JPH07153080A - High density data-recording medium and optical data-reproducing apparatus - Google Patents

Abstract

PURPOSE:To provide a high-density data-recording medium which can be made a high-density and large-capacity medium, and to obtain an optical data- reproducing apparatus which can reproduce data in a simple constitution with using the high-density data-recording medium. CONSTITUTION:A high-density data-recording medium 7 is provided, in which pits 15-17 are formed at a central position 8 of a track of a medium surface and at positions each separated a respective given distance from the central position 8 and which has a capacity of at least 2-bit or more data in an area corresponding to one pit of a different distance from the central position 8. Instead of changing the configuration of pits as above, data of an inclination of pits, the number of pits, and a size, that is, large or small of pits may be arranged to constitute the medium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high density information recording medium and an optical information reproducing device.

[0002]

2. Description of the Related Art Conventionally, as an optical disk (optical information recording medium) for reproducing information, as a reproduction-only one, application software for a computer and various data are recorded in advance in the form of pits on the disk surface. Optical ROM discs are known. Then, at the time of reproduction, an optical information reproducing device is used, and the presence or absence of pits is detected as a binary signal by scanning a light beam on a pit row recorded on such a disc surface, and information is reproduced by this. ing. FIG. 10 shows a configuration example of the optical information reproducing device. The laser beam a emitted from the semiconductor laser 2 in the optical pickup unit 1 is collimated by the collimator lens 3, is reflected by the beam splitter 4, and is condensed by the objective lens 6 via the wave plate 5. It is irradiated in the state of a beam spot on top. On this optical disk 7, as shown in FIG. 11A, many pits 9 are formed on the track center 8 to form a pit row. The reflected beam b, which is scanned and reflected by the beam spot P on the pit row, passes through the beam splitter 4, is focused by the detection lens 10, is guided to the photodetection element 11, and is reproduced by the reproduction signal c ( In addition to this, a focus error signal and a track error signal can also be detected), and information can be reproduced by this. By sending the focus error signal and the track error signal to the focus servo circuit 12 and the tracking servo circuit 13, the objective lens actuator 14 is moved in the focus direction Z (lens optical axis direction) and the tracking direction X.
Drive control can be performed (in the disk radial direction).

[0003]

Problems to be Solved by the Invention FIGS. 11 (a) to 11 (c)
Shows an example in which the pit row recorded on the track center 8 of the optical disc 7 is scanned using the beam spot P of the laser beam a, and the presence or absence of the pit 9 is detected as a binary signal by this scanning. As shown in (a), when the beam spot P is scanned on the pit row formed along the track center 8, the reproduction signal c weakens the reflected beam b due to the diffraction of light in the region where the pit 9 exists (b). The waveform corresponds to the presence or absence of the pit 9 as shown in FIG. By binarizing the waveform of the reproduced signal c thus changed with a threshold value of a predetermined level L, a binarized signal d as shown in (c) is obtained.

However, in the conventional optical disk 7, the amount of information in the pit 9 formed on the track center 8 is only 1 bit (binary value of "0" and "1"), and therefore the optical disk 7 In order to further increase the density and the capacity, it is necessary to shorten the pit length or narrow the track pitch. This means that a finer laser beam or finer adjustment is required to form the pits 9, and as a result, the cost and size of the recording apparatus itself may increase. Even if the pit length is shortened or the track pitch is narrowed to create the optical disk 7, it is necessary to improve the frequency characteristic of the reproducing apparatus that detects such a pit string, and a complicated circuit is required, resulting in high cost. Becomes Further, there is a problem that crosstalk is likely to occur during reproduction by narrowing the track pitch.

[0005]

According to a first aspect of the present invention, pits are formed at a track center position on the medium surface and at positions separated from the track center position by various fixed distances, and the distance from the track center position is formed. A high-density information recording medium having an information amount of at least 2 bits or more is provided in an area corresponding to one pit having a different value.

According to the second aspect of the invention, in the optical information reproducing apparatus for irradiating the pit formed on the track of the optical information recording medium with a beam spot and reproducing information by using the reflected beam reflected by the beam spot, At least 2 bits corresponding to the track center position of the medium surface and pits formed at various distances from the track center position and corresponding to one pit having a different distance from the track center position. For a high-density optical information recording medium having the above information amount, a 2-bit or more information amount for detecting a reflected beam from a pit formed by arranging the high-density optical information recording medium at different positions. A photodetector having a correspondingly divided light-receiving surface is provided, and the pit arrangement is recognized based on the signal detected by each light-receiving surface of the light-detecting element. The pit arrangement recognition information reproducing means having a code data generation circuit for generating code data correspond to and above the amount of information provided.

According to the third aspect of the invention, pits are formed in the track direction of the medium surface and in a direction inclined at various fixed angles from the track direction, and one pit having a different inclination angle from the track direction is formed. A high density information recording medium having an information amount of at least 2 bits is provided in the corresponding area.

According to a fourth aspect of the invention, in an optical information reproducing apparatus for reproducing information by using a reflected beam reflected by irradiating a pit formed on a track of an optical information recording medium with a beam spot, At least 2 bits or more corresponding to an area corresponding to one pit in which a pit is formed in the track direction of the medium surface and in a direction tilted at various constant angles from the track direction and the tilt angle from the track direction is different. Corresponding to the information amount of 2 bits or more for detecting the reflected beam from the pits formed with different inclination angles in the high density information recording medium A light detecting element having a divided light receiving surface is provided, and the tilt angle of the pit is recognized based on the signal detected by each light receiving surface of the light detecting element, and 2 bits or more are recognized. Provided pits inclination angle recognition information reproducing means having a code data generation circuit for generating a code data corresponding to the amount of information.

