Object lens and optical pickup device

A technology of optical pickup device and objective lens, which is applied in the direction of optics, condenser lens, optical elements, etc., and can solve problems such as the inability to measure the inclination of the objective lens

Active Publication Date: 2013-12-11
KONICA MINOLTA INC
View PDF7 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] However, the present inventors designed and tried to manufacture an objective lens with high NA (the image side numerical aperture is more than 0.7 and less than 0.9) whic

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
  • Object lens and optical pickup device
  • Object lens and optical pickup device
  • Object lens and optical pickup device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0364] Figure 11 It is a sectional view of the objective lens 2a of Example 1. Figure 11 The objective lens 2a of the shown embodiment 1 is a plastic single-piece lens, which has a first optical surface 25 disposed facing the light source and a second optical surface 26 facing the first optical surface with a larger curvature than the first optical surface. An optical disc is arranged on the second optical surface 26 side.

[0365] Although not shown in figure, the optical path difference providing structure is formed in the 1st optical surface 25. As shown in FIG. The optical path difference imparting structure is a ring-shaped diffractive structure, and has a function of correcting spherical aberration caused by temperature change.

[0366] The numerical aperture of this objective lens 2a is 0.85, and it is a dedicated objective lens for BD corresponding to the laser beam of wavelength 405nm.

[0367] As shown in Table 1, the A / B value of the objective lens 2a is 0.26, ...

Embodiment 2

[0380] Figure 12 It is a sectional view of the objective lens 2b of Example 2. Figure 12 The objective lens 2b shown is a plastic single-lens lens having an optical path difference imparting structure substantially the same in shape as in Example 1, and the A / B value is changed.

Embodiment 3

[0382] Figure 13 It is a sectional view of the objective lens 2c of Example 3. Figure 13 The objective lens of Example 3 shown is a plastic single-piece lens. The 1st optical surface 25 of the objective lens 2c of Example 3 is an aspherical shape which does not have an optical path difference providing structure.

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

PropertyMeasurementUnit
Outer diameteraaaaaaaaaa
Login to view more

Abstract

Provided is a high NA object lens which, in spite of being a high NA object lens, permits excellent measurement of inclination when the object lens is attached to an optical pickup device and which permits high precision assembly with the optical pickup device, and also provided is the optical pickup device comprising the high NA object lens. The object lens comprises: a first optical face that is formed on the light source side; a second optical face that faces the first optical face and is formed having a radius of curvature greater than that of the first optical face; and a planar end face that is positioned outside the second optical face as seen from the optical axis direction and is substantially orthogonal to the optical axis. The object lens satisfies the expression 0.12=A/B= 0.5 (1), where the image-side aperture number (NA) is 0.7 to 0.9, and, as seen from the optical axis direction, the distance of a straight line, which passes through the optical axis and the end face, within the area of the end face is A (mm), and the distance of a straight line from the optical axis to the outermost circumferential section of the end face is B (mm).

Description

technical field [0001] The present invention relates to an objective lens and an optical pick-up device, in particular to an objective lens and an optical pick-up device which can more suitably adjust the inclination when the objective lens is assembled on the optical pick-up device. Background technique [0002] In recent years, in the optical pickup device, the laser light source used as a light source for reproducing information recorded on the optical disc and recording information on the optical disc has been shortened. Laser light sources are becoming more and more practical. When using these blue-violet laser light sources, in the case of using an objective lens with the same numerical aperture (NA) as DVD (Digital Versatile Disc), it is possible to record 15 to 20 GB of information on an optical disc with a diameter of 12 cm, while increasing the NA of the objective lens When it reaches 0.85, information of 23-25 ​​GB can be recorded on a disc with a diameter of 12 ...

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
IPC IPC(8): G11B7/1374G11B7/1353G02B19/00
CPCG11B7/1374G02B19/0076G11B7/1353
Inventor 水町靖荻原贤治
Owner KONICA MINOLTA INC
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap