KR100767930B1 - Apparatus and method for multiplex of beam route, apparatus and method for processing of optical information using apparatus for multiplex of beam route - Google Patents

Abstract

An apparatus and a method for multiplexing a beam route, and an apparatus and a method for processing optical information using the multiplexing apparatus are provided to vary the incident angle of reference beam by using an optical device having a reflection surface and a convex focusing the reflected lights. An apparatus for multiplexing a beam route comprises an optical device(110), an actuator(140), a control part(130), and a lens(150). The optical device has a reflection surface of reflecting the projection light and a convex of focusing the reflected lights from the reflection surface. The actuator moves the optical device on the optical path of the projection light. The control part controls the actuator. The lens guides the reflected lights to the same area. A sensor(120) detects the permeable light from the reflection surface to measure the position of the optical device.

Description

Optical path multiplexer and optical path multiplexing method, optical information processing apparatus and optical information processing method using optical path multiplexer {Apparatus and Method for multiplex of beam route, Apparatus and Method for processing of optical information using apparatus for multiplex of beam route}

1 is a block diagram showing the configuration of an optical path multiplexer according to an embodiment of the present invention.

2 is a schematic diagram showing focus due to astigmatism of an aspherical surface of an optical element of an optical path multiplexer.

3A to 3C are schematic views illustrating a state in which a focus caused by astigmatism of FIG. 2 is incident on a detector.

4 is a block diagram illustrating a light path multiplexing method according to an embodiment of the present invention.

5 is a block diagram showing the configuration of an optical information processing apparatus using an optical path multiplexer according to an embodiment of the present invention.

6A and 6B are exemplary views illustrating angle multiplexing using a light path multiplexer.

7 is a flowchart showing an optical information recording method according to an embodiment of the present invention.

8 is a flowchart illustrating a method of reproducing optical information according to an embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

10: light source

20: first optical splitter

100: optical path multiplexer

110: optical element

120: detector

130: control unit

140: actuator

150: objective lens for the reference light

200: information light optical system

300: reference light optical system

400: regenerative light detector

500: optical information storage medium

The present invention relates to an optical path multiplexer, an optical path multiplexing method, an optical information processing apparatus using an optical path multiplexer, and an optical information processing method, and more particularly, an optical path multiplexer capable of angular multiplexing using an optical element. And an optical path multiplexing method, an optical information processing apparatus using an optical path multiplexer, and an optical information processing method.

Optical data processing apparatuses include Digital Versatile Disc (DVD), HD-DVD, Blu-ray Disc (BD), near field optical information processing apparatus, and holographic optical information processing apparatus.

The holographic optical information processing apparatus separates light having coherency generated by a laser light source into an information beam and a reference beam containing optical information, and simultaneously splits the two lights onto the optical information storage medium. When incident, the spatial interference pattern of two lights is recorded, and when only the reference light is incident on the optical information storage medium when the optical information is reproduced, the reference light is diffracted in the recorded interference pattern to reproduce the information light having the optical information.

Unlike conventional methods such as DVD, which stores brightness information one by one for each specific coordinate to store optical information, the holographic optical information processing apparatus uses Fourier transform method to convert the entire information of the plane. It is a mass storage technology that uses a page-oriented memory method that records at one point.

In addition, the holographic optical information processing apparatus uses a multiplexing technique, which is a technique of overlapping recording and reproduction of holograms at the same point in order to increase the recording density of data. Multiplexing techniques include angle multiplexing, phase-coded multiplexing, wavelength multiplexing, and shift multiplexing.

Here, the angle multiplexing method is to change the incident angle of the reference light incident on the optical information storage medium, the phase code multiplexing method is to spatially modulate the phase, and the wavelength multiplexing method is to store the optical information according to the wavelength change using a wavelength tunable laser The interference fringes recorded on the medium are changed, and the shift multiplexing is recorded while moving the optical information storage medium.

In the angular multiplexing method, a galvano mirror vibrating or rotating at a high speed of several micrometers changes the incident angle of the reference light incident on the optical information storage medium, and uses the pair of lenses to convert the reference light having the changed incident angle into the optical information. There is a method of angular multiplexing by entering one optical information storage area of a storage medium.

These galvano mirrors are made of special glass, and the coils and permanent magnets are attached for fine vibrations so that the mirrors vibrate or rotate according to electrical signals.

The galvano mirror should use a plurality of lenses for focusing incident light. Therefore, the reflective optical system using the galvano mirror has a high manufacturing cost and a large volume, which makes it difficult to use the optical information processing apparatus that is miniaturized.

