JPH0696453A - Optical information device and optical storing medium suitable for device thereof - Google Patents

Abstract

PURPOSE:To enable detection of tracking error signal effective against an optical storing medium recorded with high density by providing a multiplying means multiplying two signals outputted from a sample-and-hold means and generating a tracking error signal. CONSTITUTION:A beam 36 from a light pickup head is received by an optical detector 33 in a tracking error signal generating circuit 30. The optical detector 33 consists of two optical detecting section 34 and 35, electric signals from these section are respectively converted by I-V conversion circuit 37 and 38, and these output are respectively guided to a differential operation circuit 42 and an adder circuit 39. The signal added in the circuit 39 is inputted to a PLL circuit 40, a clock signal CLK is generated in this circuit, the signal is guided to a trigger generating circuit 41, and timing signals Sa1 and Sa2 are generated. The output of the differential operation circuit 42 is sampled-and-held with timing of the signals Sa1 and Sa2 in sample-and-hold circuits 43 and 44, after the signal held in the circuits 43 and 44 are multiplied, the signal is made a tracking error signal Vt via the sample-and-hold circuit 46, and outputted from an output terminal 47.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information device for recording / reproducing information on / from an optical disk, an optical card, etc., and particularly, it is possible to detect a tracking error signal effective for an optical storage medium for optical recording at high density. The present invention relates to an optical information device and an optical storage medium suitable for the device.

[0002]

2. Description of the Related Art Optical memory technology using an optical disk having a pit-shaped pattern as a high-density and large-capacity storage medium includes digital audio disk, video disk,
It has been put to practical use while expanding the usage of document file discs and even data files.

As shown in FIG. 25, a conventional optical storage medium 2
In the case of No. 3, generally, a spiral or concentric continuous guide groove or pit row 24 is formed. This continuous guide groove or pit row 24 is called a track, and focusing and tracking control are performed in order to accurately read the information on the optical storage medium 23 or to accurately record the information on the optical storage medium 23. Therefore, the beam from the optical pickup head must be accurately focused and traced on the track. Normally, when an optical pickup head having a light source wavelength λ of 780 nm and a lens numerical aperture NA of 0.5 is used, the track pitch on the optical storage medium 23 is 1 to 2 μm. Since it is difficult, the track 24 is schematically drawn on the optical storage medium 23.

To perform tracking control, a tracking error signal is detected, and an actuator for controlling the position of the condenser lens of the optical pickup head or the optical system is driven by the tracking error signal. A sample servo method is one of the typical detection methods of the tracking error signal.
This technique is described, for example, in USP 3919697,45532.
28, etc.

FIG. 26 is a partially enlarged view of a track on an optical storage medium according to the sample servo system. Here, the nth track is Tn, the n-2th track is Tn-2, ..., The n + 2nd track is Tn.
It is +2. In each of the tracks Tn-2 to Tn + 2, there is a clock pattern area formed with a pattern for generating timing signals Sa1 and Sa2 indicating the timing of sampling the signal obtained in the servo pattern area, and a servo signal (tracking error signal). The servo pattern area in which a pattern for generating a) and the data area in which a pattern for storing information are formed are cyclically formed as one set. In the servo pattern area, the pattern is formed at a position separated from the track by ± p / 4 (p is a track pitch).

FIG. 27 shows the configuration of a circuit for generating a tracking error signal. The beam 14 from the optical pickup head is focused on the optical storage medium 23 and then received by the photodetector 13. The electric signal from the photodetector 13 is current-voltage converted by the current-voltage (IV) conversion circuit 15, and Phase
It is guided to a Locked Loop (PLL) circuit 16 and sample-and-hold circuits 18 and 19.

The PLL circuit 16 generates a clock signal CLK synchronized with a signal obtained from a pattern recorded in the clock pattern area of the optical storage medium 23. The clock signal CLK is guided to the trigger generation circuit 17 and generates timing signals Sa1 and Sa2 indicating the timing corresponding to the position of the pattern formed in the servo pattern area of the optical storage medium 23. Sample and hold circuit 18,
At 19, the output of the IV conversion circuit 15 is sampled and held at the timing of the timing signals Sa1 and Sa2, and the signals held at the sample and hold circuits 18 and 19 are guided to the differential operation circuit 20 for differential operation. After that, the sample-and-hold circuit 21 samples and holds to provide a tracking error signal. The tracking error signal is output from the output terminal 22.

The signals held by the sample and hold circuits 18 and 19 are m1 and m2, respectively, and the beam from the optical pickup head is displaced from the center of the track x.
, M1 and m2 are approximately (Equation 1),
The sine waves have opposite phases to each other as represented by (Equation 2). FIG. 28 (a) shows m1 and m2, respectively.
It becomes like (b). (Equation 1) m1 = Asin (2πx / p) + B (Equation 2) m2 = −Asin (2πx / p) + B In (Equation 1) and (Equation 2), A is an amplitude and B is a DC component. The signal sampled and held by the sample-and-hold circuit 21, that is, the tracking error signal md is represented by (Equation 3) and is illustrated in FIG.
become that way. (Formula 3) md = m1−m2 = 2Asin (2πx / p) The generated tracking error signal is an actuator for controlling the beam emitted from the optical pickup head to be located at a desired position on the optical storage medium. Control signal.

[0009]

However, in the conventional optical storage medium, when the track pitch p is reduced in order to record a larger amount of information on one optical storage medium, the signal m1 shown in FIG. , M2 gradually decrease, and as a result, the amplitude of the tracking error signal md also decreases, and the amplitude of noise included in the tracking error signal md relatively increases. This increase in noise makes the tracking operation unstable. further,
The track pitch p is reduced and the track pitch p
When the reciprocal fp of the optical pickup head exceeds the spatial cutoff frequency fc of the optical pickup head, signals m1 and m2
Becomes 0, and the tracking error signal md cannot be obtained at all. That is, since the tracking operation cannot be performed, the information recorded on the optical storage medium cannot be reproduced.

When the wavelength of the light source of the optical pickup head is λ and the numerical aperture of the objective lens is NA, the spatial cutoff frequency fc is given by 2NA / λ.

For example, λ = 780 nm, NA = 0.45
At this time, the spatial cutoff frequency fc is fc = 2NA / λ = 1154 lines / mm 2, and there is a problem that the tracking error signal cannot be obtained when the track pitch p is 0.87 μm or less.

In view of the above problems, the present invention uses an optical system of the related art and is capable of detecting a tracking error signal up to a spatial cutoff frequency twice that of the conventional optical information device and the optical information device thereof. It is an object of the present invention to provide an optical storage medium suitable for.

Further, regarding a tracking error signal detecting method and an optical storage medium capable of detecting a tracking error signal up to a spatial cutoff frequency twice as high as that of the conventional one, Japanese Patent Laid-Open Nos. 4-38629 and 4-38633. Although some examples are disclosed in the official gazette, there are the following problems.

The groove structure of the optical storage medium is complicated and difficult to fabricate. The optical storage system is complicated because a plurality of beams have to be irradiated to the optical storage medium. Must significantly reduce the amount of information that can be recorded on the optical storage medium.

[0015]

In order to solve the above problems, the present invention provides a data recording area in which data is recorded, a servo pattern area for recording a mark or a space for obtaining a tracking error signal, and a clock. There is a clock pattern area in which a mark or space for obtaining a signal is recorded, a data string recorded in the data recording area is a virtual track, and the servo pattern area is a first servo pattern area and a second servo pattern. An optical storage medium having a region is an optical storage medium having any one of the following configurations (1) to (3).

(1) A pair of marks and spaces are formed in the first servo pattern area, and a pair of marks and spaces are also formed in the second servo pattern area.
Servo pattern areas and second servo pattern areas are alternately arranged on the virtual radiation perpendicular to the track, and the marks of the first servo pattern area and the spaces of the second servo pattern area are adjacent to each other. And a space in the first servo pattern area and a mark in the second servo pattern area adjacent to each other.

(2) A pair of marks and spaces are formed in the first servo pattern area, spaces are formed in the second servo pattern area, and the first servo pattern area and the second servo pattern are formed. Areas are alternately arranged on virtual radiation perpendicular to the track, and marks of the first servo pattern area and spaces of the second servo pattern area are arranged adjacent to each other, and the first servo pattern An optical storage medium in which an area space and a mark in the second servo pattern area are arranged adjacent to each other.

(3) One mark and two spaces are formed in the first servo pattern area, two marks and one space are formed in the second servo pattern area, and the first servo pattern is formed. The regions and the second servo pattern regions are alternately arranged on the virtual radiation orthogonal to the track, and the marks of the first servo pattern region and the spaces of the second servo pattern region are arranged adjacent to each other. An optical storage medium in which a space in the first servo pattern area and a mark in the second servo pattern area are arranged adjacent to each other.

Further, in the optical information device having the optical pickup head, the focus error signal generator and the tracking error signal generator, the optical pickup head, the focus error signal generator and the tracking error signal generator each have the following components. Optical pickup head Laser light source: Coherent beam or quasi-monochromatic beam focusing optical system: Receives the beam emitted from the laser light source and converges the beam into a small spot on the optical storage medium Beam splitting Means: a photodetector that receives and splits a beam reflected and diffracted by the optical storage medium; receives a split beam from the beam splitting means and outputs a photocurrent focus control means: the light source So that the beam emitted from the laser beam is focused at a desired position on the optical storage medium. To control the focus of the. The focus control means is
Tracking control means controlled by a signal output from the focus error signal generation unit ... The position of the focused beam is adjusted so that the beam emitted from the light source is focused at a desired position on the optical storage medium. Control. The tracking control means is controlled by a signal output from the tracking error signal generating section, a focus error signal generating section, an operational amplifier section, and receives an electric signal output from the photodetector to generate a focus error signal. And an amplifier for amplifying the focus control means of the optical pickup head to a controllable level. Tracking error signal generation section Sample-and-hold means ... Electrical signals output from the photodetector are temporally different. Timing signal generating section for sampling and holding each as two or more signals ... Outputting a signal indicating the timing at which the sample and hold means samples and holds Multiplier means ... Outputting from the sample and hold means Multiply the two signals and make a tracking error To generate a signal. The frequency of the generated tracking error signal is 2 times the frequency of the signal input to the multiplication means.
Further, the optical information device has any one of the following components (4) to (7). (4) Gain adjusting means: controlling the gain so that the amplitude of the tracking error signal becomes a desired magnitude. (5) DC signal cutoff means: cutting off the DC signal from the signal input to the multiplying means ( 6) Subtraction circuit ... Arranged on the input side of the multiplication means, and subtracting the DC signal from the signal input to the multiplication means to reduce the DC signal contained in the signal input to the multiplication means. (7) Subtraction Circuit: disposed on the output side of the multiplying means, and subtracting a DC signal or a signal having the same frequency as the signal input to the multiplying circuit from the signal output from the multiplying means to obtain the signal output from the multiplying means. Decrease the included DC signal or the signal having the same frequency as the signal input to the multiplication circuit

[0020]

In the optical information device which obtains the tracking error signal by using the above optical storage medium, when the track pitch on the optical storage medium is pt, the period of the signal inputted to the multiplying means is pt which is double, The period of the signal output from the multiplying means is pt, and the signal output from the multiplying means is used as the tracking error signal.

