CN1154542A - Multiple focus optical pickup system - Google Patents
Multiple focus optical pickup system Download PDFInfo
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- CN1154542A CN1154542A CN96109639A CN96109639A CN1154542A CN 1154542 A CN1154542 A CN 1154542A CN 96109639 A CN96109639 A CN 96109639A CN 96109639 A CN96109639 A CN 96109639A CN 1154542 A CN1154542 A CN 1154542A
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Abstract
An optical pickup system for reproducing information signals stored on a first and a second optical disks loaded on a disk tray is described wherein each of the optical disks has a different thickness. The optical system includes a light source for generating a parallel light beam and an optical device provided with a first and a second part, wherein a portion of parallel light beam impinging onto the first part is focused onto the first optical disk, and the remaining portion of the parallel light beam impinging onto the second part is focused onto the second optical disk, thereby allowing the optical pickup system to read the information signals off the respective optical disk.
Description
The present invention relates to a kind of optical pickup system, and, more specifically, relate to the optical pickup system after a kind of improve, this system that can read to approach with thick CD.
As everyone knows, a short wavelength light source and a big numerical aperture (NA) are important optical considerations in being used for realizing the optical pick-up head of high-density optical storage.Yet big NA lens are such as 0.6, preferably be with a thickness, glimmer dish such as 0.6mm uses together, if optical head that is used to read the glimmer dish is used to read the 1.2mm dish of a routine, because the dish spherical aberration that thick difference caused must obtain revising.
A kind of bifocus optical head with holographic optical elements (HOE) (HOE) has been introduced into this problem that solves.
In Fig. 1, shown bifocus optical head 100 is used for reproducing and is stored in thin and an an information signal thick CD, these two plate wheel streams place above the CD holder, wherein each in the CD has a corresponding recording surface, this is published in SPIE VOL.2338 at Kanda and Hayashi, and the article among the Optical Data Storage (1994)/283 " the bifocus optical head (DualFocas Optical Head for 0.6mm and 1.2mm Disks) that is used for 0.6mm and 1.2mm dish " is described.Bifocus optical head 100 comprises: a light source 126 is used for producing a light beam, a beam splitter 106, a collimating mirror 108, a HOE110,114, one cylindrical lenses 104 of object lens and one are provided with four photronic detectors 102, and wherein HOE 110 is designed to concavees lens, in this mode, the distance that the focal length of 1 order diffraction light beam 128 leaves object lens is more farther than 0 order diffraction light beam 124.
In optical head 100, when a thin CD 116 is placed in above the pan arrest, the 0 order diffraction light beam 124 that sees through from HOE 110 is used to reproduce information signal from a recording surface 118 of thin CD 116.In this case, from light source 126, the light beam that sends such as a laser diode is through beam splitter 106 and collimation lens 108 laggard people HOE 110, beam splitter 106 is in order to make the partly surface by wherein being adopted of light beam, and collimation lens is in order to make the light beam from beam splitter 106 become directional light.Under such a case, 0 order diffraction light beam 124 of 110 pairs of parallel beams of HOE only plays the effect of a parallel-plate.0 order diffraction light beam 124 focuses on the recording surface 118 of glimmer dish 116 by object lens 114.When 0 order diffraction light 124 by 114 when glimmer dish 116 returns HOE 110, HOE 110 plays the effect of a parallel-plate equally.This 0 order diffraction light beam 124 after passing collimation lens 108 and beam splitter 106, becomes astigmatism by cylindrical lens 104, thereby makes detector 102 can read information signal on the recording surface 118 of glimmer dish 116.
Simultaneously, for the information signal of a recording surface 120 revealing a thick CD 122 again, adopted from HOE 110 see through+1 order diffraction light beam 128.Should be noted that, except that HOE110, be similar at the function of the optics file of+1 order diffraction light beam 128 and structure and at the optical element of 0 order diffraction light beam 124 in optical head 100.In this case, the function of HOE110 is as lens, is used for combining with the object lens clock+1 order diffraction light beam 128 is focused on the recording surface 120 of thick CD 122.Therefore, the optical head 100 that uses with glimmer dish 116 can reveal the information signal on the recording surface 120 of thick CD 122 again.
Yet, have the many problems relevant with above-mentioned optical head 100.At first, HOE 110 must with the object lens 114 combined effects of playing lens, make the big and complex structure of optical head 100 volumes thus.
Another problem that exists in the prior art optical head is that a kind of HOE 110 job operations that its requires are difficult, and a kind of like this HOE 110 is normally expensive.
Therefore, a fundamental purpose of the present invention is that a kind of new optical device will be provided, and this device can be divided into several portions with a parallel beam, and respectively each part is focused on the focus of similar number.
Another object of the present invention provides the optical pickup system after a kind of the improvement, and the different CD of a plurality of some or all thickness can be read by this system.
