JPH097223A - Optical disk and recording and reproducing device therefor - Google Patents

Abstract

PURPOSE: To provide an optical disk realizing an inexpensive recording/ reproducing device while keeping interchangeability for a reproduction only optical disk in an optical disk having a reproduction exclusive ROM area and a writable RAM area. CONSTITUTION: The reflectivity of a ROM area 11 is increased to >=70% and the reflectivity of the write-in light beam in a RAM area is decreased <=40%. Consequently, recording sensitivity is improved by increasing the absorption coefficient in the RAM area while keeping the interchangeability for a reproduction only optical disk in the ROM area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc for optically recording and reproducing information by using an optical head and its apparatus,
In particular, the present invention relates to an optical disc having a read-only ROM area and a writable RAM area, and an apparatus therefor.

[0002]

2. Description of the Related Art A read-only optical disc such as a CD or a CD-ROM has a merit that software can be supplied inexpensively because it can be copied in a large amount, but it cannot be written. There is a problem that it is not suitable for the ROM area and RA
An optical disc having an M area solves these problems at the same time.

Read-only ROM area and writable R area
An optical disc having an AM area is disclosed in, for example, Japanese Patent Laid-Open No. 61-
280048, JP-A-2-42652, JP-A-3-19148, and the like.

However, the technique disclosed in Japanese Patent Laid-Open No. 61-280048 is to form a rewritable recording film on the entire surface of an optical disk, and is the most popular CD and C at present.
There is a problem that it is not compatible with a read-only optical disc such as a D-ROM.

Further, in the technique disclosed in Japanese Patent Laid-Open No. 2-42652, this problem is taken into consideration and the reflectance of the optical disk is secured at 70% or more. However, no consideration has been given to the provision of a low-priced recording / reproducing device which requires a high laser power when writing data.

Further, the technique described in Japanese Patent Laid-Open No. 3-19148 is characterized in that the ROM area and the RAM area are arranged close to each other, but this problem has not been sufficiently considered.

[0007]

Therefore, in view of the above problems, the present invention has an object to provide an optical disk capable of realizing a low-cost recording / reproducing apparatus while maintaining compatibility with a read-only optical disk. It is another object of the present invention to provide a low-cost recording / reproducing device using this optical disk and a device applying the same.

[0008]

In order to solve the above-mentioned problems, an optical disk of the present invention is an optical disk having a read-only ROM area and a writable RAM area.
Increase the reflectance of the ROM area to 70% or more and RAM
The optical disk recording / reproducing apparatus of the present invention has a structure in which the reflectance of the area is reduced to 40% or less, and the optical disk of the present invention is used to record information with an optical head having a low power output.

[0009]

Since the reflectance of the ROM area is 70% or more,
It is possible to maintain compatibility with read-only optical disks. Further, since the reflectance of the RAM area is as low as 40% or less, the absorptance can be increased as high as 60% or more, and as a result, the laser power at the time of recording can be lowered, so that the cost of the recording / reproducing apparatus can be reduced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of an embodiment of the optical disc according to the present invention, and FIG. 2 is a sectional view taken along the line AA ′ in FIG. The optical disc 10 of this embodiment has a read-only ROM area 11 and a writable RAM area 12, and the RAM area 12 is arranged on the inner and outer circumference sides of the ROM area 11. Further, ROM information formed by concave and convex pits is stored in the ROM area 11, and a tracking pre-groove is formed in the RAM area 12. Depending on the application, it is possible to form header information or the like in the RAM area 12 with uneven pits, or to slightly wobble the pre-groove to record address information, disc rotation control signal, or the like. .

As shown in FIG. 2, a metal reflective layer 1 of aluminum (hereinafter referred to as Al) is provided on a polycarbonate substrate 4 in the ROM area 11. Therefore, the reflectance of this portion is 70% or more, and the CD or CD-RO
Satisfies the M standard. Further, in the RAM region 12, an interference layer 2 made of antimony (hereinafter referred to as Sb) and / or selenium (hereinafter referred to as Se) and a reflective layer 3 made of bismuth (hereinafter referred to as Bi) are provided. A two-layer recording film is provided. By setting the film thickness of the interference layer 2 to 30 nm and the film thickness of the reflective layer 3 to 25 nm, the reflectance of the writing light is reduced to 10%. In this case, the transmittance is 20% because the thickness of the reflective layer 3 is slightly thin, but the absorptance is very high at 70%. Therefore, the recording laser beam can be efficiently absorbed, and in this embodiment, recording can be performed with a very low recording power of 2 mW (at a disk medium moving speed of 1.4 m / s and a recording frequency of 720 kHz). Yes, when the C / N ratio is 50 dB or more).

