CN101123101A - Object lens and optical pick-up device having the same - Google Patents
Object lens and optical pick-up device having the same Download PDFInfo
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- CN101123101A CN101123101A CNA2007101465006A CN200710146500A CN101123101A CN 101123101 A CN101123101 A CN 101123101A CN A2007101465006 A CNA2007101465006 A CN A2007101465006A CN 200710146500 A CN200710146500 A CN 200710146500A CN 101123101 A CN101123101 A CN 101123101A
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1372—Lenses
- G11B7/1374—Objective lenses
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/125—Optical beam sources therefor, e.g. laser control circuitry specially adapted for optical storage devices; Modulators, e.g. means for controlling the size or intensity of optical spots or optical traces
- G11B7/127—Lasers; Multiple laser arrays
- G11B7/1275—Two or more lasers having different wavelengths
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1353—Diffractive elements, e.g. holograms or gratings
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1372—Lenses
- G11B2007/13727—Compound lenses, i.e. two or more lenses co-operating to perform a function, e.g. compound objective lens including a solid immersion lens, positive and negative lenses either bonded together or with adjustable spacing
Abstract
An object lens and an optical pick-up device having the same capable of recording and/or reproducing a plurality of types of optical discs, the optical pick-up device including: a light emitting part (12,14,16) that emits lights having different wavelengths corresponding to the plurality of types of optical discs, and a light collecting part (30,32,34) that focuses a light having a wavelength corresponding to a type of a loaded optical disc and emitted from the light emitting part to form spots on the loaded optical disc. Accordingly, various types of optical discs using different wavelengths can be compatibly driven in an optical recording/reproducing apparatus capable of recording and/or reproducing high/low density optical discs.
Description
Technical field
The optic pick-up that the present invention relates to object lens and have these object lens, the optic pick-up that relates in particular to object lens and have these object lens, it is suitable for using in optic recording/reproducing device different wave length to drive various CDs, thereby goes up recorded information and/or information reproduction at CD (optical recording media).
Background technology
Along with the exploitation of image and acoustic medium, the CD that can write down a large amount of HD image and acoustic information has been developed and has generally used.CD is a kind of recording medium by laser beam record and/or reproduction.Traditionally, use CD (as CD (compact disk, Compact Disc) or DVD (digital versatile disc, Digital Versatile Disc)) at first.Yet, because the restriction of conventional optical disc (CD or DVD) recording capacity, the disks (but as blue light record/rewritable disk (BD) or high-resolution DVD (HD-DVD)) with the above high recording capacity of tens GB is developed and little by little is widely used.
The recording capacity of CD is by the size decision of the hot spot that focuses on optical disc surface.The size of hot spot (S) is proportional with the wavelength (L) of laser beam, and the numerical aperture (NA) with object lens is inversely proportional to simultaneously.Correspondingly, in order on CD, to write down bulk information, should adopt short wavelength's the laser beam and the object lens of large-numerical aperture.For example, record or information reproduction employing wavelength is the near infrared light of 780nm and the object lens of numerical aperture about 0.45 on CD.DVD has than the bigger recording capacity of CD (about 6 to 8 times), and the employing wavelength is that ruddiness and the numerical aperture of 650nm or 630nm is the object lens of 0.6 (recordable type is 0.65).If DVD has the diameter of 120mm and the track space of 0.74 μ m, then it has 4.7GB or higher recording capacity (single face).This DVD is not suitable for writing down high-resolution (HD) image data, because for example for 135 minutes high-resolution image data of recording played, needs 23GB or higher recording capacity (single face).
In order to satisfy the high-resolution recording capacity, have narrow gauge track spacing more in exploitation, adopt than ruddiness short wavelength's light (blue light that for example has 405nm or 408nm wavelength) and have numerical aperture and carried out a large amount of effort more greater than the DVD of future generation or the high-resolution CD aspects such as (the hereinafter HD-DVD of indication) of 0.6 object lens.Owing to increased numerical aperture of objective to obtain high-density capacity, so must reduce the thickness of CD according to the tolerance limit of disc tilt.Correspondingly, the thickness of CD and DVD is reduced to 1.2mm and 0.6mm respectively, and HD-DVD has the thickness of 0.6mm.For the numerical aperture of object lens, CD increases to 0.45, and DVD and HD-DVD increase to 0.65.Under the HD-DVD situation, consider recording capacity, used blue-light source.Yet the CD problem of development of new standards is and has now the compatibility of CD.And one of high-density recording media of exploitation is the BD with bigger recording capacity recently.For BD, the blue light of short wavelength (405nm to 408nm) and object lens have been used with about 0.85 numerical aperture.BD has the thickness of 0.1mm and has the recording capacity that is about ten times of DVD.
Because the fabricator has developed as HD-DVD, the CD of these new standards such as BD so the consumer is difficult to select various types of CDs with data storage wherein, because the CD of various criterion coexists as in the market, is difficult to guarantee compatible mutually with other compact disk standards.For example because HD-DVD and BD do not have compatible compact disk standards, in order to write down or play HD-DVD and BD, must use be adapted to two kinds of optic recording/reproducing devices of HD-DVD and BD respectively.Thereby the user needs a kind of general optical recording/reproducing apparatus, and this device can write down and play all types of CDs, comprises BD, HD-DVD, DVD and CD.That is, for the convenience of the users, need a kind of optical recording/reproducing apparatus that optical system is housed, optic pick-up can be suitable for using the light of different wave length to drive various CDs in this optical system.