It is well known as a physical definition that the period and the frequency are inversely related, and the doubling of the period and the halving of the frequency are the same.

In the present invention, the period of the signal required to obtain the tracking error signal having the period pt is pt which is double. That is, 1 / the frequency given by the track pitch
Since the tracking error signal can be obtained by using the signal having the frequency of 2, the optical information device and the optical information device capable of detecting the tracking error signal even if the track pitch is reduced to 1/2 of the conventional one. It becomes a suitable optical storage medium.

Further, by using the optical information device having the above-mentioned component (4), the amplitude of the input signal to the multiplying means or the output signal from the multiplying means is kept constant, so that the amplitude of the tracking error signal is increased. Will also be kept constant.

By using the optical information device having the above-mentioned components (5) to (6), the DC signal is removed from the input signal to the multiplying means, and the signal output from the multiplying means is offset or noisy. The signal becomes less.

Further, by using the optical information device having the above-mentioned component (7), a signal having the same frequency as the DC signal and the signal inputted to the multiplying means is removed from the signal outputted from the multiplying means, The signal output from the multiplication means becomes a signal with less offset and noise.

[0026]

Embodiments of the optical storage medium according to the present invention will be described in detail below with reference to FIGS. It should be noted that the same numbers are assigned when the same components can be used.

(First Embodiment) As an embodiment of the present invention, FIG. 1 shows the configuration of an optical information apparatus which writes information to each track on an optical storage medium or reads information recorded on each track. In this optical information device, an optical pickup head 28 for optically recording and reproducing information, and a position of an objective lens 8 so that a beam emitted from the optical pickup head 28 is focused on a desired track on an optical storage medium 31. A focus error signal generating circuit 29 for generating a signal for controlling the actuator 91, and a position of the objective lens 8 for moving the actuator 92 so that the beam emitted from the optical pickup head 28 scans a desired track on the optical storage medium 31. The tracking error signal generation circuit 30 generates a signal to be controlled by, and the optical storage medium 31 stores information. The optical storage medium 31 can be easily replaced.

The light source 1 emits coherent or quasi-monochromatic light, and a semiconductor laser is usually suitable. Light source 1
The divergent beam 7 having a linearly polarized light emitted from the collimator lens 2 becomes a parallel beam, and after passing through the polarization beam splitter 3, the λ / 4 plate 9 becomes a circularly polarized beam, and the objective lens 8 is emitted. Optical storage medium 31 through which light is transmitted
Focused on top. The polarization beam splitter 3 transmits 100% of the beam having the same polarization as the beam 7 emitted from the light source 1 and reflects 100% of the beam having the polarization orthogonal to the beam 7 emitted from the light source 1. It has the characteristics to Therefore, the entire beam 7 emitted from the light source 1 and directed to the optical storage medium passes through the polarization beam splitter without being reflected. The configuration of the optical storage medium 31 will be described later in detail. In the optical storage medium 4, the focused beam 7 is reflected and diffracted, and the reflected and diffracted beam 7 is reflected.
Is a linearly polarized beam having a 90 ° polarization direction different from the beam emitted from the light source 1 after passing through the λ / 4 plate 9 after passing through the lens 8 again, and enters the polarization beam splitter 3. The beam 7 that has entered the polarization beam splitter 3 is all reflected and enters the beam splitter 4. The beam splitter 4 splits the beam 7 into two beams 36 and 701. The beam splitter 4 has a characteristic of reflecting 50% of the intensity and transmitting 50% of the intensity without depending on the polarization direction of the incident beam. The beam 701 reflected by the beam splitter 4 is guided to the cylindrical lens 5, and the beam 701 transmitted through the cylindrical lens 5 becomes a beam having astigmatism, which is condensed by the lens 6 and received by the photodetector 10. On the other hand, the beam 36 transmitted through the beam splitter 4
Is received by the photodetector 33.

A focus error signal is obtained by performing a desired calculation on the signal output from the photodetector 10, and a tracking error signal is obtained by performing a desired calculation on the signal output from the photodetector 33. . Here, the focus error signal is obtained by the astigmatism method. The astigmatism method for obtaining the focus error signal is a generally well-known method from the past, for example, USP402.
Since it is disclosed in 3033, 4079247 and the like, detailed description will be omitted. The photodetector 10 has four light receiving regions, and the electric signal output from the photodetector 10 is differentially calculated by the differential operation circuit 11 of the focus error signal generation circuit 29, and the differential operation circuit 11 outputs the electric signal. The output signal is amplified by the amplifier circuit 12 and supplied to the focus control actuator 91.

FIG. 2 shows a schematic structure of the optical storage medium 31 of the present invention. In the optical storage medium 31, the spiral pit row 32 is used as a track. The actual track pitch pt is 0.
Although it is about 5 to 2 μm, it is difficult to illustrate it in an actual size, so that the track 32 is schematically drawn in the optical storage medium 31 shown in FIG.

FIG. 3 is a partially enlarged view of the track 32 on the optical storage medium 31 shown in FIG. Here, the nth track is Tn, the n-2th track is Tn-2, ..., The n + 2nd track is Tn + 2. Each track has a clock pattern area formed with a pattern for generating timing signals Sa1 and Sa2 indicating the timing of sampling a signal obtained in the servo pattern area and a servo formed with a pattern for generating a servo signal. A pattern area and a data area in which a pattern for storing information is formed are arranged periodically as one set.

There are two types of patterns recorded in the servo pattern area. The first servo pattern area,
This is the second servo pattern area. In the first servo pattern area, marks are formed on the track and at a position apart from the track by pt / 2, respectively, and these marks form a pair of marks. The mark is a general pit pattern or a pattern in which physical constants such as reflectance and Kerr rotation angle are different from those of the surroundings. No pattern is formed in the second servo pattern area. That is, the second servo pattern area has a mirror surface portion. This mirror surface portion is defined as a space. In the present invention, the pattern means a mark or a space.

The first servo pattern areas and the second servo pattern areas are alternately arranged in the direction orthogonal to the tracks. That is, the servo pattern area adjacent to the first servo pattern area is the second servo pattern area, and the servo pattern area adjacent to the second servo pattern area is the first servo pattern area. In the embodiment, the same servo pattern area is formed on the same track. Therefore, here, the servo pattern area of the tracks Tn and Tn ± 2 is the first servo pattern area, and the servo pattern area of the track Tn ± 1 is the second servo pattern area.

FIG. 4 shows a tracking error signal generation circuit 30.
Shows the configuration of. The beam 36 from the optical pickup head 28 is focused on the optical storage medium 31 and then received by the photodetector 33. The photodetector 33 has two photodetectors 34, 35.
And the two photodetectors 3 in the photodetector 33 and the mapping of the track in the beam 36 (direction of the track).
The dividing lines 48 for dividing 4, 35 are aligned. The electric signals from the photodetectors 34 and 35 are current-voltage converted by the IV conversion circuits 37 and 38, respectively. The outputs of the IV conversion circuits 37 and 38 are the differential operation circuit 42 and the addition circuit 39.
Be led to. The signals added by the adder circuit 39 are input to the PLL circuit 40, and the PLL circuit 40 causes the optical storage medium 3
A clock signal CLK synchronized with a signal obtained from the pattern recorded in the first clock pattern area is generated.
The clock signal CLK is guided to the trigger generation circuit 41,
Timing signals Sa1 and Sa2 indicating the timing corresponding to the position of the pattern formed in the servo pattern area of the optical storage medium 31 are generated. In the sample and hold circuits 43 and 44, the output of the differential operation circuit 42 is sampled and held at the timing of the timing signals Sa1 and Sa2, and the signals held by the sample and hold circuits 43 and 44 are guided to the multiplication circuit 45, After being multiplied
The tracking error signal vt is sampled and held by the sample and hold circuit 46. The tracking error signal vt is output from the output terminal 47.

The signals held by the sample and hold circuits 43 and 44 are v1 and v2, respectively, and the beam from the optical pickup head is displaced from the center of the track by x.
, V1 and v2 are approximately (Equation 4),
A sine wave having a phase difference of π / 2 as represented by (Equation 5) is obtained. The signals v1 and v2 are shown in FIG.
It becomes like (a) and (b). (Equation 4) v1 = A ₁ sin (2πx / pt) (Equation 5) v2 = A ₁ cos (2πx / pt) = A ₁ sin (2πx /
pt + π / 2) In (Equation 4) and (Equation 5), A ₁ is the amplitude. The tracking error signal vt is represented by (Equation 6) and is illustrated in FIG. 5C. (Equation 6) vt = v1v2 = A ₁ ² / 2sin (4πx / pt) The tracking error signal vt has a spatial frequency twice that of the signals v1 and v2, as shown in FIG. 5 (c). ing. Conventionally, the frequency of the signal for obtaining the tracking error signal and the frequency of the tracking error signal were the same, but when the optical storage medium 31 and the tracking error signal detection method of the present invention are used, the tracking error signal is obtained. The frequencies that the signals v1 and v2 for have are half the frequency that the tracking error signal has. This is because even if the track pitch is reduced until the tracking error signal cannot be obtained by the conventional tracking error signal detecting method, when the optical storage medium 31 and the tracking error signal detecting method of the present invention are used, Is obtained. When the optical storage medium 31 and the tracking error signal detecting method of the present invention are used, the tracking error signal can be obtained even if the track pitch is reduced to 1/2 of the conventional one. That is, it is possible to record twice as much information as the conventional one on one optical storage medium.

Further, according to the present invention, since a tracking error signal can be obtained by a simple optical system for converging one beam on an optical storage medium, an inexpensive optical information device can be obtained.

In this embodiment, the optical storage medium 3 is used.
Although the case where the first track 32 is a spiral pit row has been shown, it does not have to be a spiral shape, and even if the tracks are concentric, no problem occurs. Although the second servo pattern area is a mirror surface portion, a tracking error signal can be obtained without any problem as long as the pattern has a reflectance or a phase change rate different from the pattern formed in the first servo pattern area. The number of servo pattern areas per track is dependent on the eccentricity of the disk and the track pitch, but if it is approximately 100 to 3000, good tracking servo characteristics can be realized practically without any problems.

(Second Embodiment) In this embodiment, the same optical information device as the optical information device shown in FIG. 1 described in the first embodiment can be used. The different point is the configuration of the servo pattern area on the optical storage medium 31. Other components can be used in common with the first embodiment.

FIG. 6 shows a schematic structure of tracks on the optical storage medium 31. In the first embodiment, an example is shown in which the same servo pattern area is formed on the same track, but here, two servo pattern areas are alternately arranged in the servo pattern area of the same track. Similar to the optical storage medium shown in the first embodiment, the adjacent servo pattern areas are arranged so as to be different from each other.
Even if the track pitch is reduced to 2, the tracking error signal can be detected. In the optical storage medium having the structure shown in the present embodiment, the first servo pattern area and the second servo pattern area are alternately arranged in the same track, so that the servo pattern recorded at the position pt / 2 away from the track is formed. The pattern recorded in the area is pt / 2
Even if the data is recorded at a position slightly deviated from, the offset caused by the offset is canceled, so that the beam from the optical pickup head can be controlled on the track more stably than in the first embodiment. Is possible.