According to an aspect of the present invention, provide an optical device that is used for an optical pickup system, this device comprises: a matrix, make by refractive material, and have the end face and the bottom surface that are parallel to each other, wherein end face just is divided into N annular region; And N group M three square ring, each group in M three square rings of N group is set on the top in each annular region, and each in three square rings in each group is made by refractive material and is comprised that a width is R
MAnnular base, and a height is H
MThe annular vertical face, annular base is perpendicular to the annular vertical face, wherein N organizes the function that each group in three square rings has been made into lens, by controlling the height H of each three square ring in every group
MWith width R
M, each group in the N group can be made with different focal distance f, and wherein M and N are natural number.
According to a further aspect in the invention, an optical pickup system is provided, has been used for reproducing the information signal that is stored on the many CDs that place on the pan arrest, wherein, in the CD each has a recording surface separately, and this system comprises: a light source that is used for sending a branch of parallel beam; With a optical device with a plurality of parts, wherein each part has a different focal length, and parallel beam can be divided into each several part with the CD similar number, and each part in the parallel beam focused on respectively on the recording surface of a corresponding CD, make optical pickup system can read information signal on the recording surface of corresponding CD thus.
From below in conjunction with the description of accompanying drawing to preferred embodiment, the present invention will become obviously together with above-mentioned and other purpose and advantage, in the accompanying drawing:
Fig. 1 represents a diagrammatic side view of a prior art optical pickup system;
Figure 2 shows that a planimetric map according to an optical device of the present invention;
Figure 3 shows that the diagrammatic cross-section that optical device of the present invention intercepts along the V-V line among Fig. 2; And
Figure 4 shows that a diagrammatic side view of an optical pickup system that adopts optical device of the present invention.
Fig. 2 to Fig. 4 has provided the different views according to the optical pickup system of the present invention of the preferred embodiments of the invention.
Figure 2 shows that a planimetric map of the optical device 210 that is used for an optical pickup system, this device can be divided into a branch of parallel beam first and second portion, and first and second parts are focused on respectively on first and second focus.This optical device 210 comprises a substrate, by a kind of refractive material, such as PMMA (Poly Methyl Meta Acryllrate), a first 211 and a second portion 213 that PC (polycarbonate) and PS (Poly Styrate) make.This first 211 is expressed by a strong line (hardline).The first of light beam is incided in the first 211 of optical device 210, and the second portion of parallel beam incides on its second portion 213.
First 211 comprises one first annular substrates, is made by refractive material to have an end face and bottom surface that is parallel to each other, and is arranged on first group of S three square rings above first annular substrates.In three square rings each is made by the refractive material identical with first annular substrates, and to be provided with a width be R
SFirst annular base, S be one the expression ordinal number natural number, a height is H
SThe first annular vertical face, first annular base and the first annular vertical face are perpendicular, and one with respect to the first annular vertical face with angle θ
SThe first annular dip plane that tilts.By the control height H
SWith width R
S, make first group of S three square rings play the effect of lens, these lens have one first focal distance f
1
The second portion 213 of optical device 210 comprises one second annular substrates, is made by refractive material, has an end face and a bottom surface of being parallel to each other, and is arranged on second group of T three square rings above one second annular substrates.In three square rings each is made by refractive material, and comprises that a width is R
TSecond annular base, T be one the expression ordinal number natural number, a height is H
TThe second annular vertical face, second annular base and the second annular vertical face are perpendicular, and one with respect to the second annular vertical face with angle θ
TThe second annular dip plane that tilts.By the control height H
TWith width R
T, make second group of T three square rings play the effect of lens, these lens have a focal distance f
2, and f
2＜f
1
As shown in Figure 3, if the first annular vertical mask in each three square ring in first group of three square ring has identical height, first focal distance f
1Determine by following formula:
Wherein λ represents the wavelength of light source, R
SWidth for annular substrates.Preferably, when encircling the center of close substrate, the R in each three square ring
SIncrease.
In addition, the focal distance f of second group of T three square ring
2Also by with first focal distance f
1Identical method is determined.
As shown in Figure 4, adopt the optical pickup system 200 of optical device 210 of the present invention to comprise the light source 216 that is used for sending a light beam, a beam splitter 206 that is provided with a surface, a collimation lens 208, have 210, one cylindrical lenses 204 of optical device of first 211 and second portion 213 and one and be provided with a plurality of photronic detectors 202.