An object of the present invention is to provide an optical path multiplexer, an optical path multiplexing method, an optical information processing apparatus using an optical path multiplexer, and an optical information processing method capable of shortening an optical path and angular multiplexing.

Optical path multiplexer according to an embodiment of the present invention for achieving this object is an optical element formed with a reflective surface for reflecting the incident light and a convex surface for focusing the reflected light emitted from the reflective surface and the optical element to the incident light And an actuator for moving on the optical path of the controller and a control unit for controlling the actuator.

The optical device may further include a lens configured to incidently guide the plurality of the reflected light emitted from different positions due to the movement of the optical device.

The convex surface is provided with a spherical surface, while the reflective surface is provided with a semi-transmitting film, and the optical element has transmitted light passing through the reflective surface partially through astigmatism. Aspheric convex surface may be further provided.

In addition, a detector for detecting the transmitted light may be further provided to measure the position of the optical element.

The detector may be a four-segment detector that detects a change in the light amount distribution of the transmitted light incident on the detector according to a distance from the aspherical convex surface.

According to another aspect of the present invention, there is provided a light path multiplexing method, which splits incident light incident from a light source into reflected light and transmitted light into a semi-transmissive reflective surface of an optical device, and measures the position of the optical device by detecting the transmitted light. Changing the optical path of the reflected light by moving the position of the device to a set position, and focusing the reflected light by the optical element moved to the set position.

In the step of measuring the position of the optical element, it is possible to detect a change in the light amount distribution of the transmitted light incident on the sensor by astigmatism.

In the changing of the optical path of the reflected light, the optical device may be moved along the optical path of the incident light.

An optical information processing apparatus according to still another embodiment of the present invention includes a light source and a reference light optical system incident on the light emitted by the light source as reference light for processing optical information on an optical information storage medium, and a reflecting surface reflecting the reference light and the anti-reflection light. And an optical path multiplexer for multiplexing an optical path of the reference light by moving an optical element having a convex surface that focuses the reference light reflected and emitted from a slope to an actuator.

The information light optical system may further include an information light optical system incident on the optical information storage medium by loading data into one light divided from light emitted by the light source to make the information light.

The apparatus may further include a reproducing light detector for detecting optical information reproduced by the interference pattern recorded on the optical information storage medium.

The actuator may move the optical device on an optical path of the reference light incident to the optical device.

The optical path multiplexer further includes an objective lens for reference light between the optical element and the optical information storage medium, and the reference light reflected by the optical element is smaller than a diameter of the objective lens for reference light. The reference light objective lens, which is incident on a portion of the surface of the reference light, may guide the plurality of reference light incident to different locations by the moving optical element to the same point of the optical information storage medium.

The reflecting surface may be provided as a semi-transmitting film, and the optical path multiplexer may further include an aspheric convex surface such that the servo light partially transmitted through the reflecting surface proceeds to astigmatism. have.

The optical path multiplexer further includes a detector for detecting the servo light, wherein the detector is a quadrature sensor that detects a change in the light quantity distribution of the servo light incident on each split detection unit by the astigmatism of the aspherical convex surface. Can be detected.

The optical path multiplexer may measure the position of the optical device by a change in the light amount distribution of the servo light detected by the detector.

The optical information processing method according to another embodiment of the present invention comprises the steps of separating the servo light from the light emitted from the light source to the optical information storage medium to the optical element, and measuring the position of the optical element with the servo light and Changing the path of the light incident on the optical information storage medium by moving the position of the device to a set position; and processing the optical information on the optical information storage medium by entering the light back into the optical device.

In the processing of the optical information, the light emitted from the light source is divided into information light and reference light, the information light is loaded into the optical information storage medium by loading optical information, and the reference light is transmitted through the optical element. The optical information may be recorded into the optical information storage medium.

In the processing of the optical information, the light enters the optical information storage medium as a reference light for optical information reproduction, and generates optical information reproduction light from an interference pattern recorded on the optical information storage medium, and the optical information reproduction light Can be detected.

In the measuring of the position of the optical element, the position of the optical element may be measured by analyzing the amount of light of the servo light incident on the detector.

In the step of changing the path of the light incident on the optical information storage medium, the point where the light reflected by the optical element is incident on the objective lens for the reference light is changed to change the incident angle of the light incident on the optical information storage medium. have.

On the other hand, the step of measuring the position of the optical element and the step of processing the optical information can be performed at the same time.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

1 is a block diagram showing the structure of an optical path multiplexer according to an embodiment of the present invention.