(Third Embodiment) In this embodiment, as the optical information device, a device substantially similar to the optical information device shown in FIG. 1 described in the first embodiment can be used. The difference is that
The configuration of the servo pattern area on the optical storage medium 31, the photodetector 33 being replaced by the photodetector 51, and the configuration of the tracking error signal generation circuit 30. Other components can be used in common with the first embodiment.

FIG. 7 shows a schematic structure of tracks on the optical storage medium 31. The optical storage medium may have a structure having a track, such as a spiral shape or a concentric shape, like the optical storage medium 31 shown in the first embodiment. Here, as in the first embodiment, the nth track is Tn, the n-2th track is Tn-2, ..., The n + 2th track is Tn + 2. In each of the tracks Tn-2 to Tn + 2, a clock pattern area in which a pattern for generating timing signals Sa1, Sa2, Sa3 indicating the timing of sampling the signal obtained in the servo pattern area and a servo signal are generated. A servo pattern area in which a pattern for writing is formed and a data area in which a pattern for storing information is formed are arranged periodically as one set.

There are two types of patterns recorded in the servo pattern area. The first servo pattern area,
This is the second servo pattern area. In the first servo pattern area, marks are formed on the track and at a position apart from the track by pt / 2, respectively, and these marks form a pair of marks. The first servo pattern area also has a space. No pattern is formed in the second servo pattern area. That is, the second servo pattern area has a space. The servo pattern area adjacent to the first servo pattern area is a second servo pattern area, and the servo pattern area adjacent to the second servo pattern area is a first servo pattern area.

FIG. 8 shows the configuration of the tracking error signal generation circuit. The beam 36 of the optical pickup head 28 is received by the photodetector 51. The electrical signal from the photodetector 51 is current-voltage converted by the IV conversion circuit 37. IV
The output of the conversion circuit 37 is guided to the PLL circuit 40 and the sample and hold circuits 43, 44 and 58. The PLL circuit 40 generates the clock signal CLK synchronized with the signal obtained from the pattern recorded in the clock pattern area as shown in FIG. The clock signal CLK is guided to the trigger generation circuit 55 and generates timing signals Sa1, Sa2, Sa3 indicating the timing corresponding to the position of the pattern formed in the servo pattern area. In the sample and hold circuits 43, 44 and 58, the timing signal S
The output of the IV conversion circuit 37 is sampled and held at the timings a1 to Sa3, and the signals held by the sample and hold circuits 43 and 44 are guided to the multiplication circuit 45 and multiplied, and then input to the arithmetic circuit 63. To be done.

Sample and hold circuits 58, 43,
The signals held at 44 are v4, v5, and v6, respectively, and the signals are emitted from the optical pickup head and output from the optical storage medium 3
1 has a displacement x from the center of the track, v4 to v6 are approximately (Equation 7) to
The signal is represented by (Equation 9). (Equation 7) v4 = B ₁ (Equation _{8) v5 = -A 2 cos (} 2πx / pt) + B 2 ( Equation _{9) v6 = -A 2 sin (} 2πx / pt) + B 2 ( Formula 7) to (Formula 9 ), A ₂ is an amplitude, and B ₁ and B ₂ are DC components. The signal v7 multiplied by the multiplication circuit 45 becomes as shown in (Expression 10). (Equation 10) v7 = v5 · v6 = A 2 2/2 · sin (4πx / pt) -A
₂ B ₂ sin (2πx / pt) -A ₂ B ₂ cos (2πx /
The signal v7 multiplied by the pt) + B ₂ ² multiplication circuit 45 is sin (4π) like the tracking error signal vt in the first embodiment.
x / pt), that is, a component capable of detecting a tracking error signal up to twice the spatial cutoff frequency of the optical system is included, but other than that, the same frequency as the signals v5 and v6 input to the multiplication circuit 45. A term having a component-A ₂ B ₂ s
in (2πx / pt), -A ₂ B ₂ cos (2πx / pt)
And includes a section B ₂ ² DC component, these components become the noise or offset to the tracking error signal. The gain adjustment amplifier circuits 60 to 62 are respectively v4 to
With v6 as an input signal, the gain is adjusted and amplified so that the output signal has a level that cancels unnecessary signal components included in the output v7 of the multiplication circuit 45, and the gain adjustment amplification circuits 60 to
The output of 62 is input to the arithmetic circuit 63. Arithmetic circuit 6
3 subtracts a noise or offset component from the output v7 of the multiplication circuit 45, and the signal output from the arithmetic circuit 63 is sampled and held by the sample and hold circuit 46 and becomes the tracking error signal vt. The tracking error signal is output from the output terminal 47 and becomes a signal represented by (Equation 11). (Equation 11) vt = A ₂ ² / 2.sin (4πx / pt) The tracking error signal vt has a spatial frequency twice that of v 4 and v 5, and the optical storage medium and the tracking error signal shown in this embodiment are shown. Even when the optical information device having the detection method is used, the tracking error signal can be obtained up to twice the spatial cutoff frequency fc of the optical pickup head as in the optical storage medium shown in the first embodiment. Therefore, even when the optical pickup head 28 is configured using the same light source and objective lens as in the conventional case, the track pitch can be reduced to 1/2 of the conventional case by using the optical storage medium and the tracking error signal detection method of the present invention. It becomes possible to do. That is, it is possible to record twice as much information as the conventional one on one optical storage medium. In addition, first to
In the third embodiment, patterns are formed in the first servo pattern area on the track and at a position separated by pt / 2 from the track, and no pattern is formed in the second servo pattern area. Described the configuration. First
Since the servo pattern areas and the second servo pattern areas are alternately arranged adjacent to each other, a pattern is formed on the track in the first servo pattern area, and a track is formed in the second servo pattern area from the track. Even if a pattern is formed at a position separated by pt / 2, the expression is different,
It is clear that the structure of the present invention is shown.

(Fourth Embodiment) In this embodiment, the same optical information device as the optical information device shown in FIG. 1 described in the first embodiment can be used. The different point is the configuration of the tracking error signal generation circuit 30. Other components can be used in common with the first embodiment.

FIG. 9 shows a tracking error signal generation circuit 30.
Shows the configuration of. Most of the components are the same as the tracking error signal generation circuit shown in the third embodiment. The different point is that instead of the sample and hold circuit 58 of the tracking error signal generation circuit shown in the third embodiment, a low pass filter 53 is arranged in this embodiment to detect a DC signal. Even when the tracking error signal generation circuit according to the present embodiment is used, it is possible to obtain a tracking error signal with less offset and noise as in the tracking error signal generation circuit according to the third embodiment.

(Fifth Embodiment) Also in this embodiment, the same optical information device as the optical information device shown in FIG. 1 described in the first embodiment can be used. The different points are the configuration of the servo pattern area on the optical storage medium 31 and the configuration of the tracking error signal generation circuit 30. Other components can be used in common with the first embodiment.

FIG. 10 shows a schematic structure of tracks on the optical storage medium 31. Here, as in the first embodiment, the nth track is Tn, the n-2th track is Tn-2,
..., the n + 2nd track is set to Tn + 2.
In each of the tracks Tn-2 to Tn + 2, a clock pattern area in which a pattern for generating timing signals Sa1, Sa2, Sa3 indicating the timing of sampling the signal obtained in the servo pattern area and a servo signal are generated. A servo pattern area in which a pattern for writing is formed and a data area in which a pattern for storing information is formed are arranged periodically as one set.

There are two types of patterns recorded in the servo pattern area. The first servo pattern area,
This is the second servo pattern area. One mark and one space are formed on the track in both the first servo pattern area and the second servo pattern area.
The servo pattern area mark and the space are arranged so that the space of the first servo pattern area and the mark of the second servo pattern area and the mark of the first servo pattern area and the space of the second servo pattern area are adjacent to each other. is doing.

FIG. 11 shows the tracking error signal generation circuit 3
The structure of 0 is shown. The beam 36 from the optical pickup head 28 is focused on the optical storage medium 31, and then the photodetector 33.
Is received by. The electric signals from the photodetectors 34 and 35 are current-voltage converted by the IV conversion circuits 37 and 38, respectively. The outputs of the IV conversion circuits 37 and 38 are the differential operation circuit 4
2 and the addition circuit 39. The signals added by the adder circuit 39 are input to the PLL circuit 40, and the PLL circuit 4
At 0, the clock signal CLK synchronized with the signal obtained from the pattern recorded in the clock pattern area of the optical storage medium 31 is generated. The clock signal CLK is guided to the trigger generation circuit 41 and generates timing signals Sa1 and Sa2 indicating the timing corresponding to the position of the pattern formed in the servo pattern area of the optical storage medium 31. Also,
The signals added by the adder circuit 39 are input to the sample and hold circuits 93 and 94, and the sample and hold circuits 93 and 94 sample and hold the output of the adder circuit 39 at the timing of the timing signals Sa1 and Sa2. The signal output from the differential operation circuit 42 is input to the sample-and-hold circuit 43, and the sample-and-hold circuit 43 outputs the timing signal Sa1.
The output of the differential operation circuit 42 is sampled and held at the timing. The signal v8 held by the sample and hold circuit 43 is guided to the multiplication circuit 45, and the signals v9 and v10 held by the sample and hold circuits 93 and 94 are input to the differential operation circuit 54. The signal v11 output from the differential operation circuit 54 is also the multiplication circuit 4
Guided to 5. The signal guided to the multiplication circuit 45 is multiplied and then sampled and held by the sample and hold circuit 46 to become a tracking error signal vt.
The tracking error signal vt is output from the output terminal 47.

When the beam from the optical pickup head has a displacement x from the center of the track, v8 to v11 are sine waves approximately represented by (Equation 12) to (Equation 15), respectively. (Equation 12) v8 = A ₁ sin (2πx / pt) (Equation 13) v9 = A ₂ cos (2πx / pt) + B ₂ (Equation 14) v10 = −A ₂ cos (2πx / pt) + B ₂ (Equation 15) ) V11 = v9−v10 = 2 * A ₂ cos (2πx / pt) The tracking error signal vt is represented by (Expression 16). (Equation 16) vt = v8 · v11 = A ₁ · A ₂ · sin (4πx / pt) The tracking error signal vt has a spatial frequency twice that of v8 and v11, and is the optical storage medium shown in this embodiment. Also, when the optical information device having the tracking error signal detection method is used, the tracking error signal is up to twice the spatial cutoff frequency fc of the optical pickup head as in the optical storage medium shown in the first embodiment. can get. Therefore, even when the optical pickup head 28 is configured using the same light source and objective lens as in the conventional case, the track pitch can be reduced to 1/2 of the conventional case by using the optical storage medium and the tracking error signal detection method of the present invention. It becomes possible to do. That is, it is possible to record twice as much information as the conventional one on one optical storage medium.

(Sixth Embodiment) In this embodiment, the same optical information device as the optical information device shown in FIG. 1 described in the first embodiment can be used. Further, as the tracking error signal generation circuit, the one shown in the fifth embodiment can be used. The different point is the configuration of the servo pattern area on the optical storage medium 31.

