TW200844987A - Optical apparatus - Google Patents

Abstract

An optical scanning apparatus (1) for writing/reading information into/from an object (2) comprises an optical system (30) for optically scanning such object. The system comprises at least two light beam generators (31; 131; 231) for generating corresponding light beams (32; 132; 232), and common optical components (33; 34) and individual optical components (138; 238) for guiding the light beams to an object, receiving reflected light and guiding the reflecting light beams to an optical detector (35); the common optical components are for guiding at least two of the light beams and the individual optical components are for guiding one single light beam. A common optical component is tilted with respect to the optical axis in order to compensate for disc tilt for one of the light beams, and at least one individual optical components is tilted to compensate for disc tilt for a corresponding other light beam.

Description

200844987 Nine, invention description: [Technical field to which the invention belongs]

The present invention generally relates to an optical device. As a specific example, the present invention is directed to an optical scanning device for writing information into/to an optical information carrier. In the following, the invention will be explicitly explained with respect to a case of a disc drive for swiping an optical storage disc in which the disc is rotated and a write/read head is moved radially relative to the rotary disc. The present invention is applicable to optical disk systems as well as magneto-optical disk systems. In the following, the wording "disc drive" will be used, but it should be understood that this wording is intended to cover the magneto-disc system. Furthermore, it should be noted that the present invention is not limited to a disc drive; the present invention is also applicable to, for example, a microscope. [Prior Art] ~ τ ton Gan 々 乃 乃 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝 栝=type' records the information on the disc during the manufacturing process, and the information is only read by the user. Optical storage discs may also be of a human type, using π to store information on a disc. In addition, storage discs of different format classes 31 have been developed, such as CD, DVD, BD. Write the data in the storage space of the disc storage disc, or in order to use the I-Bike's one-disc drive, on the one hand, the rotating member, the straight-line 2 receiving and rotating-disc, and the other, including the optical component, and transmitting The q-ray beam is a laser beam and is used to store the magnetic track by the knowledge. Since the light field beam is the first to be able to store information in the 129503.d〇c 200844987 two-disc method and the method of reading optical data from a CD-ROM, it is not known here. This technique is described in more detail. = The disc is rotated, and the disc drive generally includes a motor that drives a hub in one of the central portions of the interface disc. For optical scanning of a yoke disk, a disc drive comprises: a generator device (generally one or two private _ ^ (& is a field shot one body); - an objective lens, which is used to Inside a focus on the disc; and an optical detector that uses reflected light reflected from the disc and is used to generate an electrical detector output signal. During operation, the beam should be focused on the disc. The object is configured to be axially displaceable 'and the optical disc drive includes a focus actuator member' that is used to control the axial position of the objective lens. In addition, the focus should be such that the track-track alignment or should be able to be relative to a new one. Magnetic positioning. For this purpose, at least: the mirror system is mounted for radial displacement, and the optical disc drive includes radial members for controlling the radial position of the objective lens. In many disc drives, the objective orientation is Fixed, that is, the basin shaft is flat: guided on the rotating shaft of the disc. In some disc drives, the objective lens is mounted so that its axis can be inconsistent with the rotating shaft of the disc. For whatever reason' Discs may be subject to tilting. The disc can be defined as = where 'the light beam is transmitted through it and (d) the substrate or the cover on the storage layer is not exactly perpendicular to the optical axis. The tilt may be caused by the overall tilt of the disc 'but usually caused by disc warping, And the amount of tilt depends on the position on the disc. Tilting may cause poor performance & in particular, read 129503.doc 200844987 performance, for example, jitter will increase with tilting. ^In the disc drive The tolerance margin of the disc tilt is quite narrow, and the field is narrow, at a level of 0.5 〇 or less. Therefore, a tilt compensation mechanism has been developed. A prior art square tilt objective for tilt compensation, in this case The slant actuator controls the tilt position of the objective. This method may be suitable for disc drives that use only - laser beams. ^, as different formats evolve, it is necessary to design two or more different disc format types. (example

Disc drive such as CD, DVD, BD). Such a disc drive (herein indicated by the phrase "combined disk drive") contains two or more different laser beams of different wavelengths from each other, the 纟 beam system being associated with a particular format. The problem now is that The inclined objective lens compensates for the tilt of the disc, and different lens tilt angles are required for different laser beams. In other words, if an objective lens common to two or more laser beams is tilted at a specific lens tilt angle, it is a combination. One of the different laser beams of the driver optimally compensates for the tilt of the disc, and for one or more other laser beams, the disc tilt problem may still exist. This problem is caused by manufacturing errors, such as in the laser two Alignment error of different optical components in the optical path between the polar body and the objective lens. US-2004/0114495 discloses a disc drive device comprising two different optical systems having two different objective lenses for two Different laser beams. In this case, the two different objective lenses can be tilted independently of each other to obtain optimal tilt compensation for the two laser beams. In contrast, the present invention The invention relates to a disc drive device comprising a single common objective lens for two or more laser beams. [Abstract] 129503.doc 200844987 ί:! The goal is to eliminate or at least reduce the above problem. An important aspect is the use of a light guide for a disc drive with two components and a job. These common components are used to guide different laser beams, and these individual components are used for booting only— 22. The common components include the objective lens. - Common components (eg = oblique to the laser beam - optimally compensate for the disc tilt; this will indicate "at least - a core piece that can be co-inclined" Tilting. P tilt associated with one of the other beams to compensate for the disc tilting for this other beam:: will be indicated as "individual tilt compensation". In a preferred embodiment / fixed tilt tilt tilt # Individual components are pre-collimated lenses. =, this individual component that is tilted by individual tilt compensation is an astigmatism i. This has the advantage that the component does not produce any or only a very limited number of images when tilted. Apply for a patent Further details are mentioned in the accompanying sub-items. [Embodiment] FIG. 1A is a non-intentional description of a disc drive device, which is suitable for storing information from or reading from a light-- or _CD or __ In order to rotate the disc 2, the disc drive device 1 includes a motor 4 fixed to a disfigured display (the frame is defined) - the rotary shaft 5 is for receiving and holding the disc 2, the disc drive The device ^ may comprise a rotatable or clamping hub 6 which, in the case of the spindle motor 4, is mounted on the spindle 7 of the motor 4. The disc drive device i further comprises an optical system 3〇 for borrowing The track of the disc 2 is scanned by a light beam (not shown). More specifically, at 129503.doc 200844987, the exemplary configuration towel shown in FIG. 1A, the optical system view - the first member 31 and a first-old brother A first beam generating member 41, each member being generally a laser (e.g., a laser diode), each of the laser systems being configured to generate a first beam 2 and a second beam 42, respectively. In the following, different sections of the optical path of a light beam μ," will be indicated by adding 兀a, b, c, etc., respectively, to reference numeral 32 42 .

The different types of lasers of the Younger-Laser 31 and the second Laser 41 have a different wavelength due to their individual field beams 32 42 . For example, a laser beam suitable for operation (3) has a wavelength of about 78G with a level, and a field beam suitable for operating a DVD has a wavelength of about 66 〇 (four). The disc drive unit 1 is designed to operate two or more disc types, i.e., CD and DVD. In this case, the first "light beam 32" will have the wavelengths mentioned for use with the CD or DVD, respectively, and the second laser beam 42 will be used for sharing with the DVD or CD. The wavelength mentioned. In order to implement or explain the present invention, whether the first laser beam 32 is a (3) beam and the second laser beam 42 is a DVD beam, or vice versa, it should be noted that in the disc driver device i design In the case of operating three types of discs, the optical system 30 will contain a third laser; this is not illustrated in Figure ia*. The first beam 32 is reflected by a first beam splitter 33 and then passed through a collimating lens 39 and an objective lens 34 to the (beam 32b) disc 2. The beam splitter is schematically depicted as a cube, but may have other embodiments. The first beam 32b is reflected from the can 2 (the reflected first beam 32e) and then passes through the light 129503.doc -10- 200844987 component finally reaches an optical detector 35. The second beam 42 passes through a pre-collimator lens 48, is reflected by a second beam splitter shank, passes through the first beam splitter 33, and then follows an optical path that corresponds to the optical path of the first beam 32. The indications are reference numerals 42b '42c, 42d °. It should be noted that since only one disc is operated at a time in the disc drive device practice, only one of the laser beams is active at a time, and the other laser beams are turned off. The objective lens 34 is designed to focus the active light beams 32b, 42b into a focus F on a recording layer (not shown for simplicity) of the disc 2, which is generally circular. For the sake of completeness, FIG. 1A shows that the disc drive device i further includes an actuator system 50 comprising: a radial actuator 51 for radially displacing the objective lens 34 relative to the disc 2 (for a focus actuator 52 configured to axially displace the objective lens 34 relative to the disc 2 (to achieve and maintain proper focus); and a pivot actuator or tilt actuator 53 Used to pivot the objective lens 34 relative to the disc 2 (for tilt compensation). Since such actuators are known per se, and the present invention is not related to the design and function of such actuators, the design and function of the actuators need not be discussed in detail herein. It should be noted that the meal to actuator 51, focus actuator 52 and pivot actuator 53 can be implemented as an integrated 3D actuator. The disc drive device 1 further includes a control circuit 9A having a first output 93 coupled to one of the radial actuators 51 and having a first wheel 94 coupled to one of the focus actuators 52. And has a first and a ninth light coupling to one of the pivot actuators $3 control input. The control circuit 9 129 129503.doc 200844987 is designed to generate control signals SCR' SCF, SCT for controlling the radial actuator 51, the focus actuator 52 and the pivot actuator 53, respectively. Control circuit 90 further has a read signal input 9 for receiving a read signal Sr from one of optical detectors 35.

1B illustrates that the optical detector 35 includes a plurality of detector segments, in this case four detector segments 35a, 35b, 35c, 35 (1, which are capable of providing individual detector signals A, B, respectively. C, D, the signals respectively indicate the amount of light incident on each of the quadrants of the four detector quadrants. The first and fourth segments 35a and 35d and the second and third segments 35b & 35c A separate centerline 36 has a direction corresponding to the direction of the magnetostriction. Since this four quadrant detection H is well known in the art, it is not described here (4) its design and function are explained in more detail.

Narrow apocalyptic focus F Ideally, the incident beams 32b, 42b produce a disc 2 having a fun surface, as shown in an enlarged manner, the incident beams 32b, 42b may not be perpendicular to the disc surface. Guided by the ground, in this case, 'Focus F is no longer rounded, so the aberration (" coma aberration") can cause write errors and/or read errors. In addition, the servo signal is sensitive to tilting. Generally, f' can be considered as the function of the tilt angle as follows: a curve follows the curve, and the curve is a "whole-"bath-like curve in a W line. This example of jitter is illustrated in the figure. 2, Fig. 2 is a schematic display of jitter (two axes 'any unit) as the tilt angle flat axis, any unit) has two most I: table. The figure shows the jitter W for a specific tilt angle I The increase in min丨 increases rapidly. The performance of the jitter is not only linear with the tilt angle but also has a concave 129503.doc • 12 - 200844987: a curve of the part, so called, the bathtub curve " Note that the curve shown is idealized. _ Theoretically, it can be expected - a curve that is symmetric with respect to α = 0. However, it is true

This bath curve is often T ^ %, so taking a small value may be relative to nothing. This is due to the smaller coma in the read beam, which results from misalignment and/or manufacturing errors from different optical components. Thus, an imperfect perpendicular to the surface of the disc is -9G with the disc. · Obtained under the beam of % angle - optimal tilt compensation. In the case of an early beam drive, this can be pre-compensated in the manufacturing-driver program by giving the objective a pre-tilt, so that the slice is tilted for optimum read performance. However, in the case of a multi-beam disc drive: (, drive), an additional problem is that the U angles amin for different beams are independent of one another and generally different from each other. Because of this, this compensation is only feasible for today's Wang. It is feasible, and other beam tilt problems may continue to exist in a less or lesser extent. It should be left tolerant, and it is expected to have a pivoting objective lens and a tilt actuator mechanism 碟 disc drive. This problem can be solved by actively tilting the objective lens, but this is only suitable for radial tilting. This solution provides a solution to this problem, which will be described with reference to the figures and 3. Figure 3 is a schematic block diagram showing an assembly of an optical system 3 according to the present invention for a specific embodiment having three different laser beams in a layout varying as a layout. Corresponding to Fig. 1A, the optical system 3A of Fig. 3 includes a first thunder (four), and eight has a first splitter 33 and an objective lens 34. In front of the objective lens 34, a 129503.doc -13 - 200844987 collimating lens 39 is shown. The optical system 300 further includes a second laser 131, and a second beam splitter 133 and a first pre-collimator lens 138 are disposed between the second laser m and the second beam splitter 133. The function of the pre-collimation lens 138 is to slightly reduce the divergence of the first beam 132 generated by the first replacement 131 (the magnification of the pre-collimation lens I% is generally on the order of 1.4), so that the final focus is on the disc. The portion of the transmitted laser power on the chip is increased, which helps to increase the maximum possible write speed. The optical system 300 further includes a third laser 23, a third beam splitting 23 3 and a second pre-collimating lens 238 disposed between the third laser 231 and the third beam splitter 233. The light beam 32 from the first laser 31 is reflected by the discriminator 33 and then passed through the collimator lens 39 and the objective lens 34 to the disc 2. After the reflection, the reflected beam passes through the objective lens 34, the collimator lens 39, the first beam splitter 33, the second beam splitter 133, and the third beam splitter 233 to reach the detector 35. The light beam 132 from the second laser 131 passes through the first pre-collimator lens 138, is reflected by the second beam splitter 133, and then passes through the first beam splitter 33, the collimating lens 39 and the objective lens 34 to reach the disc 2. After the reflection, the reflected beam passes through the objective lens 34, the collimator lens 39, the first beam splitter 33, the second beam splitter 133, and the third beam splitter 233 to reach the detector 35. The light beam 232 from the third laser 231 passes through the second pre-collimator lens 23, is reflected by the third beam splitter 233, and then passes through the second beam splitter 133, the first beam splitter 33, the collimator lens 39, and the objective lens 34. Arrived at disc 2. After the reflection, the reflected beam passes through the objective lens 34, the collimator lens 39, the first beam splitter 33, the 129503.doc 14 200844987 divisor 133, and the third beam splitter 233 to the debt detector 35. Thus, the objective lens 34, the collimator lens 39, the first beam splitter 33, the second beam splitter 133, and the first light state 233 are common components through which all of the laser beams 32, 132, 232 pass. In contrast, the first pre-collimating lens 138 and the second pre-collimating lens 238 are respectively composed of the second and third laser beams 132, and the respective components of the respective gums. It should be noted that in addition to the first pre-collimation lens 138 and the second pre-collimation lens 238, the optical system may contain more individual components. It should be noted that a single pre-collimating lens may also be associated with the first f-shot 31, but this is not shown in Figure 3. According to the invention, at least one of the individual components, preferably the pre-collimation lens, is tilted obliquely with respect to the optical path of the corresponding laser beam in this direction A coma aberration effect is introduced to compensate for the offset of the bathtub curve associated with the laser beam. In order to eliminate the difference in offset between several laser beams, it is possible to treat a laser beam as the main beam, which can be implemented without tilting individual components. In the example of Figure 3, the laser beam 32 is not associated with a pre-collimating lens or any other individual component that may be tilted. In addition, all other laser beams are considered to be slave beams, and each pre-collimation lens 138, 238 is tilted such that the corresponding offset of the corresponding laser beam is equal to the offset of the main beam, & Next, the objective lens 34 is tilted to reduce the residual offset to zero. Tilting a pre-collimating lens may introduce an astigmatic aberration into the corresponding beam. The coma aberration amount is a linear function of the tilt angle of the pre-collimator lens, and the astigmatic aberration amount is one of the tilt angles of the pre-collimator lens. 329503.doc 15 200844987 For a relatively small tilt angle Slightly no, (4) is also relatively small and may be too ten but the right pre-collimation lens tilt angle is relatively large, then the astigmatism image, ... speed increases. 4 To eliminate or at least reduce this problem, the tilted individual components are preferably a... lens. A #, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, Figure 4 shows schematically - the pre-collimation lens has a cross section

Axis 404 (will be treated as a ζ axis). _, VL VIII The beam guided by the spurs will pass through the refractor surfaces 4〇1 and 402 or vice versa and enter and exit (4) 〇.虞, the lower A formula assumes that the surface of each of the five halves has a conical section shape, and the shape of each lens surface of the lens surfaces 401 and 402 can be determined by describing the Z coordinate as the radial distance r from the optical axis 4G4. The function is to illustrate: where: R is the surface radius of curvature; the so-called cone parameter of the lanthanum system, which is smaller than _丨 for a hyperbolic surface, equal to -丨 for a parabolic surface, and _1 and 0 for a long ellipsoid surface Between, for a spherical surface equal to 0 and for a flat ellipsoid surface greater than q. It should be noted that this formula assumes 2 == 根据 according to the definition at the section with the optical axis 404. In the following, it is clarified that the parameters associated with the first surface 4〇1 or the second surface 4〇2 are distinguished by adding an index of 1 or 2, respectively. Further, the lens has a thickness d measured along the optical axis 4〇4, and the lens material 129503.doc -16-200844987 has a refractive index n. Thus, assuming that the lens is made of a homogeneous material, there are six parameters describing the lens, except that it is assumed to be "sufficiently large, and therefore has no lens diameter for optical properties. It should be noted that the pre-collimator lens generally has a value. The aperture ΝΑ <0·1. "=The refractive index η does depend on the material selection, but the refractive index I of the injection molded plastic has a value of 1.25, so the material change only slightly changes the refractive index. "In addition, the distance ν between the object point and the first surface is given, and given the magnification Μ 'the fixed distance b between the image point and the second surface is fixed. For the un-tilted pre-collimation lens The common points in the standard state must be one of the two curvature radii and one of the cone parameters in order to obtain a non-aberrated image. Moreover, for practical and manufacturing reasons, only厚度·6 mm (or only slightly more), choose a thickness d from a relatively narrow range between 1 · 2 mm (or only slightly larger). However, there are still only two main free parameters for changing The pre-collimation lens is transmitted with the required astigmatism properties: for example, a radius parameter and a cone parameter. The assumed radius parameter & fixed: in this case, the radius parameter heart or R]/R2 is free to change. The parameter h is fixed: in this case, the cone parameter 1^ or |^/1^ is freely changed. DETAILED DESCRIPTION OF THE INVENTION In a first embodiment, the lens 400 has a positive magnification in the range of 1 < M < 2 In this case, the focal length is positive. The inventors are seeing the election The ratio R / R2 is less than 1, and the better is to obtain the desired astigmatism property in the range 129503.doc 200844987. The optimum value for the ratio R 〗 / R2 depends on M, V, n, d and K The exact value of one lens. For a specific embodiment of the lens, at 1.4, n=1.5, KeO, the lens has an incident numerical aperture να=〇·ι〇, FIG. 5 illustrates the aberration aberration for the lens system. The case is a graph of the difference between the ratio Ri/R2, the object distance ν, and the lens thickness d. The vertical axis of the graph represents the ratio Ri/R2 'the horizontal axis of the graph represents the object distance v. The calculation point is indicated as a solid circle; the solid curve connecting the points is an interpolated value. The chart shows three such curves for three different values of the lens thickness d. It can be seen that in all f months, 0_5 <Ri/R2< 1 is applicable. For this particular embodiment, FIG. 6 is a diagram illustrating the relationship between the coma aberration generation rate, the object distance v, and the lens thickness d for the case of the astigmatism of the lens system (about the ratio) For the corresponding value of Rl/R2, please refer to Figure 5). The phrase "Hybrid aberration generation rate" is indicated here. Coma aberration generated by the inclination of the lens to ηιλ / deg expression. Since the coma aberration generation rate is generally required to be as large as possible, it can be seen that it is advantageous to make the object distance v as large as possible and to make the thickness d as small as possible. For this particular embodiment, FIG. 7 is a graph illustrating the relationship between A, object distance v and lens thickness d for the astigmatism of the lens system (for the corresponding value of the ratio RJR2, see FIG. 5, and For the corresponding value of the coma aberration generation rate, see Figure 6). It can be seen that in all cases K2 < 〇 applies 0. For a particular embodiment of the lens, at M = 14, ny .5, thickness d = 〇.8 mm, the lens has an incident numerical aperture NA = At 0·10, Fig. 129503.doc -18 - 200844987 8 is a graph illustrating the relationship between the case of the lens aberration and the one-to-one calculation. It can be seen that κι is relatively small for the second ring. & For this particular embodiment, the W9 system is a graph of the relationship between the coma aberration generation rate and the object distance νΑκι for the astigmatism of the lens system. It can be seen that Kl has a great influence on the coma aberration generation rate: when Μ is negative, the absolute value of Κι should be selected as high as possible. In either case,

The preferred system is lower than -i. Further, for practical reasons, it is preferable that the absolute value of the system Κι, K2 is less than 5, and more preferably less than 2. ''Kl' For this particular embodiment, Figure 1 is a graph illustrating the relationship between Μ, object distance ¥ and Kl for the astigmatism of the lens system. It can be seen that κ has a greater impact on K2: as the value of 々 increases, the value will also increase. In summary, according to the above, it can be concluded that an astigmatic lens (for example) of this embodiment has the following parameters: M = 1.4, R1/n 84, ^^, (4) azimuth ^ (4) Chi ^ (1) In this case, the coma aberration generation rate will be (4) about 4. The graphs show how a parameter t: affects the desired settings for other parameters and the resulting coma aberration generation rate. DETAILED DESCRIPTION OF THE INVENTION In a second embodiment, lens 4 has a positive magnification in the range of 1 < M < In this case, the focal length is positive. In contrast to the first specific embodiment, Κι is now greater than +0_5, more specifically Κι>1. For these conditions, it can be shown that the astigmatism configuration can be found, but such a configuration is more sensitive to smaller parameter settings (eg caused by tolerance). DETAILED DESCRIPTION OF THE INVENTION In a first embodiment, the lens 4 has a -negative magnification in the range. In this case, the focal length is negative, and in some cases this is advantageous, as in the case of a space-constrained application, such as in a notebook computer. In this case, in addition to the κ ΐ symbol should be positive, can be in the specific embodiment! An astigmatism property of one of the pre-collimating lenses is obtained under the same conditions. In summary, the present invention provides an optical sweep n for reading information into an object 2, reading information from the object 2, which includes an optical system 3 for optically scanning the object. The system includes at least two beam generators 31, 131, 231 'which are used to generate corresponding beams", 丨, μ; and common optical components 33, 34 and individual optical components 138, 238 for directing such Beams to an object, receive reflected light and direct the reflected beam to an optical detector 35; the common optical components are used to direct at least two of the beams and the individual optical components are used to direct a single beam - The common optical component is tilted relative to the optical axis to compensate for the tilting of the beams - and at least - the individual optical components are tilted to compensate for the tilt of the corresponding beam for the other beams. Although in the drawings and the foregoing description The present invention has been illustrated and described in detail by the embodiments of the invention 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 Straight lens. Instead of a tilt, the optical center of the lens can be offset from the optical axis to introduce coma aberration. It is also possible to combine this offset with one of the tilts. Both possibilities are worded (ie the lens has a relative to the optical axis) In addition, in the above description, it is assumed that the two refractive surfaces 401, 402 of the lens 400 are aligned with each other. It is also possible that the two refractive surfaces 4, 1, are mutually displaced and/or tilted.

Other variations to the disclosed embodiments can be understood and effected in the practice of the invention. In the scope of the patent, the words "include, and do not exclude other components or steps, and the indefinite article """ or "-" does not exclude plural. - Single-processor or other unit can perform the functions of several items cited in the patent scope. The mere fact that certain measures are recited in the dependent claims are not intended to be - a computer program can be stored/distributed on a suitable medium 'eg an optical storage medium or a solid state medium supplied with or as part of other hardware' but may also be distributed in other forms, such as via the Internet or other wired Or radio (four) system. Any reference signs in the scope of patents should not be considered as limiting. In the above, the invention has been explained with reference to the block diagrams which illustrate the functional blocks of the clothing according to the present month. It should be understood that one or more of the functional blocks may be a (four), wherein the function of the functional block is performed by an individual hardware component, but it is also possible to implement the energy block by software - or Multiple functional blocks for use with a computer program or a 129503.doc -21 - 200844987 multiple program lines or a programmable device (eg a microprocessor, a microcontroller, digital signal processing) The device is configured to perform the function of this functional block. BRIEF DESCRIPTION OF THE DRAWINGS With reference to the accompanying drawings, the above description of one or more preferred embodiments has been

Further to the present invention, β, A and other aspects, features and advantages, wherein the same reference numerals denote the same U 4 cheek-like parts, and wherein: Figure 1 is a schematic representation of a disc drive; Figure 1B A block diagram of an optical detector coupled to a signal processor is schematically illustrated; FIG. 2 is a diagram schematically showing jitter as a function of tilt angle; FIG. 3 is a diagram showing A specific block diagram of two different laser beams according to one embodiment of the present invention is a schematic block diagram of an optical system; FIG. 4 schematically shows a pre-introduction, Le only, one of the top dry lenses Figure 5 to 1 is a diagram in a diagram. [Main component symbol description] of the relationship between different turns of the flat lens 1 2 4 5 6 7 30 31 Optical scanning device / CD drive device object / CD / optical information carrier Motor rotating shaft can rotate or hold the hub shaft optical System Beam Generator / First Beam Generating Member / First Laser I29503.doc -22 · 200844987 32 First Beam 32b First Beam 32c First Beam 33 Common Optical Component / First Beam Splitter 3 4 Common Optical Component / Objective 35 optical detector '35a detector segment 35b detector segment® 35c detector segment 35d detector segment 39 collimating lens 41 second beam generating member / second laser 42b beam / optical path 42c optical path 42d optical path 44 second beam splitter 48 pre-collimator lens 50 actuator system. 51 radial actuator 52 focus actuator 53 pivot actuator or tilt actuator 90 control circuit 91 read signal input 93 First Output 129503.doc -23- 200844987 94 Second Output 95 Third Output 131 Beam Generator / Second Laser 132 Second Beam 133 Second Beam Splitter 138 Individual Learning Component / Pre-collimating Lens 231 Beam Generator / Third Laser 232 Beam 233 Third Beam Splitter 238 Individual Optical Component / Second Pre-collimating Lens 300 Optical System 400 Pre-collimating Lens 401 Refractor Surface / Lens Surface 402 Refracting mirror surface / lens surface

129503.doc -24-

Claims (1)

200844987 X. Patent application scope · · 1 · An optical scanning device (1) for writing information into/from 4 objects (2), the device is included for optical scanning An optical system (30) of the object; the optical system comprising at least two beam generators (31; 131; 231) for respectively generating corresponding beams (32; 132; 232); and a common optical component (33) 34) and individual optical components (138; 238) for directing the beams to the object, receiving the reflected light and directing the reflected beam to an optical detector (35), wherein the common optical components are Guiding at least two of the A beams and wherein the plurality of optical components are used to direct a single beam; wherein a common optical component (34) is tilted relative to the optical axis to compensate for the beams (32) One of the aberrations; and at least one of the other optical components (138; 238) is tilted to compensate for the aberration of a corresponding other beam (132; 232). _ 2. Such as (five) seeking items! An optical scanning device, wherein the optical system comprises an objective lens (34), and wherein the tilting common optical component is the objective lens. 3. An optical scanning device as claimed in claim 1, wherein the tilted individual optical component (138, 238) is a pre-collimating lens. 4. An optical scanning device as claimed in claim 1, wherein the tilted individual optical component (138; 238) is an astigmatic optical component. 5. The optical scanning device of claim 3, wherein the pre-collimating lens 〇 38; M8) has lens surfaces (4〇1, 4〇2) opposite to each other, each of which satisfies the formula: 129503.doc 200844987 R + ^ jR2 -(l + k)r2 1 + k [/? - 4r2 ~~ o^+k)? where z represents a coordinate along the optical axis of the lens, and the Z system is equal to zero by definition at the optical axis section; r represents a radial distance from the optical axis; a radius of curvature of the R-based surface; a κ-based cone parameter; the lens further has a thickness d measured along the optical axis, and the lens material has a refractive index η; wherein the lens has A positive magnification in the range of 1 &lt; Μ &lt;2; and wherein the selection ratio is less than i. 6. The optical scanning device of claim 5, wherein the ratio is in the range of 0-5 &lt; R! / R2 &lt; i. An optical scanning device according to claim 5, wherein d is in the range of 0.6 mm &lt; d S 1.2 mm. An optical scanning device such as θ, wherein κ2 &lt; An optical scanning device according to claim 3, wherein the pre-collimating lens (138; 238) has lens surfaces (401, 4〇2) opposite to each other, each satisfying a formula of one of the optical axes of the lens Coordinates, z is at a section equal to zero at the section of the optical axis; 129503.doc 200844987 r represents the radial distance from the optical axis; the radius of curvature of the R-based surface; K-system cone parameter; the lens further has along The optical axis measures a thickness d, and the lens material has a refractive index η; wherein the lens has a positive magnification 馗 in the range of 1 &lt; Μ &lt;2; and wherein κρί. 10. The optical scanning device of claim 3, wherein the pre-collimating lens (138; 238) has lens surfaces (4〇1, 4〇2) opposite each other, each satisfying the formula: [i? - ^JR2 -( 1 + k)i R + ^JR2 ^(l + k)r2 &quot;ϊ+k where z represents a coordinate along the optical axis of the lens, z is at the section perpendicular to the optical axis by definition equal to zero; r represents a radial distance from the optical axis; a radius of curvature of the R-based surface; a κ-based cone parameter; the lens further having a thickness d measured along the optical axis, and the lens material has a refractive index η; wherein the lens has -2 &lt; Μ a negative magnification Μ in the range of -1; and wherein the selection ratio RWR2 is less than 1. 11 · The optical scanning device of claim 1 ,, where the ratio is in the range of 129503.doc 200844987 (^<Rj/Rel. 12. If the optical scanning of the request item 1〇 is set, 'where d is in 〇·6 Within the range of mmSdSl .2 mm 13. The optical broom device of claim 1G, where K2 &lt; 〇 14. 14. In the optical scan of claim 5, where η = 1·5, Kl = 0, d =0.6 匪, object distance V=5lnm, R is =〇·95, Κ2=_〇·128. 15·The optical scanning of claim 5 is in the middle of the clothes, where η=1·5, d=〇 8 mm, Κ1=&lt;_1, object distance V=5 axis, 0.92 take/IM0.95, _〇· sand 〇5. I6·Optical scan of claim 10, where η=1 ·5, Ki = 〇, d = 〇6 face, object distance V = 5inm, R is = 〇.95, Κ 2 = _0.128. π, such as the request item π) optical scanning device, where n = i5 d = 〇8 — Kl &gt; 1, object distance v=5 mm, 〇()9&lt;p /r&gt; Λ •92&lt;Rl/Re〇.95,·0·82€κ2κ) 5. 18·------- 1 i · 7 one for writing the poor news to an optical information carrier (2) / from the optical information disk to take the Begong body (2) master information, the device is optical Scanning an optical system (3〇) of the information carrier; ^ applying the scanning device to any one of claims 1 to 17 to add μ 19 · a disc drive device } for writing information to Ai Xiong's read information from the CD, and the disc drive device is implemented in the 哕9/18. The 129503.doc is implemented.