Referring to FIG. 1, the optical path multiplexer 100 includes an optical element 110, an actuator 140 for linearly moving the optical element 110, and a detector 120 for detecting light incident from the optical element 110. The control unit 130 and the lens 150 are configured to control the actuator 140 by analyzing the light detected by the detector 120.

The optical element 110 includes an incident surface 111 through which incident light IL passes and is incident, a reflective surface 112 reflecting incident light IL transmitted through the incident surface 111, and a reflective surface 112. A spherical convex surface 113 for collecting reflected light RL reflected to one focal point is provided.

The reflective surface 112 is formed by coating a non-polarization semi-transmitting film capable of partially reflecting and partially transmitting the incident light IL. The semi-transmissive film is a thin film made of a metal such as molybdenum (Mo), and silicon (silicon, Si) and oxygen (oxygen, O), and is an oxide of molybdenum silicon (MoSiO-based material) or molybdenum silicon. Molybdenum silicides such as nitride oxides (MoSiON-based materials) may be used. By selecting the oxygen content or the nitrogen and oxygen content of the molybdenum silicide, the transmittance of the semipermeable membrane can be adjusted.

Transmitted light (TL) partially transmitted through the reflective surface 112 is used to detect the position of the optical element, and the optical element 110 focuses the transmitted light TL according to astigmatism. An aspheric convex surface 114 is further provided.

The spherical convex surface 113 is spherical and has one focal point and forms an image, while the aspherical convex surface 114 is aspheric and has long focus and short focus. In this case, the spots away from the optical axis do not form an image on the same plane, but form a plurality of images on different planes, indicating a distortion of image.

The actuator 140 preferably moves the optical element 110 on the optical path of the incident light IL so that the incident light IL incident to the optical element 110 is always incident, and the actuator 140 has a piezoelectric element. element), a small linear motor, and the like can be used.

Detector 120 is a four-segment detector for detecting the change in the amount of light transmitted through the reflection surface 112 of the optical element 110, PN photodiode, avalan which is an optical sensor that converts light energy into electrical energy Avalanche photodiode or the like may be used.

The controller 130 calculates a focus signal (FS) from the change in the amount of light of the transmitted light TL detected by the detector 120 to determine the position of the optical element 110 and to move the optical element 110. Control 140. The focus signal FS will be described in detail with reference to FIGS. 2 and 3.

The reflected light RL is reflected on the reflecting surface 112 of the optical element 110 and is incident on the lens 150. The reflected light RL has a width smaller than the diameter of the lens 150 and is applied to a portion of the lens 150. The incident light and the lens 150 change the propagation angle of the reflected light RL according to the incident point of the incident reflected light RL. Since the reflected light RL transmitted through the lens 150 passes the focal point of the lens 150, even if the optical path of the reflected light RL incident on the lens 150 changes as the optical element 110 moves, the lens is changed. The reflected light RL passing through 150 may pass all the focal points of the lens 150 by varying the incident angle.

2 is a schematic diagram showing focus due to astigmatism of an aspherical surface of an optical element of an optical path multiplexer.

Referring to FIG. 2, the transmitted light TL emitted from the aspheric convex surface 114 of the optical element 110 and incident on the detector 120 has a long focal point C and a short focal point A due to astigmatism. )

The transmitted light TL is focused in a short line A in the xy direction, and in a long focus C, it is focused in a long line in the -xy direction, and the central portion of the short focus A and the long focus C is focused. In (B), the focus is circular.

Of course, the direction of the aspherical surface of the aspherical surface convex surface 114 may be changed to focus in the form of a line in the xy direction at the short focal point A, and may be focused in the form of a line in the xy direction at the long focal point C.

When the detector 120 is provided between the short focal point A and the long focal point C, the distribution of the transmitted light TL incident on the detector 120 varies depending on the distance between the optical element 110 and the detector 120. Can be measured.

3A to 3C are schematic views illustrating a state in which a focus caused by astigmatism of FIG. 2 is incident on a detector. FIG. 3A shows the detector 120 located at the short focal point A. FIG. 3B shows the detector 120 located at the central part B of the short focal point A and the long focal point C. FIG. When 120 is located at the long focal point C, the distribution of transmitted light TL incident on the detector 120 is shown.

3A to 3C, the detector 120 is a four-segment detector and includes a first split detector 121, a second split detector 122, a third split detector 123, and a fourth split detector ( 124). The amount of light incident on the first split detector 121 a, the amount of light incident on the second split detector 122 b, the amount of light incident on the third split detector 123 c, the fourth split detector When the amount of light incident on 124 is d, the change in the distribution of the transmitted light TL incident on the detector 120 is defined as a focus signal (Focus Signal, FS), and FS = (a + d)-(b + c). Can be measured.

When the detector 120 is located at the short focal point A, that is, when the optical element 110 moves and approaches the detector 120, the detector 120 is moved to the first split detector 121 and the fourth split detector 124. Since the light amount of the incident transmitted light TL is greater than the light quantity of the transmitted light TL incident on the second split detector 122 and the third split detector 123, the focus signal FS may have a positive value. Indicates.

When the detector 120 is located at the central portion B of the short focal point A and the long focal point C, the servo light S incident to the detector 120 becomes circular and the focus signal FS is zero. )

When the detector 120 is located at the long focal point C, that is, when the optical device 110 is far from the detector 120, the focus signal FS represents a negative value.

Accordingly, the controller 130 may obtain the focus signal FS by the change in the amount of light transmitted from the detector 120 to determine the position of the optical device 110, and control the actuator 140 to control the optical device. 110 may be moved to a desired position.

4 is a block diagram illustrating a light path multiplexing method according to an embodiment of the present invention.

Referring to FIG. 4, the incident light IL incident to the optical device 110 of the optical path multiplexer 100 is divided into the reflected light RL and the transmitted light TL by the reflecting surface 112. The reflected light RL is incident to the desired incident point through the lens 150, and the transmitted light TL is incident on the detector 120 while being focused according to the astigmatism of the aspherical convex surface. The detector 120 measures the amount of light a, b, c, d of the transmitted light TL incident on the split detection units 121, 122, 123, and 124. The controller 130 calculates the focus signal FS and FS = (a + d) − (b + c) from the light amount distribution of the transmitted light TL measured by the detector 120 to determine the position of the optical element 110. Measure (S10).

The control unit 130 moves the optical element 110 from the measured position of the optical element 110 to the position set by using the actuator 140 to determine the optical path of the reflected light RL by the incident light IL again incident. Change (S20).

When light is incident on the optical element 110 whose position is changed again, the reflected light RL is changed by the optical path and focused by the convex surface 113 (S30).

As the reflected light RL whose optical path is changed is transmitted through the lens 150, the reflected light RL becomes a reflected light RL having an incident angle different from that of the preceding reflected light RL at the focal point of the lens 150. At this time, when the position of the optical element 110 is measured again, and the optical element 110 is moved to the set position and the incident light IL is incident again, the preceding reflected light RL and the incident angle are changed at the focal point of the lens 150. It becomes another reflected light RL.

By repeating the above process, it is possible to perform angular multiplexing in which light having different incident angles is incident at one point.

The optical path multiplexer described above may be used in a holographic data storage (HDS) optical information processing device, an optical measuring device such as a three-dimensional scanner, a micro processing device using a laser, an image forming device using a light, and an inspection device of a printed circuit board. Can be. In addition, the optical path multiplexer may be embodied by various modifications or changes to the device and components of the device using light.

Hereinafter, an optical information processing apparatus capable of multiple recording and reproducing optical information using the above-described optical path multiplexer will be described.

5 is a block diagram showing the configuration of an optical information processing apparatus using an optical path multiplexer according to an embodiment of the present invention.

Referring to FIG. 5, an optical information processing apparatus includes an information light optical system 200 and an information light I that are loaded with data into light to form an information beam I and enter the optical information storage medium 500. Optical path multiplexer 100 for multiplexing the optical path of the reference light optical system 300 and the reference light (R) for providing a reference beam (R) for interfering to record the interference pattern on the optical information storage medium 500 by interference ). And a reproduction light detector 400 for detecting the reproduction information of the optical information when the optical information is reproduced.

The light emitted from the light source 10 is divided by the first light splitter 20 and provided to the information light optical system 200 and the reference light optical system 300, respectively. The light source 10 has good coherency. He-Ne laser, Ar laser, and semiconductor laser may be used, and the light emitted from the light source 10 may be blue light having a wavelength between 450 nm and 500 nm or green light having a wavelength between 500 nm and 570 nm. light).

A collimator lens 11 for converting the light emitted from the light source 10 into parallel light is provided, and a half-wave plate for adjusting the amount of parallel light passing through the collimator lens 11 and converting it into P-polarized light. (Half Wave Plate, HWP; 12) is provided.

The first light splitter 20 divides the light passing through the half-wave plate 12 and provides the information light optical system 200 and the reference light optical system 300, respectively. The first light splitter 20 is a non-polarization type. Non-Polarizer Beam Splitters are preferred.

The light split in the first light splitter 20 and incident on the information light optical system 200 is used as the information light I, and the light incident on the reference light optical system 300 is used as the reference light R.

The information light optical system 200 includes a shutter 201, a beam expander 202, a second light splitter 210, a quarter wave plate QWP 211, and a spatial light modulator. A modulator, an SLM 220, a spatial filter 230, and a Fourier transform lens 240.

The shutter 201 may open the information light I incident to the information light optical system 200 at the time of recording the optical information and block the information light when the optical information is reproduced, and the beam expander 202 may transmit the information light having passed through the shutter 201 ( Expand I) to an area suitable for loading data in the spatial light modulator 220.

The second light splitter 210 is a polarizer beam splitter that transmits P-polarized light and reflects S-polarized light, and transmits the information light I of P-polarized light incident through the beam expander 202.

The quarter wave plate 211 converts the information light I of the P polarization incident from the second light splitter 210 into a circularly polarized light and enters the spatial light modulator 220, and the spatial light modulator 220. Information light I of circularly polarized light incident from

The spatial light modulator 220 reflects spatial light of a digital micro-mirror device (DMD) capable of modulating binary data on a pixel basis and loading the information into the information light (I). Modulators are used.

The information light I loaded with data from the spatial light modulator 220 is converted into S-polarized light while passing through the quarter wave plate 211, and the information light I of the S-polarized light is reflected by the second light splitter 210. And enter the spatial filter 230 provided at one side of the second light splitter 210.

The spatial filter 230 includes a first lens 231 to which the information light I is incident, a pin hole 232 having a diameter of several tens of micrometers or less, and a second lens 233 for converting the information light I into parallel light. ) Is provided. The spatial filter 230 removes the high-frequency spike noise generated by the information light I by the scattering of various fine materials in the optical path to form a Gaussian beam having a flat intensity distribution.

The Fourier transform lens 240 performs Fourier transform on the information light I passing through the spatial filter 230 and enters the optical information storage medium 500.

On the other hand, the reference light optical system 300 includes a reflection mirror 301 to enter the reference light (R) to the optical path multiplexer 100, the optical path multiplexer 100 is an optical element 110, a detector (Photodiode; 120, the controller 130, an actuator 140, and an objective lens 150 for reference light are angularly multiplexed with the reference light R incident on the optical information storage medium 500.

The reference light R split by the first light splitter 20 and incident on the reference light optical system 300 is reflected by the reflection mirror 301 to be incident on the optical element 110. The optical element 110 is a semi-transmissive film ( The reference light R is divided by the reflecting surface 112 coated with a semi-transmitting film to generate a servo beam S for angular multiplexing.

The reference light R is reflected by the reflective surface 112 of the optical element 110 and incident on the optical information storage medium 500. The servo light S is transmitted through the reflective surface 112 and incident on the detector 120. )to be.

The reference light R is reflected on the reflecting surface 112 of the optical element 110 and is incident on the optical information storage medium 500 through the reference light objective lens 150. The reference light objective lens 150 is the reference light objective. The incident angle of the reference light R incident on the optical information storage medium 500 is changed according to the incident point of the reference light R incident on the lens 150.

The detector 120 is a four-segment detector for detecting a change in the amount of light of the servo light S transmitted through the reflecting surface 112 of the optical element 110, and the controller 130 detects the servo light S detected by the detector 120. Control the actuator 140 to move the optical element 110 in accordance with the change in the amount of light. The actuator 140 preferably moves the optical element 110 on the optical path of the reference light R so that the reference light R incident to the optical element 110 is always incident.

When the reference light R and the information light I enter the optical information storage medium 500, an interference pattern is recorded, and the reference light R is blocked by the shutter 201 so that only the reference light R is used as the optical information storage medium ( When the light enters the light source 500, an optical information reproduction beam (OR) is generated by the interference pattern recorded on the optical information storage medium 500.

The optical information storage medium 500 is a silver salt photosensitive plate coated with gelatin mixed with silver salts such as AgBr on a substrate such as polyethylene resin or glass, which was first used by Shankoff of the United States in 1968, and is a kind of very transparent derivative protein. Gelatin (Dichromatic Gelatin; DCG), Photopolymer, a type of photocurable polymer in which interference patterns are recorded by the change of monomer into polymer, Thermoplastic, whose thickness is changed by exposure. Photochromic material, which changes color by color, and a bacteriorhodosin (Halobacterium Salinarium), which has a photosensitive characteristic in the form of a transmembrane as a photoreceptor.

The optical information storage medium 500 is provided with a reproduction light detector 400 for detecting the optical information reproduction light (OR) on the opposite side of the incident side of the information light (I), the optical information storage medium 500 and the reproduction light The detection lens 410 is provided between the detectors 400.

The reproduction light detector 400 may employ an image sensing device having a pixel array such as a charge-coupled device (CCD) and a complementary metal-oxide semiconductor (CMOS).

The detection lens 410 converts the optical information reproduction light OR generated by the optical information storage medium 500 into parallel light and enters the reproduction light detector 400.

As described above, the configuration of the optical information processing apparatus capable of recording and reproducing optical information has been described. However, the optical information reproducing apparatus capable of reproducing optical information except for the information optical optical system 200 may be configured. In the above-described configuration, an optical information recording apparatus capable of recording optical information may be configured except for the reproduction light detector 400 and the detection lens 410.

The angle multiplexing for changing the incident angle of the reference light R incident on the optical information storage medium 500 in the above optical information processing apparatus will be described.

6A and 6B are exemplary views illustrating angle multiplexing using a light path multiplexer.

FIG. 6A illustrates a case where the optical element 110 is closest to the detector 120 and the reference light R is incident on the objective lens 150 for the reference light. The case is shown far away.

The optical element 110 is moved by the actuator 140, and moves along the optical path of the reference light R incident to the optical element 110.

Accordingly, the reference light R incident on the incident surface 111 of the optical element 110 is incident on the same point of the incident surface 111 even when the optical element 110 moves, and the reflective surface 112 of the optical element 110 is incident. The point where the servo light S transmitted through) passes through the aspherical convex surface 114 and enters the detector 120 also enters the same point of the detector 120 regardless of the movement of the optical element 110. However, the shape in which the servo light S transmitted through the aspherical surface 114 is incident on the detector 120 is distorted according to the distance between the optical element 110 and the detector 120 due to astigmatism. ) It is different from the phenomenon.

Meanwhile, the reference light R reflected by the reflecting surface 112 of the optical element 110 and incident on the objective lens 150 for the reference light has an area smaller than the diameter of the objective lens 150 for the reference light. As it moves, it is incident on a portion of the objective light for reference light 150. The plurality of reference lights R incident on other portions of the reference light objective lens 150 are refracted by the reference light objective lens 150 and incident at the same point. When the optical information storage medium 500 is positioned at this point, A plurality of reference lights R having different incidence angles are incident on one optical information storage area.

For example, when the optical element 110 moves and enters the reference light R into the reference light objective lens 150 closest to the detector 120, the reference light R is reflected by the reference light objective lens 150. It is refracted to enter the optical information storage medium 500. In this case, the point at which the reference light R is incident on the optical information storage medium 500 is the same as the point at which the reference light R passes through the center of the objective lens 150 for the reference light, and has a predetermined angle of incidence θ. ).

Even when the optical element 110 is farthest from the detector 120 and the reference light R is incident on the objective lens 150 for the reference light, the point where the reference light R is incident on the optical information storage medium 500 is referred to as the reference light ( R) is the same as the point of incidence passing through the center of the objective light lens 150 for reference light, and represents a difference?

Accordingly, the variation in the incident angle of the reference light R incident on the optical information storage medium 500 by the movement of the optical element 110 is determined in the range of 2θ, and the light amount distribution of the servo light S detected by the detector 120 is determined. By measuring the position of the optical element 110 to adjust the position of the optical element 110 with the actuator 140 can be angular multiplexing of the reference light (R) incident on the optical information storage medium (500).

7 is a flowchart showing an optical information recording method according to an embodiment of the present invention.

Referring to FIG. 7, the light emitted from the light source 10 is split into the information light I and the reference light R in the first light splitter 20, and the reference light R is reflected by the reflection mirror 301. It is incident on the optical element 110 of the optical path multiplexer 100. The optical element 110 generates the servo light S transmitted through the semi-transparent reflective surface 112 from the reference light R, and the servo light S is incident on the detector 120. The detector 120 detects the light amount of the servo light S incident to each split detector as a four-segment detector, and the controller 130 detects the light amount of the servo light S detected by each split detector of the detector 120. In comparison, the focus signal FS is obtained to measure the position of the optical device 110 (S110).

The controller 130 selects the optical element 110 using the actuator 140 on the optical path of the reference light R incident on the optical element 110 at the position of the optical element 110 determined by the focus signal FS. The optical path of the reference light R incident on the optical information storage medium 500 is changed by moving to the position of the optical information storage medium 500 (S120).

The light emitted from the light source 10 is divided into the information light I and the reference light R in the first light splitter 20 so that the information light I enters the information light optical system 200 and the reference light R Enters the reference light optical system 300. The information light I is loaded into the optical information storage medium 500 by loading the optical information from the spatial light modulator 220 of the information light optical system 200, and the reference light R is reflected by the reflection mirror 301 so that the optical light is reflected. The light is incident on the optical information storage medium 500 through the optical element 110 of the multiplexer 100 and the objective lens 150 for the reference light. The information light I and the reference light R form an interference pattern on the optical information storage medium 500 to record optical information (S130).

When recording optical information with the information light I and the reference light R, the optical path multiplexer 100 detects the servo light S transmitted through the reflecting surface 112 of the optical element 110 to detect the focus signal ( FS) may measure the position of the optical element 110. Therefore, the position of the optical element 110 can be measured simultaneously with the recording of the optical information, and the optical element 110 can be moved to the next position immediately after the recording of the optical information.

According to the position of the optical element 110, the reference light R is incident to another point of the objective lens 150 for the reference light by the changed optical element 110 and the optical information storage area of the optical information storage medium 500. It is incident by changing the incident angle. Therefore, angle multiplexing for recording a plurality of optical information in one optical information storage area of the optical information storage medium 500 can be performed.

8 is a flowchart illustrating a method of reproducing optical information according to an embodiment of the present invention.

Referring to FIG. 8, when the reference light R emitted from the light source 10 is incident on the optical element 110 of the optical path multiplexer 100, the optical element 110 passes through the semi-transparent reflective surface 112. Generate the servo light (S). The detector 120 detects the light amount of the servo light S incident to each split detector as a four-segment detector, and the controller 130 detects the light amount of the servo light S detected by each split detector of the detector 120. In operation S210, the position of the optical device 110 is measured by obtaining the focus signal FS.

The controller 130 selects the optical element 110 using the actuator 140 on the optical path of the reference light R incident on the optical element 110 at the position of the optical element 110 determined by the focus signal FS. The optical path of the reference light R incident on the optical information storage medium 500 is changed by moving to the position of the optical information storage medium 500 (S220).

The reference light R is incident again to the optical information storage medium 500 through the optical path multiplexer 100 and diffracted to the interference pattern recorded on the optical information storage medium 500 to generate optical information reproduction light OR. (S230).

The optical information reproduction light OR enters the reproduction light detector 400 through the detection lens 410, and the reproduction light detector 400 detects the optical information reproduction light OR (S240).

When generating the optical information reproduction light with the reference light (R), it is possible to measure the position of the optical element 110 by detecting the servo light (S) at the same time, and immediately after the optical information reproduction light (OR) detection the optical element 110 You can move it to the next location.

According to the position of the optical element 110, the reference light R is incident to another point of the objective lens 150 for the reference light by the changed optical element 110 and the optical information storage area of the optical information storage medium 500. It is incident by changing the incident angle. Therefore, a plurality of optical information recorded by angular multiplexing can be reproduced in one optical information storage area of the optical information storage medium 500.

As mentioned above, preferred embodiments of the present invention have been described in detail, but those skilled in the art to which the present invention pertains should understand the present invention without departing from the spirit and scope of the present invention as defined in the appended claims. It will be appreciated that various modifications or changes can be made. Therefore, changes in the future embodiments of the present invention will not be able to escape the technology of the present invention.

As described above, according to the present invention, compared to injecting the reference light into the optical information storage medium with a galvano mirror and a pair of lenses for angular multiplexing, it is a very small type that reflects and focuses the reference light while moving on the path of the incident reference light By using an optical path multiplexer that can multiplex optical paths with optical devices, the optical path of reference light can be shortened and the volume and cost of the optical information processing device can be reduced.

Claims (23)

An optical element having a reflective surface for reflecting incident light and a convex surface for focusing the reflected light emitted from the reflective surface; An actuator for moving the optical element on an optical path of the incident light; And And a controller for controlling the actuator. The optical path multiplexer of claim 1, further comprising a lens configured to guide the plurality of the reflected light emitted from different positions by the movement of the optical element to the same point. The optical path multiplexer of claim 1, wherein the convex surface is spherical. According to claim 1, wherein the reflective surface is provided with a semi-transmitting film (semi-transmitting film), the optical element is aspheric (aspheric) convex so that the transmitted light partially transmitted through the reflective surface proceeds in astigmatism (astigmatism) An optical path multiplexer further comprising a face. 5. The optical path multiplexer according to claim 4, further comprising a detector for detecting the transmitted light to measure the position of the optical element. 6. The optical path multiplexer according to claim 5, wherein said detector is a four-segment detector which detects a change in the light quantity distribution of said transmitted light incident on said detector according to a distance from said aspherical convex surface. Dividing the incident light incident from the light source into reflected light and transmitted light into a semi-transmissive reflective surface of the optical element, and detecting the transmitted light to measure the position of the optical element; Changing the optical path of the reflected light by moving the position of the optical element to a set position; And And focusing the reflected light by the optical element moved to the set position. 8. The method of claim 7, wherein the measuring of the position of the optical element comprises detecting a change in the light amount distribution of the transmitted light incident on the sensor by astigmatism. 8. The optical path multiplexing method according to claim 7, wherein the changing the optical path of the reflected light moves the optical element along the optical path of the incident light. Light source; A reference light optical system for incident light emitted from the light source into reference light for processing optical information in an optical information storage medium; And An optical path multiplexer for multiplexing an optical path of the reference light by moving an optical element having a reflective surface reflecting the reference light and a convex surface that focuses the reference light reflected from the reflective surface to an actuator; Optical information processing apparatus comprising a. 11. The optical information processing according to claim 10, further comprising an information optical optical system in which data is loaded into one light divided from the light emitted by the light source to make the information light and enter the optical information storage medium. Device. The optical information processing apparatus according to claim 10, further comprising a reproduction light detector for detecting the optical information reproduced by the interference pattern recorded on the optical information storage medium. The optical information processing apparatus according to claim 10, wherein the actuator moves the optical element on an optical path of the reference light incident on the optical element. The optical path multiplexer of claim 10, further comprising an objective lens for reference light between the optical element and the optical information storage medium, wherein the reference light reflected by the optical element is smaller than a diameter of the objective lens for reference light. The reference light objective is incident on a portion of the surface of the objective light objective lens, and the reference light objective lens is configured to guide the plurality of reference light incident to different positions by the moving optical element to the same point of the optical information storage medium. Optical information processing device, characterized in that. 11. The method of claim 10, wherein the reflecting surface is provided with a semi-transmitting film (semi-transmitting film), the optical path multiplexer aspheric convex (aspheric) convex so that the servo light partially transmitted through the reflecting surface proceeds to astigmatism (astigmatism) Optical information processing apparatus further comprising a surface. 16. The apparatus of claim 15, wherein the optical path multiplexer further comprises a detector for detecting the servo light, wherein the detector is a quadrature detector and the servo light is incident on each split detection unit of the detector by astigmatism of the aspherical convex surface. And an optical information processing apparatus for detecting a change in the light quantity distribution of the light. The optical information processing apparatus according to claim 16, wherein the optical path multiplexer measures the position of the optical element by a change in the light quantity distribution of the servo light detected by the detector. Separating the servo light into the optical element from the light emitted from the light source and incident on the optical information storage medium, and measuring the position of the optical element with the servo light; Changing the path of the light incident on the optical information storage medium by moving the position of the optical element to a set position; And Injecting the light back into the optical device to process the optical information in the optical information storage medium; Optical information processing method comprising a. 19. The method of claim 18, wherein the processing of the optical information divides the light emitted from the light source into information light and reference light, and the information light loads the optical information and enters the optical information storage medium. Is input to the optical information storage medium through the optical element to record the optical information. 19. The method of claim 18, wherein the processing of the optical information comprises generating the optical information reproduction light from an interference pattern recorded on the optical information storage medium by entering the optical information storage medium as the reference light for optical information reproduction. And detecting the reproduction information of the optical information. 19. The optical information processing method according to claim 18, wherein the measuring of the position of the optical element comprises measuring the position of the optical element by analyzing the amount of light of the servo light incident on the detector. 19. The method of claim 18, wherein the changing of the path of the light incident on the optical information storage medium comprises changing the point where the light reflected by the optical element is incident on the objective lens for the reference light, thereby entering the optical information storage medium. And an angle of incidence of the light. 19. The optical information processing method according to claim 18, wherein the step of measuring the position of the optical element and the processing of the optical information are performed simultaneously.

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