KR100806062B1 - Optical pickup apparatus and optical recording/reproducing system employing the optical pickup apparatus - Google Patents

Abstract

An optical pickup apparatus having two actuators and an optical recording / reproducing system employing the optical pickup apparatus are disclosed. An optical pickup apparatus according to the present invention comprises first and second actuators for individually driving two objective lenses, respectively, for recording / reproducing different types of optical recording media, and the first and second actuators. At least one of the three-axis drive, the first actuator is characterized in that the optical path is formed to the rear of the actuator, the second actuator is characterized in that the optical path is formed to the side of the actuator.

Description

Optical pickup apparatus and optical recording / reproducing system employing the optical pickup apparatus

Fig. 1 schematically shows the structure of a conventional actuator in which two objective lenses are arranged in one lens holder.

FIG. 2 schematically illustrates a conventional optical pickup apparatus in which one objective lens is disposed in each of two separately driven actuators.

Figure 3 schematically shows an optical pickup apparatus according to the present invention having two actuators.

FIG. 4 shows the structure of the first actuator shown in FIG. 3 in more detail.

5A and 5B schematically show the structure of the track coil and the first magnet portion of the first actuator, respectively.

6A and 6B schematically show the structures of the focus coil, the tilt coil and the second magnet portion of the first actuator, respectively.

FIG. 7 shows the structure of the second actuator shown in FIG. 3 in more detail.

8 shows the structure of the fine pattern coil of the second actuator.

9A and 9B schematically show the structures of the magnet portion and the fine pattern coil of the second actuator, respectively.

※ Explanation of code about main part of drawing ※

100 ......... optical pickup unit 101 ......... base

110 ......... 1st Actuator 111,151 .... Holder

112,152 ..... lens holder 113,153 ..... objective lens

114 ......... Track Coil 115 ......... Focus Coil

116 ..... Tilt coil 117 ......... 1st magnet part

118 ......... the second magnet 119 ......... the yoke

120,158 ..... Suspension Wire 150 ......... 2nd Actuator

154,146 ..... Magnet 155,157 ..... York

160 ......... fine pattern coil

The present invention relates to an optical recording / reproducing system employing an optical pickup apparatus and the optical pickup apparatus, and more particularly to an optical pickup / reproducing system employing two actuators and an optical recording / reproducing system employing the optical pickup apparatus. It is about.

With the development of the industry, as the amount of information to be processed and recorded increases, there is a demand for an optical recording medium and an optical recording / reproducing system with higher recording density. In response to these demands, new optical recording / reproducing systems such as Blu-ray disc (BD) systems or HD-DVD systems have been proposed. However, such new systems also need to be compatible with existing systems such as CDs or DVDs. In particular, in the case of a BD system or an HD-DVD system, an object lens having a larger numerical aperture is required because light having a wavelength of 405 nm which is very short compared with the conventional one is used. Therefore, in order to make all CD / DVD / HD-DVD / BD compatible, the optical pickup device of the optical recording / reproducing system should be equipped with two objective lens optical systems. For example, an objective lens optical system for CD / DVD / HD-DVD and a BD objective lens optical system separate from the optical system should be provided in the optical pickup apparatus.

As a method of providing two objective lens optical systems in one optical pickup apparatus, there are a method of providing separate actuators for driving two objective lenses, respectively, and a method of driving both objective lenses with one actuator.

FIG. 1 schematically shows the structure of a conventional actuator 10 in which two objective lenses are arranged in one lens holder. In the conventional actuator 10 shown in FIG. 1, two objective lenses 12 and 13 are disposed in one lens holder 11. In general, however, negative resonance does not occur when the lens holder is driven only when the position of the objective lens coincides with the center of mass, driving center and support center of the lens holder. However, in the case of Fig. 1, since none of the objective lenses 12 and 13 are located at the center of the lens holder 11, negative resonance is inevitable during driving in the focus and track directions. Therefore, servo control becomes very difficult and complicated. In addition, when assembling the optical pickup apparatus, the relative skew of the two objective lenses should be adjusted. After adjusting the skew of one objective lens first, without affecting the first adjusted objective lens, It is very difficult to accurately adjust the skew for other objectives. Moreover, the two objective lenses should be arranged along the radial or tangential direction of the optical recording medium. When the radial lenses are arranged in the radial direction, the size of the optical pickup device or the size of the optical recording / reproducing system is arranged in the circumferential direction of the optical recording medium. Is bound to grow.