FIG. 12 shows a schematic structure of tracks on the optical storage medium 31. In the fifth embodiment, one mark and one space are formed on the track in both the first servo pattern area and the second servo pattern area.
The servo pattern area mark and the space are arranged so that the space of the first servo pattern area and the mark of the second servo pattern area and the mark of the first servo pattern area and the space of the second servo pattern area are adjacent to each other. Was. In this embodiment, pt from the track is recorded in both the first servo pattern area and the second servo pattern area.
Marks are formed at positions ½ apart from each other, and one space is formed on the track. The space of the first servo pattern area, the mark of the second servo pattern area, and the mark of the first servo pattern area, respectively. And the marks and spaces in the servo pattern area are arranged so that the spaces in the second servo pattern area are adjacent to each other. further,
The distance in the direction orthogonal to the track of the marks of the adjacent first servo pattern area and second servo pattern area is 2
・ The distance between the two marks is set to be pt.

With the optical storage medium shown in this embodiment, the tracking error signal can be detected as in the case of using the optical storage medium shown in the fifth embodiment.

(Seventh Embodiment) In this embodiment, the same optical information device as the optical information device shown in FIG. 1 described in the first embodiment can be used. The different points are the configuration of the servo pattern area on the optical storage medium 31 and the configuration of the tracking error signal generation circuit 30. Other components can be used in common with the first embodiment.

FIG. 13 shows a schematic structure of tracks on the optical storage medium. The configuration is almost the same as that of the optical storage medium shown in the first to sixth embodiments. The difference is that one mark is formed on the track in the first servo pattern area and no mark is formed in the second servo pattern area.

FIG. 14 shows the configuration of the tracking error signal generation circuit. Beam 36 of optical pickup head 28
Is received by the photodetector 33. The electric signals from the photodetectors 34 and 35 are current-voltage converted by the IV conversion circuits 37 and 38, respectively. The outputs of the IV conversion circuits 37 and 38 are input to the adder circuit 39 and the differential operation circuit 42. The output of the adder circuit 39 is guided to the PLL circuit 40 and the sample and hold circuit 44. The output of the differential operation circuit 42 is guided to the sample and hold circuit 43. PLL
The circuit 40 generates a clock signal CLK synchronized with a signal obtained from a pattern recorded in the clock pattern area of the optical storage medium as shown in FIG. The clock signal CLK is guided to the trigger generation circuit 41 and generates the timing signal Sa1 indicating the timing corresponding to the position of the pattern formed in the servo pattern area. In the sample and hold circuits 43 and 44, the timing signal Sa1
The signal input at the timing of is sampled and held. The signals held by the sample and hold circuits 43 and 44 are guided to the multiplication circuit 45, multiplied, and then input to the differential operation circuit 54.

When the signals held by the sample and hold circuits 43 and 44 are v12 and v13, respectively, and the beam emitted from the optical pickup head and focused on the optical storage medium 31 has a displacement x from the center of the track. , V12, and v13 are approximately (Equation 17) to (Equation 1), respectively.
The signal is represented by 8). (Equation _{17) v12 = -A 3 sin (} 2πx / pt) ( Equation _{18) v13 = -A 4 cos (} 2πx / pt) + B 4 ( Equation 17) and (Equation 18), A _3, A ₄ is an amplitude , B
₄ is the DC component. Signal v1 multiplied by the multiplication circuit 84
4 becomes as shown in (Equation 19). (Equation 19) v14 = v12 · v13 = A 3 A 4/2 · sin (4πx / p
t) −A ₃ B ₄ sin (2πx / pt) The signal v14 multiplied by the multiplication circuit 45 is a term of sin (4πx / pt), that is, the spatial cut of the optical system, similar to vt in the first embodiment. Although it contains a component that can detect the tracking error signal up to twice the off frequency,
In addition to that, the term -A ₃ B ₄ sin (2πx / pt) having the same frequency component as the signal v8 input to the multiplication circuit 45 is included, and this component becomes noise with respect to the tracking error signal.

The gain adjusting / amplifying circuit 60 receives v12 as an input signal, adjusts and amplifies the gain so that the output signal has a level that cancels out an unnecessary signal component contained in the output v14 of the multiplying circuit 45, and the gain adjusting and amplifying is performed. The output of the circuit 60 is input to the differential operation circuit 54. The differential operation circuit 54 subtracts the noise component from the output v14 of the multiplication circuit 45, and the operation circuit 54
The signal output from the sample and hold circuit 4
Sampled and held at 6 to become a tracking error signal vt. The tracking error signal is output from the output terminal 47 and becomes a signal represented by (Equation 20). (Equation _{20) vt = A 3 A 4} /2 · sin (4πx / pt) The tracking error signal vt is, v12, and doubled spatial frequency of v13, the optical storage medium and the tracking error shown in this example Even when the optical information device having the signal detecting method is used, the tracking error signal is up to twice the spatial cutoff frequency fc of the optical pickup head as in the optical storage mediums shown in the first to sixth embodiments. can get.
When the tracking error signal is detected by using the optical storage medium and the tracking error signal detecting method according to the present embodiment, the tracking error signal can be obtained only from the signal when sampling is performed at the timing Sa1. Even if the power of the beam of the light source 1 of the pickup head 28 varies depending on time, a tracking error signal can be stably obtained. Also, the timing is S
Since the tracking error signal can be obtained only from the signal obtained by sampling at a1, the servo pattern area can be reduced and the unnecessary servo pattern area can be used as the data area. That is, it becomes possible to record and reproduce a larger amount of information on the optical storage medium.

(Eighth Embodiment) As another embodiment of the present invention, FIG. 15 shows a schematic structure of a track on an optical storage medium. The configuration is almost the same as that of the optical storage medium shown in the first to seventh embodiments. The difference is that a mark is formed at a position pt / 2 away from the track in the first servo pattern area, and no mark is formed in the second servo pattern area. The tracking error signal generation circuit is the same as the configuration described in the seventh embodiment, that is, FIG.
A circuit having the configuration shown in can be used. Since the operation of the circuit has been described in detail in the seventh embodiment, it will be omitted here.

The signals held by the sample and hold circuits 43 and 44 are v12 and v13, respectively, and the beam emitted from the optical pickup head 28 and focused on the optical storage medium 31 has a displacement x from the center of the track. At this time, v12 and v13 are signals which are approximately represented by (Equation 21) and (Equation 22), respectively. (Equation _{21) v12 = -A 3 cos (} 2πx / pt) ( Equation _{22) v13 = -A 4 sin (} 2πx / pt) + B 4 ( Equation 21) and (Equation 22), A _3, A ₄ is an amplitude , B
₄ is the DC component. Signal v1 multiplied by the multiplication circuit 45
4 becomes as shown in (Equation 23). (Equation 23) v14 = v12 · v13 = A 3 A 4/2 · sin (4πx / p
t) -A ₃ B ₄ cos (2πx / pt) The signal v14 multiplied by the multiplication circuit 45 is a term of sin (4πx / pt), that is, the spatial cut of the optical system, similar to vt in the first embodiment. It includes a component capable of detecting the tracking error signal up to twice the off frequency. The component that becomes noise is canceled by the differential operation circuit 54. The tracking error signal vt is output from the output terminal 47 and becomes a signal represented by (Equation 24). (Equation _{24) vt = A 3 A 4} /2 · sin (4πx / pt) In the case of an optical storage medium shown in the present embodiment, the optical storage medium and the tracking error signal detection as shown in the first to seventh embodiment Similar to the method, the tracking error signal can be obtained up to twice the spatial cutoff frequency fc of the optical pickup head. Further, when the tracking error signal is detected using the optical storage medium shown in this embodiment, the signal when sampling is performed when the timing is Sa1 as in the case of the optical storage medium shown in the seventh embodiment. Since the tracking error signal can be obtained only from, the tracking error signal can be stably obtained even if the power of the beam of the light source of the optical pickup head changes. Further, since the tracking error signal can be obtained only from the signal obtained by sampling when the timing is Sa1, the servo pattern area can be reduced, and the unnecessary servo pattern area can be used as the data area. . That is, it becomes possible to record and reproduce a larger amount of information on the optical storage medium.

(Ninth Embodiment) In each of the optical storage media shown in the first to eighth embodiments, a clock pattern area is provided to form a pattern, but the clock pattern area is formed in the data area or servo pattern area. It is of course possible to eliminate the pattern in the clock pattern area or the clock pattern area by forming a pattern having the same function as the pattern formed in the above.

FIG. 16 shows another embodiment of the present invention.
Shows the schematic structure of the tracks on the optical storage medium. The configuration is almost the same as that of the optical storage medium shown in FIG. 13 of the seventh embodiment. The difference is that the mark to be formed in the servo pattern area is the same as the mark to be formed in the clock pattern area. In the optical storage medium according to the present embodiment, the servo pattern area and the clock pattern area can be reduced, and the unnecessary servo pattern area or clock pattern area can be used as the data area. That is, it becomes possible to record and reproduce a larger amount of information on the optical storage medium.

(Tenth Embodiment) As a further embodiment of the present invention, FIG. 17 shows a schematic structure of a track on an optical storage medium. The configuration is almost the same as that of the optical storage medium shown in FIG. 13 of the seventh embodiment. The difference is that the mark to be formed in the servo pattern area is the same as the mark to be formed in the clock pattern area, and the mark is formed in the data area. Width w2 of mark for obtaining clock signal and tracking error signal
Is set to be larger than the width w1 of the mark recorded in the data area. Further, the optical storage medium shown in this embodiment is suitable as a recordable optical storage medium, and it is preferable that the marks for obtaining the clock signal and the tracking error signal are recorded beforehand as a pit pattern.
The marks recorded in the data area are recorded by the same recording method as the conventional one. As the recording medium, a material that has been often used conventionally, such as a phase change medium or a magneto-optical medium, can be applied.

In the optical storage medium according to the present embodiment, the servo pattern area and the clock pattern area are present in the data area, so that the entire area of the optical storage medium can be used as the data area. A lot of information can be recorded and reproduced.

(Eleventh Embodiment) As a further embodiment of the present invention, FIG. 18 shows a schematic structure of a track on an optical storage medium. The configuration is almost the same as that of the optical storage medium shown in the first to tenth embodiments. The difference is that the optical storage medium 31
It is the configuration of the upper servo pattern area and the configuration of the tracking error signal generation circuit 30. Other components can be used in common with the first embodiment.

FIG. 18 shows a schematic structure of tracks on the optical storage medium. The configuration is almost the same as that of the optical storage medium shown in the first to tenth embodiments. The difference is that one mark is formed on the track in the first servo pattern area,
In the second servo pattern area, one mark is formed on the track and one mark is formed at a position pt / 2 away from the track. The part where no mark is formed is a space. The marks are arranged so that the marks in the first servo pattern region and the spaces in the second servo pattern region are adjacent to each other, and the spaces in the first servo pattern region and the marks in the second servo pattern region are adjacent to each other.

