Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Zoom lens, video enlarging/projecting system, video projector, rear projector, and multivision system

A zoom lens and lens technology, applied in the field of zoom lenses

Active Publication Date: 2005-12-07
PANASONIC CORP
View PDF5 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0017] Therefore, in a wide-angle lens for a projector, for example, when projecting to a screen size of about 782 to 178 cm, securing performance against changes in the projection distance becomes a big problem.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Zoom lens, video enlarging/projecting system, video projector, rear projector, and multivision system
  • Zoom lens, video enlarging/projecting system, video projector, rear projector, and multivision system
  • Zoom lens, video enlarging/projecting system, video projector, rear projector, and multivision system

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0219] Next, Example 1 of Embodiment 1 will be described. The lens structure of embodiment 1 and figure 1 , 2 The structure is the same, it is F at the wide-angle end NO = 2.5, focal length f = 37.08, half angle of view = 24.2° design example. Each value of said formula (1)-(12) of Example 1 is as follows.

[0220] Formula (1) f2g / f2top=-0.22

[0221] Formula (2) frear / f2top=0.33

[0222] Formula (3) (1 / f1 / abe1) / (1 / frear)=-0.01

[0223] Formula (4) nd11 = 1.78472

[0224] Formula (5) nd4 = 1.7725

[0225] Formula (6) vd4 = 49.62

[0226]Formula (7) f4r / bfw=1.08

[0227] Formula (8) bfw / fw=2.07

[0228] Formula (9) fw / f1g=0.16

[0229] Formula (10) fw / f2g=-0.78

[0230] Formula (11) fw / f3g=0.59

[0231] Formula (12)|(DG1-DG3) / fw|=0.11

[0232] Next, Table 1 shows specific numerical values, and Table 2 shows zoom data. In Table 1, ri (mm) is the radius of curvature of each surface of the lens, di (mm) is the thickness of the lens or the distance between the lenses...

Embodiment 2

[0249] Next, Example 2 of the second embodiment will be described. Example 2 and Figure 5 , 6 The structure is the same, it is F at the wide-angle end NO = 2.4, focal length f = 55.83, half angle of view = 16.7° design example. Each value of said formula (1)-(7), (8b)-(11b), (12) of Example 2 is as follows.

[0250] Formula (1) f2g / f2top=-0.15

[0251] Formula (2) frear / f2top=0.276

[0252] Formula (3)(1 / f1 / abe1) / (1 / frear)=-0.0144

[0253] Formula (4) nd11 = 1.78472

[0254] Formula (5) nd4 = 1.7725

[0255] Formula (6) vd4 = 49.62

[0256] Formula (7) f4r / bfw=1.67

[0257] Formula (8b) bfw / fw=1.39

[0258] Formula (9b) fw / f1g=0.394

[0259] Formula (10b) fw / f2g=-1.5

[0260] Formula (11b) fw / f3g=0.82

[0261] Formula (12)|(DG1-DG3) / fw|=7.5×10 -5

[0262] Next, Table 3 shows specific numerical values, and Table 4 shows zoom data. In Table 3, r1-r4 are the first lens group, r5-r14 are the second lens group, r15-r31 are the third lens group, and r15 is the apert...

Embodiment 3

[0288] Next, Example 3 of the third embodiment will be described. The lens structure of embodiment 3 and Figure 13 , 14 The structure is the same, it is F at the wide-angle end NO = 2.5, focal length f = 96.39, half angle of view = 10.25° design example. Each value of said formula (1), (2), (5)-(7), (8c)-(11c), and (12a) of Example 3 is as follows.

[0289] Formula (1) f2g / f2top=-0.54

[0290] Formula (2) frear / f2top=0.86

[0291] Formula (5) nd4 = 1.7725

[0292] Formula (6) vd4 = 49.62

[0293] Formula (7) f4r / bfw=2.05

[0294] Formula (8c) bfw / fw=0.89

[0295] Formula (9c) fw / f1g=0.53

[0296] Formula (10c) fw / f2g=-1.82

[0297] Formula (11c) fw / f3g=1.14

[0298] Formula (12a)|(DG1-DG3) / fw|=0.15

[0299] Next, Table 7 below shows specific numerical values, and Table 8 shows zoom data. In Table 7, r1-r8 are the first lens group, r9-r20 are the second lens group, r21-r39 are the third lens group, and r21 is the aperture.

[0300]

ri

di

...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A zoom lens having three or more groups of lenses. When viewed from the long conjugate distance side, a first lens group (11) having a positive refractive power and a second lens group (12) having a negative refractive power are arranged in order of mention. Among the lenses of the second lens group (12), the first lens (12a) from the long conjugate distance side has a positive refractive power. With this, the distortion aberration is reduced to a low level.

Description

technical field [0001] The present invention relates to a zoom lens, and more particularly to a zoom lens used in a projector or the like that enlarges and projects an image of a spatial light modulator on a screen. Background technique [0002] In a projector using reflective spatial modulation elements of the three primary colors of red, green, and blue, a prism for guiding illumination light and a prism for color synthesis are disposed between the projection lens and the spatial modulation element. Therefore, the projection lens requires a long back focus. Since the spectral characteristics of the color synthesizing prism depend on the incident angle, an optical system in which the pupil position on the side with the shorter conjugate distance is sufficiently far from the spatial modulation element, that is, telecentricity is required. [0003] As a four-group zoom lens having a long back focus and telecentricity that does not vary depending on zooming, there is a zoom l...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): G02B15/20G03B21/10
Inventor 木村俊介高桥昌之山本义春
Owner PANASONIC CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com