Summary of the invention
Therefore, the optic pick-up that the invention provides object lens and have these object lens, it can be suitable for using different wave length to drive multiple CD by a plurality of object lens that write down and/or reproduce high/low disc density are set in optic recording/reproducing device.
The optic pick-up that the present invention provides object lens simultaneously and has these object lens, these object lens can be suitable for reproducing the CD that all kinds have different-thickness or recording density by using the multi-wavelength.
According to an aspect of the present invention, a kind of optic pick-up that writes down and/or reproduce the polytype CD with four kinds of different recording density is provided, this optic pick-up comprises: the light radiating portion, its emission has the light corresponding to three kinds of different wave lengths of described polytype CD, so that this light radiating portion is launched the light that has corresponding to the wavelength of institute's loading optical disk type; And light collects part, and it will focus on from light described smooth radiating portion emission, that have corresponding to the wavelength of institute's loading optical disk type, to form hot spot on the CD of described loading.
According to an aspect of the present invention, described polytype CD comprises HD-DVD, DVD and CD.
According to an aspect of the present invention, the light radiating portion can comprise that transmitted wave is about a plurality of light sources of the light of the light of the light of 400nm, the about 600nm of wavelength and the about 700nm of wavelength.
According to an aspect of the present invention, the light of light radiating portion emission have with the polytype CD in the corresponding wavelength of at least a form.
According to an aspect of the present invention, this optic pick-up also comprises: holographic element, and it is arranged on light and collects between in part and a plurality of light source at least one; And the optical detection part branch, it collects the positional information of part by utilizing the light detecting signal from the holographic element diffraction to obtain light.
According to an aspect of the present invention, light is collected part and is one and adopts object lens of different numerical apertures according to the radiative wavelength of light radiating portion, is suitable for reproducing the polytype CD.
According to an aspect of the present invention, object lens are divided into two border circular areas with light shaft coaxle at least, make the first area comprise optical axis be common to the light of all different wave lengths of light radiating portion emission, and be common at least two kinds of wavelength with the contiguous second area in first area.
According to an aspect of the present invention, object lens also comprise the 3rd zone, this region adjacent second area and be used for the single wavelength that different wave length has intermediate length.
According to an aspect of the present invention, object lens are provided with at least three concentric on the optical axis different border circular areas, and differently use described zone according to the respective type of CD.
According to an aspect of the present invention, when record or reproduction polytype CD, a zone in three zones of object lens is shared at least.
According to an aspect of the present invention, optic pick-up also comprises a light path conversion portion, be used for changing the emission of light radiating portion light the direction of propagation and the light direct light collected part.
According to a further aspect of the invention, the light path conversion portion comprises a relay lens, and it will convert parallel rays to from the light of light radiating portion before light is directed to light collection unit branch.
According to an aspect of the present invention, provide an optic pick-up that can write down and/or reproduce the polytype CD, this optic pick-up comprises: a plurality of light sources, its emission have the light corresponding to three kinds of different wave lengths of described polytype CD; And a plurality of object lens, its focus on by a plurality of light emitted, have the light with the corresponding wavelength of loading optical disk, on the CD that loads, to form a hot spot.
According to an aspect of the present invention, one object lens that can write down and/or reproduce the optic pick-up of polytype CD are provided, wherein said object lens use the light of three kinds of different wave lengths and use different numerical apertures according to the multi-wavelength, can reproduce the polytype CD with different-thickness compatiblely.
According to an aspect of the present invention, object lens use the light of at least three kinds of wavelength.
According to an aspect of the present invention, object lens are divided into two concentric on optical axis border circular areas at least, make to comprise that the first area of optical axis is common to three kinds of wavelength, and the second area adjacent with the first area are common to two kinds of wavelength.
According to an aspect of the present invention, object lens are provided with holographic lens on its part surface.
According to an aspect of the present invention, object lens are divided into three concentric on optical axis border circular areas at least, make and comprise that the first area of optical axis is provided with stepped region on its surface, be common to three kinds of wavelength, be provided with stepped region with the contiguous second area in first area and produce aberrations, and be provided with holographic lens on its surface to limit the aberration that a kind of wavelength produces with contiguous the 3rd zone of second area to limit two kinds of wavelength.
According to a further aspect of the invention, one optic pick-up is provided, this device uses and multiplely writes down and/or reproduce the polytype CD with different-thickness, and this optic pick-up comprises: emission has the light source corresponding to the light of the wavelength of institute's loading optical disk type; And first object lens and second object lens that use different numerical apertures according to the light wavelength of light emitted.
According to an aspect of the present invention, object lens are provided with stepped region or diffraction region on its at least one surface, and when writing down or reproduce the CD of any kind, this zone is by shared.
According to an aspect of the present invention, be used as second-order diffraction light (secondary diffraction light) according to wavelength by a part of light of object lens diffraction.
According to an aspect of the present invention, the degree of depth of the hologram pattern of object lens is determined in the reference wavelength of the diffraction light of 660nm to 790nm based on scope.