Accordingly, an optical pickup device having a separate actuator for driving two objective lenses, respectively, has been proposed. 2 illustrates an optical pickup apparatus disclosed in the Korean patent application. As shown in FIG. 2, the conventional optical pickup device 20 includes two actuators 21 and 24, and the objective lens holders 22 and 25 of the respective actuators 21 and 24 respectively have objectives. The lenses 23 and 26 are mounted one by one. However, the actuator of the optical pickup device 20 disclosed in the above-mentioned Korean patent application basically only describes the two-axis drive for the CD or DVD, and the three-axis drive (that is, essential for driving the HD-DVD or BD) Focus, track and tilt drive). Furthermore, since the conventional optical pickup apparatuses 20 all use the same type of actuator, in order to secure an appropriate optical path, the space utilization of the optical pickup apparatus becomes inefficient.

The present invention is directed to improving the above-mentioned conventional problem. Accordingly, an object of the present invention is to provide an optical pickup device in which at least one actuator includes two actuators capable of three-axis driving, and which is more efficient in space utilization than in the prior art.

Further, another object of the present invention is to provide an optical recording / reproducing system employing the optical pickup device having two actuators capable of three-axis driving.

An optical pickup apparatus according to the present invention comprises first and second actuators for individually driving two objective lenses, respectively, for recording / reproducing different types of optical recording media, and the first and second actuators. At least one of the three-axis drive is characterized in that.

For example, the first actuator may include: a lens holder on which an objective lens is mounted and movably supported by a support member; A pair of focus, track and tilt coils attached to both sides of the lens holder; First magnet parts disposed at both sides of the lens holder to interact with the track coil; And a pair of second magnet parts disposed at both sides of the lens holder and interacting with the focus and tilt coils.

Here, the second magnet portion has a magnetic pole surface opposite to each other, and consists of two magnets arranged in the vertical direction.

In this case, the coil surfaces of the focus coil and the tilt coil are parallel to the second magnet portion, an upper portion of the coil surface opposes an upper side magnet of the second magnet portion, and a lower portion of the coil surface is the second magnet portion. Opposite the lower magnet.

In addition, the first magnet portion has a magnetic pole surface opposite to each other, and consists of two magnets arranged in the left and right directions.

In this case, the coil surface of the track coil is parallel to the first magnet portion and opposes both the left and right magnets of the second magnet portion.

According to the present invention, the pair of focus coils, track coils, tilt coils, first magnet parts and second magnet parts are arranged on both sides of the lens holder in a point symmetric manner.

Meanwhile, the first actuator further includes yokes respectively disposed at both sides of the lens holder, and the first magnet part and the second magnet part are respectively attached to both surfaces of one yoke.

In addition, the second actuator may include, for example, a lens holder on which an objective lens is mounted, the lens holder being movably supported by a support member; A fine pattern coil formed of a plurality of coils finely provided on a substrate and installed through both side surfaces of the lens holder; And a pair of third magnet parts disposed in the lens holder and opposing both surfaces of the fine pattern coil.

Here, the fine pattern coil, the substrate; And a plurality of focus / tilt coils and track coils each minutely formed on both sides of the substrate.

For example, at both sides of the substrate, one focus / tilt coil may be formed at the left and right sides of the substrate, and two track coils may be formed at the center of the substrate in the longitudinal direction.

Meanwhile, the third magnet part is in contact with a first magnet having a first magnetic pole surface, a second magnet having a second magnetic pole surface in contact with a side surface of the first magnet and opposite to the first magnetic pole surface, and an upper surface of the first magnet. And a third magnet having a second magnetic pole surface, a fourth magnet having a first magnetic pole surface in contact with an upper surface of the second magnet and a side surface of the third magnet.

In this case, one of the focus / tilt coils is located between the first magnet and the third magnet, the other is between the second magnet and the fourth magnet, and one of the track coils is the first magnet. Between the and the second magnet, the other one is located between the third magnet and the fourth magnet.

According to the present invention, the first actuator may have a light path formed to the rear of the actuator, and the second actuator may have a light path formed to the side of the actuator.

Further, the two objective lenses may be arranged in the tangential direction or the radial direction of the optical recording medium.

Meanwhile, according to the present invention, an optical recording / reproducing system capable of recording / reproducing for different types of optical recording media by providing an optical pickup apparatus having the above-described structure is provided.