In system 200, have thickness when one, be placed on the pan arrest as the glimmer dish 215 of 0.6mm, the light of the second portion 213 by optical device 210 is used to reproduce the information signal on the recording surface 212 of glimmer dish 215.In this case, from light source 216, as, a laser diode, the light beam that sends enters optical device 210 by beam splitter 206 and collimation lens 208, beam splitter is by in order to make the partly surface by wherein being adopted of light beam, and collimation lens is in order to make the light beam from beam splitter become directional light.The surface of beam splitter 206 is configured to a kind of like this mode, also, with a predetermined angle with respect to inclined light shaft, and optical axis to be central point and the focus on corresponding recording surface 212,214 by detector 202 form.Preferably, predetermined angle is 45 °.Under such a case, the second portion 213 of optical device 210 is by having played the effect of object lens above the recording surface 212 that parallel beam is focused on glimmer dish 215.Incide on the collimation lens 208 through optical device 210 beam reflected from recording surface 212, collimation lens 208 is used to and will converges on the detector 202 through the beam splitter 206 that is arranged between collimation lens 208 and the detector 202 from optical device 210 beam reflected.The surface of beam splitter 206 can make the light beam by collimation lens 208 see through.Collimation lens 208 is set between beam splitter 206 and the optical device 210.The light beam that passes through from beam splitter 206 incides on the cylindrical lens 204, thereby make the light that passes it become astigmatism, make detector 202 read information signal on the recording surface 212 of glimmer dish 215 thus by adopting a kind of astigmatic method, such as, a focus error signal.Cylindrical lens 204 is arranged between beam splitter 206 and the detector 202.
In addition, have thickness when one, as 1.2mm, thick CD be placed on the pan arrest, the light of the first 211 by optical device 210 is used to reveal the information signal on the recording surface 214 of thick CD 217 again.In this case, the effect of object lens is played by the first 211 of optical device 210 by the recording surface 214 that will focus on thick CD 217 from the parallel beam that wherein sees through.Therefore, it makes detector 202 can read the information signal on the recording surface 212 of thick CD 217.
Compare with the optical head 100 of prior art, the size of optical system 200 of the present invention has reduced, and simple in structure, requires the element than peanut.This point realizes by having adopted an optical device 210 of the present invention therein, the object lens 114 in the optical head 100 of prior art have been removed thus, reduced the sum of the element that constitutes this system, this point will be again can reduce the length of the light path that light beam must pass through, thereby cause the overall dimensions of system to reduce.
Although invention has been described at a kind of optical pickup system, this system has adopted therein and a kind ofly first and second portion of a parallel beam can have been focused on an optical device on first and second focus respectively, thereby be used for that read to approach and thick CD, by adopting one can will focus on optical device on separately the focus respectively therein with the same number of parallel beam each several part of CD, the conception that proposes above can be extended to an optical pickup system, and this system can use with the some CDs with different-thickness.
Though the present invention is described at preferred embodiment, under the condition of the spirit and scope of the present invention that propose in the claims below not departing from, other corrections and variation can be carried out.
Claims (22)
1, optical device that is used for an optical pickup system, described device comprises:
A substrate is made by refractive material, has an end face and a bottom surface of being parallel to each other, and wherein end face is divided into N annular region; And
N group M three square ring, each group in M three square rings of N group be placed in each annular region above, each three square ring in every group are made by refractive material and are comprised that a width is R
MAnnular base and a height be H
MThe annular vertical face, annular base is vertical with the annular vertical face, wherein N organizes the effect that each group in three square rings has been made into lens, each group in the N group is made into by controlling the height H of each three square ring in every group
MWith width R
MAnd having a different focal distance f, M and N are natural number.
2, optical device as claimed in claim 1, the wherein height H of each three square ring in every group
MRoughly be equal to each other.
3, optical device as claimed in claim 2, wherein every group focal distance f is determined by following formula:
Wherein λ represents the wavelength of light source.
4, optical device as claimed in claim 3, wherein when ring during near center of substrate, the R of each three square ring
MIncrease.
5, optical device as claimed in claim 4, refractive material wherein be by poly methylmeta acryllrate (PMMA), polycarbonate (PC), or Poly styrate (PS) makes.
6, optical pickup system is used for reproducing the information signal that is stored on the many CDs that are placed on the pan arrest, and wherein each CD has a corresponding recording surface, and described system comprises:
Produce the device of a branch of parallel beam; And
Optical device with a plurality of parts, wherein each part has a different focal length, and directional light can be divided into and the same number of each several part of CD, and each part in the directional light focused on the recording surface of a corresponding CD, make optical pickup system can read information signal on the recording surface of corresponding CD thus.
7, optical pickup system as claimed in claim 6 also comprises sniffer.
8, optical pickup system as claimed in claim 7, parallel beam generation device wherein comprises:
A light source that is used to produce a light beams;
Be used for beam reflection to corresponding recording surface and make the beam splitting arrangement that see through to arrive sniffer from the recording surface beam reflected; And
Be used for also to produce the device of parallel beam thus from beam splitting arrangement beam reflected collimation.
9, optical pickup system as claimed in claim 8, collimator apparatus is wherein also assembled the light beam from CD reflection.