According to a further aspect in the invention, one optic pick-up that can write down and/or reproduce the polytype CD is provided, this optic pick-up comprises: first to the 3rd light source, its emission has the light corresponding to first to the 3rd different wave length of described polytype CD, and the CD of each type has one the different recording capacity that depends on correspondence in described first to the 3rd emission wavelength; One or more object lens, its focus on from described one or more light emitted, have light corresponding to the wavelength of institute's loading optical disk, to form hot spot according to type on institute's loading optical disk, described type can be selected in the CD with four kinds of different recording capacity; And one or more optical detection part branches, be used for the light that collectiong focusing reflects on described CD and from CD, to detect information signal.
According to an aspect of the present invention, provide a record and/or reproduction to have the method for the polytype CD of four kinds of recording densitys, this method comprises: emission is corresponding to the light of three kinds of different wave lengths of polytype CD; And the emission light that will have corresponding to the wavelength of loading optical disk type focuses on the loading optical disk, forms a hot spot.
Others of the present invention and/or advantage part will be set forth in the following description, and part can will be more apparent by describing, or know by enforcement of the present invention.
Description of drawings
These and/or others of the present invention and advantage will become apparent in to the description of the embodiment of the invention below in conjunction with accompanying drawing and more understandable, in the described accompanying drawing:
Fig. 1 is the schematic diagram according to the optic pick-up of the embodiment of the invention.
Fig. 2 is that the light that about 700nm wavelength is shown incides according on the lens in the optic pick-up of the embodiment of the invention, forms a hot spot on CD;
Fig. 3 is that the light that about 600nm wavelength is shown incides according on the lens in the optic pick-up of the embodiment of the invention, forms a hot spot on DVD;
Fig. 4 is that the light that about 400nm wavelength is shown incides according on the lens in the optic pick-up of the embodiment of the invention, forms a hot spot on HD-DVD;
Fig. 5 is that light that about 700nm wavelength is shown incides on the lens according to first design example in the optic pick-up of the embodiment of the invention, forms a hot spot on CD;
Fig. 6 is that light that about 600nm wavelength is shown incides on the lens according to first design example in the optic pick-up of the embodiment of the invention, forms a hot spot on DVD;
Fig. 7 is that light that about 400nm wavelength is shown incides on the lens according to first design example in the optic pick-up of the embodiment of the invention, forms a hot spot on HD-DVD.
Embodiment
To describe embodiments of the invention in detail now, its example is shown in the drawings, and identical Reference numeral is represented components identical in institute's drawings attached.In order to explain the present invention, these embodiment are described with reference to the accompanying drawings.
Fig. 1 is the schematic diagram according to the optic pick-up of the embodiment of the invention.This optic pick-up has an optical texture and a light path throw-over gear, and it can be suitable for driving the various types of CDs that use different wave length and have different recording density.Generally speaking, optic pick-up is a kind ofly to come recorded information or reproduce the device that is recorded in the information on the CD in non-contacting mode by the light that receives the reflection of CD signal recording surface by launching a laser beam to the signal recording surface of CD.
With reference to Fig. 1, optical take-up apparatus can use different wavelength and have record and/or information reproduction on various types of CDs 10 of different recording density.This optic pick-up comprises: a plurality of (for example three) light source 12,14 and 16, and the form of their corresponding CDs 10 is launched the different wavelength of laser bundle respectively; A plurality of (for example two) object lens 20 and 22, their focus on light from a plurality of light sources 12,14 and 16 to form hot spot on the signal recording surface of CD 10; A plurality of optical detection parts divide 30,32 and 34, and they receive the light that reflects from CD 10 after a plurality of object lens 20 and 22 focus on the CD 10; And a plurality of light path conversion portions 40 and 60, they are optionally with one of a radiative part a plurality of object lens 20 of guiding of light source 12,14 and 16 and 22 and will divide one of 30,32 and 34 to a plurality of optical detection parts from the photoconduction of CD 10 reflections.
A plurality of light sources 12,14 and 16 are configured to laser diode, launch the different wavelength of laser bundle respectively corresponding to the form of all kinds CD 10 that uses different wave length.For example a plurality of light sources can comprise first light source 12, and its transmitted wave is about the blue light (particularly, 540nm or littler) of 400nm, is applicable to HD-DVD or BD with high relatively recording density.Secondary light source 14 transmitted waves are about the ruddiness (particularly, 600nm to 660nm) of 600nm, and it is applicable to that recording density is lower than the DVD of HD-DVD.The 3rd light source 16 transmitted waves are about the infrared light (particularly, 700nm to 800nm) of 700nm, and it is applicable to that recording density is lower than the CD of DVD.Yet, should be appreciated that, according to others, a plurality of light sources can include only two light sources (for example, be suitable for first light source of HD-DVD or BD record and be suitable for the secondary light source of DVD record) or comprise the emission different wave length more than three light source.By the light of first light source 12 emission through object lens 20 and 22 both, and by secondary light source 14 and the 3rd light source 16 selectively only by one in a plurality of object lens 20 and 22.As shown in Figure 1, secondary light source 14 and the 3rd light source 16 integrally are arranged in the holistic smooth unit 18.Yet, be appreciated that in others secondary light source 14 and the 3rd light source 16 can be provided with respectively.The 3rd light source 16 can be assembled to such an extent that separate and be arranged on the outside of light unit 18 with secondary light source 14, but this is dispensable.