According to the invention described in claim 5, pits having various pit numbers are formed on the track of the medium surface, and at least 2 bits or more are formed in an area corresponding to one pit having a different pit number. A high density information recording medium having an information amount is provided.

According to a sixth aspect of the invention, in an optical information reproducing apparatus for reproducing information by using a reflected beam reflected by irradiating a beam spot on a pit formed on a track of an optical information recording medium, A high-density information recording medium in which pits having various pit numbers are formed on a track of a medium surface and which has an information amount of at least 2 bits or more corresponding to an area corresponding to one pit having a different pit number. On the other hand, the high-density information recording medium is provided with a photo-detecting element having a light-receiving surface divided corresponding to an information amount of 2 bits or more for detecting a reflected beam from pits formed with different pit numbers. , A code data generation time for recognizing the number of pits on the basis of the signal detected by each light receiving surface of the photodetector to generate code data corresponding to an information amount of 2 bits or more. The number of pits recognition information reproducing means having provided.

According to the seventh aspect of the invention, pits having various pit diameters are formed on the track of the medium surface, and at least 2 bits or more are formed in an area corresponding to one pit having a different pit diameter. A high density information recording medium having an information amount is provided.

According to an eighth aspect of the invention, there is provided an optical information reproducing apparatus which reproduces information by irradiating a beam spot on a pit formed on a track of an optical information recording medium and using a reflected beam reflected by the beam spot. High-density information recording medium in which pits having various pit diameters are formed on a track on the medium surface and which has an information amount of at least 2 bits or more corresponding to an area corresponding to one pit having different pit diameters. On the other hand, the high-density information recording medium is provided with a photo-detecting element having a light-receiving surface divided corresponding to the information amount of 2 bits or more for detecting a reflected beam from pits formed with different pit diameters. , A code data generation time for recognizing a pit diameter based on a signal detected by each light receiving surface of the photodetector and generating code data corresponding to an information amount of 2 bits or more. The pit diameter recognition information reproducing means having provided.

[0013]

According to the inventions of claims 1, 3, 5, and 7,
In the area equivalent to one pit, the pit arrangement (the degree of distance from the track center), the pit inclination, the number of pits, and the size (diameter) of the pit have at least 2 bits of information, so that It is possible to significantly increase the information amount in the same medium area as compared with the case where one pit has an information amount of 1 bit.

According to the second aspect of the present invention, the detection signals from the plurality of light receiving surfaces are binarized, and parallel / serial conversion is simply performed by using the code data generation circuit. It becomes possible to obtain code data having the above information amount, and moreover, it is possible to reproduce using the pit having the same shape as the conventional one.

In the inventions according to claims 4, 6 and 8,
By binarizing each detection signal from a plurality of light receiving surfaces and performing parallel / serial conversion by using the data conversion table of the code data generation circuit, code data having an information amount of 2 bits or more corresponding to 1 pit can be obtained. It is possible to obtain the information, and moreover, it is possible to reproduce by using the pit having the same shape as the conventional one. Also, by using the data conversion table, various reproduction methods (pit inclination, pit number,
It is possible to correspond to the size of the pit).

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention described in claim 1 will be described with reference to FIG. Prior art (see FIGS. 10 and 11)
The description of the same parts as those of is omitted, and the same reference numerals are used for the same parts.

In the present embodiment, pits are formed at the position of the track center of the medium surface and at a position distant from the position of the track center by various fixed distances, and one pit having a different distance from the track center position is formed. A high-density information recording medium having an information amount of at least 2 bits is provided in the corresponding area. Hereinafter, as a specific example, an example showing “4 values” according to the pit arrangement position (that is, an example having an information amount of 2 bits per 1 pit) is shown in FIG.
Description will be made based on (e). (A) shows the shapes (~) of various pits arranged at positions separated by various fixed distances from the position of the track center 8 on the disk surface of the optical disk 7 as the high density information recording medium. . Then, a pit 15 is formed on the track center 8,
The pit 16 is formed at a position shifted by 1/4 track from the track center to the upper side (in the figure), and the pit 17 is formed at a position shifted from the track center to the lower side (in the figure) by 1/4 track. Shows the state without pits.

As described above, when the beam spot P is irradiated on the pits 15 to 17 arranged at various fixed distances from the track center 8 and the reflected beam b is detected by the photodetector 11, The state is as shown. The photo-detecting element 11 uses the light-receiving surfaces A and B to detect "4 values".
It is divided into two. At this time, the light amount of the reflected beam b is weakened by the diffraction of light by the pits 15 to 17, and the light receiving surfaces A and B
The dark areas 18 to 20 of the beam (in this case, the dark areas are areas in which the light intensity of the reflected beam b on the light receiving surface is weakened by the diffraction of the light from the pits, are indicated by hatching). it can. In other words, in the pit 15 on the track center 8, a dark portion 18 is formed in both regions of the light receiving surfaces A and B by crotch. 1/4 of the pit 16 shifted to the upper side of the track, a dark portion 19 is formed on the light receiving surface B side, and
A dark portion 20 is formed on the light-receiving surface A side in the pit 16 which is shifted downward from the four tracks. No dark area is possible without the pit.