FIG. 19 shows the configuration of the tracking error signal generation circuit. Beam 36 of optical pickup head 28
Is received by the photodetector 33. The electric signals from the photodetectors 34 and 35 are current-voltage converted by the IV conversion circuits 37 and 38, respectively. The outputs of the IV conversion circuits 37 and 38 are input to the adder circuit 39 and the differential operation circuit 42. The output of the adder circuit 39 is guided to the PLL circuit 40 and the sample and hold circuits 93 and 94. Differential operation circuit 42
Is output to the sample and hold circuit 43.
The PLL circuit 40 generates a clock signal CLK synchronized with a signal obtained from a pattern recorded in the clock pattern area of the optical storage medium as shown in FIG. The clock signal CLK is guided to the trigger generation circuit 41 and generates timing signals Sa1 to Sa3 indicating the timing corresponding to the position of the pattern formed in the servo pattern area. In the sample and hold circuits 43, 93 and 94, the signals input at the timings of the timing signals Sa1 to Sa3 are sampled and held, respectively. The signal held by the sample and hold circuit 43 is guided to the multiplication circuit 45. On the other hand, the signals held by the sample and hold circuits 93 and 94 are processed by the differential operation circuit 54.
To the multiplication circuit 54 after being differentially operated.

Sample and hold circuits 43, 93,
The signals held at 94 are respectively v15 to v17,
When the beam emitted from the optical pickup head and condensed on the optical storage medium 31 has a displacement x from the center of the track, v15 to v17 are approximately (Equation 25) to
The signal is represented by (Expression 27). (Formula 25) v15 = A ₂ sin (2πx / pt) + B ₂ (Formula 26) v16 = A ₂ cos (2πx / pt) + B ₂ (Formula 27) v17 = −A ₂ cos (2πx / pt) + B ₂ ( In Expressions 25) to 27, A ₂ is the amplitude and B ₂ is the DC component. The signal v18 that has been differentially calculated by the differential calculation circuit 54 is as shown in (Expression 27). (Equation 27) v18 = v16−v17 = 2A ₂ cos (2πx / pt) Further, the signal v19 multiplied by the multiplication circuit 45 is (Equation 2
8). (Equation 28) v19 = v15 · v18 = A 2 2 sin (4πx / pt) -2A 2
The signal v19 multiplied by the B ₂ cos (2πx / pt) multiplication circuit 45 has a sin (4πx / pt) term, that is, twice the spatial cutoff frequency of the optical system, as in the case of vt in the first embodiment. Up to and including the component that can detect the tracking error signal,
In addition to that, the term -2A ₂ B ₂ cos (2πx / pt) having the same frequency component as the signal v18 input to the multiplication circuit 45 is included, and this component becomes noise with respect to the tracking error signal.

The gain adjusting / amplifying circuit 60 uses v18 as an input signal, adjusts and amplifies the gain so that the output signal has a level that cancels out unnecessary signal components included in the output v19 of the multiplying circuit 45, and then gain adjusting and amplifying. The output of the circuit 60 is input to the differential operation circuit 56. The differential operation circuit 56 subtracts the noise component from the output v19 of the multiplication circuit 45, and the signal output from the differential operation circuit 56 is sampled and held by the sample and hold circuit 46 and becomes the tracking error signal vt.

Even when the optical information recording medium having the optical storage medium and the tracking error signal detecting method shown in this embodiment is used, the optical pickup head has the same as the optical storage medium shown in the first to tenth embodiments. Spatial cutoff frequency f
The tracking error signal can be obtained up to twice c.

(Twelfth Embodiment) As a further embodiment of the present invention, FIG. 20 shows a schematic structure of a track on an optical storage medium. The configuration is almost the same as that of the optical storage medium shown in FIG. 18 of the eleventh embodiment. The difference is that the marks in the first servo pattern area are on the track and the two marks in the second servo pattern area are pt from the track.
That is, they are formed at a position apart from each other. The distance between the two marks formed in the second servo pattern area is pt in the direction orthogonal to the track. The marks are arranged so that the marks in the first servo pattern area and the spaces in the second servo pattern area and the spaces in the first servo pattern area and the marks in the second servo pattern area are adjacent to each other. .

The tracking error signal generation circuit is the eleventh
The circuit described in the embodiment, that is, the circuit having the configuration shown in FIG. 19 can be used. Since the operation of the circuit has been described in detail in the eleventh embodiment, it will be omitted here.

Sample and hold circuits 43, 93,
The signals held at 94 are respectively v15 to v17,
When the beam emitted from the optical pickup head and condensed on the optical storage medium 31 has a displacement x from the center of the track, v15 to v17 are approximately (Equation 29) to
The signal is represented by (Expression 31). (Equation 29) v15 = A ₂ cos (2πx / pt) + B ₂ (Equation 30) v16 = A ₂ sin (2πx / pt) + B ₂ (Equation 31) v17 = −A ₂ sin (2πx / pt) + B ₂ ( In Equations 29) to 31), A ₂ is the amplitude and B ₂ is the DC component. The signal v18 which has been differentially calculated by the differential operation circuit 54 is as shown in (Expression 32). (Expression 32) v18 = v16−v17 = 2A ₂ sin (2πx / pt) Further, the signal v19 multiplied by the multiplication circuit 45 is (Expression 3
As shown in 3). (Equation 33) v19 = v15 · v18 = A 2 2 sin (4πx / pt) -2A 2
B ₂ sin (2πx / pt) When the optical information medium having the optical storage medium and the tracking error signal detection method according to the present embodiment is used, the first to the first
Similar to the optical storage medium shown in the first embodiment, up to twice the spatial cutoff frequency fc of the optical pickup head,
A tracking error signal is obtained.

(Thirteenth Embodiment) In this embodiment, the same optical information device as that shown in FIG. 1 can be used. The difference is that the tracking error signal generation circuit 3
0 configuration. Other components can be used in common with the first embodiment.

FIG. 21 shows the configuration of the tracking error signal generation circuit. As the optical storage medium, for example, an optical storage medium having a track configuration as shown in FIG. 3 is used. The beam 36 of the optical pickup head 28 is received by the photodetector 33. The electric signals from the photodetectors 34 and 35 are current-voltage converted by the IV conversion circuits 37 and 38, respectively. The outputs of the IV conversion circuits 37 and 38 are the differential operation circuit 42 and the addition circuit 3
Guided to 9. The signals added by the adder circuit 39 are PLL
The PLL circuit 40, which is input to the circuit 40 and the light amount detection circuit 66, generates a clock signal CLK synchronized with a signal obtained from a pattern recorded in the clock pattern area of the optical storage medium 31. The clock signal CLK is guided to the trigger generation circuit 41 and generates timing signals Sa1 and Sa2 indicating the timing corresponding to the position of the pattern formed in the servo pattern area of the optical storage medium. In the sample and hold circuits 43 and 44, the timing signal S
The output of the differential operation circuit 42 is sampled and held at the timings a1 and Sa2. The signals held by the sample and hold circuits 43 and 44 are input to the gain adjusting circuits 49 and 50, respectively, and the gain adjusting circuits 49 and 50 are input.
Then, the gain is controlled so that the output amplitude remains constant even if the input amplitude level changes. Gain adjusting circuit 49, 50
The gain is controlled by converting the signals added by the adder circuit 39 into a control voltage by the light amount detection circuit 51. As the gain adjusting circuits 49 and 50, generally known gain adjusting circuits using active and passive elements such as a method of controlling a gate voltage of a field effect transistor and a method of controlling a voltage applied to a PIN diode are applied. it can. Gain adjustment circuit 49, 5
The output of 0 is guided to the multiplication circuit 45, multiplied, and then sampled and held by the sample and hold circuit 46 to become a tracking error signal. The tracking error signal vt is output from the output terminal 47.

The signals v1 and v2 output from the sample and hold circuits 43 and 44 are the same as v1 and v2 described in the first embodiment, and are represented by (Equation 4) and (Equation 5), respectively. The signals output from the gain adjusting circuits 49 and 50 are v20 and v21, respectively. When the beam emitted from the optical pickup head 28 and focused on the optical storage medium 31 has a displacement x from the center of the track, v20,
v21 is a sine wave having a phase difference of π / 2, which is approximately represented by (Expression 34) and (Expression 35). (Formula 34) v20 = Asin (2πx / pt) (Formula 35) v21 = Acos (2πx / pt) = Asin (2πx /
pt + π / 2) In (Expression 34) and (Expression 35), A is the amplitude. Even if the intensity of the beam emitted from the optical pickup head 28 changes, or even if the optical storage medium is replaced with an optical storage medium having a different reflectance, in the tracking error signal detection method of the present invention, the gain adjustment circuit is used. The amplitude A is kept constant by 49 and 50. Tracking error signal v
t is represented by (Expression 36). (Equation 36) vt = v20v21 = A ² / 2sin (4πx / pt) The amplitude of the tracking error signal vt is as shown in (Equation 21). Although proportional to the square, in the tracking error signal detection method of the present invention, the gain adjusting circuits 49 and 50 change the light emitted from the optical pickup head 28 even if the intensity of the beam changes. Even if the optical storage medium is exchanged for the storage medium, the amplitude A is kept constant, so that the amplitude level of the tracking error signal vt is kept constant. When the tracking error signal is detected by the tracking error signal detecting method of the present invention, the amplitude level of the tracking error signal is kept constant, so that the tracking control system does not oscillate and stable tracking control is realized. It

(Fourteenth Embodiment) In this embodiment as well,
The same optical information device as that shown in FIG. 1 can be used. The different point is the configuration of the tracking error signal generation circuit 30. Other components can be used in common with the first embodiment.

FIG. 22 shows the configuration of the tracking error signal generation circuit. Beam 36 of optical pickup head 28
Is received by the photodetector 33. The electric signals from the photodetectors 34 and 35 are current-voltage converted by the IV conversion circuits 37 and 38, respectively, and the timing signals Sa1 and Sa2 are generated by the same signal flow as in the first or thirteenth embodiment. To be done. In the sample and hold circuits 43 and 44, the differential operation circuit 42 is operated at the timing of the timing signals Sa1 and Sa2.
The output of is sampled and held. The signals held by the sample-and-hold circuits 43 and 44 are input to the gain adjusting circuits 49 and 50, respectively, so that the gain adjusting circuits 49 and 50 keep the output amplitude constant even if the input amplitude level changes. Gain is controlled. The gains of the gain adjusting circuits 49 and 50 are controlled by setting the outputs of the sample and hold circuits 43 and 44 to the amplitude detecting circuits 67 and 6, respectively.
In step 8, the control voltage is converted into a control voltage. Amplitude detection circuit 67, 68
For example, when the optical storage medium is exchanged, the amplitude output from the sample and hold circuits 43 and 44 is first detected and held, depending on the depth of the groove or pit in the optical storage medium. Therefore, it is possible to input a signal having a constant amplitude to the multiplication circuit 45 even when an optical storage medium having a different modulation rate is used or an optical storage medium having a different reflectance is used. Gain adjusting circuit 49, 50
Like the thirteenth embodiment, is a gain adjustment using generally known active and passive elements such as a method of controlling the gate voltage of the field effect transistor and a method of controlling the voltage applied to the PIN diode. Circuit can be applied. The outputs of the gain adjusting circuits 49 and 50 are guided to the multiplying circuit 45, multiplied, and then sampled and held by the sample and hold circuit 46 to become tracking error signals. The tracking error signal vt is output from the output terminal 47.