A plurality of object lens 20 and 22 focus on the light that is sent by a plurality of light sources 12,14 and 16, and form hot spot on the signal recording surface of CD 10.A plurality of object lens 20 and 22 comprise first object lens 20 and second object lens 22, first object lens 20 have the small value aperture of suitable HD-DVD, DVD or CD, be used for focusing at least one light that sends in a plurality of light sources 12,14 and 16, second object lens 22 have the large-numerical aperture of suitable BD, are used for focusing at least one light that sends in a plurality of light sources 12,14 and 16.Yet, be appreciated that a plurality of object lens 20 and 22 can comprise the object lens more than two, so that object lens have the more accurate numerical aperture corresponding with CD 10 types.
As mentioned above, first object lens 20 can be divided at least three subregions, and they are differently used according to the respective type of CD 10.Simultaneously, first object lens 20 are provided with stepped region or diffraction region at least one surface of its subregion, and this surface is shared at record or when playing various types of CD 10.According to wavelength by the part of the light of first object lens, 20 diffraction as second-order diffraction light (secondarydiffraction light), thereby increased diffraction efficiency.Object lens 20 and 22 are practicablely dispersed or are concentrated with focused light, and can be according to wavelength variations light utilization ratio.
A plurality of optical detection parts divide 30,32 and 34 receptions to be focused on the light of CD 10 backs from CD 10 reflections by a plurality of object lens 20 and 22, and detect information signal and error signal.A plurality of optical detection parts divide 30,32 and 34 to comprise that first optical detection part divides 30 and second optical detection part to divide the 32 and the 3rd optical detection part to divide 34, wherein, first optical detection part divides 30 to receive from 12 emissions of first light source and by first object lens 20 and second object lens 22 and focus on the CD 10 back from the light of CD 10 reflections, and second optical detection part divides the 32 and the 3rd optical detection part to divide 34 to receive from secondary light source 14 and 16 emissions of the 3rd light source and by first object lens 20 and focus on the CD 10 back from the light of CD 10 reflections.Yet, be appreciated that a plurality of optical detection parts divide 30,32 and 34 can comprise that the optical detection part more than three divides or two light that test sections are reflected from CD 10 with detection.
First optical detection part divides 30 to comprise a HD-DVD detecting device 30a and a BD detecting device 30b, and HD-DVD detecting device 30a detects from the light through first object lens 20 of HD-DVD reflection, and BD detecting device 30b detects from the light through second lens 22 of BD reflection.Second optical detection part divides the 32 and the 3rd optical detection part to divide 34 to detect the light through 20 reflections of first object lens from DVD or CD.Second optical detection part divides 32 to be wholely set in light unit 18 with secondary light source 14 and the 3rd light source 16.The 3rd optical detection part divides 34 can be wholely set in light unit 18 with secondary light source 14 and the 3rd light source 16, or is installed separately with secondary light source 14 and the 3rd light source 16, and is arranged on 18 outsides, light unit.
A plurality of light path conversion portions 40 and 60 comprise the first light path conversion portion 40, it optionally with first light source, 12 radiating portion photoconductions to one of first object lens 20 and second object lens 22, and will divide 30 through the photoconduction of first object lens 20 and the reflection of second object lens 22 to first optical detection part from CD 10.A plurality of light path conversion portions 40 and 60 also comprise the second light path conversion portion 60, it will be from the photoconduction of secondary light source 14 or the emission of the 3rd light source 16 to first object lens 20, and will divide the 32 and the 3rd optical detection part to divide 34 through the photoconduction of first object lens, 20 reflections to second optical detection part from CD 10.Should be appreciated that according to other aspects of the invention, a plurality of light path conversion portions 40 and 60 can comprise the light path conversion portion that is used for guide lights more than two.
The first shown light path conversion portion 40 comprises: polarization beam apparatus 41, the light that it reflects according to the light polarization component or transmission is launched from first light source 12; First beam splitter 42, the light of its reflection from the light of first light source 12 emission and transmission from secondary light source 14 and 16 emissions of the 3rd light source; Second beam splitter 43, the light of its transmission from the light of first light source 12 emission and reflection from secondary light source 14 and 16 emissions of the 3rd light source; Half-wave plate 44, it optionally changes the polarisation of light component that incides polarization beam apparatus 41 from first light source 12; First quarter-wave plate 45, it changes after first object lens 20 focus on the CD 10 from CD 10 polarization of reflected light components; And second quarter-wave plate 46, it changes after second lens 22 focus on the CD 10 from CD 10 polarization of reflected light components.First quarter-wave plate 45 and second quarter-wave plate 46 are the adjustable wave plates of thickness, are used to realize 1/4th phase shifts, and by birefringence linearly polarized light are converted to circularly polarized light, and vice versa.The first light path conversion portion 40 also comprises electric driver part 44a, drives half-wave plate 44 with incoming call.The polarization beam apparatus 41 and first beam splitter 42 can integral body as shown be set together, but are not that such was the case with.
Hereinafter, 1 course of work and the work effect of describing the optic pick-up of object lens 20 with above structure and 22 with reference to the accompanying drawings.But optic pick-up according to the present invention has all kinds CD 10 (for example HD-DVD, DVD and CD) that can pass through to use object lens 20 compatible recordings and/or reproduction different recording density, or by using the optical texture of two object lens 20 and the 22 various types of CDs 10 of broadcast (for example BD, HD-DVD, DVD and CD).The light that is sent by light source 12,14 and 16 comprises the p polarized light component and the s polarized light component of estimated rate.The embodiment of the invention will illustrate that the light that hypothesis light source 12,14 and 16 sends mainly is the example of s polarized light component.
