents that this Zooming-projection camera lens 1 is positioned at the combination diopter of second, third and the 4th lens combination 20,30 and 40 that dwindle when end; Fw represents that this Zooming-projection camera lens 1 is positioned at the system's focal length when amplifying end; Ft represents that this Zooming-projection camera lens 1 is positioned at the system's focal length when dwindling end.

Zooming-projection camera lens 1 of the present invention at the numerical value embodiment in the specific implementation process shown in following table one:

Table one

Design according to the numerical value embodiment in the last table, the longitudinal aberration of Zooming-projection camera lens 11 of the present invention, lateral chromatic aberration, filed curvature, distortion aberration and MTF characteristic all have good calibration result.

In fact, formed the inverted structure of dwindling by the Zooming-projection camera lens of the present invention 1 that the foregoing description disclosed, wherein screen (being that image can throw plane thereon) is as an imaging side, and the picture plane (is the display device surface, for example: be as an image source side DMD imager).Yet when display device side was assessed the optical property of Zooming-projection camera lens, screen was to be regarded as the image source side, and imager is to be regarded as the imaging side, this Zooming-projection camera lens be taken as the epitome optical system (Reduction OpticalSystems, ROS).Adopt this assessment mode, Zooming-projection camera lens 1 of the present invention in the optical appearance of amplifying end shown in Fig. 2 A to Fig. 2 E figure, and in the optical appearance of dwindling end shown in Fig. 3 A to Fig. 3 E.

Claims (7)

1. Zooming-projection camera lens, be projected to the imaging side in order to raw video and form the projection image an image source side, it is characterized in that: the optical projection system of this Zooming-projection camera lens is started at from the imaging side, include successively: one has negative dioptric first lens combination, one has second lens combination of positive diopter, one has the 3rd lens combination of positive diopter, one has negative dioptric the 4th lens combination and has the 5th lens combination of positive diopter, when this Zooming-projection camera lens is held when dwindling the end variation from amplifying, first lens combination and the 5th lens combination maintain static, and second to the 4th lens combination is then all towards the imaging side shifting; This Zooming-projection camera lens satisfies following condition:

$\left|\frac{\mathrm{fw}23}{\mathrm{fw}}\right|-\left|\frac{\mathrm{ft}23}{\mathrm{fw}}\right|>0.06743---1)$

$\left|\frac{\mathrm{fw}23}{\mathrm{ft}}\right|-\left|\frac{\mathrm{ft}23}{\mathrm{ft}}\right|>0.05621---2)$

$\left|\frac{\mathrm{fw}234}{\mathrm{fw}}\right|-\left|\frac{\mathrm{ft}234}{\mathrm{fw}}\right|>0.11256---3)$

$\left|\frac{\mathrm{fw}234}{\mathrm{ft}}\right|-\left|\frac{\mathrm{ft}234}{\mathrm{ft}}\right|>0.09383---4)$

In above-mentioned formula 1), 2), 3), 4) in, fw23 represents that this Zooming-projection camera lens is positioned at the combination diopter of second and third lens combination when amplifying end; Ft23 represents that this Zooming-projection camera lens is positioned at the combination diopter of second and third lens combination when dwindling end; Fw represents that this Zooming-projection camera lens is positioned at the system's focal length when amplifying end; Ft represents that this Zooming-projection camera lens is positioned at the system's focal length when dwindling end; Fw234 represents that this Zooming-projection camera lens is positioned at the combination diopter of second, third and the 4th lens combination when amplifying end; Ft234 represents that this Zooming-projection camera lens is positioned at the combination diopter of second, third and the 4th lens combination of dwindling when end; Fw represents that this Zooming-projection camera lens is positioned at the system's focal length when amplifying end; And ft represents that this Zooming-projection camera lens is positioned at the system's focal length when dwindling end.

2. Zooming-projection camera lens as claimed in claim 1 is characterized in that: each eyeglass of first to the 5th lens combination adopts global surface glass nitre material to process.

3. Zooming-projection camera lens as claimed in claim 2 is characterized in that: when being installed in this Zooming-projection camera lens on the projection display equipment, the image source side is meant the imager of this projection display equipment, and the imaging side is meant that image can throw screen thereon.

4. Zooming-projection camera lens as claimed in claim 3 is characterized in that: this Zooming-projection camera lens further includes an aperture, and this aperture is positioned at the imaging side of the 4th lens combination, and moves with the 4th lens combination.

5. Zooming-projection camera lens as claimed in claim 4 is characterized in that: this aperture is an auto iris.

6. Zooming-projection camera lens as claimed in claim 5 is characterized in that: the image source side in the 5th lens combination also is provided with a combined prism and a parallel-plate.

7. Zooming-projection camera lens as claimed in claim 4 is characterized in that: in the focusing process, have first variable spacing between this second lens combination and first lens combination, its scope is from 10.4069 millimeters to 3.8000 millimeters; Have second variable spacing between the 3rd lens combination and second lens combination, its scope is from 25.0924 millimeters to 15.3404 millimeters; Have the 3rd variable spacing between the 4th lens combination and the 3rd lens combination, its scope is from 3.5800 millimeters to 16.5894 millimeters; Have the 4th variable spacing between the 4th lens combination and the 5th lens combination, its scope is from 0.1533 millimeter to 3.5056 millimeters.

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