10, as the optical pickup system of claim 10, collimator apparatus wherein is arranged between sniffer and the optical device.
11, as the optical pickup system of claim 10, beam splitting arrangement wherein is set between collimator apparatus and the sniffer.
12, as the optical pickup system of claim 11, wherein beam splitting arrangement is configured to a kind of like this mode, promptly with a predetermined angle with respect to inclined light shaft, and optical axis is to be formed by central point on the sniffer and the lip-deep convergent point of respective record.
13, optical pickup system as claimed in claim 8, optical device wherein comprises:
A substrate is made by refractive material, has an end face and a bottom surface of being parallel to each other, and wherein end face is divided into N annular region;
N group M three square ring, each group in M three square rings of N group be placed in each annular region above, each ring in every group three square ring is made by refractive material and is comprised that a width is R
MAnnular base and a height be H
MThe annular vertical face, annular base is vertical with the annular vertical face, wherein N organizes each group in three square rings and is made into to be used for the effect of lens, each group in the N group is made into by controlling the height H of each three square ring in every group
MWith width R
MHave a different focal distance f, M and N are natural number.
14, optical pickup system as claimed in claim 8, beam splitting arrangement wherein can will partly reflex on the CD from the light beam of light source, and the light beam through optical device is partly passed through and the arrival sniffer.
15, optical pickup system is used for reproducing the information signal that is stored on first and second CD that is placed on the pallet, and wherein, each CD with a recording surface has different thickness, and described system comprises:
A device that is used for producing a branch of parallel beam;
Optical device with first and second portion, wherein incide that part of being focused on first CD in the first in the parallel beam, and it is remaining that part of in the parallel beam, the part that promptly incides on the second portion is focused on second CD, thereby makes this optical pickup system can alternately read the lip-deep information signal of respective record; And
Pick-up unit is used for reading the information signal of corresponding CD.
16, as the optical pickup system of claim 15, parallel beam generation device wherein comprises:
A light source that is used to produce a light beams;
Be used for beam reflection to recording surface and make from the recording surface beam reflected thoroughly to the beam splitting arrangement of sniffer; And
Be used for also to produce the device of parallel beam thus from beam splitting arrangement beam reflected collimation.
17, as the optical pickup system of claim 16, collimator apparatus is wherein also assembled the light beam from CD reflection.
18, as the optical pickup system of claim 16, first CD wherein has the thickness of 0.6mm.
19, as the optical pickup system of claim 16, second CD wherein has the thickness of 1.2mm.
20, as the optical pickup system of claim 16, wherein, the first of optical device comprises:
One first annular substrates is made by refractive material, has an end face and a bottom surface of being parallel to each other, and
Be arranged on first group of T three square rings above first annular substrates, each three square ring is made by refractive material, and a width is arranged is R
TFirst annular base, a height is H
TThe first annular vertical face, first annular base and the first annular vertical face are perpendicular, wherein first group of T three square ring play the effect of lens, these lens can have one first focal distance f 1, wherein first focal distance f
1Be by changing height H
TWith width R
TControl.
21, as the optical pickup system of claim 20, wherein, the second portion of this optical device comprises:
One second annular substrates is made by refractive material, has an end face and a bottom surface of being parallel to each other, and
Be arranged on second group of S three square rings above second annular substrates, each three square ring is made by refractive material, and a width is arranged is R
SSecond annular base, a height is H
SThe second annular vertical face, second annular base and the second annular vertical face are perpendicular, wherein second group of S three square ring play the effect of lens, these lens can have one second focal distance f
2, second focal distance f wherein
2Be by changing height H
SWith width R
SControl.
22, as the optical pickup system of claim 21, second focal distance f wherein
2Less than first focal distance f
1
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN96109639A CN1154542A (en) | 1995-08-31 | 1996-09-02 | Multiple focus optical pickup system |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR28010/95 | 1995-08-31 | ||
| CN96109639A CN1154542A (en) | 1995-08-31 | 1996-09-02 | Multiple focus optical pickup system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1154542A true CN1154542A (en) | 1997-07-16 |
Family
ID=5120489
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN96109639A Pending CN1154542A (en) | 1995-08-31 | 1996-09-02 | Multiple focus optical pickup system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1154542A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108474936A (en) * | 2016-01-12 | 2018-08-31 | 三星电子株式会社 | Compound lens and display equipment with it |
-
1996
- 1996-09-02 CN CN96109639A patent/CN1154542A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108474936A (en) * | 2016-01-12 | 2018-08-31 | 三星电子株式会社 | Compound lens and display equipment with it |
| US10890695B2 (en) | 2016-01-12 | 2021-01-12 | Samsung Electronics Co., Ltd. | Compound lens and display device having the same |
| CN108474936B (en) * | 2016-01-12 | 2022-04-22 | 三星电子株式会社 | Compound lens and display device having the same |
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