With reference to Fig. 1, the short-wavelength light of the about 400nm of wavelength that is sent by first light source 12 is diffracted into three divided beams through diffraction grating 52, is used to detect the tracking error signal.This diffraction light enters polarization beam apparatus 41 through half-wave plate 44, and polarization beam apparatus 41 transmits the s polarized light component of the light that light source 12 sends, and reflection p polarized light component.
The a part of light that is sent by light source 12 passes the polarization beam apparatus 41 and first beam splitter 42, and enters into first object lens 20 and second object lens 22.When by relay lens 47 and 48, light is converted into parallel rays.When by first quarter-wave plate 45 and second quarter-wave plate 46, linearly polarized light is converted into circularly polarized light.Light forms hot spot (with reference to " S " among Fig. 4) by first quarter-wave plate 45 and second quarter-wave plate, 46 backs by first object lens 20 and second object lens 22 on the signal recording surface of CD 10, and from CD 10 reflections.This moment circularly polarized light sense of rotation become with incide CD 10 on light opposite.
Light by CD 10 reflections passes through first quarter-wave plate 45 and second quarter-wave plate 46 via first object lens 20 and second object lens 22, and converts linearly polarized light to, becomes the p polarized light.This p polarized light advances to the polarization beam apparatus 41 and first beam splitter 42 via first relay lens 47 and second relay lens 48.Part light arrives the polarization beam apparatus 41 and first beam splitter 42, and sees through second beam splitter 43, is divided 30 to detect by optical receiver lens 53 by first optical detection part.As mentioned above, the light that is sent by light source 12 passes first object lens 20 and second object lens 22 simultaneously.
By the long wavelength light of secondary light source 14 and the about 600nm to 700nm of the 3rd light source 16 emission, through the second light path conversion portion 60 and enter first beam splitter 42.The light that 42 reflections of first beam splitter are launched by secondary light source 14 and the 3rd light source 16 by the light and the transmission of 12 emissions of first light source.Be arranged on the light of the holographic element 51 transmission specific wavelengths between the second light path conversion portion 60 and first beam splitter 42, and the light of other wavelength of diffraction.At this moment, no matter wavelength how, by the light of holographic element 51 diffraction as primary diffraction light (primary diffraction light).
A part of light by secondary light source 14 and 16 emissions of the 3rd light source advances to first object lens 20 through first beam splitter 42.When through first relay lens 47, light is converted into parallel rays.When through first quarter-wave plate 45, linearly polarized light is converted into circularly polarized light.This light through first quarter-wave plate 45 after, on the signal recording surface of CD 10, form hot spot (with reference to " S " among Fig. 2 and Fig. 3) by first object lens 20, and from CD 10 reflection.This moment circularly polarized light sense of rotation become with incide CD 10 on light opposite.
Pass through quarter-wave plate 45 from the light of CD 10 reflections via first object lens 20, and be converted into linear p polarized light.This p polarized light advances to first beam splitter 42 via first relay lens 47.Part light arrives first beam splitter 42, sees through the second light path conversion portion 60 and passes optical receiver lens 54 and divided 32 and 34 to detect by the second and the 3rd optical detection part.As mentioned above, the light by light source secondary light source 14 and 16 emissions of the 3rd light source only passes through first object lens 20.
As mentioned above, first object lens 20 are lens of HD-DVD/DVD/CD compatibility, but its light and the light compatible recording of secondary light source 14 and 16 emissions of the 3rd light source and/or various types of CD 10 (HD-DVD, DVD and CD) that reproduction has different recording density by focusing on 12 emissions of first light source.When shining on first object lens 20 to parallel rays shown in Figure 4, can realize the optimum reproducing operation as Fig. 2.Simultaneously, to shown in Figure 4, first object lens 20 are divided into three border circular areas concentric on optical axis as Fig. 2, so that use different numerical apertures according to different wavelength.The first area (" A " zone) that comprises optical axis is common to three kinds of wavelength, and the second area adjacent with the first area (" B " zone) is common to two kinds of wavelength, and three zone adjacent with second area (" C " zone) only is used for a kind of wavelength.
The light that Fig. 2 illustrates about 700nm wavelength incides according on the object lens in the optic pick-up of the embodiment of the invention 20 and form a hot spot on CD type CD 10.Can on CD, write down and/or information reproduction by the numerical aperture of using the first area (" A " zone) that comprises optical axis in first object lens 20.Area B and C are not used on CD and focus on.
The light that Fig. 3 illustrates about 600nm wavelength incides according on the object lens in the optic pick-up of the embodiment of the invention 20 and form a hot spot on DVD type CD 10.Can on DVD, write down and/or information reproduction by the numerical aperture of using second area in first object lens 20 (" B " zone).First area A and the 3rd zone C also are used for focusing on DVD.
The light that Fig. 4 illustrates about 400nm wavelength incides according on the object lens in the optic pick-up of the embodiment of the invention 20 and form a hot spot on HD-DVD type CD 10.As shown in the figure, this HD-DVD uses first area A and second area B, but does not use zone C.Yet, according to aspects of the present invention, be similar to DVD, by using the numerical aperture of the second area (" B " zone) in first object lens 20, or, can on HD-DVD, write down and/or information reproduction by the relative second area B of use, than the numerical aperture in the 3rd big zone of second area numerical aperture (" C " zone).