The amplitude of the signal output from the multiplication circuit 45 is proportional to the square of the amplitude A of the signal input to the multiplication circuit 45. In the tracking error signal detection method of the present invention, the gain adjustment circuit 49, According to 50, a multiplication circuit for multiplying a signal having a constant amplitude even when an optical storage medium having a different modulation rate depending on the depth of a groove or a pit in the optical storage medium or an optical storage medium having a different reflectance is used. 45
, The amplitude level of the tracking error signal is kept constant. When the tracking error signal is detected by the tracking error signal detecting method of the present invention, the amplitude level of the tracking error signal is kept constant, so that the tracking control system does not oscillate and stable tracking control is realized. It

(Fifteenth Embodiment) In this embodiment as well,
The same optical information device as that shown in FIG. 1 can be used. The different point is the configuration of the tracking error signal generation circuit 30. Other components can be used in common with the first embodiment.

FIG. 23 shows the configuration of the tracking error signal generation circuit. Beam 36 of optical pickup head 28
Is received by the photodetector 33. The electrical signals from the photodetectors 34 and 35 are current-voltage converted by the IV conversion circuits 37 and 38, respectively, and the timing signals Sa1 and Sa2 are changed by the same signal flow as in the first, thirteenth and fourteenth embodiments. Is generated. In the sample and hold circuits 43 and 44, the differential operation circuit 42 is operated at the timing of the timing signals Sa1 and Sa2.
The output of is sampled and held. The signals held by the sample-and-hold circuits 43 and 44 are guided to the multiplication circuit 45, multiplied and then sampled and held by the sample-and-hold circuit 46. The signal output from the sample-and-hold circuit 46 is input to the gain adjusting circuit 50, and the gain adjusting circuit 50 controls the gain so that the output amplitude is constant even if the input amplitude level changes. The gain of the gain adjusting circuit 50 is controlled by converting the output of the sample and hold circuit 46 into a control voltage by the amplitude detecting circuit 70. Similar to the fourteenth embodiment, if the amplitude detection circuit 70 is configured to detect and hold the amplitude output from the sample-and-hold circuit 46 first when the optical storage medium is exchanged, for example, the optical storage medium It is possible to output a signal having a constant amplitude from the gain adjusting circuit 69 even when an optical storage medium having a different modulation rate is used depending on the depth of a groove or a pit in, or when an optical storage medium having a different reflectance is used. Then, the output of the gain adjusting circuit 50 becomes the tracking error signal vt.

The amplitude of the signal output from the multiplying circuit 45 is proportional to the square of the amplitude A of the signal input to the multiplying circuit 45. In the tracking error signal detecting method according to the present invention, the gain adjusting circuit 50 is also used. A signal having a constant amplitude is output from the output terminal 47 when an optical storage medium having a different modulation rate depending on the depth of a groove or a pit in the optical storage medium is used, or when an optical storage medium having a different reflectance is used. It becomes possible to output, that is, the amplitude level of the tracking error signal is kept constant. When the tracking error signal is detected by the tracking error signal detecting method of the present invention, the amplitude level of the tracking error signal is kept constant, so that the tracking control system does not oscillate and stable tracking control is realized. This is similar to the thirteenth and fourteenth embodiments.

As can be understood from the above description of the thirteenth to fifteenth embodiments, the present invention is an optical information device for detecting a tracking error signal by multiplication, wherein a gain adjusting circuit is provided at the input or output of the multiplying circuit. By keeping the amplitude of the tracking error signal constant, a tracking error signal with stable amplitude can be obtained.

(Sixteenth Embodiment) Also in this embodiment,
The same optical information device as that shown in FIG. 1 can be used. The different point is the configuration of the tracking error signal generation circuit 30. Other components can be used in common with the first embodiment.

FIG. 24 shows the configuration of the tracking error signal generation circuit. Beam 36 of optical pickup head 28
Is received by the photodetector 33. The electric signals from the photodetectors 34 and 35 are current-voltage converted by the IV conversion circuits 37 and 38, respectively. The outputs of the IV conversion circuits 37 and 38 are led to the differential operation circuit 42 and the addition circuit 39. The signals added by the adder circuit 39 are input to the PLL circuit 40, and the PLL circuit 40 generates a clock signal CLK synchronized with the signal obtained from the pattern recorded in the clock pattern area of the optical storage medium. Clock signal CLK
Is guided to the trigger generation circuit 41 to generate timing signals Sa1 and Sa2 indicating the timing corresponding to the position of the pattern formed in the servo pattern area of the optical storage medium. The sample and hold circuits 43 and 44 sample and hold the signals input at the timings of the timing signals Sa1 and Sa2. The DC component of the signal output from the differential operation circuit 42 is cut off by the capacitor 90, and is guided to the sample and hold circuits 43 and 44. Output v2 of the sample and hold circuits 43 and 44
2, v23 is guided to the multiplication circuit 45, and after being multiplied, the output signal becomes v24, which is sampled and held by the sample and hold circuit 46, and the tracking error signal vt
Becomes The tracking error signal vt is output from the output terminal 47.

The signals v22 and v23 sampled and held at the timing of the timing signals Sa1 and Sa2 have a displacement x from the center of the track where the beam emitted from the optical pickup head 28 and focused on the optical storage medium 31. Then, ideally, the DC component is not included, and (Equation 37),
The sine wave has a phase difference of π / 2 as represented by (Expression 38). (Formula 37) v22 = A ₁ sin (2πx / pt) (Formula 38) v23 = A ₁ cos (2πx / pt) = A ₁ sin (2πx)
/ Pt + π / 2) In (Equation 37) and (Equation 38), A is the amplitude.
V22 and v23 shown in (Expression 37) and (Expression 38) are the first
V1 shown in (Equation 4) and (Equation 5) described in the embodiment of
Similar to v2. However, if the output of the differential operation circuit 42 does not have the capacitor 90 for cutting off the direct current, the photodetector 33 is improperly arranged, and the beam 36 is emitted from the photodetector 33.
In the case where the light is not incident on the center of the beam, or when the beam focused on the optical storage medium has coma aberration, etc., two signals as expressed by (Expression 39) and (Expression 40) are used. v2
2 and v23 have different amplitudes, and v22 and v23
DC component is included in each. (Formula 39) v22 = A ₅ sin (2πx / pt) + B ₅ (Formula 40) v23 = A ₆ cos (2πx / pt) + B _{6 In} (Formula 39) and (Formula 40), A ₅ and A ₆ are amplitudes. , B
₅ and B ₆ are DC components. Multiplying circuit 4 for v22 and v23 including the DC component as expressed by (Formula 39) and (Formula 40)
The signal v24 input to 5 and multiplied is a signal including noise and DC offset, as shown in (Expression 41). (Equation 41) v24 = v22 · v23 = A 5 · A 6/2 · sin (4πx / p
_{t) -A 5 B 6 sin (} 2πx / pt) -A 6 B 5 cos (2
In _{πx / pt) + B 5 B} 6 present invention, the signal output from the differential operational circuit 42 cuts off a DC component by the capacitor 90, since the input to the sample-and-hold circuits 43 and 44, light Even when the positions of the detector 36 and the beam 36 received by the photodetector 33 are improper, the beam focused on the optical storage medium 31 has coma, etc., the multiplication circuit The signals v22 and v23 input to the signal 45 are (equation 37),
The signal does not include a DC component as represented by (Equation 38), and the multiplied signal v24 also becomes a signal that does not include noise and offset as represented by (Equation 42). (Equation 42) v24 = v22 · v23 = A 5 A 6/2 · sin (4πx / p
t) When the tracking error signal is detected by the tracking error signal detection method of the present invention, the signal does not include noise and offset, so that more stable tracking control can be performed as compared with the first embodiment. .

The first to sixteenth embodiments of the present invention are described based on the optical information device shown in FIG. 1 for easy understanding. The present invention relates to a tracking error signal detection method and an optical storage medium suitable for the method, and does not depend on the focus error signal detection method or the configuration of the optical pickup head. For example,
As a method of detecting the focus error signal, USP3876
Of course, the method disclosed in 841, 4006293, etc. is also applicable.

The optical system is also configured so that the beam 36 for detecting the tracking error signal is obtained and the photodetector 3
It is clearly understood from the above description that the components 3 or 51 are arranged without any restriction on other components. Therefore, in this embodiment, an example in which the tracking error signal is detected and the information is recorded / reproduced optically is described. However, the tracking signal is optically detected to record / reproduce the information in the data area. Can be done with a magnetic head without any problems,
The present invention can be applied. For example, magneto-optical recording, magnetic recording, and the like correspond to configurations having such different heads.

Further, in FIG. 1, the output from the tracking error signal generation circuit is directly connected to the tracking control actuator 92 for the sake of easy understanding, but it is of course necessary to drive the tracking control actuator. If you need to boost to the level,
An amplifier circuit may be added. The optical information device of the present invention generates the tracking error signal by multiplying the input signal by the multiplication circuit, and the frequency of the generated tracking error signal is the frequency of the signal input to the multiplication circuit. Is twice that of
Even if various changes are made to other parts, no problem occurs.

As can be understood from the above-described first to sixteenth embodiments, when the optical storage medium and the tracking error signal detecting method of the present invention are used, FIG.
As shown in, it is possible to obtain a tracking error signal having the same track pitch and the cycle of the tracking error signal.

That is, the tracking error signal can be detected without reversing the polarity of the tracking error signal and without adding special work to the track of the optical storage medium. For example, a desired track is searched for. When doing so, it is possible to search stably and quickly.

[0093]

As is apparent from the above description, according to the present invention, a data recording area for recording data, a servo pattern area for recording a mark or a space for obtaining a tracking error signal, and a clock signal are obtained. Has a clock pattern area in which a mark or space for recording is recorded, the data string recorded in the data recording area is a virtual track, and the servo pattern area has a first servo pattern area and a second servo pattern area. The optical storage medium is an optical storage medium having any one of the following configurations (1) to (3).

(1) A pair of marks and spaces are formed in the first servo pattern area, and a pair of marks and spaces are also formed in the second servo pattern area.
Servo pattern areas and second servo pattern areas are alternately arranged on the virtual radiation perpendicular to the track, and the marks of the first servo pattern area and the spaces of the second servo pattern area are adjacent to each other. And a space in the first servo pattern area and a mark in the second servo pattern area adjacent to each other.

(2) A pair of marks and a space are formed in the first servo pattern area, and a space is formed in the second servo pattern area, and the first servo pattern area and the second servo pattern are formed. Areas are alternately arranged on virtual radiation perpendicular to the track, and marks of the first servo pattern area and spaces of the second servo pattern area are arranged adjacent to each other, and the first servo pattern An optical storage medium in which an area space and a mark in the second servo pattern area are arranged adjacent to each other.

(3) One mark and two spaces are formed in the first servo pattern area, and two marks and one space are formed in the second servo pattern area. The regions and the second servo pattern regions are alternately arranged on the virtual radiation orthogonal to the track, and the marks of the first servo pattern region and the spaces of the second servo pattern region are arranged adjacent to each other. An optical storage medium in which a space in the first servo pattern area and a mark in the second servo pattern area are arranged adjacent to each other.

Further, in the optical information device having the optical pickup head, the focus error signal generator and the tracking error signal generator, the optical pickup head, the focus error signal generator and the tracking error signal generator each have the following components. Optical pickup head Laser light source: Coherent beam or quasi-monochromatic beam condensing optical system: Receives the beam emitted from the laser source and converges the beam into a small spot on the optical storage medium Beam splitting Means: a photodetector for receiving and splitting a beam reflected and diffracted by the optical storage medium; a photodetector for receiving a split beam from the beam splitting means focus control means: the light source So that the beam emitted from the laser beam is focused at a desired position on the optical storage medium. To control the focus of the. The focus control means is
Tracking control means controlled by a signal output from the focus error signal generation unit ... The position of the focused beam is adjusted so that the beam emitted from the light source is focused at a desired position on the optical storage medium. Control. The tracking control means is controlled by a signal output from the tracking error signal generating section, a focus error signal generating section, an operational amplifier section, and receives an electric signal output from the photodetector to generate a focus error signal. And an amplifier for amplifying the focus control means of the optical pickup head to a controllable level. Tracking error signal generation section Sample-and-hold means ... Electrical signals output from the photodetector are temporally different. Timing signal generating section for sampling and holding each as two or more signals ... Outputting a signal indicating the timing at which the sample and hold means samples and holds Multiplier means ... Outputting from the sample and hold means Multiply the two signals and make a tracking error To generate a signal. The frequency of the generated tracking error signal is 2 times the frequency of the signal input to the multiplication means.
Further, the optical information device has any one of the following components (4) to (7). (4) Gain adjusting means ... Controls the gain so that the amplitude of the tracking error signal becomes a desired magnitude. (5) DC signal cutoff means ... Cuts off the DC signal from the signal input to the multiplication means. 6) Subtraction circuit ... Arranged on the input side of the multiplication means and subtracting the DC signal from the signal input to the multiplication means to reduce the DC signal included in the signal input to the multiplication means. (7) Subtraction Circuit: disposed on the output side of the multiplying means, and subtracting a DC signal or a signal having the same frequency as the signal input to the multiplying circuit from the signal output from the multiplying means to obtain the signal output from the multiplying means. Optical information for obtaining a tracking error signal by using the optical storage medium of the above (1) to (4) to reduce a DC signal included therein or a signal having the same frequency as the signal input to the multiplication circuit. In the reporter, the track pitch is pt
At this time, the period of the signal used to obtain the tracking error signal becomes pt twice, and the tracking error signal can be obtained using a signal having a frequency half the frequency given by the track pitch. Even if the track pitch is reduced to 1/2, it is possible to detect the tracking error signal, and it is possible to use the conventional two
It is possible to record twice as much information.

Further, the ratio of the servo pattern area occupied on the optical storage medium can be made extremely small, and most or all of the servo storage area on the optical storage medium can be used as the data area.

Further, by using the optical information device having the above component (4), the amplitude of the input signal to the multiplying means or the output signal from the multiplying means is kept constant, so that the amplitude of the tracking error signal is increased. Is also kept constant, and stable tracking control is realized without causing oscillation of the tracking control system due to excessive servo gain and instability of tracking control due to insufficient servo gain.

By using the optical information device having the above-mentioned components (5) to (6), the DC signal is removed from the input signal to the multiplying means, and the signal output from the multiplying means is offset or noisy. Since the signal has a small amount, it is possible to stably perform tracking tracking on a desired track.

Further, by using the optical information device having the above-mentioned component (7), signals having the same frequency as the DC signal and the signal input to the multiplying means are removed from the signal output from the multiplying means, Since the signal output from the multiplying means becomes a signal with less offset and noise, it is possible to more stably track the desired track.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an optical information device showing an embodiment of the present invention.

FIG. 2 is a front view of an optical storage medium showing an embodiment of the present invention.

FIG. 3 is a partially enlarged schematic configuration diagram of a track on the optical storage medium of the present invention.

FIG. 4 is a circuit diagram of a circuit for detecting a tracking error signal using the optical storage medium of the present invention.

FIG. 5 is a waveform diagram showing the principle of signal detection using the optical storage medium of the present invention.

FIG. 6 is a partially enlarged schematic configuration diagram of a track on an optical storage medium showing another embodiment of the present invention.

FIG. 7 is a partially enlarged schematic configuration diagram of a track on an optical storage medium showing another embodiment of the present invention.

FIG. 8 is a circuit diagram of a circuit for detecting a tracking error signal using another optical storage medium of the present invention.

FIG. 9 is a circuit diagram of a circuit for detecting a tracking error signal using another optical storage medium of the present invention.

FIG. 10 is a partially enlarged schematic configuration diagram of a track on an optical storage medium showing another embodiment of the present invention.

FIG. 11 is a circuit diagram of a circuit for detecting a tracking error signal using another optical storage medium of the present invention.

FIG. 12 is a partially enlarged schematic configuration diagram of a track on an optical storage medium showing another embodiment of the present invention.

FIG. 13 is a partially enlarged schematic configuration diagram of a track on an optical storage medium showing another embodiment of the present invention.

FIG. 14 is a circuit diagram of a circuit that detects a tracking error signal according to an embodiment of the present invention.

FIG. 15 is a partially enlarged schematic configuration diagram of a track on an optical storage medium showing another embodiment of the present invention.

FIG. 16 is a partially enlarged schematic configuration diagram of a track on an optical storage medium showing another embodiment of the present invention.

FIG. 17 is a partially enlarged schematic configuration diagram of a track on an optical storage medium showing another embodiment of the present invention.

FIG. 18 is a partially enlarged schematic configuration diagram of a track on an optical storage medium showing another embodiment of the present invention.

FIG. 19 is a circuit diagram of a circuit that detects a tracking error signal according to another embodiment of the present invention.

FIG. 20 is a partially enlarged schematic configuration diagram of a track on an optical storage medium showing another embodiment of the present invention.

FIG. 21 is a circuit diagram of a tracking error signal detection circuit showing another embodiment of the present invention.

FIG. 22 is a circuit diagram of a tracking error signal detection circuit showing another embodiment of the present invention.

FIG. 23 is a circuit diagram of a tracking error signal detection circuit showing another embodiment of the present invention.

FIG. 24 is a circuit diagram of a tracking error signal detection circuit showing another embodiment of the present invention.

FIG. 25 is a front view of a conventional optical storage medium.

FIG. 26 is a partially enlarged schematic configuration diagram of a track on a conventional optical storage medium.

FIG. 27 is a circuit diagram of a circuit for detecting a tracking error signal using a conventional optical storage medium.

FIG. 28 is a waveform diagram showing the principle of signal detection using a conventional optical storage medium.

[Explanation of symbols]

 1 Light Source 2 Collimating Lens 3 Polarizing Beam Splitter 4 Beam Splitter 5 Cylindrical Lens 6 Condensing Lens 7 Beam 8 Objective Lens 9 Quarter Wave Plate 10 Photodetector 11 Differential Operation Circuit 12 Amplifying Circuit 13 Photodetector 14 Beam 15 IV conversion circuit 16 PLL circuit 17 Trigger generation circuit 18 Sample-and-hold circuit 19 Sample-and-hold circuit 20 Differential operation circuit 21 Sample-and-hold circuit 22 Output terminal 23 Optical storage medium 24 Track 28 Optical pickup head 29 Focus error signal generation Circuit 30 Tracking error signal generation circuit 31 Optical storage medium 32 Track 33 Photodetector 34 Photodetector section 35 Photodetector section 36 Beam 37 IV conversion circuit 38 IV conversion circuit 39 Adder circuit 40 PLL circuit 41 Trigger raw Circuit 42 Differential operation circuit 43 Sample-and-hold circuit 44 Sample-and-hold circuit 45 Multiplier circuit 46 Sample-and-hold circuit 47 Output terminal 48 Dividing line 49 Gain adjustment circuit 50 Gain adjustment circuit 51 Photodetector 53 Low-pass filter 54 Differential operation circuit 55 Trigger generation circuit 56 Differential operation circuit 58 Sample and hold circuit 60 Gain adjustment circuit 61 Gain adjustment circuit 62 Gain adjustment circuit 63 Operation circuit 66 Light intensity detection circuit 67 Amplitude detection circuit 68 Amplitude detection circuit 70 Amplitude detection circuit 90 Capacitor 91 Focus control Actuator 92 Tracking control actuator 93 Sample-and-hold circuit 94 Sample-and-hold circuit 701 beam

Claims (32)