When various signals detected by the two-divided light-receiving surfaces A and B are reproduced and converted into digital values, binarized waveforms as shown in (c) and (d) are obtained.
In this case, the waveform of Sa in (c) shows a change in the amount of light detected on the light-receiving surface A, which changes corresponding to pits 15 and 17 and Sa = '1'.
The waveform of Sb in (d) shows a change in the amount of light detected on the light-receiving surface B, which changes corresponding to pits 15 and 16 and Sb = '1'. It should be noted that all values other than "1" are "0". Next, the binarized signals Sa and Sb detected in this manner are sent to a code data generation circuit (not shown) (see FIG. 2 described later) to generate a code data signal So as shown in (e). . In this case, when Sa = 1 and Sb = 1, So =
When '11' and Sa = 0 and Sb = 1, So =
When “01” and Sa = 1 and Sb = 0, So =
When Sa = 0 and Sb = 0 for '10', So =
A code data signal of "00" can be generated. Therefore, as can be seen from this specific example, it can be understood that the information held by one pit can be doubled to two bits (that is, four-valued) as compared with the conventional one by adding information to the "pit arrangement" of. From this, it is possible to further increase the information amount of one pit by increasing the pit arrangement and the number of divisions of the photodetecting element 11.

As described above, the arrangement of pits in the area corresponding to one pit (degree of distance from the track center)
By having at least 2 bits or more in the information amount, it is possible to significantly increase the information amount in the same medium area as compared with the conventional one pit having the information amount of 1 bit. This makes it possible to provide a high-density recording medium. Further, in this case, since the amount of information can be increased without shortening the pit length or narrowing the track pitch as in the conventional case, a recording device for producing a high-density recording medium can be inexpensively and simply configured. Can be provided at.

Next, an embodiment of the invention described in claim 2 will be described with reference to FIGS. 1 and 2. The description of the same parts as those in the first aspect of the present invention will be omitted, and the same reference numerals will be used for the same parts.

In this embodiment, a high density information recording medium (optical disk 7 in FIG. 1A) as described in the invention of claim 1 is used, and a track center 8 is formed on this high density information recording medium.
Pits 15 formed with different placement distances from the position
A light detecting element 11 having a light receiving surface (here, two light receiving surfaces A and B) divided corresponding to the information amount of 2 bits or more for detecting the reflected beam b from 17 to 17 is provided. A pit having a code data generation circuit for recognizing the arrangement of the pits 15 to 17 based on the signals detected by the light receiving surfaces A and B of the detection element 11 and generating code data corresponding to the information amount of 2 bits or more. The arrangement recognition information reproducing means is provided.

FIG. 2 shows a concrete configuration example of the pit arrangement recognition information reproducing circuit 21 as the pit arrangement recognition information reproducing means. The pit arrangement recognition information reproducing circuit 21 includes an amplifier 22a connected to the photodetector element 11,
22b, waveform shaping circuits 23a and 23b connected to the subsequent stages of the amplifiers 22a and 22b, and the waveform shaping circuit 2
It is composed of a parallel-serial conversion circuit 24 (shift register) as a code data generation circuit connected to the subsequent stage of 3a and 23b, a synthetic signal generation circuit 25, and a signal reproduction clock generation circuit 26. In this case, the synthesized signal generation circuit 25 includes the adder 25a and the waveform shaping circuit 2
5b, and the signal reproduction clock generation circuit 26
Is a phase comparator 26a, an LPF circuit 26b, a VCO
It is composed of a circuit 26c and a 1 / N frequency divider 26d.
It should be noted that although the code signal generation clock signal CLK is generated from the combined signal generation circuit 25 and the signal reproduction clock generation circuit 26 and sent to the parallel-serial conversion circuit 24, these circuits 25 and 26 are not directly related to the present invention. Therefore, the description thereof will be omitted below.

A method for reproducing 2-bit (4-valued) information for one pit by the pit arrangement recognition information reproducing circuit 21 using the optical discs 7 having different pit arrangements in such a configuration will be described. Now, by irradiating the beam spot P on the surface of the optical disc 7 having the pits 15 to 17 having different pit arrangements as shown in FIG. 1A, the light receiving surfaces A and B of the photodetector 11 are shown in FIG. As shown in), the beam state is different in the intensity of light. The signals from the light receiving surfaces A and B pass through the amplifiers 22a and 22b, respectively, and are binarized by the waveform shaping circuits 23a and 23b.
(C) The signals Sa and Sb described in (d) are obtained. The binarized signals Sa and Sb are sent to the parallel-serial conversion circuit 24, so that Sa, 0, Sb, 0
4 bit parallel data is converted into 2 bit serial data, and the code data signal S as shown in FIG.
get o. The code data signal So has a 2-bit information amount (4 values) for one pit, and thus information can be reproduced from the optical disc 7 having different pit arrangements. Since the code data is used here for edge detection instead of level detection, a parallel-serial conversion circuit 24 for converting 4-bit parallel data into 2-bit serial data is used as the code data generation circuit. Moreover, since the signal frequency increases as the amount of information increases, a method of simply converting the parallel data Sa and Sb into serial data may be used.

As described above, the detection signals from the plurality of light receiving surfaces (light receiving surfaces A and B) are binarized and simply parallel / serial converted using the code data generation circuit (parallel-serial conversion circuit 24). The code data signal So having an information amount of 2 bits or more corresponding to one pit can be easily obtained by simply doing so, and thus the circuit configuration is simple, and high-speed processing (high frequency) is possible. An information reproducing device can be provided. Also, since the pits (pits 15 to 17) having the same shape as the conventional ones can be used for reproduction, it is not necessary to narrow the track pitch to achieve high density, so that the influence of crosstalk during reproduction is considered. It is possible to perform highly reliable signal detection.

Next, an embodiment of the invention described in claim 3 will be described with reference to FIG. The description of the same parts as those in the first and second aspects of the present invention is omitted, and the same parts are designated by the same reference numerals.

This embodiment shows a modification of the high density information recording medium (see FIG. 1A) of the invention described in claim 1. That is, in the optical disc 7 as a high density information recording medium, pits are formed in the track direction T of the disc surface and in a direction inclined at various constant angles from the track direction T, and the inclination angle from the track direction T is different. An area corresponding to one pit has an information amount of at least 2 bits or more. Fig.3 (a)-
(C) shows a specific example thereof, and is an example in the case of having 2-bit (4-valued) information for one pit due to the inclination of the pit. In (a), in the track direction T
A pit 27 is formed in parallel with the
The pit 28 is formed at an angle of + θ to the upper side, and the pit 29 is formed at an angle of −θ to the lower side from the track direction T, and the state without a pit is shown. Here, as shown in (b), the photodetector element 11 is composed of four light-receiving surfaces A, B, C, and D, and the dark portion 3 corresponds to the inclination of the pits 27 to 29 of.
0 to 32 are formed. Binary signals Sa, Sb, Sc and Sd (not shown in FIG. 1) corresponding to these dark portions 30 to 32.
(C) and (d) and FIG. 4 described later) are obtained, and the code data signal So is obtained. If the areas of the dark areas 30 to 32 are set to "1" and the areas other than the dark area are set to "0", Sa, Sb, Sc, and Sd in the dark area 30 are 1, 1, 1, 1 so that the code data signal is obtained. '11' is assigned to So, and similarly, Sa, Sb, Sc, and Sd are 0, 1, 0, and 1 in the dark part 31, so '10' is assigned, and in the dark part 32, Sa, Sb, Sc, Since Sd is 1,0,1,0, '01' is assigned, and in the state without pit, S
'0 because a, Sb, Sc, Sd are 0, 0, 0, 0
Assign 0 '. In this way, the code data signal So
By giving the information of the inclination of the pits 27 to 29, it is possible to double the information amount of one pit to 2 bits (four values) as compared with the conventional one. Therefore, also in the case of the present embodiment, the amount of information contained in one pit can be increased by increasing the type of pit inclination and the number of divisions of the light-receiving surface of the photodetector element 11, thereby increasing the density. A recording medium capable of recording can be provided.

Next, an embodiment of the invention described in claim 4 will be described with reference to FIGS. The description of the same parts as those in the first to third aspects of the present invention is omitted, and the same parts are designated by the same reference numerals.

This embodiment shows a modification of the optical information reproducing apparatus (see FIG. 2) of the invention described in claim 2 described above. That is, a high density information recording medium (see the optical disk 7 in FIG. 3A) having an information amount in the inclination of the pits 27 to 29 as described in the invention of claim 3 is used, and this high density information recording medium is used. The light-receiving surface divided corresponding to the information amount of 2 bits or more for detecting the reflected beams b from the pits 27 to 29 formed with different tilt angles from the track direction T (here, the light-receiving surface divided into four). A, B, C, and D) are provided, and the pit 27 is formed based on the signals detected by the light receiving surfaces A to D of the photodetector 11.
A code data generation circuit 3 for recognizing tilt angles of 29 to 29 and generating code data corresponding to an information amount of 2 bits or more.
4 is provided with pit inclination angle recognition information reproducing means.

FIG. 4 shows a circuit configuration of a pit tilt angle recognition information reproducing circuit 33 as a pit tilt angle recognition information reproducing means. Here, the code data generation circuit 34
Comprises a data conversion table circuit (memory IC) 35 having a data conversion table TB ₁ and a parallel-serial conversion circuit 24. Light receiving surface A of the light detection element 11
The amplifiers 22a to 22d and the waveform shaping circuit 2 are provided in the subsequent stage of the to D.
3a to 23d are sequentially connected. The waveform shaping circuits 23a to 23d are connected to the data conversion table circuit 35.

In such a structure, pits 27-2
A method of reproducing 2-bit (4-valued) information for 1 pit by the pit tilt angle recognition information reproducing circuit 33 using the optical disks 7 having different inclinations of 9 will be described. Figure 3
After the reflected beams b from the pits 27 to 29 in (a) are detected on the light receiving surfaces A to D, they pass through the waveform shaping circuits 23a to 23d to obtain the binarized signals Sa to Sd. This Sa ~ Sd
4 bit address data of the data conversion table circuit 3
It is input to 5 and converted into 2-bit parallel data S ₁ and S ₂ . FIG. 5 shows the contents of the data conversion table TB ₁ of the data conversion table circuit 35.
When Sa, Sb, Sc and Sd are 0, 1, 0 and 1, 1 and 0 are assigned to the corresponding values of S ₁ and S ₂ . By inputting the data S ₁ and S ₂ thus converted into the parallel-serial conversion circuit 24, it is possible to generate the serial-converted code data signal So as shown in FIG. As a result, the code data signal S
It is possible to make o have information corresponding to the inclination of the pits 27 to 29.

As described above, the reflected beam b from each pit is received by the plurality of divided light receiving surfaces (light receiving surfaces A to D), each detection signal is binarized, and the data conversion table TB is obtained.
₁ is used to convert into 2-bit parallel data S ₁ and S ₂ , and then parallel-serial conversion is performed to generate the code data signal So.
It is possible to easily reproduce an information amount of 2 bits or more corresponding to a pit, thereby providing an optical information reproducing device capable of high speed processing. Further, by using the data conversion table TB ₁ , it is possible to support various reproduction systems by simply rewriting the table contents.

Next, an embodiment of the invention described in claim 5 will be described with reference to FIG. The description of the same parts as those in the first to fourth aspects of the present invention is omitted, and the same parts are designated by the same reference numerals.

This embodiment shows a modification of the high-density information recording medium (see FIGS. 1 (a) and 3 (a)) of the invention described in claims 1 and 3 described above. That is, in the optical disc 7 as the high density information recording medium, pits having various pit numbers are formed on the track T on the disc surface.
It has an information amount of at least 2 bits or more for an area corresponding to one pit having a different number of pits. 6 (a) to 6 (c) show specific examples thereof, and 2 bits (4 values) per 1 pit depending on the number of pits.
This is an example in the case of having information of. In (a), three pits 36 are formed in one pit frame in
Two pits 37 are formed in the pit frame, one pit 38 is formed in one pit frame, and one pit is not formed in. (B) shows a state of the photo-detecting element 11 having four-divided light receiving surfaces A, B, C, D, and dark portions 39 to 41 are formed corresponding to the number of pits 36 to 38. To be done. The code data signal So is obtained based on the binarized signals Sa to Sd detected from the light receiving surfaces A to D. Now, assuming that the areas of the dark areas 39 to 41 are "1" and the areas other than the dark areas are "0", Sa, Sb, Sc, Sd in the dark area 39 are 1, 0, 1, 1 and "1" is 3 Since “11” is assigned to the code data signal So, the dark portion 40 has Sa, Sb, S
Since c, Sd become 1, 0, 0, 1 and two '1's are included,' 10 'is assigned, and Sa, Sb,
Since Sc and Sd are 1,0,0,0 and one '1' is included, '01' is assigned, and '00' is assigned without the pit. By thus providing the code data signal So with the information of the number of the pits 36 to 38, the information amount of one pit is doubled as compared with the conventional one.
It can be a bit (4 values). Therefore, also in the case of the present embodiment, the amount of information contained in one pit can be increased by increasing the number of types of pits and the number of divisions of the light receiving surface of the photodetector element 11, which allows high density recording. It is possible to provide a recording medium capable of performing the above.

Next, an embodiment of the invention described in claim 6 will be described with reference to FIGS. 4 and 7. The description of the same parts as those in the first to fifth aspects of the present invention will be omitted, and the same reference numerals will be used for the same parts.

This embodiment shows a modification of the optical information reproducing apparatus (see FIGS. 2 and 4) of the invention described in claims 2 and 4. That is, the high density information recording medium (see the optical disk 7 of FIG. 6A) having the information amount in the number of pits 36 to 38 as described in the invention of claim 5 is used. A light receiving surface divided corresponding to the information amount of 2 bits or more for detecting the reflected beams b from the pits 36 to 38 formed with different pit numbers (here, four light receiving surfaces A, B, C, D) is provided, and a code corresponding to an information amount of 2 bits or more by recognizing the number of pits based on the signals detected by the light receiving surfaces A to D of the photodetector 11 A pit number recognition information reproducing means having a code data generating circuit 34 for generating data is provided. In this case, the pit number recognition information reproducing circuit as the pit number recognition information reproducing means,
The configuration is the same as that of the pit tilt angle recognition information reproducing circuit 33 of the invention described in claim 4 (see FIG. 4) (for this reason, the same reference numeral 33 is used). However, here, the table contents of the data conversion table circuit 35 in the code data generation circuit 34 are changed to the data conversion table T as shown in FIG.
From B ₁ to data conversion table TB ₂ as shown in FIG.
Converted to.

In such a structure, the pit number recognition information reproducing circuit 3 is used by using the optical disks 7 having different pit numbers.
The case of reproducing 2-bit (4-valued) information for 1 pit by 3 will be described. 4 of the binarized signals Sa to Sd
The bit data is input to the data conversion table circuit 35, and the data conversion table TB ₂ is used to output S ₁ and S ₂ 2 data.
It is assigned to bit data. The signals S ₁ and S ₂ are converted into a serial code data signal So (see FIG. 6C) by the parallel-serial conversion circuit 24.
As a result, the pits 36 to 38 are added to the code data signal So.
The information corresponding to the number of can be given.

Therefore, the binary signals Sa to Sd are converted into 2-bit parallel data S using the data conversion table TB _2.
By converting to ₁ , S ₂ and performing parallel-serial conversion to generate the code data signal So, it is possible to easily reproduce the information amount of 2 bits or more corresponding to 1 pit generated by the number of pits. As a result, it is possible to provide an optical information reproducing device capable of high-speed processing. Also, by simply rewriting the contents of the data conversion table from TB _{1 to} TB ₂ , various reproduction systems can be supported.

Next, an embodiment of the invention described in claim 7 will be described with reference to FIG. The description of the same parts as those in the first to sixth aspects of the present invention will be omitted, and the same reference numerals will be used for the same parts.

In this embodiment, the high density information recording medium of the invention described in claims 1, 3 and 5 (FIGS. 1A and 3) is used.
(A), FIG. 6 (a)) shows a modified example.
That is, the optical disc 7 as a high density information recording medium
Has pits with various pit diameters (sizes) formed on the track T of the disc surface, and has an information amount of at least 2 bits or more in an area corresponding to one pit having a different pit diameter. It is a thing. 8 (a)-
(C) shows a specific example thereof, and is an example in the case of having 2-bit (4-valued) information for one pit depending on the pit diameter. In (a), the case where the diameter of 1 pit 42 is large, the case where the diameter of 1 pit 43 is smaller than, the case where the diameter of 1 pit 44 is smaller than 1 Not showing. (B) is a four-divided light receiving surface A, B,
1 shows a state of the photodetector element 11 having C and D,
Dark areas 45 to 47 are formed corresponding to the sizes of the large, medium and small pits 42 to 44 of. The code data signal So is obtained based on the binarized signals Sa to Sd detected from the light receiving surfaces A to D. Now, assuming that the areas of the dark areas 42 to 44 are "1" and the areas other than the dark areas are "0", Sa, Sb, Sc, and Sd in the dark area 45 are 1, 1, 1, 1 so that the code data signal is obtained. Assign '11' to So,
In the dark part 46, Sa, Sb, Sc, Sd are 1, 0, 0,
Since it is 1, “10” is assigned, and in the dark area 47 of S
'0 because a, Sb, Sc, Sd are 1,0,0,0
1'is assigned and '00' is assigned without the pit. By thus providing the code data signal So with information on the size of the pits 42 to 44,
The amount of information in one pit can be doubled to two bits (four values) as compared with the conventional one. Therefore, also in the case of the present embodiment, the amount of information contained in one pit can be increased by increasing the kind of pit size and the number of divisions of the light receiving surface of the photodetector element 11. A recording medium capable of various recording can be provided.

Next, an embodiment of the present invention will be described with reference to FIGS. 4 and 9. The description of the same parts as those in the first to seventh aspects of the invention is omitted, and the same parts are denoted by the same reference numerals.

This embodiment shows a modification of the optical information reproducing apparatus (see FIGS. 2 and 4) of the invention described in claims 2, 4 and 6. That is, the high density information recording medium having the information amount in the size of the pits 42 to 44 as described in the invention of claim 7 (the optical disk 7 of FIG. 8A).
Reflected beam b from pits 42 to 44 formed with different pit diameters on this high density information recording medium.
The light-receiving surface divided corresponding to the information amount of 2 bits or more (here, the light-receiving surfaces A, B, C
D) is provided, and the photodetector 1 is provided.
Pit diameter recognition information reproducing means having a code data generation circuit 34 for recognizing the pit diameter based on the signals detected by the respective light receiving surfaces A to D and generating code data corresponding to the information amount of 2 bits or more. Is provided. In this case, the pit diameter recognition information reproducing circuit as the pit diameter recognition information reproducing means is the invention according to claims 4 and 6 described above (Fig. 4).
(Refer to FIG. 3) and the pit inclination angle recognition information reproducing circuit 33 (pit number recognition information reproducing circuit 33) has the same configuration (for this reason, the same reference numeral 33 is used). However, here, the table contents of the data conversion table circuit 35 in the code data generation circuit 34 are changed to the data conversion table T as shown in FIG.
From B ₂ to data conversion table TB ₃ as shown in FIG.
Converted to.

In such a structure, the pit diameter recognition information reproducing circuit 3 is used by using the optical disks 7 having different pit diameters.
The case of reproducing 2-bit (4-valued) information for 1 pit by 3 will be described. 4 of the binarized signals Sa to Sd
The bit data is input to the data conversion table circuit 35, and the data conversion table TB ₃ is used to output ₂ of S ₁ and S ₂ .
It is assigned to bit data. The signals S ₁ and S ₂ are converted into a serial code data signal So (see FIG. 8C) by the parallel-serial conversion circuit 24.
As a result, the pits 42 to 44 are added to the code data signal So.
It is possible to provide information corresponding to the size of.

Therefore, the binary signals Sa to Sd are converted into 2-bit parallel data S by using the data conversion table TB _3.
By converting to ₁ , S ₂ and performing parallel-serial conversion to generate the code data signal So, it is possible to easily reproduce the information amount of 2 bits or more corresponding to one pit generated by the size of the pit. As a result, it is possible to provide an optical information reproducing device capable of high speed processing. Also,
By simply rewriting the contents of the data conversion table to TB ₁ , TB ₂ → TB ₃ , various reproduction systems can be supported.

[0045]

According to the first aspect of the present invention, pits are formed at the track center position on the medium surface and at positions separated from the track center position by various fixed distances, and the distance from the track center position is different. Since a high-density information recording medium having an information amount of at least 2 bits is provided in the area corresponding to the pits, the pits are arranged at least in the area corresponding to one pit (the distance from the track center). Since the information amount of 2 bits or more is provided, the information amount in the same medium area is significantly increased as compared with the conventional case where 1 bit information amount is provided for 1 pit, and the high density and large size are achieved. The capacity can be further improved.

According to a second aspect of the invention, there is provided an optical information reproducing apparatus which reproduces information by irradiating a pit formed on a track of an optical information recording medium with a beam spot and using a reflected beam reflected by the beam spot. At least 2 bits corresponding to the track center position of the medium surface and pits formed at various distances from the track center position and corresponding to one pit having a different distance from the track center position. For a high-density optical information recording medium having the above information amount, a 2-bit or more information amount for detecting a reflected beam from a pit formed by arranging the high-density optical information recording medium at different positions. A photo-detecting element having a correspondingly divided light-receiving surface is provided, and the pit arrangement is recognized based on the signal detected by each light-receiving surface of the photo-detecting element, and 2 bits are recognized. Since the pit arrangement recognition information reproducing means having the code data generating circuit for generating the code data corresponding to the above information amount is provided, the code data generating circuit is used by binarizing each detection signal from the plurality of light receiving surfaces. By simply performing parallel / serial conversion, code data having an information amount of 2 bits or more corresponding to one pit can be obtained, thereby providing an optical information reproducing device having a simple structure and capable of high speed processing. be able to. Also,
Since it is possible to play using pits with the same shape as before, there is no need to shorten the pit length or narrow the track pitch, so problems such as crosstalk during playback are eliminated and high reliability is achieved. Signal detection can be performed.

According to the third aspect of the present invention, pits are formed in the track direction of the medium surface and in a direction tilted at various constant angles from the track direction, and one pit having a different tilt angle from the track direction is formed. Since the high-density information recording medium having the information amount of at least 2 bits or more is provided for the corresponding region, the inclination of the pits in the region corresponding to 1 pit has the information amount of at least 2 bits. It is possible to significantly increase the amount of information in the same medium area as compared with the case where the conventional one pit has an amount of information of 1 bit, and it is possible to further improve high density and large capacity.

According to a fourth aspect of the present invention, there is provided an optical information reproducing apparatus for reproducing information by using a reflected beam reflected by irradiating a pit formed on a track of an optical information recording medium with a beam spot. At least 2 bits or more corresponding to an area corresponding to one pit in which a pit is formed in the track direction of the medium surface and in a direction tilted at various constant angles from the track direction and the tilt angle from the track direction is different. Corresponding to the information amount of 2 bits or more for detecting the reflected beam from the pits formed with different inclination angles in the high density information recording medium 2 bits or more are provided by providing a photodetector element having a divided light-receiving surface, and recognizing the tilt angle of the pit based on the signal detected by each light-receiving surface of the photodetector element. Since the pit tilt angle recognition information reproducing means having the code data generating circuit for generating the code data corresponding to the information amount is provided, the detection signals from the plurality of light receiving surfaces are binarized and the data conversion of the code data generating circuit is performed. By performing parallel / serial conversion using the table, it is possible to obtain code data having an information amount of 2 bits or more corresponding to one pit, and thus an optical information reproducing device having a simple structure and capable of high-speed processing can be obtained. Can be provided. In addition, since it is possible to reproduce by using pits having the same shape as the conventional one, there is no need to shorten the pit length or narrow the track pitch, and problems such as crosstalk during reproduction can be eliminated and reliability can be improved. High signal detection can be performed. Furthermore, by using the data conversion table, it is possible to support various reproduction methods by simply rewriting the table contents.

According to a fifth aspect of the present invention, pits having various pit numbers are formed on the track of the medium surface, and at least two bits or more are formed in an area corresponding to one pit having a different pit number. Since a high-density information recording medium having an information amount is provided, the information amount of at least 2 bits or more is given to the number of pits in the area corresponding to 1 pit, so that 1 bit information can be obtained for 1 pit of the related art. It is possible to significantly increase the amount of information in the same medium region as compared with the case where the amount is given, and to further improve high density and large capacity.

According to a sixth aspect of the present invention, there is provided an optical information reproducing apparatus for reproducing information by irradiating a pit formed on a track of an optical information recording medium with a beam spot and using a reflected beam reflected by the beam spot. A high-density information recording medium in which pits having various pit numbers are formed on a track of a medium surface and which has an information amount of at least 2 bits or more corresponding to an area corresponding to one pit having a different pit number. On the other hand, the high-density information recording medium is provided with a photo-detecting element having a light-receiving surface divided corresponding to an information amount of 2 bits or more for detecting a reflected beam from pits formed with different pit numbers. A code data generation circuit for recognizing the number of pits based on the signal detected by each light receiving surface of the photodetector and generating code data corresponding to an information amount of 2 bits or more. Since the pit number recognition information reproducing means is provided, it corresponds to one pit by binarizing each detection signal from the plurality of light receiving surfaces and performing parallel / serial conversion using the data conversion table of the code data generation circuit. It is possible to obtain the code data having the information amount of 2 bits or more, and thus it is possible to provide the optical information reproducing apparatus having a simple structure and capable of high speed processing. In addition, since it is possible to reproduce by using pits having the same shape as the conventional one, there is no need to shorten the pit length or narrow the track pitch, and problems such as crosstalk during reproduction can be eliminated and reliability can be improved. High signal detection can be performed. Furthermore, by using the data conversion table, it is possible to support various reproduction methods by simply rewriting the table contents.

According to a seventh aspect of the present invention, pits having various pit diameters are formed on the track of the medium surface, and at least two bits or more are formed in an area corresponding to one pit having a different pit diameter. Since a high-density information recording medium having an information amount is provided, the pit diameter has an information amount of at least 2 bits or more in an area corresponding to 1 pit, so that 1 bit of information can be obtained for 1 pit of the related art. It is possible to significantly increase the amount of information in the same medium region as compared with the case where the amount is given, and to further improve high density and large capacity.

According to an eighth aspect of the present invention, there is provided an optical information reproducing apparatus for reproducing information by using a reflected beam reflected by irradiating a pit formed on a track of an optical information recording medium with a beam spot. High-density information recording medium in which pits having various pit diameters are formed on a track on the medium surface and which has an information amount of at least 2 bits or more corresponding to an area corresponding to one pit having different pit diameters. On the other hand, the high-density information recording medium is provided with a photo-detecting element having a light-receiving surface divided corresponding to the information amount of 2 bits or more for detecting a reflected beam from pits formed with different pit diameters. A code data generation circuit for recognizing a pit diameter based on a signal detected by each light receiving surface of the photo detection element and generating code data corresponding to an information amount of 2 bits or more Since the pit diameter recognition information reproducing means is provided, it corresponds to one pit by binarizing each detection signal from the plurality of light receiving surfaces and performing parallel / serial conversion using the data conversion table of the code data generation circuit. It is possible to obtain the code data having the information amount of 2 bits or more, and thus it is possible to provide the optical information reproducing apparatus having a simple structure and capable of high speed processing. In addition, since it is possible to reproduce by using pits having the same shape as the conventional one, there is no need to shorten the pit length or narrow the track pitch, and problems such as crosstalk during reproduction can be eliminated and reliability can be improved. High signal detection can be performed. Furthermore, by using the data conversion table, it is possible to support various reproduction methods by simply rewriting the table contents.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a state of a signal detection method when information is provided in a pit arrangement which is an embodiment of the invention described in claim 1.

FIG. 2 is a block diagram showing a configuration of an optical information reproducing apparatus when information is provided in a pit arrangement which is an embodiment of the invention described in claim 2;

FIG. 3 is a schematic diagram showing a state of a signal detection method when information is given to a pit inclination which is an embodiment of the invention described in claim 3.