Should be appreciated that according to other aspects of the invention, first object lens 20 are not to be divided into three border circular areas concentric on optical axis.For example, first object lens 20 can be divided into two zones with different numerical apertures or more than three zone.
In first object lens 20, three kinds of wavelength of the about 400nm of wavelength, about 600nm and about 700nm are (" A " zone) use in the first area; Middle wavelength (600nm) in three kinds of wavelength in the 3rd zone (" ℃ " zone) use.Second area (" B " zone) uses wavelength 400nm and 700nm.
Hereinafter, will the object lens 20 and 22 and the design example of CD that according to the present invention aspect is applicable to optic pick-up be described.
(first design example)
1: lens surface
Radius-of-curvature: 2.48673, thickness: 1.220000
Refractive index: 708077.323398
Asphericity coefficient
K：-0.583682，A：0.486247E-02，B：-0.156383E-01，C：0.104780E-01
D：-0.266329E-03，E：-0.196094E-02，F：0.509163E-03
G：-0.211577E-04
The order of diffraction is inferior: 1.000000, and reference wavelength 580.00
Holographic constant
C1：-1.4972E-02，C2：-6.1318E-04，C3：-5.1651E-05
2: lens surface
Radius-of-curvature :-4.87608, thickness: 1.650040, refractive index: 1.0
Asphericity coefficient
K：-0.796785E18，A：0.130931E-01，B：-0.733309E-01，C：0.119418E+00
D：-0.891914E-01，E：-0.307483E-01，F：-0.402059E-02
| Specification | CD | DVD | HD-DVD |
| Entrance pupil diameter (mm) | 2.38 | 3.0 | 2.95 |
| Disk thickness (mm) | 1.2 | 0.6 | 0.6 |
| Work is apart from (mm) | 1.65 | 2.06 | 2.03 |
| Focal length (mm) | 1.42 | 1.41 | 1.36 |
| Numerical aperture (NA) | 0.51 | 0.65 | 0.65 |
(second design example)
1: lens surface
Radius-of-curvature: 0.89201, thickness: 0.700000
Asphericity coefficient
K：-0.828174，A：0.411225E-01，B：-0.402860E-01，C：0.873249E-01
D：-0.122036E+00，E：0.406357E-01，F：0.000000E+00
G：0.000000E+00，H：0.000000E+00
The order of diffraction is inferior: 1.000000, and reference wavelength 580.00
Holographic constant
C2：-1.0532E-02，C4：1.4855E-02，C6：-2.2659E-02
C7：1.1255E-02
2: lens surface
Radius-of-curvature :-3.81755, thickness: 0.194400
Asphericity coefficient
K：13.037934，A：0.184267E+00，B：0.364630E-02，C：-0.271803E+00
D：0.364147E+00，E：-0.129875E+00
| Specification | The A-dish | The B-dish | The C-dish |
| Entrance pupil diameter (mm) | 1.25 | 1.76 | 1.76 |
| Disk thickness (mm) | 0.8 | 0.4 | 0.4 |
| Work is apart from (mm) | 0.54 | 0.78 | 0.74 |
| Focal length (mm) | 1.42 | 1.41 | 1.36 |
| Numerical aperture (NA) | 0.45 | 0.63 | 0.65 |
(the 3rd design example)
1: lens surface
Radius-of-curvature: 0.89201, thickness: 0.700000
Asphericity coefficient
K：-0.828174，A：0.411225E-01，B：0.402860E-01，C：0.873249E-01
D：-0.122036E+00，E：0.406357E-01，F：0.000000E+00
G：0.000000E+00，H：0.000000E+00
The order of diffraction is inferior: 2.000000, and reference wavelength 690～750.00
Holographic constant
C2：-0.52E-02，C4：0.7427E-02，C6：-1.133E-02
C7：0.0627E-02
2: lens surface
Radius-of-curvature :-3.81755, thickness: 0.194400
Asphericity coefficient
K：13.037934，A：0.184267E+00，B：0.364630E-02，C：-0.271803E+00
D：0.364147E+00，E：-0.129875E+00
Fig. 5 is that light that about 700nm wavelength is shown incides according on the lens of first design example in the optic pick-up of the embodiment of the invention and form a hot spot on CD.Fig. 6 is that light that about 600nm wavelength is shown incides according on the lens of first design example in the optic pick-up of the embodiment of the invention and form a hot spot on DVD.Fig. 7 is that light that about 400nm wavelength is shown incides according on the lens of first design example in the optic pick-up of the embodiment of the invention and form a hot spot on HD-DVD.
Can obviously find out from top description, the object lens of many aspects and optic pick-up according to the present invention with these object lens, by a plurality of object lens that write down and/or reproduce high/low disc density are set, can drive the various types of CDs that use different wave length in optic recording/reproducing device compatiblely.And the object lens of aspect can be play the various types of CDs with different wave length or recording density by using different wave length compatiblely according to the present invention.
Although illustrated and described several embodiments of the present invention, but those skilled in the art should understand that, under situation about not deviating from, can make modification to embodiment by the principle of the present invention of claims and equivalent technical solutions restricted portion thereof and spirit.
Claims (33)
1. optic pick-up that can write down and/or reproduce polytype CD with four kinds of different recording density, this optic pick-up comprises:
Light radiating portion, its emission have the light corresponding to three kinds of different wave lengths of described polytype CD, so that this light radiating portion is launched the light that has corresponding to the wavelength of institute's loading optical disk type; And
Light is collected part, and it will focus on from light described smooth radiating portion emission, that have corresponding to the wavelength of institute's loading optical disk type, to form hot spot on the CD of described loading.
2. optic pick-up as claimed in claim 1, wherein, three kinds in described four polytype CDs comprise HD-DVD, DVD and CD.
3. optic pick-up as claimed in claim 1, wherein, described smooth radiating portion comprises the 3rd light source of the light of the secondary light source of light of first light source, emission 600nm wavelength around of the light of emission 400nm wavelength around and emission 700nm wavelength around.
4. optic pick-up as claimed in claim 3, wherein, described smooth radiating portion emission has the light corresponding at least two kinds wavelength in the described polytype CD.
5. optic pick-up as claimed in claim 3 wherein, also comprises:
Holographic element, it is arranged on described light and collects between in part and the described a plurality of light source at least one; And
The optical detection part branch, it comes detection signal by utilizing from the light of described holographic element diffraction, thereby obtains the positional information that described light is collected part.
6. optic pick-up as claimed in claim 1, wherein, it is object lens that described light is collected part, it adopts different numerical apertures according to described smooth radiating portion wavelength of light emitted, can play any in the described polytype CD compatiblely.
7. optic pick-up as claimed in claim 6, wherein, described object lens are divided at least two border circular areas about light shaft coaxle.
8. optic pick-up as claimed in claim 7, wherein, the first area that comprises optical axis in two of described object lens zones be common to described smooth radiating portion emission, be used on three kinds of the CD of described type, reproducing and/or the light of all wavelengths of record.
9. optic pick-up as claimed in claim 8 wherein, is common to the contiguous second area in described first area and reproduces in the CD of described type two kinds and/or at least two kinds of wavelength of record.
10. optic pick-up as claimed in claim 9, wherein, described object lens are also told the 3rd zone, and the described second area of this region adjacent and only being used for reproduces on the CD of described type a kind of and/or the single wavelength of record.
11. optic pick-up as claimed in claim 10, wherein, described single wavelength is the wavelength that has intermediate length in all three kinds of wavelength.
12. optic pick-up as claimed in claim 6, wherein, described object lens are divided at least three concentric on the optical axis different border circular areas, and differently use described zone according to the type of institute's loading optical disk.
13. as the optic pick-up in the claim 12, wherein, the first area in three zones of described object lens is common to all wavelengths of described smooth radiating portion emission.
14. optic pick-up as claimed in claim 1 wherein, also comprises:
The light path conversion portion is used for changing the direction of propagation of the light of described smooth radiating portion emission, and this photoconduction is collected part to described light.
15. optic pick-up as claimed in claim 14, wherein, described light path conversion portion comprises relay lens, and this relay lens will convert parallel rays to from the light of described smooth radiating portion before light is directed to described smooth collection unit branch.
16. optic pick-up as claimed in claim 1, wherein, transmitted wave was about the light of 400nm when described smooth radiating portion was HD-DVD or Blu-ray Disc when institute's loading optical disk, transmitted wave is about the light of 600nm when institute's loading optical disk is DVD, and transmitted wave is about the light of 700nm when institute's loading optical disk is CD.
17. the optic pick-up that can write down and/or reproduce the polytype CD with four kinds of different recording density, this optic pick-up comprises:
A plurality of light sources, its emission have the light corresponding to three kinds of different wave lengths of described polytype CD; And
A plurality of object lens, its focus on by described a plurality of light emitted, have light, on the CD that is loaded, to form hot spot corresponding to the wavelength of the type of institute's loading optical disk.
18. optic pick-up as claimed in claim 17, wherein, described a plurality of light sources comprise:
First light source, when institute's loading optical disk was HD-DVD or Blu-ray Disc, transmitted wave was about the light of 400nm;
Secondary light source, when institute's loading optical disk was DVD, transmitted wave was about the light of 600nm; And
The 3rd light source, when institute's loading optical disk was CD, transmitted wave was about the light of 700nm.
19. optic pick-up as claimed in claim 17, wherein, described a plurality of object lens comprise:
First object lens, it focuses on the light of first wavelength, and focuses on the light of second wavelength.
20. optic pick-up as claimed in claim 17, wherein, described a plurality of object lens comprise:
First object lens, the light of its light with the about 400nm of wavelength, the about 600nm of wavelength and the light of the about 700nm of wavelength focus on the CD of corresponding first, second and the 3rd type; And
Second object lens, its light with the about 400nm of wavelength focuses on the CD of the 4th type.
21. object lens that can write down and/or reproduce the optic pick-up of polytype CD, wherein, described object lens use the light of at least three kinds of wavelength, and according to the different numerical aperture of a plurality of wavelength uses, can reproduce the polytype CD that has different-thickness or use different wave length compatiblely.
22. object lens as claimed in claim 21, wherein, described object lens are divided at least two concentric on optical axis border circular areas, make and comprise that the first area of optical axis is common to all three kinds of wavelength, on three types of CDs, to focus on, the second area adjacent with this first area is common to two kinds of wavelength, focuses on two kinds in three types of CDs.
23. object lens as claimed in claim 22 wherein, comprise the holographic lens that is positioned on the part surface.
24. object lens as claimed in claim 21, wherein, described object lens are divided at least three concentric on optical axis border circular areas, make and comprise that the first area of optical axis is provided with stepped region on the surface, to be common to three kinds of wavelength, the second area contiguous with described first area is provided with stepped region, produces aberration to limit two kinds of wavelength, and be provided with holographic lens on the surface with contiguous the 3rd zone of described second area, produce aberration to limit a kind of wavelength.
25. one kind is used the multi-wavelength to have the optic pick-up that writes down and/or reproduce on the polytype CD of different-thickness, this optic pick-up comprises:
Light source, its emission have the light corresponding to the wavelength of institute's loading optical disk type;
First object lens, it adopts different numerical apertures according to the light wavelength of described light emitted, with focus on send from described light source, corresponding to the light of first kind CD; And
Second object lens, its light wavelength according to described light emitted adopts different numerical apertures, with focus on send from described light source, corresponding to the light of the second type CD.
26. optic pick-up as claimed in claim 25, wherein, each comfortable at least one surface of described first object lens and second object lens is provided with stepped region or diffraction region, and this zone is shared at record or when reproducing in the described polytype CD any.
27. optic pick-up as claimed in claim 25, wherein, described first object lens and the second object lens both are according to light wavelength, and diffraction is from a part of light of described light emitted, to be used as second-order diffraction light.
28. optic pick-up as claimed in claim 27, wherein, described first object lens comprise hologram pattern, and this pattern has the degree of depth of determining in the reference wavelength of the diffraction light of 660nm to 790nm based on scope.
29. the optic pick-up that can write down and/or reproduce the polytype CD, this optic pick-up comprises:
First to the 3rd light source, its emission have the light corresponding to first to the 3rd different wave length of described polytype CD, and the CD of each type has one the different recording capacity that depends on correspondence in described first to the 3rd emission wavelength;
One or more object lens, its focus on from described one or more light emitted, have light corresponding to the wavelength of institute's loading optical disk, to form hot spot according to type on institute's loading optical disk, described type can be selected in the CD with four kinds of different recording capacity; And
One or more optical detection part branches are used for the light that collectiong focusing reflects on described CD and from CD, to detect information signal.
30. optic pick-up as claimed in claim 29, wherein:
When institute's loading optical disk is HD-DVD or Blu-ray Disc, the light of the about 400nm of the described first light emitted wavelength;
When institute's loading optical disk was DVD, described secondary light source transmitted wave was about the light of 600nm; And
When institute's loading optical disk is CD, the light of the about 700nm of described the 3rd light emitted wavelength.
31. optic pick-up as claimed in claim 29, wherein, described one or more object lens comprise: focus on and to have described first first object lens to the light of three-wavelength.
32. optic pick-up as claimed in claim 29, wherein, described one or more object lens comprise:
First object lens, its focus wave are about the light of 400nm, the light of the about 600nm of wavelength and the light of the about 700nm of wavelength; And
Second object lens, its focus wave is about the light of 400nm.
33. optic pick-up as claimed in claim 29 wherein, also comprises:
One or more light path conversion portions, during it optionally will divide from a part of photoconduction of described light emitted to described object lens and with the described optical detection part of guides reflected light one.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR20060068762 | 2006-07-21 | ||
| KR68762/06 | 2006-07-21 | ||
| KR34851/07 | 2007-04-10 | ||
| KR1020070034851A KR100903143B1 (en) | 2006-07-21 | 2007-04-10 | Object lens and optical pick-up apparatus having the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101123101A true CN101123101A (en) | 2008-02-13 |
| CN101123101B CN101123101B (en) | 2011-06-08 |
Family
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2007101465006A Expired - Fee Related CN101123101B (en) | 2006-07-21 | 2007-06-22 | Object lens and optical pick-up device having the same |
Country Status (2)
| Country | Link |
|---|---|
| KR (1) | KR100903143B1 (en) |
| CN (1) | CN101123101B (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3993870B2 (en) | 2002-06-10 | 2007-10-17 | 松下電器産業株式会社 | Compound objective lens, optical head device, optical information device, computer, optical disk player, car navigation system, optical disk recorder, optical disk server |
| US7193954B2 (en) * | 2003-03-31 | 2007-03-20 | Konica Minolta Holding, Inc. | Optical pickup device and objective lens for the optical pickup device |
| JP2005209299A (en) * | 2004-01-23 | 2005-08-04 | Pioneer Electronic Corp | Optical pickup and recording reproducing device |
| CN100397509C (en) * | 2004-09-22 | 2008-06-25 | 索尼株式会社 | Optical pickup and optical disk apparatus |
| JP2006114081A (en) * | 2004-10-12 | 2006-04-27 | Konica Minolta Opto Inc | Objective lens and optical pickup system |
-
2007
- 2007-04-10 KR KR1020070034851A patent/KR100903143B1/en active IP Right Grant
- 2007-06-22 CN CN2007101465006A patent/CN101123101B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN101123101B (en) | 2011-06-08 |
| KR100903143B1 (en) | 2009-06-16 |
| KR20080008946A (en) | 2008-01-24 |
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