Hereinafter, an optical pickup apparatus and an optical recording / reproducing system according to the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 schematically shows an optical pickup device 100 according to a preferred embodiment of the present invention having two actuators. As shown in FIG. 3, two actuators 110 and 150 which are driven independently of each other are provided in the base 101 of the optical pickup apparatus 100. In FIG. 3, the two actuators 110 and 150 are arranged in the tangential direction of the optical disc D. As shown in FIG. However, according to the embodiment, it is also possible to design the two actuators 110 and 150 to be arranged in the radial direction of the optical disc D. According to a preferred embodiment of the present invention, one or both of the two actuators 110 and 150 shown in FIG. 3 are three-axis drive actuators. For example, the first actuator 110 may be a BD actuator for three-axis driving, and the second actuator 150 may be a CD / DVD actuator for two-axis driving, or vice versa. However, in order for both BD and HD-DVD to be compatible, both actuators 110 and 150 must drive three axes. In this case, one of the two actuators 110 and 150 is used for BD, and the other actuator is used for CD / DVD / HD-DVD.

Meanwhile, for efficient space utilization in the optical pickup apparatus, as shown in FIG. 3, the two actuators 110 and 150 have different optical paths. For example, in the case of the first actuator 110 disposed toward the center of the base 101, an optical path is formed behind the actuator as indicated by the arrow A. FIG. On the other hand, in the case of the second actuator 150 disposed toward the edge of the base 101, a light path is formed to the side of the actuator as indicated by the arrow (B). Accordingly, two optical systems including, for example, a light source, a beam splitter, and the like associated with the two actuators 110 and 150 may be formed in a sufficiently large space on the base 101.

4 shows an exemplary structure of the first actuator 110 shown in FIG. 3. Referring to FIG. 4, the first actuator 110 includes a lens holder 112 on which an objective lens 113 is mounted, and a pair of tracks, focuses, and tilts attached to both sides of the lens holder 112, respectively. Coils 114, 115, and 116, the first magnet part 117 disposed on both sides of the lens holder 112 and interacting with the track coil 114, and disposed on both sides of the lens holder 112, to provide the focus and tilt coils. And a pair of second magnet portions 118 interacting with 115, 116. Here, the lens holder 112 is supported to be movable to the holder 111 installed in the base 101 of the optical pickup device 100 through a plurality of suspension wires 120. For example, in the three-axis drive, the suspension wire 120 is used on each side of the lens holder 112, three, six in total. In addition, the first and second magnet parts 117 and 118 are also fixed to both sides of the yoke 119 installed on the base 101, respectively.

In the case of the first actuator 110 shown in FIG. 4, since magnets and coils for driving the first actuator 110 are installed at both sides of the first actuator 110, the first actuator 110 may be disposed of the first actuator 110. The central part becomes relatively empty. Therefore, the optical path is formed backward along the center line of the first actuator 110 from the objective lens 113.

The structure of the track coil 114 and the first magnet portion 117 of the first actuator 110 is shown in more detail in FIGS. 5A and 5B. Referring to the perspective view of FIG. 5A and the front view of FIG. 5B, the first magnet part 117 has a magnetic pole surface opposite to each other, and is composed of two magnets 117a and 117b disposed in the left and right directions. The two magnets 117a and 117b have a vertically long rectangular shape and are fixed to contact each other on one surface of the yoke 119. The track coil 114 has a coil surface parallel to the first magnet portion 117 and faces both the left and right magnets 117a and 117b of the first magnet portion 117. That is, one side of the track coil 114 faces the left magnet 117a of the first magnet part 117, and the other side of the track coil 114 faces the right magnet 117b. In this case, when a current is applied to the coil, electromagnetic force is generated in the left and right directions according to the direction of the current according to Fleming's law of damage. Therefore, the lens holder 112 can be driven in the left and right directions.

6A and 6B show more detailed structures of the focus coil 115, the tilt coil 116, and the second magnet portion 118 of the first actuator 110, respectively. Referring to the perspective view of FIG. 6A and the front view of FIG. 6B, the second magnet part 118 includes two magnets 118a and 118b disposed in the vertical direction with the magnetic pole surfaces opposite to each other. For example, the second magnet part 118 is attached to the upper magnet 118a with the magnetic pole surface of the N pole facing the front on the lower magnet 118b with the magnetic pole surface of the S pole facing the front. The two magnets 118a and 118b are fixed to contact each other on one surface of the yoke 119, respectively.

The focus coil 115 and the tilt coil 116 are overlapped with each other at the front of the second magnet part 118. Here, the coil surfaces of the focus coil 115 and the tilt coil 116 are parallel to the second magnet part 118, and both oppose the upper and lower magnets 118a and 118b of the second magnet part 118. have. That is, the upper portion of the coil surface of the focus coil 115 and the tilt coil 116 is opposite to the upper magnet 118a of the second magnet portion 118 and the lower portion of the coil surface is the second magnet portion 118. Of the lower magnet 118b. In such a structure, when a current is applied to the coil, electromagnetic force is generated in the vertical direction along the direction of the current by Fleming's law of external damage. Therefore, the lens holder 112 can be driven in the vertical direction.

As shown in FIG. 4, the pair of track coils 114, the focus coils 115, the tilt coils 116, the first magnet part 117, and the second magnet part 118 having the above-described structure The lens holder 112 is disposed on both sides in a point symmetrical manner. Accordingly, the lens holder 112 may be driven in the up, down, left, right, and tilt directions according to the current direction applied to the respective coils 114, 115, and 116 while maintaining the balance of the lens holder 112.

Meanwhile, FIG. 7 shows an exemplary structure of the second actuator 150 shown in FIG. 3. Referring to FIG. 7, the second actuator 150 includes a lens holder 152 on which an objective lens 153 is mounted, a fine pattern coil 160 installed through both side surfaces of the lens holder 152, and And a pair of third magnet parts 154 and 156 disposed inside the lens holder 152 so as to face both surfaces of the fine pattern coil 160, respectively. Here, the lens holder 152 is supported to be movable to the holder 151 installed on the base 101 of the optical pickup device 100 through a plurality of suspension wires 158. For example, in the case of three-axis driving, three suspension wires 158 are used on both sides of the lens holder 152, and a total of six suspension wires 158 are used. A fine pattern coil (FPC) 160, which will be described later, includes a plurality of coils finely provided on a substrate. The pair of third magnet parts 154 and 156 facing the fine pattern coil 160 are fixed to two yokes 155 and 157 which are installed through the inside of the lens holder 152 from the base 101, respectively. In the case of the second actuator 150 illustrated in FIG. 7, since the magnet and the coil for driving the second actuator 150 are disposed inside the second actuator 150, the optical path 153 is an objective lens 153. ) To the side of the second actuator (150).

8 exemplarily illustrates a structure of the fine pattern coil 160 used in the second actuator 150. Referring to FIG. 8, the fine pattern coil 160 includes a substrate 161, a plurality of focus / tilt coils 162 and 164, and a track coil 163 formed on the substrate 161. For example, the substrate 161 may be a PCB substrate, and the focus / tilt coils 162 and 164 and the track coils 163 may be patterns formed by minutely etching a metal layer on the PCB substrate. Here, as shown in FIG. 8, the focus / tilt coils 162 and 164 are formed at the left and right sides of the substrate 161, respectively, and two track coils 163 may be formed at the center of the substrate 161 in the vertical direction. Can be. Meanwhile, although only one side of the substrate 161 is shown in FIG. 8, the coils described above are formed on the opposite side of the substrate 161 in the drawing. That is, focus / tilt coils 162 and 164 and track coils 163 are formed on both surfaces of the substrate 161. In addition, in the fine pattern coil 160, the focus / tilt coils 162 and 164 simultaneously serve as a focus coil and a tilt coil. However, by stacking the focus / tilt coils 162 and 164 in multiple layers, some of the focus / tilt coils 162 and 164 may be formed to serve as focus coils and some to serve as tilt coils.

9A and 9B schematically illustrate a structure between the third magnet parts 154 and 156 and the fine pattern coil 160 of the second actuator 150, respectively.

First, referring to FIG. 9A, the third magnet part 154 is formed of a first magnet 154a having a first magnetic pole surface and a first magnetic pole that is in contact with a side surface of the first magnet 154a and is opposite to the first magnetic pole surface. A second magnet 154b having a second magnetic pole surface, a third magnet 154c in contact with an upper surface of the first magnet 154a, and having a second magnetic pole surface, and an upper surface and a third surface of the second magnet 154b. And a fourth magnet 154d in contact with the side of the magnet and having a first magnetic pole surface. For example, the magnetic pole surfaces of the N poles face the front face of the first magnet 154a and the fourth magnet 154d, and the magnetic pole faces of the silver S pole face the front face of the second magnet 154b and the third magnet 154c. Can be arranged.

As shown in FIG. 9B, another third magnet part 156 having the same structure as the third magnet part 154 is disposed to face the fine pattern coil 160. That is, the fine pattern coil 160 is disposed between two third magnet parts 154 and 156. In this case, one of the focus / tilt coils 162 and 164 of the fine pattern coil 160 is located between the first magnet 154a and the third magnet 154c, and the other is made of the second magnet 154b and the first magnet. Four magnets 154d, one of the track coils 163 is located between the first magnets 154a and the second magnets 154b, and the other is made of the third magnets 154c and It is located between four magnets 154d. Therefore, when a current is applied to the focus / tilt coils 162 and 164, electromagnetic force is generated in the vertical direction according to the direction of the current by Fleming's law of damage. Therefore, the lens holder 152 can be driven in the vertical direction. In addition, when a current is applied to the track coil 163, electromagnetic force is generated in the left and right directions according to the direction of the current according to Fleming's law of damage. Therefore, the lens holder 152 can be driven in the left and right directions.

As described above, according to the present invention, when at least two or more types of objective lenses are to be employed for recording / reproducing various optical recording media such as BD / HD-DVD / DVD / CD, etc. The resonant problem of the lens holder generated when the actuator is driven can be improved.

Further, according to the present invention, since two lens holders are used, the burden of securing both the BD moving distance and the HD-DVD / DVD / CD moving distance in one lens holder can be reduced. Furthermore, according to the present invention, the optical paths of two actuators are efficiently arranged in the optical pickup device, thereby making efficient use of the space of the optical pickup device. Therefore, a slimmer optical recording / reproducing system can be provided.

Claims (16)

An optical pickup apparatus comprising first and second actuators for individually driving a plurality of objective lenses for recording / reproducing different types of optical recording media, respectively. The first and second actuators are arranged such that each objective lens is located on the same circumference of the optical recording medium, And at least one of the first and second actuators is a three-axis drive. The method of claim 1, The optical actuator of claim 1, wherein the optical path is formed to the rear of the actuator, the second actuator is optical path is formed to the side of the actuator. The method of claim 1, The first actuator is: A lens holder mounted with an objective lens and supported by the support member so as to be movable; A pair of focus coils, a pair of track coils, and a pair of tilt coils respectively attached to both sides of the lens holder; First magnet parts disposed at both sides of the lens holder to interact with the track coil; And And a pair of second magnets disposed at both sides of the lens holder and interacting with the focus coil and the tilt coil. The method of claim 3, wherein The first magnet unit has a magnetic pole surface opposite to each other, and the optical pickup device, characterized in that consisting of two magnets arranged in the left and right directions. The method of claim 4, wherein The coil surface of the track coil is parallel to the first magnet portion, the optical pickup device, characterized in that opposing both the left and right magnets of the first magnet portion. The method of claim 3, wherein The second magnet part has a magnetic pole surface opposite to each other, and the optical pickup device, characterized in that consisting of two magnets arranged in the vertical direction. The method of claim 6, The coil surface of the focus coil and the tilt coil is parallel to the second magnet portion, an upper portion of the coil surface is opposite to an upper side magnet of the second magnet portion, and a lower portion of the coil surface is a lower side magnet of the second magnet portion. Opposite pickup apparatus, characterized in that facing. The method of claim 3, wherein And the pair of focus coils, a pair of track coils, a pair of tilt coils, a first magnet part, and a second magnet part are arranged on both sides of the lens holder in a point symmetric manner. The method of claim 8, And the first actuator further comprises yokes respectively disposed on both sides of the lens holder, wherein the first magnet portion and the second magnet portion are attached to both sides of one yoke, respectively. The method of claim 1, The second actuator is: A lens holder mounted with an objective lens and supported by the support member so as to be movable; A fine pattern coil formed of a plurality of coils finely provided on a substrate and installed through both side surfaces of the lens holder; And And a pair of third magnet parts disposed inside the lens holder and opposing both surfaces of the fine pattern coil, respectively. The method of claim 10, The fine pattern coil, a substrate; And a plurality of focus / tilt coils and track coils each minutely formed on both sides of the substrate. The method of claim 11, On both sides of the substrate, one focus / tilt coil is formed on the left and right sides of the substrate, the optical pickup device, characterized in that two track coils are formed in the longitudinal direction in the center of the substrate. The method of claim 12, The third magnet part has a first magnet having a first magnetic pole surface, a second magnet having a second magnetic pole surface in contact with a side surface of the first magnet and opposite the first magnetic pole surface, and a second magnet in contact with an upper surface of the first magnet. And a fourth magnet having a magnetic pole surface, and a fourth magnet having a first magnetic pole surface in contact with an upper surface of the second magnet and a side surface of the third magnet. The method of claim 13, One of the focus / tilt coils is positioned between the first magnet and the third magnet, and the other is located between the second magnet and the fourth magnet portion, Wherein one of the track coils is positioned between the first magnet and the second magnet portion, and the other is located between the third magnet and the fourth magnet portion. delete An optical recording / reproducing system capable of recording / reproducing for different types of optical recording media by providing the optical pickup apparatus according to any one of claims 1 to 14.

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