FIG. 4 is a block diagram showing a configuration of an optical information reproducing device when information is given to a pit inclination, the number of pits, and a pit diameter, which is an embodiment of the invention described in claims 4, 6, and 8.

FIG. 5 is a schematic diagram showing contents of a data conversion table which is an embodiment of the invention described in claim 4.

FIG. 6 is a schematic diagram showing a state of a signal detection method when information is given to the number of pits, which is an embodiment of the invention described in claim 5.

FIG. 7 is a schematic diagram showing contents of a data conversion table which is an embodiment of the invention described in claim 6;

FIG. 8 is a schematic diagram showing a state of a signal detection method when information is given to a pit diameter, which is an embodiment of the invention described in claim 7;

FIG. 9 is a schematic diagram showing contents of a data conversion table which is an embodiment of the invention described in claim 8;

FIG. 10 is an optical path diagram showing a configuration example of a conventional optical information reproducing device.

FIG. 11 is a schematic view showing a state of a conventional signal detection system from a pit.

[Explanation of symbols]

7 Optical Information Recording Medium (High Density Information Recording Medium) 8 Track Center 9 Pits 11 Photo Detecting Element 21 Pit Arrangement Recognition Information Reproducing Means 24 Code Data Generating Circuit 27 to 29 Pits 33 Pit Tilt Angle Recognition Information Reproducing Means (Pit Number Recognition Information) Reproducing means, pit diameter recognition information reproducing means) 34 code data generating circuit 36 to 38 pit 42 to 44 pit A, B, C, D light receiving surface

Claims (8)

[Claims] 1. A pit is formed at a track center position on a medium surface and at a position distant from the track center position by various fixed distances, and an area corresponding to one pit having a different distance from the track center position is formed. And a high-density information recording medium having an information amount of at least 2 bits or more. 2. An optical information reproducing apparatus for irradiating a pit formed on a track of an optical information recording medium with a beam spot, and reproducing information by using a reflected beam reflected by the beam spot. And a pit is formed at a position distant from the track center position by various constant distances and has an information amount of at least 2 bits or more corresponding to an area corresponding to one pit having a different distance from the track center position. The high-density optical information recording medium is divided corresponding to the amount of information of 2 bits or more for detecting the reflected beam from the pits formed by arranging the high-density optical information recording medium at different positions. A photo-detecting element having a light-receiving surface is provided, and the arrangement of pits is recognized based on the signal detected by each light-receiving surface of the photo-detecting element to handle an information amount of 2 bits or more. An optical information reproducing apparatus characterized in that a pit arrangement recognition information reproducing means having a code data generating circuit for generating code data is provided. 3. A pit is formed in a track direction of a medium surface and in a direction inclined at various constant angles from the track direction, and an area corresponding to one pit having a different inclination angle from the track direction is formed. A high density information recording medium having an information amount of at least 2 bits or more. 4. An optical information reproducing apparatus for irradiating a pit formed on a track of an optical information recording medium with a beam spot and reproducing information by using a reflected beam reflected by the beam spot. A pit is formed in a direction tilted at various fixed angles from the track direction, and a high amount having at least 2 bits of information corresponding to an area corresponding to one pit having a different tilt angle from the track direction. With respect to a high density information recording medium, a light receiving surface divided corresponding to an information amount of 2 bits or more for detecting a reflected beam from a pit formed with different inclination angles in the high density information recording medium is provided. A photodetector having the same is provided, and the tilt angle of the pit is recognized based on the signal detected by each light receiving surface of the photodetector, and the code corresponding to the information amount of 2 bits or more is detected. An optical information reproducing apparatus comprising pit inclination angle recognition information reproducing means having a code data generating circuit for generating the encoded data. 5. A pit having a different number of pits is formed on a track of a medium surface, and an area corresponding to one pit having a different number of pits has an information amount of at least 2 bits or more. Characteristic high density information recording medium. 6. An optical information reproducing apparatus for irradiating a beam spot on a pit formed on a track of an optical information recording medium and reproducing information by using a reflected beam reflected by the beam spot. For a high-density information recording medium in which pits with various pit numbers are formed and an information amount of at least 2 bits or more is provided corresponding to an area corresponding to one pit with different pit numbers, A high-density information recording medium is provided with a photo-detecting element having a light-receiving surface divided corresponding to the amount of information of 2 bits or more for detecting reflected beams from pits formed with different numbers of pits. A pit number recognition information having a code data generation circuit for recognizing the pit number based on the signal detected by each light receiving surface and generating code data corresponding to an information amount of 2 bits or more An optical information reproducing apparatus characterized in that it is provided with an information reproducing means. 7. A pit having various pit diameters is formed on a track of a medium surface, and an information amount of at least 2 bits or more is provided in an area corresponding to one pit having a different pit diameter. Characteristic high density information recording medium. 8. An optical information reproducing apparatus for irradiating a pit formed on a track of an optical information recording medium with a beam spot and reproducing information by using a reflected beam reflected by the beam spot. For a high-density information recording medium in which pits having various pit diameters are formed and the information amount of at least 2 bits or more corresponds to the area corresponding to one pit having different pit diameters, A high-density information recording medium is provided with a photo-detecting element having a light-receiving surface divided corresponding to the amount of information of 2 bits or more for detecting a reflected beam from pits formed with different pit diameters. Pit diameter recognition information having a code data generation circuit for recognizing the pit diameter based on the signal detected by each light receiving surface and generating code data corresponding to an information amount of 2 bits or more An optical information reproducing apparatus characterized in that it is provided with an information reproducing means.