[Claims] 1. A data recording area in which data is recorded, a servo pattern area in which a mark or space for obtaining a tracking error signal is recorded, and a clock pattern area in which a mark or space for obtaining a clock signal is recorded. In the optical storage medium having, the data string recorded in the data recording area is a virtual track, the servo pattern area has a first servo pattern area and a second servo pattern area, and the first servo pattern area includes A pair of marks and spaces are formed, and a pair of marks and spaces are also formed in the second servo pattern area.
The first servo pattern areas and the second servo pattern areas are alternately arranged on the virtual radiation perpendicular to the tracks, and the marks of the first servo pattern areas and the spaces of the second servo pattern areas are formed. An optical storage medium which is arranged so as to be adjacent to each other, and a space of the first servo pattern area and a mark of the second servo pattern area are arranged to be adjacent to each other. 2. A mark in a first servo pattern area is formed on an extension line of a track, and a mark in a second servo pattern area is formed on an extension line of a track when a space between two adjacent tracks is set to a track pitch pt. To pt / 2
2. It is formed at a position separated only by 1.
The optical storage medium described. 3. The light according to claim 1, wherein the mark of the first servo pattern area is formed on the extension line of the track, and the mark of the second servo pattern area is also formed on the extension line of the track. Storage medium. 4. A mark in the first servo pattern area is formed at a position separated by pt / 2 from an extension line of the track, where a distance between two adjacent tracks is a track pitch pt, and a second servo pattern is formed. 2. The optical storage medium according to claim 1, wherein the mark of the area is also formed at a position separated by pt / 2 from the extension line of the track. 5. A data recording area for recording data, a servo pattern area for recording a mark or space for obtaining a tracking error signal, and a clock pattern area for recording a mark or space for obtaining a clock signal. In the optical storage medium having, the data string recorded in the data recording area is a virtual track, the servo pattern area has a first servo pattern area and a second servo pattern area, and the first servo pattern area includes A pair of marks and a space are formed, a space is formed in the second servo pattern area, and the first servo pattern area and the second servo pattern area are alternately arranged on the virtual radiation orthogonal to the track. Optical storage medium disposed in. 6. The mark of the first servo pattern area is formed on an extension line of the track.
The optical storage medium described. 7. A mark in the first servo pattern area is formed at a position separated by pt / 2 from an extension line of the track, where a space between two adjacent tracks is a track pitch pt. The optical storage medium according to claim 5. 8. A data recording area for recording data, a servo pattern area for recording a mark or space for obtaining a tracking error signal, and a clock pattern area for recording a mark or space for obtaining a clock signal. In the optical storage medium having, the data string recorded in the data recording area is a virtual track, the servo pattern area has a first servo pattern area and a second servo pattern area, and the first servo pattern area includes One mark and two spaces are formed, two marks and one space are formed in the second servo pattern area, and the first servo pattern area and the second servo pattern area are orthogonal to the track. Of the first servo pattern area and the second Are arranged such space servo pattern area is adjacent, the first servo pattern area space and optical storage media mark of the second servo pattern area are arranged adjacent. 9. The optical storage medium according to claim 8, wherein the spaces in the first servo pattern area are continuous. 10. A mark in the first servo pattern area is formed on an extension line of the track, and two marks in the second servo pattern area are respectively formed on the tracks when the distance between two adjacent tracks is a track pitch pt. 10. The distance between two marks formed at a position separated by pt / 2 from the extension line of the line and formed in the second servo pattern region in the direction orthogonal to the track is pt. The optical storage medium described. 11. A mark of a first servo pattern area is formed on an extension line of a track, and two marks of a second servo pattern area are formed on one side when a space between two adjacent tracks is a track pitch pt. 10. The optical storage medium according to claim 8, wherein the mark is formed on the extension line of the track, and the other mark is formed at a position separated by pt / 2 from the extension line of the track. 12. A clock pattern area and a data area have a shared area.
The optical storage medium according to any one of the above. 13. The optical storage medium according to claim 1, wherein the optical storage medium has an area shared by the clock pattern area and the servo pattern area. 14. The optical storage medium according to claim 1, wherein the optical storage medium has an area shared by the servo pattern area and the data area. 15. The optical storage medium according to claim 1, wherein the clock pattern area, the servo pattern area, and the data area have areas shared with each other. 16. The optical storage medium according to claim 14, wherein the width of the mark formed in the servo pattern area is larger than the width of the mark formed in the data area. 17. A track in which only the first servo pattern area is formed in the servo pattern area and a track in which only the second servo pattern area is formed in the servo pattern area are alternately arranged. 17. The optical storage medium according to any one of 1 to 16. 18. A servo pattern region of the same track, wherein first servo pattern regions and second servo pattern regions are alternately arranged.
16. The optical storage medium according to any one of 16 to 16. 19. The optical storage medium according to claim 1, wherein the number of first or second servo pattern areas formed in one track is 100 to 3000. 20. In an optical information device having an optical pickup head, a focus error signal generator and a tracking error signal generator, the optical pickup head emits a coherent beam or a quasi-monochromatic beam from the laser light source. A converging optical system that receives the generated beam and converges the beam into a minute spot on the optical storage medium;
A beam splitting unit that receives and splits the beam reflected and diffracted by the optical storage medium, a photodetector that receives the split beam from the beam splitting unit and outputs a photocurrent, and a beam emitted from the light source are Focus control means for controlling the focus of the focused beam so as to be focused at a desired position on the optical storage medium, and a beam emitted from the light source is focused at a desired position on the optical storage medium. And a tracking control means for controlling the position of the focused beam so that the focus control means is controlled by a signal output from the focus error signal generation section, and the tracking control means is output from the tracking error signal generation section. The focus error signal generator is controlled by a signal, and receives a focus error by receiving an electric signal output from a photodetector included in the optical pickup head. A tracking error signal generating section, which performs an operation for generating a signal and further amplifies the focus control means of the optical pickup head to a controllable level, and the tracking error signal generating section is an electric signal output from the photodetector. And sample and hold means for sampling and holding each of them as two or more signals different in time, a timing signal generating section for outputting a signal indicating the timing at which the sample and hold means sample and hold, and the sample and hold. The multiplication means has a multiplication means for multiplying two signals output from the means to generate a tracking error signal, and a gain adjustment means for controlling a gain so that the amplitude of the tracking error signal becomes a desired magnitude. The frequency of the generated tracking error signal is An optical information apparatus which is twice the frequency included in the signal input to. 21. An optical information apparatus according to claim 20, wherein the gain adjusting means is arranged on the input side of the multiplying means. 22. An optical information apparatus according to claim 20, wherein the gain adjusting means is arranged on the output side of the multiplying means. 23. A plurality of amplitude detecting means for respectively detecting the amplitudes of a plurality of signals inputted to the multiplying means, and a gain control so that the amplitudes of the plurality of signals inputted to the multiplying means have respective desired magnitudes. 22. A light according to claim 21, further comprising a plurality of possible gain adjusting means, wherein the gains of the plurality of gain adjusting means are controlled on the basis of signals detected by the plurality of amplitude detecting means. Information device. 24. An amplitude detecting means for detecting the amplitude of the signal output from the multiplying means, and a gain adjusting means capable of controlling the gain so that the amplitude of the signal output from the multiplying means has a desired magnitude. However, the gain of the plurality of gain adjusting means is
23. The optical information device according to claim 22, wherein the optical information device is controlled on the basis of signals detected by the plurality of amplitude detecting means. 25. The beam reflected by the optical storage medium is received by a photodetector, and the gain of the gain adjusting means is controlled based on a signal output from the photodetector. 24. The optical information device according to any one of to 24. 26. In an optical information device having an optical pickup head, a focus error signal generator and a tracking error signal generator, the optical pickup head emits a coherent beam or a quasi-monochromatic beam from the laser light source. A converging optical system that receives the generated beam and converges the beam into a minute spot on the optical storage medium;
A beam splitting unit that receives and splits the beam reflected and diffracted by the optical storage medium, a photodetector that receives the split beam from the beam splitting unit and outputs a photocurrent, and a beam emitted from the light source are Focus control means for controlling the focus of the focused beam so as to be focused at a desired position on the optical storage medium, and a beam emitted from the light source is focused at a desired position on the optical storage medium. And a tracking control means for controlling the position of the focused beam so that the focus control means is controlled by a signal output from the focus error signal generation section, and the tracking control means is output from the tracking error signal generation section. The focus error signal generator is controlled by a signal, and receives a focus error by receiving an electric signal output from a photodetector included in the optical pickup head. A tracking error signal generating section, which performs an operation for generating a signal and further amplifies the focus control means of the optical pickup head to a controllable level, and the tracking error signal generating section is an electric signal output from the photodetector. And sample and hold means for sampling and holding each of them as two or more signals different in time, a timing signal generating section for outputting a signal indicating the timing at which the sample and hold means sample and hold, and the sample and hold. The multiplication means generates a tracking error signal by multiplying two signals output from the means, and the DC signal cutoff means cuts off the DC signal from the signal input to the multiplication means. The frequency of the tracking error signal is the signal input to the multiplication means. An optical information apparatus which is twice the frequency included in the. 27. In an optical information device having an optical pickup head, a focus error signal generator and a tracking error signal generator, the optical pickup head emits a coherent beam or a quasi-monochromatic beam from the laser light source. A converging optical system that receives the generated beam and converges the beam into a minute spot on the optical storage medium;
A beam splitting unit that receives and splits the beam reflected and diffracted by the optical storage medium, a photodetector that receives the split beam from the beam splitting unit and outputs a photocurrent, and a beam emitted from the light source are Focus control means for controlling the focus of the focused beam so as to be focused at a desired position on the optical storage medium, and a beam emitted from the light source is focused at a desired position on the optical storage medium. And a tracking control means for controlling the position of the focused beam so that the focus control means is controlled by a signal output from the focus error signal generation section, and the tracking control means is output from the tracking error signal generation section. The focus error signal generator is controlled by a signal, and receives a focus error by receiving an electric signal output from a photodetector included in the optical pickup head. A tracking error signal generating section, which performs an operation for generating a signal and further amplifies the focus control means of the optical pickup head to a controllable level, and the tracking error signal generating section is an electric signal output from the photodetector. And sample and hold means for sampling and holding each of them as two or more signals different in time, a timing signal generating section for outputting a signal indicating the timing at which the sample and hold means sample and hold, and the sample and hold. Multiplying the two signals output from the means to generate a tracking error signal; and subtracting a direct current signal from the signal input to the multiplying means to generate a direct current signal included in the signal input to the multiplying means. And a subtraction circuit for decreasing the subtraction circuit, Disposed force side, the frequency of the tracking error signal has generated in the multiplication means, the optical information apparatus is twice the frequency included in the signal input to the multiplication means. 28. In an optical information device having an optical pickup head, a focus error signal generator and a tracking error signal generator, the optical pickup head emits a coherent beam or a quasi-monochromatic beam from the laser light source. A converging optical system that receives the generated beam and converges the beam into a minute spot on the optical storage medium;
A beam splitting unit that receives and splits the beam reflected and diffracted by the optical storage medium, a photodetector that receives the split beam from the beam splitting unit and outputs a photocurrent, and a beam emitted from the light source are Focus control means for controlling the focus of the focused beam so as to be focused at a desired position on the optical storage medium, and a beam emitted from the light source is focused at a desired position on the optical storage medium. And a tracking control means for controlling the position of the focused beam so that the focus control means is controlled by a signal output from the focus error signal generation section, and the tracking control means is output from the tracking error signal generation section. The focus error signal generator is controlled by a signal, and receives a focus error by receiving an electric signal output from a photodetector included in the optical pickup head. A tracking error signal generating section, which performs an operation for generating a signal and further amplifies the focus control means of the optical pickup head to a controllable level, and the tracking error signal generating section is an electric signal output from the photodetector. And sample and hold means for sampling and holding each of them as two or more signals different in time, a timing signal generating section for outputting a signal indicating the timing at which the sample and hold means sample and hold, and the sample and hold. Multiplication means for multiplying two signals output from the means to generate a tracking error signal, and subtracting from the signal output from the multiplication means a DC signal or a signal having the same frequency as the signal input to the multiplication circuit The signal included in the signal output from the multiplication means A subtraction circuit for reducing a signal or a signal having the same frequency as the signal input to the multiplication circuit, the subtraction circuit being arranged on the output side of the multiplication means and having the frequency of the tracking error signal generated by the multiplication means. Is an optical information device having a frequency twice that of a signal input to the multiplication means. 29. A DC signal proportional to the amount of light incident on the photodetector when the beam reflected by the optical storage medium is received by the photodetector and the signal output from the photodetector is input to the AC blocking means. And a DC signal included in the signal input from the multiplying means or output from the multiplying means by subtracting the DC signal from the signal input to the multiplying means or output from the multiplying means based on the DC signal 29. The optical information device according to claim 27, wherein the tracking error signal is detected by reducing 30. The optical information device according to claim 20, wherein the photodetector comprises a plurality of light receiving portions. 31. An optical information apparatus according to claim 20, wherein the detection of the tracking error signal and the recording, erasing or reproduction of information are all performed by an optical pickup head. 32. A magnetic head capable of applying a magnetic field is provided in the vicinity of an optical storage medium, and a tracking error signal is detected by an optical pickup head, and information is recorded, erased or reproduced by the magnetic head. The optical information device according to any one of claims 20 to 30, characterized in that: