CN100530379C - Light path structure for picking up signal in laser reading head - Google Patents
Light path structure for picking up signal in laser reading head Download PDFInfo
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- CN100530379C CN100530379C CNB200610061769XA CN200610061769A CN100530379C CN 100530379 C CN100530379 C CN 100530379C CN B200610061769X A CNB200610061769X A CN B200610061769XA CN 200610061769 A CN200610061769 A CN 200610061769A CN 100530379 C CN100530379 C CN 100530379C
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Abstract
A signal pick-up light path structure of laser fetching head consists of reflection beam from disc, single lens, and cylindrical mirror and PDIC protection glass. It is featured as setting flat glass used for increasing astigmation effect between single lens and cylindrical mirror.
Description
Technical field
The present invention relates to field of optical storage technology, more specifically to light path structure for picking up signal in laser reading head.
Background technology
In the whole light path design of optical storage, the light path of picking up signal part is extremely important, has determined the efficient and the accuracy rate of PDIC (being used for light signal is converted to the light detection chip of electric signal) read output signal.Up to the present, because Blu-ray Disc is to the high-precision requirement of reading system, present stage still can not Design and Machining goes out the reading system of blue-light high-density optical disk; Existing C D and DVD technology can not be applied in the blu-ray system also because of precision reaches the design function imperfection inadequately simultaneously.Former CD, the light path structure for picking up signal in laser reading head of DVD comprise light beam, simple lens, cylindrical mirror, the PDIC cover glass from disc, and in astigmatism prism group, simple lens and cylindrical mirror are combined into bifocal lens.Light beam from disc arrives the PDIC cover glass through bifocal lens, and PDIC converts light signal electric signal analysis to, handles.Because the horizontal direction of bifocal lens and the focal length of vertical direction are inequality, so when the incident light of this optical system was just burnt, the outgoing hot spot will become ellipse.Utilize oval this characteristic that distributes of light intensity of CD, produce focus error signal, and, come disc information, out-of-focus appearance etc. is carried out analysis and judgement with the input signal of this signal as subsequent conditioning circuit.Although this design can be used for CD, DVD, but in blu-ray system, this design causes the signal equalization degree substantial deviation equilibrium point that obtains on the final PDIC detector, and exceeded the regulating power of back-end circuit, near simultaneously burnt state symmetry burnt and far away reduces, and makes whole design not play a role.Therefore in astigmatism prism group, depend merely on the astigmatism effect that cylindrical mirror can not produce requirement, and then the light signal that PDIC receives do not reach permissible accuracy, to such an extent as to can't finish reading of signal.If design cylindrical mirror and processing in addition once more, not only improved manufacture difficulty, also increased a large amount of research and development and production cost simultaneously, do not meet the present market-oriented requirement of China.
Summary of the invention
Thereby technical matters to be solved by this invention provides the light path structure for picking up signal in laser reading head that a kind of astigmatism effect that can improve light beam improves the precision of the light signal that PDIC receives.
Its reflected light path of the present invention comprises light beam, simple lens, cylindrical mirror, the PDIC cover glass from disc, it is characterized in that: the folded light beam from disc is a blue wave band of laser; Between simple lens and cylindrical mirror, be provided with in order to produce the sheet glass of astigmatism.
The present invention is owing to increase the sheet glass that produces astigmatism between simple lens and cylindrical mirror, not only can reduce the design and the difficulty of processing of cylindrical mirror, reduce cost, can also improve simultaneously the precision of the light signal that PDIC receives, improve and remedy that the hot spot light intensity changes unequal a plurality of problem on the detector.。
Description of drawings
Accompanying drawing is the light path structure for picking up signal in laser reading head structural drawing in the embodiment of the invention.
Among the figure: 1, simple lens, 2, sheet glass, 3, cylindrical mirror, 4, the PDIC cover glass, 5, the mechanical positioner of cylindrical mirror.
The present invention is further illustrated with reference to the accompanying drawings.
Embodiment
Light path structure for picking up signal in laser reading head among the embodiment comprises folded light beam, simple lens 1, cylindrical mirror 2, the PDIC cover glass 4 from disc, is provided with between simple lens and cylindrical mirror in order to increase the sheet glass 3 of astigmatism effect.Cylindrical mirror 2 is by mechanical positioner 5 fixed positions.
Following brief introduction is the advantage of blue wave band of laser laser instrument once.
Be that optical read head still is its core in the light storage device blue-ray DVD of future generation of blue wave band of laser laser instrument of 405～488nm based on wavelength.It is that the red laser of 650nm and numerical aperture are 0.6 object lens that the DVD technology of current popular adopts wavelength, and disc thickness is 0.6mm.And the blue-ray DVD technology to adopt wavelength be the blue laser of 450nm, be 0.85 object lens by numerical aperture, the spot definition with focusing on of success is reduced to minimum degree.
The memory capacity of blue-ray DVD single-surface single-layer disc is defined as 23.3GB, 25GB and 27GB, wherein peak capacity (27GB) is nearly 6 times of current ruddiness DVD single-surface single-layer disc capacity (4.7GB), this is enough to store the high-definition digital video content that surpasses 2 hours reproduction times, perhaps surpasses the standard television program of 13 hours reproduction times.This only is the capacity that single-surface single-layer is realized, just as traditional ruddiness DVD disc, blue-ray DVD can also be made single-surface double-layer, two-sided bilayer equally.
Brief description is the light path structure for picking up signal in laser reading head mentality of designing among the embodiment once.
1, the present invention a kind ofly will change into the picking up signal light path that satisfies photoelectric detector PD IC request for utilization from the folded light beam of disc.
2, in the light path of this picking up signal part, mainly utilize the unidirectional focus characteristics of cylindrical mirror, adopt the method for astigmatism focus servo method.Astigmatism methord mainly is an optical characteristics of utilizing imagery of cylindrical mirror.After a branch of light vertically passed through cylindrical mirror, the initial shape in the cross section of light beam such as vertical ellipse crossfaded into positive circle at the focus place of cylindrical mirror subsequently, crossfaded into the transverse axis ellipse after again.Utilize this optical characteristics of cylindrical mirror, when being positive circle on the optical detection device of reflected light at PDIC, be judged as focusing.In this optical system the cylindrical mirror technological requirement of using not high, better the simplified design method, reduce cost, shorten time cycle of design and element processing.
3, the parameter of Xuan Ding PDIC is fixed, and according to its parameter, is designed for the optical system of blue wave band of laser optical storage.The design simple lens assembles parallel beam to adapt to the requirement of subsequent optical path, and using astigmatism element sheet glass simultaneously increases astigmatism, improves precision, and guarantees to have enough luminous energies to arrive on the PDIC.
4, last, go up the light signal that obtains according to PDIC, utilization drops on parameters such as spot intensity on the detector, size, directly reflects information such as laser head out-of-focus appearance, disc information and other high-frequency signals by signal TES (tracking signal), FES (focus signal), the RF (integrated error signal) of the subsequent conditioning circuit output of PDIC.
So signals collecting light path partly of our design, at first utilize simple lens to converge light, not only utilize simultaneously the unidirectional focus characteristics of astigmatism element cylindrical mirror, and utilize astigmatism element sheet glass to increase astigmatism, the combination of two kinds of astigmatism elements, requirement to employed cylindrical mirror in the light path reduces, and makes and can realize degree of precision at lower cost.When the receiving trap of PDIC not on the focal plane at cylindrical mirror, just obtain ellipse light spot, produce focus error signal, and, come disc information, out-of-focus appearance etc. is carried out analysis and judgement with the input signal of this signal as subsequent conditioning circuit.
Claims (1)
1, light path structure for picking up signal in laser reading head, its reflected light path comprise folded light beam, simple lens, cylindrical mirror, the PDIC cover glass from disc, it is characterized in that: the folded light beam from disc is a blue wave band of laser; Between simple lens and cylindrical mirror, be provided with in order to produce the sheet glass of astigmatism.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB200610061769XA CN100530379C (en) | 2006-07-19 | 2006-07-19 | Light path structure for picking up signal in laser reading head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB200610061769XA CN100530379C (en) | 2006-07-19 | 2006-07-19 | Light path structure for picking up signal in laser reading head |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101004926A CN101004926A (en) | 2007-07-25 |
| CN100530379C true CN100530379C (en) | 2009-08-19 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB200610061769XA Expired - Fee Related CN100530379C (en) | 2006-07-19 | 2006-07-19 | Light path structure for picking up signal in laser reading head |
Country Status (1)
| Country | Link |
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| CN (1) | CN100530379C (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101256785B (en) * | 2007-12-21 | 2011-12-07 | 清华大学深圳研究生院 | Blue light mother disc player |
| CN108226901B (en) * | 2018-02-06 | 2024-03-01 | 武汉万集光电技术有限公司 | Laser radar optical system |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5473586A (en) * | 1992-02-28 | 1995-12-05 | Pioneer Electronic Corporation | Optical pickup for an optical disc |
| JP2000348365A (en) * | 1999-06-08 | 2000-12-15 | Sankyo Seiki Mfg Co Ltd | Optical pickup device |
| JP2001034965A (en) * | 1999-07-19 | 2001-02-09 | Ricoh Co Ltd | Focus error detector |
| US6266302B1 (en) * | 1998-03-12 | 2001-07-24 | Nec Corporation | Optical disk apparatus |
| JP2004158102A (en) * | 2002-11-06 | 2004-06-03 | Nec Corp | Optical head device and optical recording/reproducing device |
| US20060028932A1 (en) * | 2004-08-09 | 2006-02-09 | Kenji Nakamura | Optical pickup device |
| JP2006079797A (en) * | 2004-08-09 | 2006-03-23 | Sanyo Electric Co Ltd | Optical pickup device |
-
2006
- 2006-07-19 CN CNB200610061769XA patent/CN100530379C/en not_active Expired - Fee Related
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5473586A (en) * | 1992-02-28 | 1995-12-05 | Pioneer Electronic Corporation | Optical pickup for an optical disc |
| US6266302B1 (en) * | 1998-03-12 | 2001-07-24 | Nec Corporation | Optical disk apparatus |
| JP2000348365A (en) * | 1999-06-08 | 2000-12-15 | Sankyo Seiki Mfg Co Ltd | Optical pickup device |
| JP2001034965A (en) * | 1999-07-19 | 2001-02-09 | Ricoh Co Ltd | Focus error detector |
| JP2004158102A (en) * | 2002-11-06 | 2004-06-03 | Nec Corp | Optical head device and optical recording/reproducing device |
| US20060028932A1 (en) * | 2004-08-09 | 2006-02-09 | Kenji Nakamura | Optical pickup device |
| JP2006079797A (en) * | 2004-08-09 | 2006-03-23 | Sanyo Electric Co Ltd | Optical pickup device |
Non-Patent Citations (2)
| Title |
|---|
| 光盘光学系统象差容限的研究. 张平.华中理工大学学报，第16卷第6期. 1988 |
| 光盘光学系统象差容限的研究. 张平.华中理工大学学报，第16卷第6期. 1988 * |
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| CN101004926A (en) | 2007-07-25 |
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Granted publication date: 20090819 Termination date: 20130719 |