JP2003523036A - Thin optical head - Google Patents

Abstract

(57) [Summary] An optical head of a type used for reading / writing an optical disk is provided. The optical head has a low profile, for example, less than about 5 mm, more preferably less than about 3 mm, perpendicular to the axis of rotation of the disk. Substantially all the components of the optical system, including the laser light source and the objective lens, the intermediate element, and the photodetector, are provided in the optical head and fixedly attached to each other. Virtually all optical head elements move as a unit during tracking and / or focusing. The optical head is preferably manufactured using, for example, a wafer laminating technique and / or a wafer scale technique in which substantially flat elements are laminated to form the optical head.

Description

Detailed Description of the Invention

The present invention relates to a patent application number 09 / 457,104 (agent file number 41544) (December 7, 1999).
) Is a continuation application of the present invention, and should be made a part of the present application by being mentioned here. As a cross reference, U.S. Patent Application Serial No. 09 / 315,398 Removable Optical Storage Device and
System (May 20, 1999) (Attorney Docket No. 4154-1), US Patent Application No. 60/140,
633 Combination Mastered and Writeable Medium and Use in Electronic Book
There is Internet Appliance (June 23, 1999) (agent reference number 4154-2-PROV).

TECHNICAL FIELD The present invention relates to an optical head for use in writing from an optical disk to a read optical disk, and more specifically, a space in which almost all optical components from a laser source to an objective lens are fixed. Relates to an optical head kept in a relationship.

BACKGROUND ART Important factors affecting the design of an optical system (eg, having an optical disc reader / writer, typically a laser or other light source, lenses, reflectors, and other components). One of these is the size of the optical system in terms of both mass, volume, and / or size, and the size and shape (spot size and quality) of the light reaching the optical disc. Although a number of systems have been used and proposed, typical prior art systems include multiple components of the system, such as moving an objective lens with respect to a laser or other light source (eg, for focusing). We have used large enough large-scale optical components to perform the function of focusing or tracking only by moving them.

It has been considered that relatively large size components are related to spot size such that the data layer of the disc is significantly separated from the physical surface of the disc (hence the optical path is typically Pass through the disc substrate or other portion of the disc, and pass a substantial distance of about 0.6 millimeters or more of the disc thickness before reaching the data layer), resulting in approximately Needed.

Such a, although potentially useful, to accommodate relatively large and large components, regardless of the underlying cause that would provide relative movement between the optical components. The method represents a certain disadvantage. Disadvantages include the relatively large forming elements required, as well as the costs associated with installing and adjusting the optical alignment between components that are movable relative to each other. Such alignments may be manual and / or individual alignments or adjustments that may result in an undesired increase in manufacturing or processing costs for read / write devices as well as contributing to design, maintenance, repair and other costs. The procedure is included. As a result, the optics may be able to reduce or eliminate the need for relative movement between optical components during normal operation, eg, at least a number of alignment procedures in the manufacturing process of a read / write device. It would be useful to provide a head method, system, and apparatus.

Many early optical disks and other optical storage systems included devices for connecting and using, for example, 12 inch (larger) diameter disks, and relatively large format read / write devices. Has been provided. As optical storage technology has been developed, however, it has increased attention to provide viable and practical systems of relatively small size. For some applications, eg individual electronic devices (PDEs), eg “Removable Optical S
As described in US patent application Ser. No. 09 / 315,398 for "torage Device and System" (herein incorporated by reference), optical disk read / write devices have a height of approximately 10.5 millimeters. Width of 50 millimeters and 40
It is stated to have relatively small feature elements such as millimeter depth. In general, practical read / write devices include media, media cartridges (in addition to the components associated with and affecting the laser or beam of light optics).
Medium rotation motor, power and / or power conditioning, signal processing, focus, if any)
Multiple components may be configured in the form factor, including tracking, or other servo electronics. Therefore, it would be advantageous to provide an optical head device, system, and method that occupy a relatively small volume to facilitate relatively small feature elements. In addition to considering the overall volume, the constraints imposed by the need to accommodate the desired geometrical elements and / or other read / write elements are other dimensions (horizontal dimension is the axis of the optical arm). The requirement for a relatively small vertical profile or dimension (where vertical is the optical term) is also important, although the reduction in requirements in parallel and the vertical dimension are perpendicular to the horizontal axis is also important. It would be advantageous to provide an optical head device system and method that is relatively small in certain dimensions (having a direction parallel to the axis of rotation of the disk). Equipment with a low vertical profile requires a minimum optical path for at least multiple optical designs (including, for example, finite collaborative designs) and is remarkable (read / read).
This is especially problematic because the writing beam generally reaches the optical disc generally normally to the surface of the disc). So for example PED
Optics that can reduce the size requirements such as less than about 12 millimeters, preferably less than about 5 millimeters, and more preferably less than about 3 millimeters. It would be useful to provide a head device system and method.

For example, multiple optical read / write devices, including relatively large devices such as audio compact disc (CD) players in typical home stereo systems, are currently power managed or powered (typically Accessing AC line-level power supplies etc.) has relatively little current implications. As a result, it is possible to provide an optical design that is a relatively inefficient optical power in many such systems (eg, overfilling a lens or the like to accommodate a source of a non-circular laser). Feasible). In contrast, application number 09 /
Light weight, portable devices such as those mentioned in 315,398 (supra) and / or 60 / 140,633 generally have a limited collection of power sources (and more limited heat compared to larger systems). It also has wasting capacity). As a result, it is useful to provide an optical head device system and method as follows. It avoids excessive energy inefficiency and / or unnecessary heat production,
It is capable of achieving the desired optical quality, including circular or other optical features.

DISCLOSURE OF THE INVENTION The present invention contemplates that substantially all components of an optical head from a laser or other light source to an objective lens work together as a unit (eg, for focusing and / or tracking purposes), ie A practical and viable system is provided in which approximately each of the optical components in the optical head are secured together.

In one embodiment, the optical head is based on a wafer scale manufacturing method.
Preferably, a silicon or similar wafer, which is conventionally formed with electronic components, has optical components stacked or arranged on the wafer, preferably at least a plurality of components prior to cutting the wafer. And form the optical components of the optical head. In one embodiment, the first mirror / spacer level is located on the wafer and also includes one or more levels of optical elements (typically similar to the "chip" percentage after cutting the wafer). Proportional to) is placed on top of the spacer. In one embodiment, alignment of multiple or all optical layers on the spacer is accomplished by a laser source (preferably mounted on the wafer) emitting laser light.
Operates while using the emitted laser light to assist in placement and alignment.

In one embodiment, the read / write beam passes through one of the optical layers in a direction generally parallel to the plane of the disc. Providing a configuration where a substantial portion of the optical path is parallel to the plane of the disc helps provide a relatively low vertical profile. By providing a system in which wafer scale manufacturing methods can be used and which can be manufactured by stacking individual components such as spacers, optical components, etc., relatively low manufacturing cost, small size and high cost. It is possible to construct an optical head with high accuracy, light weight, low profile and small spot size. As used here, "read /
"Write" refers to both read-only and read-write configurations.

In one interpretation of the type of optical head that can be used for optical disks, a read / write device is provided. The optical head has a low profile. For example, less than about 3 mm, preferably less than about 3 mm in the vertical direction parallel to the axis of rotation of the disc. Nearly all of the components of the optical system, including the laser source, objective lens, intervening optics, and photodetector, are provided in the optical head and are fixedly mounted to each other. Nearly all the optical elements of the optical head act as a unit, eg during tracking and / or focusing. Preferably, the optical heads are manufactured at wafer scale or using stacking techniques such as stacking generally planar components to achieve the final optical head configuration.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention may be used in the context of multiple devices and device configurations, including the subject matter described in aforementioned US patent application Ser. No. 09 / 315,398. In the configuration shown in FIG. 1, the read / write drive device 112 interfaces with a host device 114 (e.g., music and / or video player, camera, and personal computer such as an electronic book or other text reader and the like) at an interface 116. Electronic equipment (PE
D) may be connected). In the embodiment shown in FIG. 1, the device 11
2 has a hub 112 which is coupled or centered with respect to a disk rotation motor 124 under the control of a motor control 126, typically the optical disk 1.
Holds or houses an optical medium such as 18. In one embodiment, medium 1
Reference numeral 18 is a first surface medium as shown in the aforementioned US patent application Ser. No. 09 / 315,398, which is hereby incorporated by reference. The bits on medium 118 are read or written using optical head 128 (details are described below). The optical head sends data or signals 132 to the interface 1 for example.
Data is provided to the read / write electronics 134 for transfer to the host 114 via 16. In one embodiment, the optical head 128 comprises substantially any component or device that controls or affects the laser or optical beam along its entire path from generation to arrival and / or reflection and detection from the media 118. Refraction, reflection, diffraction for controlling a laser or other light source, lens, grating, hologram, corrugated plate, mirror, beam splitter, beam of light, and controlling a photodiode or other photodetector, etc.,
Alternatively, it has an optical element. Preferably, the optical head includes a plurality or all of the optical elements for controlling and / or modulating the laser and for conditioning, digitizing and / or processing the detection signals. Information or signals provided by the optical head 128 may be used by arm control electronics 13 to operate or control the optical arm 142, eg, for tracking and / or focusing purposes.
8 to 136. The power supply or regulator 114 provides electrical power for electronic components and / or motors or actuators. Various configurations of drive 112 may include other components not shown in FIG. Such arrangements include mechanical elements for receiving and ejecting media 118 and / or media cartridges, content control electronics, microprocessors or other processors, data storage memory devices, data encryption / decryption electronics, And / or other components that are readily apparent to those of skill in the art after understanding the present specification.

The size, mass, volume, shape, and / or vertical, horizontal, and / or lateral dimensions or requirements of the optical head 128 and / or cost depend on the overall feasibility and cost of the drive device 112. Give a constraint to. In particular, the position configuration of the drive device 112 imposes a position, size, shape or cost of the other components of the drive 112, among other things, as described in US patent application Ser. This is important where it is desirable to have 112 generally applied.

FIG. 2 depicts a general or schematic diagram of the positional relationship of optical head 128 and optical arm 142 with respect to medium 118 according to one embodiment of the present invention. Figure 2
In this embodiment, the optical head 128 is fixed to the optical arm 142.
As will be described in more detail below, preferably all components of optical head 128 are fixed or secured together. In other words, there is generally no relative movement of any optical component of optical head 128 with respect to any other component of optical head. Rather, in the illustrated embodiment, the entire optical head 128 operates on the media 118 as a unit to reach (ie, track) or focus the desired alignment of the data on the media 118.

In the preferred embodiment, the optical path is constructed as follows. That is, the optical path length from the source to the objective lens (measured along the optical axis following any folding of the optical path) is generally wider than the distance from the objective lens to the data surface of the medium. Is composed of. In one embodiment, the ratio of the source-objective path length to the objective-data surface path length is at least about 5. As used herein, "objective" or "objective lens" is a component that focuses light on the recording layer or recording surface of the medium. This is typically a conventional refractive lens, but may have reflective, diffractive, or holographic elements. As used herein, the "objective" or "objective lens", although typically the last or final component along the optical path before the light reaches the medium.
"May also include items that are not the last optical component before arriving at the medium. The optical path length from the objective lens to the data surface is the numerical aperture of the lens, the distance from the disk surface (if any) to the data surface, and the minimum "working distance" between the optical head and the disk surface. Fulfills the functions of several elements, including. In one embodiment, the optical path length from the source to the objective lens is preferably provided greater than about 2.5 millimeters, preferably greater than about 4 millimeters, and more preferably about 4.5 millimeters. Wider than mm is desirable. One embodiment in accordance with the present invention requires achieving such a source-objective path length in providing a flat device, preferably with less than about 10.5 millimeter read / write devices. Shape element with a (vertical) profile,
More preferably, it may consist of profile elements with a profile smaller than or equal to about 6 millimeters.

In the illustrated embodiment, the medium 118 rotates 212 about an axis of rotation 214 that defines what may be referred to herein as the vertical direction. Disk rotation 212 provides for alignment of the light beam at (continuous) peripheral positions on disk 118. Alignment with the desired radial position (tracking) is provided by operating the optical head 128 in the direction with the radial elements. Rotation 216 of the optical arm 142 about the generally vertical axis 218 preferably causes the arc 222 to extend the location of the beam of light to reach the disc 118 throughout the predetermined radial range of the disc 118. Determine. In the illustrated embodiment,
To provide focus adjustment, the entire optical head 128 is moved as a unit along a path having vertical elements by pivoting 224 an arm 142 about a generally horizontal axis 226. Although the one shown in FIG. 2 is not the correct scale,
The overall vertical dimensions for constructing the components represented in FIG.
It is sufficient to illustrate that it can be affected by 28 vertical profiles or heights 232.

FIG. 2 illustrates an embodiment in which not only the optical components of the optical head 128 cooperate, but the optical head operates with the (generally rigidly coupled) optical arm 142. If the components of the optical head (preferably including at least the light source and the objective lens) do not work with each other, it is also possible to provide an embodiment in which the optical head may work with respect to several or all arms. For example, in the embodiment of FIG. 11, the optical head 128 may be connected to the arm 142 by a moveable or flexible, preferably resilient leaf element. Leaf element 242 may include all or part of a flexible printed circuit (flex circuit), for example to provide a signal to and from optical head 128. Multiple flex circuit materials or devices may be used. As an example, Kapton (
EI du Pont de Nemours and Company of Wilmington, D
A flex circuit using a substrate having a polyimide material available from elaware is provided and formed or mounted thereon to include one or more copper traces or regions and / or one or more electronic components. Accompany. Preferably, the movement of head 128 with respect to arm 142 may be explicitly controlled by the use of voice coil 244 or other electromagnetic or electronic device or the like to move the head toward or away from arm 142.

3-5 show an optical head 128 according to one embodiment of the present invention. In the depicted example, the objective lens 312 is placed by the lens mount 314 on the quarter wave plate 316. In some embodiments, the functionality of some or all quarter wave plates may be provided by coatings other than plates. The lens mount can be formed from multiple materials including iron, glass, or silicon. The quarter wave plate can be formed from multiple materials including mica and quartz. In some embodiments, the quarter wave plate functionality may be provided by a coating. The bottom of the quarter wave plate 316 is an optical block, referred to herein as a periscope 318. The periscope 318 is generally transparent at least at the wavelength of the laser light and, as will be described in more detail below, a first angle (preferably 45 degrees to vertical) surface 322 that generally acts as a mirror.
Determine. Suitably, the 45 degree surface 322 may be coated with a generally reflective coating such as an aluminum or reflective chrome coating. In the depicted example, the periscope 318 also has an internal polarization splitter surface 324 that preferably makes an angle of 45 degrees (with respect to the vertical). The surface 324 is generally reflective (acts approximately like a mirror) for light with a first polarization and is generally transparent for light with a second polarization. Periscope blocks are for example fused silica or SF
It may be made of a plurality of substances having 2 (flint glass).

An optical die or “optical element unit” (OEU) under the periscope 318
326 is present. The use of the word "DIE" is convenient and does not limit the invention to only the parallelepiped, parallelepiped or other shapes depicted. The OEU 326 is provided with lenses, gratings, holograms, and / or other optical components or devices as detailed below.

The OEU 326 is connected by spacer blocks 332 and 334 to a submount 336 (preferably sliced silicon or similar wafer as described in more detail below) provided below. In the depicted embodiment, the submount 3
36 is placed on a printed circuit board 338 or flex circuit.

The optical path has its origin at a laser diode 612 mounted in association with a submount 336 using, for example, a laser mount 614. In one embodiment, the laser beam is not collimated, but with a configuration that is generally divergent from the laser source towards the objective lens forming a finite conjugate imaging system. In this configuration, the beam-shaping optics primarily or fully circularize the light and / or fully or partially correct aberrations, and also provide beam aiming capability. Limited conjugate image system (point −
One potential advantage of point imaging systems is that the substantial reduction effectively eliminates or eliminates the aberrations produced by the laser. However, the rounding lens 352a may produce sufficient aberrations that the second lens or other optical element 352b is desirable to correct the aberrations. It is also possible to place a lens or other optical element on the surface of the submount 336 between the laser and mirror block 332, for example for rounding or other optical purposes. In one embodiment, lenses or similar optics 352a, 352b along the optical path are provided to at least partially compensate for angular error in the mount of the laser diode (and hence the beam direction). Composed.

In the depicted embodiment, the laser diode is a side-emitting laser diode, and the horizontal laser beam 616 output by laser diode 612 is preferably incorporated as one surface of spacer 332. Mount 338
Is reflected by a 45 degree surface 618 located in relation to the vertical beam. In one embodiment, a portion of the emitted laser beam is reflected back (eg, from OEU 326) for purposes of monitoring and controlling laser power output. In one embodiment, the laser is a red light laser. However, preferably, the present invention may include the use of shorter wavelength lasers, such as blue light lasers (eg, to achieve reduced spot size and increased data density). In the meantime, some details (eg shape or lens power, other optical elements, squeeze size, etc.) can be modified to accommodate shorter wavelength light, but a red light laser (cooperating, optical arm). Mounted at one end of each of the optical elements, each formed from one or more optical element plates with a plurality of optical elements, and / or defining an optical path with a major length through a glass or other solid material, The same general configuration of optical heads, such as that used with configurations having substantially all optical components) is retained.

As shown in FIG. 16, the use of surface 618 to rotate a horizontal beam 616 to a vertical beam is accomplished by a vertical cavity, surface emitting laser (VCSEL) 1612 (US patent application Ser. No. 09 / 315,398, supra). Can be eliminated from the design by providing a non-side-emitting laser such as, and configured or arranged to emit in a generally vertical direction 1614. VCSELs are also useful for reasons of substantial beam rounding and aberration reduction or elimination.

As shown in FIG. 7, in one embodiment submount 336 is formed from a small (sliced) portion of a wider silicon (or other) wafer 712 (FIG. 7). The wafer is formed using typical wafer fabrication techniques and preferably has a plurality of other electronic components that form a plurality or all of the drive circuitry. Examples include high frequency laser modulators, preamplifiers, laser diode drivers, photodetectors and related circuits, power or control circuits, tracking or focusing servos, data read / write electronics and others. Multiple silicon chip areas (as described below,
Wafer 712 formed by, for example, being cut and separated by slicing), then optically guided pick and place techniques or the like, a plurality of laser diodes and a plurality leading to 714a-714x. And a plurality of spacer bars with integrated mirrors 716a, 716b, 716c. Each spacer bar 716 has a plurality of four
It has a 5 degree mirror surface (718a, 718b, 718c, etc.). Laser diode 714 and mirror 718 of spacer bar 716 are provided to couple the laser with laser power, control, or similar circuitry, and with corresponding mirror 718 to provide for substantial alignment of the laser's output beam. Located on wafer 712 in relation to the electronic components on the wafer. After the desired components are placed on the wafer 712, the wafer is sliced or cut, for example, along multiple lines (812a, b, c, 814a, b, c shown in FIG. 8). As shown in FIG. 8, preferably the right and left (respectively) position of the truncated spacer bar 716 causes each resulting chip to be left and right spacer 33.
Cut lines 812a, b, c are defined to have 2 and 334. In the resulting configuration shown in FIG. 9, each chip 912 has a laser diode 714, a turning mirror 618, and a spacer 332 in the desired configuration or alignment.
Mounted 334, it preferably has sufficient space 914 left to accommodate various electronic components formed as part of wafer 712.

Although multiple shapes and sizes of devices can be used with the present invention, in one embodiment submount 336 has a length 512 of about 5 mm and a lateral dimension 412 of about 1.5 mm.

The optical die or optical element (OE) block 326 (disposed by spacers 332 and 334) disposed on the submount 336 has a number of different configurations depending on the desired function. Good. In the embodiment shown in FIG. 3, OEU 326 includes a plurality of beam shaping optics 352 and servo optics 354. In one embodiment, the beam shaping optics 352a and 352b are provided as toroidal or cylindrical lenses (or those that perform generally similar functions), such as for circularizing a laser beam wholly or partially, for aberrations, etc. Is provided to correct. Preferably, these optical elements are arranged to control the desired overfill of the objective, for example in order to average out crosstalk with light efficiency.

The optical elements 352a, 352b, and 354 can be lenses or similar reflective optical elements, gratings or holograms, or other diffractive optical elements and the like.
In some embodiments, the optical element is an approximate step shape, continuous shape, portion or "
It can be formed in the optical die using etching techniques including telephoto "lenses, Fresnel lenses, and others. Generally, when not feasible because of the relative sensitivity of the diffractive optical element to wavelength, Refractive optical elements are preferred.

The OEU is a generally planar (rectangular planar hexahedron) block preferably located between the substrate or submount and the periscope. The OEU is provided with a plurality of optical elements or components, the configuration, manufacture, function and location of which may be different in different embodiments. FIG. 18 illustrates an embodiment where the OEU 1802 has: They are forward sense optics 1804,
Servo optics 1806, beam shaping optics 1808 and 1810, patterned absorbing coating 1812, patterned reflective coating 1814, non-reflective coating 1816 and alignment marks 1912 and 1914 (FIG. 9).
Is.

As shown in FIG. 18, forward direction detection optics 1804 is used to diffract a plurality of output laser light returns 1820 and 1826 towards a detector 1828 mounted, for example, on silicon or substrate 1830. Good. The function of detector 1828 is to provide detection of the output laser power, eg, for use in control or servo circuitry to adjust the desired read and write power levels of laser 1832. One of skill in the art can readily understand the use of the signal provided by detector 1828 to control the power in laser 1832. The forward direction detecting element 1804 is a reflection hologram (etched surface relief hologram of the upper surface of the OEU 1802 shown in FIG. 18) with or without an additional reflective coating such as chrome or aluminum. . Other surface or bottom of periscope 1836 or bottom of OEU 1
It may also be possible to place reflective optics or forward direction optics at other locations, such as 848. Providing forward-direction detecting optics 1804 as a transmissible hologram or aperture with polarized light to a detector mounted elsewhere than on substrate 1830, such as mounted on top surface 1838 of periscope 1836. Is also possible. Also the substrate 183
It is also possible to provide an advancing optics 1804 in the form of a prism, for example an etched prism or a mirror surface, to direct the light towards a detector 1828 mounted at zero or elsewhere. Is.

In the embodiment of FIG. 18, OEU 1802 also includes servo optical element (SOE) 18
Has 06. Servo optics 1806 serves to modify the light returning from disk 1842 and / or one or more detectors for the purpose of generating useful tracking, focus, and / or data signals (discussed below). The returned light is guided to the array 1844. SOE 1806 may be a hologram or a refractive element that is formed or etched. In FIG. 18, S
Although the OE 1806 is depicted on the top surface 1846 of the OEU 1802, it is also possible to place the SOE on the bottom surface 1848 of the optical block 1802. It is also possible to provide an embodiment in which more than one optical element is used with two or more lenses, apertures, holograms, etc. to modify the light returning from the disc. Periscope 1836 with one or more SOE elements
It is also possible to provide embodiments that are located elsewhere than on the OEU 1802 such that they are located on the surface of the. The SOE 1806 may be, for example, a cylindrical or toric lens, for example of the type used with quadrant detectors in what is commonly referred to as an astigmatic focusing scheme. Refractive elements may be manufactured by etching, pressing, machining, or molding, and may be coated or uncoated.

The beam shaping optics 1808 and 1810 may be refractive and / or diffractive components placed in the path of the output beam, for example correcting the angular divergence of the laser beam, and in particular the objective lens 1854. Achieve the desired beam profile at aperture 1852. With respect to the size and shape of the objective lens 1854, the size and intensity profile of the laser beam reaching the objective lens 1854 (profil
The relationship between e) affects the shape of the focused spot on the disc 1856 and hence the ability to determine the data mark, and also track-track (
track-to-track) and in-track cross-talk
Affect the amount of. If the light source 1832 is an edge-emitter laser diode as shown, then initially the laser beam may take the form of a generally elliptical Gaussian beam. The beam arriving at the objective lens 1854 may have one elliptic axis that is generally tangent to the disc track and may have another elliptical axis that is generally radial to the disc track. The intensity of the laser light around the circumference of the objective lens 1854 in the radial and tangential directions (expressed as a percentage of the central beam intensity) is referred to as the rim intensity in these directions. Special drive designs may set a lower or upper limit for rim strength. In at least some embodiments, there may be constraints to provide a relatively high amount or percentage of light reaching the disc than the laser, especially in the case of low power drives for portable devices, for example. In such cases, lower rim strengths are generally preferred, as it is implied that lens overfilling will generally be avoided, thus avoiding leakage or consumption of light energy. In some embodiments, the rim strength does not exceed about 80% tangentially and / or about 40% radially (as compared to center or maximum strength). In one embodiment, the rim strength is preferably no less than about 50% tangentially and no more than about 15% radially. At the limit of low rim intensity, all of the available light is passed through the lens. Consequently, in at least one embodiment, beam shaping optics 1808 and 1810 are configured to help modify the beam at lens 1854 to reach the desired intensity (or other) profile. In at least one embodiment, one or both beam shaping lenses 1808 or 1810 are anamorphic and aspherical elements.

In the embodiment of FIG. 18, the output beam 1858 is the opposite surface 1 of the OEU 1802.
It is also possible to provide an embodiment in which two optical elements 1808, 1810 formed on 846, 1848 are passed through, but only one optical element is located in OEU 1802 in the path of output beam 1858. Is. Eg low surface area 1
862, top surface 1864 (which surface is also in the path of the reflected beam in the illustrated arrangement), inclined reflective surface 1866 (also in the path of the returning beam), and On the periscope 1836, such as the interior surface 1868 (which is also in the path of the returning beam) and others, such that one or more refractive or diffractive elements are placed to affect the output beam. It is also possible to provide various embodiments. The optical elements in the output beam path are also useful (core) for other than (or in addition to) controlling rim intensity.
The function of may be fulfilled. Beam steering optics may be provided to correct for laser beam pointing errors (said error is laser diode 183).
2 off-axis mount etc.). It is also possible that at least partial correction of pointing errors due to tangential and / or radial translation or rotation of OEU 1802 is provided. This approach is facilitated when the beam shaping optics have optical power in both directions (tangential and radial). In general, the range of beam steering adjustments is at least partially limited by wavefront errors introduced by positional errors (positional errors are those that degrade the slot profile and data and servo signals on the disc). It Another function that can be achieved by diffractive or refractive optics in the output beam path is the correction of laser diode aberrations. Since the surface is generally aspherical, aberrations may be planned to cancel that they are typically inherent in light sources such as laser diodes.

In some embodiments, a portion of the surface of OEU 1802 (or other component, such as periscope 1836) may have a top surface 1846 or a bottom surface 1
848 Patterned absorbent coating 1 (or side or end surface)
812 coated. Absorption coatings can be used to control unwanted light paths within the optical head. With a laser and detector in close proximity and a surface with many variable reflectivities in close proximity (substrate 1830, OEU 18
02 surface, periscope 1836, lens 1854, lens mount, etc.), the potential for optical detectors to reach unwanted light causing various types of false signals, such as focus or tracking offsets. potential) exists. In some embodiments, substantially all surfaces not provided to allow the passage of desired light are coated with an absorbing (or reflective) coating. Alternatively, optical raytracing (or experimental observation) may determine unwanted light paths, and black (or low reflectance) designed to minimize unwanted signals. The optimal placement of the material space may be determined.

Multiple materials can be used as an absorbent coating, such as a single layer of highly absorbent material such as germanium or silicon. If desired, such an absorber layer can be provided with an additional coating, such as a non-reflective coating, to provide further performance improvements. In some embodiments, the absorptive coating is a multilayer absorber / non-reflector (eg, chrome / non-reflector layer).

In some embodiments, multiple areas of the OEU (or other component) are provided with a patterned reflective coating 1814. These are arranged and constructed to perform similar functions to the patterned absorbent coatings described above. The patterned reflective coating is used to deflect unwanted light that diminishes on the detector, and would otherwise flood the detector. In addition, a reflective coating can be used to help direct light towards the detector, as in the case of forward detection optics 1804. The reflective coating may be made of multiple materials with suitable reflectivity and adhesion, including single or multiple layer coatings of metals or metal alloys such as aluminum, gold, silver, chrome and other metals. Including. It can be made from single or multiple dielectric coatings. Other materials for use as reflective coatings will be readily apparent to those of skill in the art upon understanding this specification.

In some embodiments, the non-reflective coating is itself designed to reduce reflections that can lead to unwanted signals on, for example, the detector and to reduce the amount of optical power return loss in the system. Provided on selected surfaces or portions of the. In general, anti-reflective coatings can be used on surfaces that do not have optical contact with other surfaces of similar index of refraction. In such cases,
If there is no non-reflective coating, there will always be multiple reflection losses. For example, typically a glass-air interface reflects about 4% of light (normal incidence). When the OEU 1802 is connected to the periscope 1836 with a solder-pad, there is a gap (typically a few μm in size) that is filled with air and without the application of a non-reflective coating. Unwanted reflections can occur. When the optical block 1802 is close to the periscope 1836 (eg, fixed or bonded configuration), a plurality or all of the optical elements 18 are provided.
04, 1806, 1810 may be formed by etching or similar processes to provide an area in the lower portion of the upper surface 1846, thereby creating an air gap. Multiple materials can be used for the antireflective coating. In one embodiment, a single or multiple layer thin film of a dielectric, typically magnesium fluoride, is used to a given thickness to reduce or substantially eliminate reflection of light over a particular wavelength and angular range. You can After understanding this specification, those skilled in the art will readily understand how to select and apply non-reflective coatings.

In some embodiments, alignment marks 1912, 191 are provided to assist in optical alignment of the OEU for assembly to a substrate or periscope.
4 is provided. In some embodiments, alignment marks 1912, 19
14 is sized and shaped to overlap and compliment corresponding marks on substrate 1830 or other components such as periscope 1836. The aim is to facilitate placement with a precision of about 10 μm or less and precise positioning. Multiple materials and procedures can be used to form the alignment marks. In one embodiment, the alignment marks are photolithographically defined lines or targets, which may have been formed in some other photolithographic process during manufacture of the OEU, and Alternatively, it may be etched or coated along with other components such as forward direction sensing elements or servo optics. The marks can be on the top surface (FIG. 19) or the bottom surface.

Almost all optical components of the OEU in some embodiments are associated with patterned lithographic and / or etching in glass (or other optical material) or associated with multiple coating processes. Formed. Such a process is
Suitable for "wafer scale" processing. That is, a relatively large (eg, 3 inch to 6 inch diameter) wafer of glass or optical material should be a large number of individual parts, with each part being on a "chip" scale (1 mm to 5 mm or less). It may be lithographically patterned to define. All individual parts on the wafer may be processed (etched, coated, etc.) at the same time, leading to low cost individual pans. Further cost savings are provided by forming multiple optical elements 1804, 1806, 1808, 1810 on a single block 1802, with relative alignment of the optical components on the block 1802 being pre-defined and high. Photographic printing or similar techniques as provided with precision are used. In this way, it is possible to reduce the cost of arranging the individual optical elements in a costly procedure, especially in the manufacture of small devices having a plurality of optical elements in the size of about 1 mm to 5 mm. .

OEU 326 is preferably formed from glass or plastic (eg, polycarbonate, acrylic, or other) with optical elements formed therein in place prior to assembly. It is relatively insensitive to temperature and water absorption (or other chemical effects) and can be combined with other components using high temperature techniques such as solder reflow. Glass is preferred unless there is no problem. In one embodiment, OEU 1802 is adhesively connected to periscope 1836. Preferably the upper surface 18 of OEU1802
One or both of the inner surfaces, such as 46, has one or more grooves or motes 2102, 2104 formed (FIG. 21). In one example, the width and depth of each moat is approximately 100 micrometers. In one approach, the top surface 1846 is placed in the desired alignment or position proximate to the top surface of the prism or periscope 1836, and then the adhesive is applied to edge 2.
It is introduced along 106, 2108 and is allowed to “carry” or flow into the interior of 2110, 2112 by capillarity. The motes 2102, 2104 receive excess adhesive and prevent the adhesive from flowing generally inward beyond the placement of the motes 2102, 2104 (adhesive toward the interior of the motes 2102, 2104 may be lens 1810 or other). Because it can potentially collide with optical elements).

In one embodiment, optical die 326 is placed in a desired manipulable position with the aid of light provided by laser diode 612. In this embodiment, the laser diode is connected to at least the power and control circuitry prior to mounting the optical die 326, and the silicon submount 336 provides the laser light output provided by the laser diode 612, optionally a photodiode or similar. Detector arrays (including those on submount 1830) can be provided with sufficient power. In one embodiment, the alignment device for positioning and mounting the optical die associated with submount 1830 includes beam shaping optics 352a, 352b, such that optical die 326 is moved and positioned.
And / or monitoring the nature of the light transmitted through one or both of the servo optics 354. Preferably, the optical die 326 is mounted in relation to the spacers 332, 334 using known techniques such as solder reflow. The optical die is positioned while the light is emitted by the laser (or other light source), and the position and / or focus or other nature of the light causes the optical die positioner (preferably a servo or control signal for the positioner). Using the detected light to define, etc., using a procedure that is used to guide
The placement of the optical die can at least partially compensate for various errors in the placement of the laser (or other light source).

The use of active alignment techniques (ie, using light provided by a laser to assist in the placement of components during manufacturing) is also possible, at least in part with respect to photodetector 356. Correct the error in the relative position of other light sources). In one embodiment, after the optical die has been placed and secured, the periscope block, preferably with the objective lens already mounted thereon, is placed using active alignment. In one embodiment, the mirror is located near the objective lens (eg, to mimic the reflection provided by an optical disc) and the periscope block is associated with a photodetector and the reflected light is in the desired or re-closed matching pattern. Are moved to form. In at least one embodiment, it is believed that movement of the periscope block is most feasible for alignment of the reflected beam in the vertical direction (ie, the direction perpendicular to the horizontal direction of the optical arm). Consequently, in at least some embodiments, it is believed to be useful for selecting a photodetector type or configuration that is relatively insensitive to horizontal beam placement errors. In that way, active alignment techniques can be used to position the periscope block to provide maximum accuracy of vertical beam placement, where the photodetector is most sensitive to error.

Although it is possible in multiple configurations to place the optical die 326 prior to the placement of the other components (eg, periscope 318, lens 312, etc.), spacers 332 in another embodiment. Optical die 32 with respect to 334
It is also possible to separately assemble a plurality or all of the periscope 318, quarter wave plate 316, and / or lens 312 with respect to the optical die 326 prior to mounting 6. Regardless of the order in which the various components are aligned and mounted, embodiments of the present invention provide many advantages resulting from the adoption of wafer scale assembly techniques and / or multilayer (stacking) assembly techniques for optical head fabrication. It is believed to be provided. Simplifying overall drive 112 assembly by providing a relatively low cost, practical mold for assembly of the optical head to achieve the desired (generally fixed) alignment between components. To be done. This is because, for example, the assembly of the optical head and the arm 142 which can be performed at a relatively low cost in a drive manufacturing or assembly factory.
This is because the marginal alignment has already been performed while a relatively lower and higher tolerance assembly of the head to is achieved.

The periscope 318 is mounted using, for example, solder reflow, adhesive, or similar assembly techniques, and the periscope mirror 322 is in a desired position with respect to the optical die beam shaping optics 352ab to reflect the beam in the horizontal direction 358.
, The direction of which is substantially parallel to the data surface of disk 362. The polarizing beamsplitter 324 is generally parallel to the periscope mirror 322 (ie, at an angle of approximately about 45 degrees to the vertical) in the depicted embodiment, and is preferably aligned with the surface of the end block 364 of the periscope 318. It may be formed by a coating (PBS coating) disposed on the surface of the first block of periscope 318 with the coated surface. PBS324 is PB
It is chosen and adopted in such a way that when S reaches PBS (“first polarization”), it can be largely reflected in the polarization of the laser light. In this way, those skilled in the art will understand how to control or select polarized light or polarized beams.

As a result, the PBS is oriented in a vertical upward direction (ie, disks 362 and 366).
Laser beam (toward). The beam passes through the quarter-wave plate 316 and thus through the objective lens 312 aligned with the quarter-wave by the lens mount 314. The objective lens 312 reads the disc 362.
/ Desired spot size (focus) on the writing surface (preferably the first surface)
Is generally configured to provide.

The height 514 from the printed circuit board 338 to the lens 314 in the depicted device is approximately 2.9 millimeters, although multiple sizes and shapes of the device may be used in embodiments of the present invention. . In one embodiment, the distance from the objective lens 312 to the surface of the disc 362 (defined as the safe distance for the optical system) is about 0.3 millimeters.

The light that reaches the disk 362 and is reflected by the disk 362 is reflected by the objective lens 312 and the quarter-wave plate 316 depending on whether or not the data pits exist or do not exist in the irradiated disk portion and the above-mentioned portion. Pass vertically downward. In this regard (e.g., two passes through the quarter wave plate 316), the polarization of the reflected light that reaches the PBS coating is different from the first polarization, and the PBS coating 324 is nearly all reflected light. Are allowed to pass through the PBS coating and pass through servo optics 354 and continue vertically downward toward photodetector array 356.

Multiple types of photodetector arrays are used, including quadrant detectors, Φ detectors, and others, and the type of servo optics 354 is selected according to the type of detector used, and is understood herein. It can be easily understood by those skilled in the art.

In one embodiment, the substrate 1830 is a first and second (“A” and “B”) substrate.
Optical detectors 2201, 2202 (FIG. 22) are provided to detect reflected light used for focusing, tracking, and / or providing data signals. In the depicted embodiment, each detector array comprises three equal shaped parallel detectors 2211, 2212, 2213, 2221, 2222, 2223. One advantage of a detector array having three parallel plate-like detectors in a detector array is that the output is relatively insensitive to the placement or position of the beam in the horizontal direction 2210. This means that there is a relatively high tolerance for misalignment of the optical components (laser 1832, OEU1802, periscope 1836, and / or lens 1854 mount) during manufacturing. This means that the movement or alignment of the reflected beam (at the detector) in the horizontal direction 2110 of the detector is
It is small compared to these alignment deficiencies that cause movements or deficiencies in their alignment with critical components in the (horizontal 2110 vertical) direction. Slow tolerance requirements for at least multiple alignment parameters help reduce manufacturing costs.

The provision of two detector schemes 2201, 2202 allows the use of the differential detection approach. Differential detection is non-differential (single Detector array) schemes and generally provide improved performance. In one embodiment, tracking-focus crosstalk is less than about 0.25 micrometer peak-to-peak (pp), and preferably less than about 0.1 micrometer pp. In one embodiment, tracking-track crosstalk is less than about 5%, and preferably less than 2%. The two detector scheme working configuration shown in FIG. 22 receives the reflected (returning) light beam 1842 and produces first and second reflected beams 2302, 2304 as shown in FIG. SOE1806
Can be implemented by providing As shown in FIG. 23, the first and second
Beams 2302, 2304 of the first and second detectors 2201, 2201 of FIG.
Beams 2203, 2 therein, each of which is directed to hit an area of 2202.
Define the footprint of 204. Preferably the first and second beams 2302,
The 2304 has different optical properties such as having different focal points or focal plane positions. It is also possible to construct different optics such that the focal points of the first and second beams are respectively on opposite sides of the detector plane. In the example shown in FIG. 23, both foci 2306, 2308 are located on the same side of the surface 2314 of the detectors 2201, 2202. Each focus 2306, 230 at a different location 2310, 2312 from the detector surface 2314 at a different location.
By having 6, the optical properties of the first and second beams 2302, 2034 are different. Different focal points 2306, 2 of the first and second beams 2302, 2304
The provision of 308 may be useful in a differential detection scheme for several reasons.

[0050]   In one embodiment, the focus error signal "FES" for detector 2201 is
From three parallel bar-shaped detection areas of detectors 2211 and 2212, 2213
It is obtained by combining each signal. Focus error signal for detector 2202
Similarly, “FES” has three parallel bars for each detector 2221 and 2222, 2223.
It is obtained by combining the respective signals of the detection area in the shape of a circle. In one embodiment, "FES_ACall
The focus error signal of the first detector or "A" detector which is exposed is the first array
The outermost region of A, ie A₁2211 and A_Two2213 signal from the central area A
_ThreeIt is obtained by subtracting from 2212. Expressed as an expression, FES_A= A_Two− (A₁+ A_Three) Becomes
. Similarly, in this embodiment, the focus error signal of the second detector 2202 is FE
S_B= B_Two− (B₁+ B_Three). In this method, two detectors 2201 and 220
FES signals from each of the two beams 2203 and 220 impinging on both detectors.
Related to the size of the 4 footprint. Footprints 2203 and 2204
The size of, for example, a rotary focusing device such as an optical arm pivot 224 (FIG. 2).
It depends on the degree of focusing of the light spot on medium 1856 (FIG. 18) at.

24A and 24B respectively vary depending on the degree of focusing on the medium.
It is a figure which shows the magnitude | size of FES _A signal 2402a and FES _B signal 2402b. In one embodiment, the focus is the distance 186 of the objective lens from the information layer 1864 of the medium 1856.
It can be expressed as 2 (eg, μm). The effect that the distances 2310 and 2312 of the respective focal points 2306 and 2308 of the first beam 2302 and the second beam 2304 are different is that the FES from the detectors 2201 and 2202 results from the different focal points.
The signal shapes are as shown in FIGS. 24A and 24B, respectively. Each FES signal 240
2a and 2402b are regions 2406a and 2406b close to the reference focus, respectively.
In, it is substantially non-linear (a steep curve). In such a non-linear region, it is rather difficult and / or inaccurate to use the focus error signal FES _A or FES _B as the control signal for controlling the focus independently. However, as shown in FIG. 25, the combination of signal 2404 of the negative or reverse the FES _B signal FES _B signal 2402b, resulting combination focus error signal FES _A -FES _B 2502 is around the reference focal points 2506 In the capture region 2504 of the above, it becomes substantially linear. Thus, in the example involving the two different focal lengths 2310 and 2312 described above (on the same side of the detection surface 2314 in the illustrated embodiment), there is a substantially linear combination of focus error signals, at least in the capture region 2504. At least that area is available for controlling the focus motor or actuator. In one embodiment, the capture area is 10 μm in front and behind the reference focus. In one embodiment, the combined focus error signal FES _A -FES _B 2502 has a maximum deviation from the straight line (eg, from the optimum straight line) at any point within the capture region of less than about 10%, preferably less than about 2%. Deviation).

Similarly, the combined tracking error signal is represented as TES = (A ₁ −A ₃ ) + (B ₁ −B ₃ ), and the combined data signal is represented as data = (A ₁ + A ₂ + A ₃ + B ₁ + B _2). + B ₃ )
It can be expressed as. In one embodiment, the combined tracking error signal TES has a maximum deviation from the straight line (eg, deviation from the optimum straight line) at any point within the capture region of less than about 10%, preferably less than about 2%. .

[0053]   If desired, for example, the effect of changes in signal amplitude (differences in disc reflectivity, or
Or the blur of the light beam relative to the stroke of the actuator).
Both S and TES can be standardized to full power in each signal. For example,
The normalized FES and TES signals are FES_normal= [(A₁+ A_Three−A_Two) / (A₁+ A_Two+ A
_Three)] − [(B₁+ B_Three-B_Two) / (B₁+ B_Two+ B_Three)], TES_normal= [(A₁−A_Three) / (A₁+
A_Three)] ＋ [(B_Three-B₁) / (B₁+ B_Three)],It can be expressed as. Area of two detectors
Various combinations of signals from the
Can be digitalized and digitally combined (or
Tell).

In one embodiment, the relative size of the central elements of each detector 2212 and 2222 is adjusted to reduce the crosstalk of the tracking signal TES to reduce the objective lens and / or (
There can be different detected position focus signals FES for different groove shapes of media 1856 (on grooved media) or different pit shapes on media with premastered pits.

An example of the path of the electric signal to the optical head 128 and the path of the electric signal from the optical head is shown in FIG. In the embodiment of FIG. 6, the printed circuit board 338.
Although a submount 336 is provided on top of the above, in the embodiment of FIG. 12, the submount 336 has a flex circuit 338 '(eg, Kap).
The ton-copper flex circuit) is housed in a cutout 1212 provided in the ton-copper flex circuit. Flexible circuit 338 ′ is preferably electrically connected to optical head 318 by wire bonding between optical head bonding pad 1216 and flexible circuit bonding pad 1218. The flexible circuit 338 'is, for example, B
It is preferably physically bonded by an epoxy or another adhesive such as that sold by Eposy Technology, Inc. of illerica, MA under the trademark Epo-Tek H70E-2.
Some or all of the flexible circuit and other elements can be coated or encapsulated to protect. The flexible circuit 338 'includes the optical head 128.
Preferably including all or part of the elements used for control and / or signal processing. It will be readily apparent to those skilled in the art who understand the present invention how to provide alternative paths for electrical signals to and from the optical head.

One of the key factors in the design of devices according to embodiments of the present invention relates to thermal management. Many laser diodes or other light sources can also be large sources of heat. In addition, many electrical and electronic components such as power supplies or air conditioners, resistors, diodes and other components are added to the total heat load. It is not without thinking of using a laser device whose output is close to 200 mW. When the temperature rises, the electronic components and / or the medium in the drive (magnetic disk device) and the PED including the drive and other devices may be damaged or the performance may deteriorate. Although temperature changes can significantly change the performance characteristics of lasers and other components, it is difficult and sometimes costly to adequately compensate for these changes. Furthermore, the product value of a product that generates heat conspicuously may decrease its commercial value. Conventional electronics and electro-optics have typically used relatively large and heavy, high power consuming components such as large and / or heavy heat sinks and fans. However, the present invention is preferably a low profile (or small) device and is suitable for use with PEDs and other small and lightweight low power devices. Therefore, it is preferable that the optical head is formed so as not to generate a large amount of heat, concentrate heat, or raise the temperature that adversely affects the device or parts or deteriorates the performance. In at least one embodiment, at least a portion of the underside of the flexible circuit 338 '(preferably having portion 1214 extend to some or all of cutout 1212) acts as, for example, a heat sink or heat dissipation device. It is preferred to have a coating or layer of thermally conductive material such as copper. In one embodiment, if submount 614 is included, then submount 614 is formed from a substantially thermally conductive material such as, for example, nitrate nitrate or silicon carbide. The submount is such that the heat generated by the laser is effectively spread over a relatively large area, such that heat concentration and temperature rise (local) does not occur (eg, on the laser diode and / or mount 614). (Compared to) has a relatively large area.

In addition to the method of electronic coupling and thermal management of optical head 128 and arm 142, one embodiment of the present invention also illustrates mechanical attachment or coupling of the optical head to arm 142. In the embodiment shown in FIG. 13, the first arm 131
2a and the second arm 1312b provide an area 1313 for receiving the optical head.
Is defined. A plurality of flexible prongs 1314a and 1314b, 131
4c and 1314d are connected to the arm. Each prong has an angled protrusion formed to contact a portion of the optical head when the optical head is received in the area 1313. When the optical head reaches the desired position (eg, by a mechanism that grips and moves the optical head), each protrusion is secured to a portion of the optical head using, for example, an adhesive, and UV light is applied when possible. It is preferred to steel or secure the prongs with an epoxy or other steeling agent by or other curing steps.

In one embodiment of the invention shown in FIG. 14, detector 1412 is located outside mirror block 332. In this example, PBS 1424 is arranged to reflect light 1426 from laser source 1428 into substantially horizontal path 1432. This light is then transmitted by the reflecting surface 1438 to the objective lens 312.
Is reflected vertically toward. The reflected back light has different polarizations but passes through similar paths 1434 and 1432, passes through PBS 1424 and along horizontal path 1442, and is reflected downward 1444 toward detector 1412 by reflective surface 1446. It In one embodiment, the area under the optical block 326 'surrounding the path of the reflected light 1444 is coated with an absorptive coating such as non-reflective (black) chrome to help protect the detector 1412 from stray light. In one embodiment, the underside of an optics block 326 'that surrounds the center of beam 1426 is such that the outermost annular portion of beam 1426 is reflected downward toward feedback detector 1448 to control the power of the laser. It has an annular reflective coating. Other areas can be coated with absorbing or reflective coatings to control stray light. This will be apparent to one of ordinary skill in the art who understands the present invention.

Another embodiment is shown in FIG. 10 partially matches the structure of the embodiment of FIGS. 3-6, but in FIG. 10, a silicon (or similar) submount 1036 having a laser 1012 and a detector 1056 attached thereto is substantially vertical. , That is, perpendicular to the surface or plane of the disk 1062. Optical die 1026
Are separated from the submount 1046 by spacers 1032 and 1034, and the reflecting mirror 1018 is another structure. Light 1012 from the laser passes through beam-shaping optics 1052a and 1052b and enters mirror block 1022. The read / write beam is reflected downwardly on the inner surface 1024 of the PBS and passes through the quarter wave plate 1016 and the objective lens 1013 to the disk 1062. The reflected light whose polarization has changed passes through the PBS 1024, is reflected by the reflecting surface 1023, passes through the servo optical element 1054 of the optical die 1026, and reaches the photodetector 1056. Although various sizes and shapes of devices can be used with the present invention, in one embodiment optical die 1026 and block 1022 are used.
Has a vertical height of about 1.8 mm, and the quarter-wave plate 1016 and the lens 10 are
The total height 1074 of 13 is about 1.02 mm. In one embodiment, the combined lateral length 1076 of the optical die 1026 and the block 1022 is about 4.0 mm.

Another embodiment of the present invention is shown in FIG. In the embodiment of FIG. 16, the laser 6
The 12 and photodiode 356 are not mounted on separate chips or submounts, but rather on the lower surface of the optical die 326. In the illustrated embodiment, an area of the lower surface of the optical die 326 may be used, for example, to control the stray light and / or define the area for coupling the photodetector 356, the laser 612, other elements, circuits. The perimeter 1512 of the detector is selectively metallized or coated to form reflective or absorbing regions. In one embodiment, a lead wire 1514 is provided on one surface of the laser diode to provide an output to the laser 612 for exchanging data and control signals. In one embodiment, the free surface of laser 612 can also be directly connected to a heatsink (including some or all of the optical arm, if desired) for effective thermal management. The configuration of FIG. 16 not only provides effective thermal management, but does not require the placement of a silicon board 338 or submount 336, which results in a low vertical height and a low profile optical head.

Another embodiment of the present invention is shown in FIG. In the example of FIG. 26, a first reflected beam path that impinges on a first detector array 2610 and a second detector array 2612, respectively, by a second beam splitting surface 2602 that is part of periscope 2604. 2606 and a second reflected beam path 2608 are generated. The embodiment of FIG. 26 is compared with FIGS. 18 and 23. In FIG. 23, the SOE optics 1806 performs two functions: splitting the reflected beam 1842 into a first beam 2302 and a second beam 2304 and providing two different focal lengths 2310 and 2312. There is. By splitting the two spatially separated reflected beams 2606 and 2608 (and the effect of the original beam splitting surface 324) by the additional beam splitting surface 2602, it was constructed for beam splitting of the type shown in FIG. No need to place servo optics. If desired, the optical power added to the two reflected or return beams 2606 or 2608 may not be altered or changed (ie, the return or reflected beam paths 2606 and 2608).
It is possible to dispense with the use of servo optics or other optics to generate the). For example, in the different sized embodiment of FIG. 27, one return beam that forms a virtual focus 2702 ahead of the detector array 2612 and an actual focus in front of the second detector array 2610. A second return beam is shown. Since these positions 2704 and 2702 are natural images of a point on the disc (the same distance from the position of the laser light source to the disc), no extra focusing power is required. That is, SOE is not required.

The use of no SOE (ie the embodiment of FIGS. 26 and 27, etc.) has the advantage of being advantageous in correcting laser aiming errors. If the OEU includes outgoing beam shaping optics 1808 and 1810 and return or reflected beam optics 1806, adjusting the OEU 1802 to compensate for laser aiming errors, for example, the SOE.
1806 also moves. Due to such movement of the SOE 1806, the SOE 1
Errors in the positioning of 086 and detector array 1844 (which may be uncorrectable) may occur. Without the SOE element 1806, it is possible to adjust the mounting position of the OEU 1802 without moving the SOE element (eg, to correct for laser aiming errors). The necessary alignment of the detector is done by the objective lens 185
Other methods such as translating 4 can be used.

From the above description, one will appreciate the numerous advantages of the present invention. The present invention includes the recognition of small spots suitable for high density data (eg, facilitated by the use of a first surface medium) so that substantially all optical elements are included in a small and / or lightweight package. For example, the optical package or the entire head (rather than moving only the objective lens) can be moved for tracking and / or focusing. The present invention not only provides a device that is sufficiently small and / or lightweight to secure all optical elements to each other, but also allows these elements to extend in various spatial directions, for example, Small vertical head (low profile) with a form factor of a type suitable for use in small, portable drives (magnetic disk drives) and host devices (eg personal electronics).
I will provide a. The present invention provides a highly efficient optical head, such as by employing an optical design that does not substantially overuse or waste optical energy or other energy. The present invention can perform some or all of the manufacturing processes at a relatively low cost, such as by using wafer scale manufacturing technology and / or planar or stacking technology to manufacture the optical head. One of the features of an optical head as described herein that includes multiple optical elements on various surfaces of one or more optical blocks is that substantially the majority of the optical path from the laser source to the objective lens is: It is a solid medium such as glass, and only part of the optical path passes through the air. In one embodiment, the percentage of solid medium (relative to the optical path through the air), such as glass, in the optical path from the laser source to the objective lens is greater than about 50%, preferably greater than 75%, and more preferably. More than 85%. In one embodiment, 5,000 μm of the total optical path of 5,500 μm from the laser to the objective lens is glass or other solid material (eg, optical block 1802 and periscope 1836). About 450 μm of the total optical path from the laser to the OEU 1802 can occur between the optical block 1802 and the periscope 1836 and / or between the periscope 1836 (quarter wave plate 316) and the objective lens 1854. Light passes through the air in the path.

The present invention can be variously modified. It is also possible to utilize only some, but not all, of the invention. For example, to provide an optical head that is sufficiently small and / or lightweight to be able to move the entire optical head (eg, for tracking and / or focusing) without utilizing wafer scale technology and / or layered manufacturing technology. can do. In one embodiment, some or all of the optical elements provided in or on a separate optical die 326 may be replaced by a periscope or optical block 3.
22 does not include a separate optical die 326 (i.e., the prism / optical element combination is directly attached to spacers 322 and 32).
4 arrangement) is also possible. Similarly, in an embodiment, substantially all optical elements (other than the objective lens and quarter wave plate 316) have two units (
The optical element unit and the periscope unit) are provided in or on the surface of the optical element unit, but it is also possible that the optical element unit and the periscope unit are composed of three or more units to provide the optical element. In the illustrated embodiment, the polarized beam splitter was used to discriminate between the light emitted and reflected, but the light 1722 (FIG. 17) emitted and reflected using another technique or device, including a diffraction grating. It is apparent to those skilled in the art who understand the invention that the discrimination is possible. In the example, the periscope redirects from vertical to horizontal and from horizontal to vertical, which is used to reduce the height profile without unduly limiting the length of the optical path. be able to. Configurations utilizing multiple internal reflections between three or more surfaces, which are typically parallel, are also possible, for example to reduce the profile of the optical head. In some embodiments, the periscope prism (or other stacked optical head element) is substantially symmetrical (eg, for increased manufacturing efficiency). In the embodiment, substantially all the optical elements of the optical head are fixed to each other, but some of the optical elements may be movable. For example, it is possible to provide a device in which the objective lens is movable relative to one or more optical elements of the optical head, for fine (or coarse) focusing, tracking, etc. Although wafer scale and / or stacking techniques are used in the described embodiments, it will be appreciated by those skilled in the art who understand the present invention that it is possible to provide some or all of the optical elements using integrated optics. Would be easy to understand. An optical head with periscope parts and / or substantially all optical elements immovable relative to each other has been described with a device in which the optical arm rotates about an axis parallel to the axis of rotation for tracking. It is also possible to provide a device in which the optical head substantially described herein is moved in another way, such as by providing an element such as a rail, so that the optical head performs a linear (or radial) tracking movement. . In the embodiment, a diode 1712 (FIG. 17) or other laser was used as the light source, but in the embodiment of the present invention, a superluminescent diode 1714 or an incandescent light source, a fluorescent light source, an arc light source, a vapor light source is used. It is possible to use light sources other than laser light, such as other light sources. The output of an optical fiber or other light transmitting element that transmits light generated by a laser or other light generator 1718 (which can be located remotely from the optical head, if desired) to (or within) the optical head. It is also possible to provide a light transmitting element such as the section 1716 as a light source of the optical head. The use of fiber optics helps with thermal management (because the laser can be placed away from the optical head) and also with the beam being circular.

The present invention, in various embodiments, includes various components, methods, sub-combinations, subsets, etc. substantially as described herein with reference to the drawings, methods,
Includes processes, systems and / or equipment. It will be apparent to those skilled in the art who understand the present invention how to make and use the present invention. The invention, in various embodiments, includes apparatus and processes not shown and / or described herein or without elements of the embodiments described herein. Elements not included include, for example, elements used in conventional equipment or processes to improve performance, facilitate implementation, or reduce implementation costs. The present invention includes new terms and terminology used in the prior art and similar techniques to facilitate the description of new elements and processes, but includes all conventional usage of such terminology. Not a thing.

The above description of the invention is for purposes of illustration and description. The above description is not meant to limit the disclosed forms of the invention. While the description of the invention includes one or more embodiments and certain modifications and improvements, other modifications and improvements will occur within the skill and knowledge of those of ordinary skill in the art who understand the invention. (Possibly) within the scope of the present invention. The right to obtain modified or interchangeable and / or equivalent structures and functions with respect to the claimed scope, or modified examples including scope and steps with or without disclosure herein The purpose is to do. Also, the purpose is not to make the invention for which all patents are available public.

[Brief description of drawings]

FIG. 1 is a simplified block diagram of a read / write drive device connected to a host device, of the type that may be used in connection with embodiments of the present invention.

FIG. 2 is a perspective view of an optical arm and an optical disc according to an exemplary embodiment of the present invention.

FIG. 3 is a perspective view of an optical head according to an exemplary embodiment of the present invention.

FIG. 4 is a plan view of the optical head of FIG.

5 is a side view of the optical head of FIG.

FIG. 6 is a cross-sectional view through a portion of an optical head and a disk in the vicinity according to an embodiment of the present invention.

FIG. 7 is a partial exploded perspective view of a wafer and a partially mounted spacer element according to one embodiment of the present invention.

FIG. 8 is a plan view of a portion of a wafer with mounted spacer components.

FIG. 9 is a plan view of a piece of wafer section that results from cutting a wafer.

FIG. 10 is a vertical sectional view through a part of an optical head and an optical disk according to an embodiment of the present invention.

FIG. 11 is a partial perspective view showing an optical arm and a relatively movable optical head according to an embodiment of the present invention.

FIG. 12 is a partial exploded perspective view of an optical arm and an optical head according to an embodiment of the present invention.

FIG. 13 is a partial perspective view of a portion of an optical arm with mount pins according to one embodiment of the present invention.

FIG. 14 is a vertical sectional view of an optical head according to an embodiment of the present invention.

FIG. 15 is a side view of an optical head component with a laser mounted on the surface of an optical die according to one embodiment of the present invention.

FIG. 16 is a side view of an optical head component using a VCSEL according to one embodiment of the present invention.

FIG. 17 is a block diagram illustrating components that may be used in providing various embodiments of the invention.

FIG. 18 is a horizontal sectional view of an optical head according to an embodiment of the present invention.

FIG. 19 is a plan view of an optical element unit (OEU) according to an embodiment of the present invention.

FIG. 20 is a bottom view of an optical element unit according to an embodiment of the present invention.

FIG. 21 is a lateral sectional view of an optical element unit (OEU) according to an embodiment of the present invention.

FIG. 22 is a plan view of an optical detector portion of an optical head substrate according to an embodiment of the present invention.

FIG. 23 is a side view of a portion of the substrate shown in FIG. 22 in combination with corresponding portions of an optical element unit (OEU) according to one embodiment of the present invention, with selected light rays visible. This is indicated by hatching for this purpose.

FIG. 24A is a graph of focus error signal (FES) as a function of focus in a first detector medium according to an embodiment of the present invention.

FIG. 24B is a graph of focus error signal (FES) as a function of focus in a second detector medium according to an embodiment of the present invention.

FIG. 25 is a graph of differential focus error signal (FES) as a function of focus in a medium according to an embodiment of the present invention.

FIG. 26 is a side view of the optical head in which the path of the central axis of the selected beam of light is represented by an arrow according to the embodiment of the present invention.

FIG. 27 is a side view of the optical head, in which paths of selected light beams are represented by arrows according to an embodiment of the present invention.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G11B 7/22 G11B 7/22 (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE, TR), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, G M, KE, LS, MW, MZ, SD, SL, SZ, TZ, UG, ZW), EA (AM, AZ, BY, KG, KZ) , MD, RU, TJ, TM), AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, BZ, CA, CH, CN, CR, C , CZ, DE, DK, DM, DZ, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, MZ, NO, NZ, PL, PT, RO, RU, SD, SE, SG , SI, SK, SL, TJ, TM, TR, TT, TZ, UA, UG, UZ, VN, YU, ZA, ZW (72) Inventor Blankenberger, David El 8051 Longmont, Colorado, USA Ridgeviewway 2141 (72) Inventor Breitberg, Michael Eff 80302 Boulder Broken Fence Road, Colorado, USA 440 (72) Inventor Freeman, Robert Dee United States Colorado, USA 80516, elite-en Place 4747 F-term (reference) 5D118 AA02 BA01 CD02 CD03 CF01 DB21 5D119 AA02 AA20 CA10 FA33 JA12 JA32 JA43 JA64 JA65 LB05

Claims (112)

[Claims] 1. An optical head used in an optical read / write device for use with a read / write medium, the light source emitting light at an initial light emitting position, and a fixed position with respect to the initial light emitting position. At least one first photodetector array mounted and having at least one first surface defining a photodetector surface; first and second beam shaping optics for receiving light emitted at said light emitting location The light emitting location including an element and at least one third optical element configured to direct at least a portion of the light reflected from the medium along a path to reach the first photodetector array. An optical element unit mounted at a fixed position with respect to the optical head, the optical head starting from the initial light emitting position and reaching at least the read / write medium. The optical head is characterized in that providing at least one first optical path. 2. The optical element unit has first and second surfaces facing each other, and the first and second beam shaping optical elements are provided on the first and second surfaces, respectively. The device according to claim 1. 3. The optical element unit includes at least one fourth optical element configured to provide a first focusing surface of at least a first portion of light reflected from the medium, the first optical element comprising: The apparatus of claim 1, wherein the focusing surface is at a first distance from the first photodetector array. 4. An optical element provided in the optical element unit is configured to generate a second beam from at least a portion of the light reflected from the medium, the second beam being the second beam. An apparatus according to claim 3, characterized in that it impinges on a second photodetector array spaced from one photodetector array. 5. The apparatus of claim 4, wherein the second beam has a second focusing surface at a second distance from the second photodetector array. 6. The device of claim 5, wherein the second distance is different than the first distance. 7. The apparatus of claim 5, wherein the first focusing surface and the second focusing surface are on the same side of the photodetector surface. 8. The apparatus of claim 5, wherein the first and second focusing surfaces are located opposite the photodetector surface. 9. The first photodetector array and the second photodetector array,
The device of claim 5, wherein the devices are substantially coplanar. 10. A second optical block mounted in a fixed position with respect to said optical element unit, said second optical block at least partially bending said first optical path, wherein said second optical block is not vertical. The device of claim 1 defining at least a portion of one optical path. 11. At least one for directing said at least first portion of said light reflected from said medium by said second optical block along a second path at least partially different from said first optical path. The apparatus of claim 10 including one first beam splitter. 12. The apparatus according to claim 11, wherein the second optical block includes a second beam splitter. 13. The apparatus of claim 12, wherein at least one of the first and second beam splitters is a polarizing beam splitter. 14. The optical element unit does not include an optical element configured to alter a focusing surface of light reflected from the medium.
The device according to. 15. The optical element unit further comprises at least one first forward light detecting optical element configured to direct at least a portion of the light from the first optical path to a forward light detecting detector. The apparatus of claim 1, comprising: 16. The apparatus according to claim 15, further comprising a circuit for controlling an output level of the light source using a signal from the detector for detecting forward light. 17. The device according to claim 1, wherein at least a part of at least one first surface of the optical element unit is coated. 18. The device of claim 17, wherein the coating is a substantially reflective coating. 19. The device of claim 17, wherein the coating is a substantially absorbent coating. 20. A position for reducing the incidence of stray light on the photodetector,
18. The device of claim 17, wherein the coating is applied. 21. The device of claim 17, wherein the coating is an antireflection coating. 22. The device according to claim 1, wherein the optical element unit has at least one first alignment mark located on at least one first surface of the optical element unit. 23. The device of claim 1, wherein the light source is an edge emitter laser. 24. The device of claim 1, wherein the light source is a VCSEL. 25. The light source is a blue light laser.
The device according to. 26. At least one first surface of the optical element unit adjacent to the second optical block is at least one first surface formed on the surface proximate at least a portion of an edge of the surface. The apparatus of claim 10 including a moat region. 27. The moat receives at least a portion of an adhesive introduced along the edge such that the adhesive does not extend beyond the mote and extends inside the edge. The device according to claim 26. 28. An optical head for a read / write device, comprising: a light source, first and at least a portion of the light from the light source directed to a data medium, and the light reflected from the data medium spaced apart. Two optical detector arrays, each of the photodetector arrays being responsive to light at a position along a first axis of the photodetector array, An optical system that provides an output that is substantially insensitive to light at a position along a second axis of the detector array that is normal to the detector array. 29. The first photodetector array includes first, second, and third substantially parallel bar-shaped photodetector regions, and the second photodetector array includes fourth and third photodetector regions. 29. The device of claim 28, including fifth and sixth substantially parallel bar-shaped photodetector regions. 30. Further comprising a circuit for combining signals from the first and second, third, fourth, fifth and sixth photodetector regions to provide at least a focus error signal and a data signal. 30. The device according to claim 29, characterized in that 31. A circuit further comprising a circuit for combining outputs from the first, third, fourth, and sixth photodetector array regions to provide at least a first tracking error signal. 29. The device according to 29. 32. The apparatus of claim 30, wherein the focus error signal is substantially a linear function of the focus of the focus area including the reference focus point. 33. The size of at least the second and fifth photodetector areas relative to the first and third photodetector areas is selected to reduce crosstalk between the focus error signal and the tracking error signal. 30. The method according to claim 29, wherein
The device according to. 34. An objective lens for determining the rim light intensity at each outer peripheral position of the rim with respect to the central light intensity, wherein the rim light intensity is less than about 80% in the tangential direction. The device according to claim 1. 35. An objective lens for determining the light intensity of the rim at the outer peripheral position of each rim with respect to the light intensity of the center is further included, and the light intensity of the rim is less than about 80% in the radial direction. The device according to claim 1. 36. An objective lens for determining the rim light intensity at each outer peripheral position of the rim with respect to the central light intensity is further included, wherein the rim light intensity is less than about 50% in the tangential direction. The device according to claim 1. 37. The optical system further comprises an objective lens for determining the light intensity of the rim at the outer peripheral position of each rim with respect to the light intensity of the center, wherein the light intensity of the rim is less than about 15% in the radial direction. The device according to claim 1. 38. A portion of more than 50% of the total length of the first optical path is in a solid structure and a portion of less than 50% of the total length of the first optical path is in air. 1. The device according to 1. 39. A method of forming an optical head, comprising attaching a first light source to a substrate; etching at least first and second beam shaping optical elements of a first optical element unit; Mounting the optical element unit to the substrate in a position such that the first and second optical elements receive at least a portion of the light generated by the light source. 40. The method of claim 39, further comprising attaching a second optical block to the first optical block. 41. The method of claim 40, wherein the step of attaching the second optical block is performed before the step of attaching the first optical block to the substrate. 42. The method of claim 40, wherein the second optical block is configured to direct at least a portion of the light along a path that is not substantially vertical. 43. An optical disc read / write drive device, comprising: an optical arm movable with respect to an optical medium housed in a predetermined position of the drive; and at least a light source and an objective lens connected to the optical arm. An apparatus including an optical head, wherein the light source and the objective lens are maintained in a substantially fixed spatial relationship at least during a first movement of the optical arm. 44. The device of claim 43, wherein the first movement is a tracking movement. 45. The apparatus according to claim 43, wherein the first movement is a focusing movement. 46. The device of claim 43, wherein the light source comprises a laser. 47. The apparatus of claim 43, wherein the light source is an edge emitting laser diode. 48. The apparatus of claim 43, wherein the light source comprises a VCSEL. 49. The light source of claim 4, wherein the light source comprises an optical fiber.
The apparatus according to item 3. 50. A method of assembling elements of an optical disk read / write drive for determining the position of an optical medium, the step of mounting an optical arm movably with respect to the position of the optical medium located in the drive. And connecting an optical head to the optical arm including at least one light source and an objective lens, the light source and the objective lens being substantially fixed during at least a first movement of the optical arm. And a step of maintaining the spatial relationship established. 51. The method of claim 50, wherein the light source comprises a laser. 52. The method of claim 50, wherein the light source is an edge emitting laser diode. 53. The method of claim 50, wherein the light source comprises a VCSEL. 54. The light source of claim 5, wherein the light source comprises an optical fiber.
The method described in 0. 55. The method of claim 50, wherein the first movement is a tracking movement. 56. The method of claim 50, wherein the first movement is a focusing movement. 57. An optical disc read / write drive, comprising arm means for supporting an optical system movably with respect to an optical medium disposed in the drive, and light from a light emitting means for transmitting light from the optical medium. Optics coupled to said arm means for delivering to a position, said light emitting means and said optics means being in a substantially fixed spatial relationship at least during a first movement of said arm means. A device characterized by being maintained. 58. The apparatus of claim 57, wherein the light source comprises a laser. 59. The apparatus of claim 57, wherein the light source is an edge emitting laser diode. 60. The apparatus of claim 57, wherein the light source comprises a VCSEL. 61. The light source of claim 5, wherein the light source comprises an optical fiber.
7. The device according to 7. 62. The apparatus of claim 57, wherein the first movement is a tracking movement. 63. The apparatus of claim 57, wherein the first movement is a focusing movement. 64. An optical head used in a surface-defining optical medium read / write device, comprising: a first silicon wafer chip having an electronic component formed on an upper surface; and a fixed position attached to the chip. A light source and at least one first light source disposed at a fixed position with respect to the chip, arranged to receive the light emitted from the light source and reflect the light to change its direction. A component including a mirror and an optical element mounted at a fixed position with respect to the light source, wherein an optical element included in the component including the optical element is at least a part of the light reflected from the mirror. A component including the optical element for receiving and changing light, and an objective lens mounted at a fixed position with respect to the component including the optical element for focusing light on the medium. , Light from the light source travels along an initial optical path, the light is reflected by the first mirror to a component including the optical element, and passes through the objective lens along a path including a first path. And an objective lens configured to move at least to the medium. 65. The optical head of claim 64, further comprising at least one first spacer attached to the chip. 66. The optical head of claim 65, wherein the first mirror is integrally formed as a part of the spacer. 67. The apparatus of claim 64, wherein the light source comprises a laser. 68. The apparatus of claim 64, wherein the light source is an edge emitting laser diode. 69. The apparatus of claim 64, wherein the light source comprises a VCSEL. 70. The light source according to claim 6, wherein the light source comprises an optical fiber.
The device according to 4. 71. The apparatus of claim 64, wherein the first path is substantially parallel to the plane defined by the medium. 72. The apparatus of claim 64, wherein the component containing the optical element comprises an optical die and an adjacent periscope block. 73. The total vertical distance from the light source to the surface of the medium is about 5 m.
65. The device of claim 64, which is less than m. 74. The apparatus of claim 64, further comprising a photodetector mounted in a fixed position with respect to the chip. 75. The apparatus of claim 74, wherein the photodetector is a segmented photodetector. 76. The component including the optical element includes at least one first optical element that discriminates between emitted light and reflected light.
The device according to 4. 77. At least one component including the optical element receives reflected light from the medium along a second path and supplies at least a portion of the reflected light to the photodetector. 77. The apparatus of claim 74, further comprising a first optical element. 78. The apparatus of claim 77, wherein the second path is substantially parallel to the axis of rotation of the medium. 79. A component including the optical element includes a periscope block, the periscope block receiving light along the second path and reflecting the light along a third path. 79. The apparatus of claim 78, wherein the third path is substantially parallel to the plane of the medium. 80. A fourth periscope block disposed along the initial optical path and extending from the third path and substantially parallel to an axis of rotation of the medium.
80. At least one first means for reflecting at least a portion of the light is included in the path, the first means being adapted to substantially discriminate light reflected from the medium. The described device. 81. The apparatus of claim 80, wherein the first means comprises a polarizing beam splitter. 82. The first means for distinguishing by substantially transmitting light reflected from the medium and substantially reflecting at least some other light. The device according to. 83. The first means discriminates by substantially reflecting light reflected from the medium and substantially transmitting at least some other light. The device according to. 84. At least one first quarter wave plate disposed substantially along the optical path between the polarizing beam splitter and the objective lens. Item 80. The apparatus according to item 80. 85. The apparatus of claim 69, wherein the first path is substantially perpendicular to the axis of rotation of the medium. 86. The apparatus of claim 69, wherein the first path is substantially parallel to the axis of rotation of the medium. 87. A substantially finite conjugate structure if the optical path is not collimated along the optical path between the light source and the objective lens.
70. The device of claim 69 having a conjugate configuration). 88. A method of using a surface defining optical medium read / write device, the method comprising: forming electronic components on a first silicon wafer chip; and mounting a light source in a fixed position with respect to the chip. And arranging at least one first mirror at a fixed position with respect to the light source and the chip so as to receive the laser light emitted from the laser diode and reflect the light to change its direction. And a step of mounting a component including an optical element at a fixed position with respect to the spacer, wherein the optical element included in the component including the optical element receives at least a part of the light reflected from the mirror. And the objective lens is placed in a fixed position with respect to the component including the optical element to focus the light on the medium. A step of applying a starting optical path for the laser light, the starting optical path starting from the light source and passing through the first mirror to a component including the optical element. Further arriving at least the medium via an objective lens such that a part of the starting optical path from a component including the optical element to the objective lens includes a first optical path. A method comprising. 89. The method of claim 88, further comprising mounting a photodetector at a fixed location with respect to the chip. 90. Light is reflected from the medium and travels along a path of the reflected light that includes at least a second optical path that is substantially parallel to an axis of rotation of the medium, the reflected light 89. The method of claim 88, further comprising using a component including an optical element to position at least a portion of the initial optical path along a path different from the path of light. 91. The component including the optical element includes a periscope block, and the periscope block has a first reflecting surface that receives light along the second path and reflects the light along a third path. 89. The method of claim 88, wherein said third path is substantially parallel to said media plane. 92. A polarized beam for the periscope block disposed along the optical path to reflect light from the third path to a fourth path substantially parallel to an axis of rotation of the medium. 92. The method of claim 91, further comprising disposing a splitter, wherein the polarizing beam splitter is substantially transparent to light reflected from the medium. 93. The method further comprising disposing at least one first quarter wave plate substantially along the starting optical path between the polarizing beam splitter and the objective lens. 93. The method of claim 92, wherein 94. An optical head device for use in an optical medium reading / writing device defining a surface, the first substrate having electronic components disposed on the surface, and a fixed position with respect to the substrate. A light emitting means attached to the light emitting means, the light emitting means being in a fixed position with respect to the substrate, receiving the light emitted from the light emitting means, reflecting the light and changing its direction. At least one first mirror means disposed with respect to the optical emission means, and an optical element attached to the light emitting means at a fixed position, the optical element included in the means including the optical element, Means for receiving and modifying at least a portion of the light reflected from the mirror means, the means including the optical element, and a fixed position relative to the means including the optical element for focusing the light on the medium. attachment Objective means for defining at least a starting optical path for the light, the starting optical path starting from the light emitting means and including the optical element via the first mirror means. And an objective unit that reaches at least the medium via the objective unit. 95. The apparatus of claim 94, further comprising at least one first spacer means attached to the substrate. 96. The apparatus of claim 94, wherein the means comprising the optical element comprises the substrate. 97. The apparatus of claim 94, further comprising photodetector means mounted in a fixed position with respect to the substrate. 98. The apparatus of claim 94, further comprising means for discriminating between emitted light and reflected light. 99. Further comprising means for receiving light reflected from said medium along a second path and supplying at least a portion of said reflected light to said photodetector means. Item 95. The apparatus according to Item 95. 100. Means for receiving light along the second path and reflecting the light along the third path, the third path being substantially parallel to a surface of the medium. 95. The device of claim 94, wherein 101. The method of claim 94, further comprising means for reflecting light from the third path to a fourth path that is substantially parallel to the axis of rotation of the medium.
The device according to. 102. The apparatus of claim 94, wherein the substrate is selected from silicon wafer chips and flexible circuit boards. 103. The device of claim 102, wherein the flexible circuit board comprises polyimide. 104. The apparatus of claim 94, wherein the light emitting means is selected from edge emitting laser diodes and VCSELs. 105. The flexible circuit board means further comprising: a circuit on the board connected to a circuit on the flexible circuit board means.
The device according to. 106. The substrate has a major surface extending to a first surface, the first portion of the flexible circuit board means being substantially parallel to the first surface and the flexible surface. 106. The apparatus of claim 105, wherein at least a second portion of the sex circuit board means is not parallel to the first surface. 107. The apparatus of claim 105, wherein the substrate is at least partially disposed in a cutout provided in the flexible circuit board means. 108. The apparatus of claim 105, wherein the flexible circuit board means includes at least one first thermally conductive coating that exchanges heat with at least a portion of the substrate. 109. A method of manufacturing an optical head, the method comprising: forming a plurality of electronic circuits on a silicon wafer having at least a first surface defining a surface; and at least a first light source comprising at least the electronic circuit. Mounting a plurality of light sources on the silicon wafer so as to be arranged adjacent to a part, and arranging a plurality of spacer bars each having a longitudinal axis, wherein each bar is Defining a plurality of mirror surfaces such that the mirror surface is at an angle of about 45 degrees with respect to the surface of the wafer surface; and cutting the wafer along a plurality of score lines to provide a plurality of Providing a wafer chip, wherein at least a portion of the wafer chip comprises at least a light source attached thereto and the spacer bar. Two parts, at least a part of the score line intersecting at least a part of the spacer bar, and providing output and control signals to the first light source, whereby the light source emits light. Emitting, and positioning at least one first optical component with respect to the light source of at least one first chip while the light source on the chip emits light. And how to. 110. The first optical component is a component that includes an optical element having a plurality of optical elements formed thereon, and wherein the step of positioning includes substantially at least one of the optical elements of the light. 110. The method of claim 109, wherein the first optic is moved to one center. 111. The optical head includes at least one photodetector, the first optical component is a periscope block defining a path for emitting reflected light, and the positioning step comprises: 110. The method of claim 109, further comprising moving the first optical component until an emission axis is in a predetermined relationship with the photodetector. 112. The method of claim 109, wherein an objective lens is mounted over the first optical component during the positioning step.