In this embodiment, A is used as the metal reflective layer 1.
l as the interference layer 2, Sb and Se as the interference layer 2, and B as the reflection layer 3.
i is used, but the metal reflective layer 1 is not limited to this, and a metal reflective layer containing Al or gold (hereinafter referred to as Au) as a main component is used as the metal reflective layer 1 and Sb is used as the interference layer 2.
An interference layer containing Se as a main component and a reflective layer containing Bi as a main component can be used as the reflective layer 3.

The ROM area 11 of this embodiment will be described in more detail. ROM area 11 is a CD or CD-
Lead-in part, TOC compliant with ROM format
Section, program section, and lead-out section. Therefore, the optical disc of this embodiment is a CD or a CD-R.
Meets the requirements of OM and is a regular CD or CD
-The ROM area can be reproduced by a ROM player.

Here, writing of data to the RAM area will be described. A part of the laser light incident from the substrate 4 side is reflected at the boundary between the substrate 4 and the interference layer 2, and the rest is the interference layer 2.
Proceed to. Part of the energy of the light that has entered the interference layer 2 is absorbed in the interference layer 2 to cause a phase change in the interference layer 2 and decrease, and the remaining light energy is reduced to the boundary between the interference layer 2 and the reflection layer 3. Reach Here, a part of the light is transmitted and goes out to the back side of the reflection layer 3, and the rest is reflected and absorbed while returning to the interference layer 2 again, and reaches the boundary between the interference layer 2 and the substrate 4. At the boundary between the interference layer 2 and the substrate 4, a part thereof is reflected again and travels into the interference layer 2 and the remainder travels into the substrate 4. At this time, approximately 60 to 90 (%) of the energy of the incident light is absorbed in the interference layer 2, and data can be written efficiently. Further, by increasing the film thickness of the reflective layer 3, the amount of light transmitted through the reflective layer 3 can be reduced.

Here, the reflectance in the present invention is the substrate 4
At the boundary between the interference layer 2 and the interference layer 2, it can be defined as [(amount of light reflected from the substrate side reflected at this boundary) / (amount of incident light entering the boundary from the substrate side)] × 100 (%).

3 to 5 are sectional views in the radial direction of the boundary area between the ROM area 11 and the RAM area 12 of this embodiment. As shown in FIG. 3, the pits 5 in the ROM area 11 and the RAM area 1
It is desirable to clearly separate the two lands 7 and the grooves 8, but it is difficult in practice. Therefore, as an embodiment of this embodiment, as shown in FIGS.
A gap portion is provided between 1 and the RAM area 12. Also,
Since the lead-in portion and the lead-out portion are provided on the inner peripheral portion and the outer peripheral portion of the ROM area 11, respectively, the gap portion is preferably the lead-in portion or the lead-out portion. When the disc manufacturing process is performed such that the metal reflective layer 1 is formed in the ROM area 11 and then the two-layer recording films 2 and 3 are formed in the RAM area 12, the structure shown in FIG. 4 is obtained. On the contrary, when the two-layer recording films 2 and 3 are formed in the RAM area 12 and then the metal reflective layer 1 is formed in the ROM area 11, the structure is as shown in FIG. In the above embodiment, the track pitch is 1.6 μm and the pits 5 are
Has a width of 0.4 μm, an optical depth of λ / 4 (λ is a recording / reproducing laser wavelength), and a width of the groove 8 is 0.7 μm.
The optical depth is λ / 8 and the width of the land 7 is 0.9 μm.

In the above embodiment, the ROM area 1
Although the RAM areas 12 are provided on both sides of 1, the positional relationship between the RAM area and the ROM area may be reversed, and one area may be divided into two areas 12 inside or It goes without saying that only one of the outer side is sufficient.

Next, another embodiment of the optical disk according to the present invention will be described. FIG. 6 is a plan view of another embodiment of the optical disk according to the present invention, and FIGS. 7 to 10 are cross-sectional views of main parts of different embodiments of the present embodiment. The optical disc 71 of this embodiment has a read-only ROM area 72 and a writable RAM area 73, and the RAM area is arranged in a part of the ROM area 72. RAM with such a small area
Although it is not easy to form the area, the RAM area is formed by the following embodiment.

As shown in FIG. 7, the ROM area has A
forming a metal reflection film 75 containing l or Au as a main component,
In the RAM area, an interference film 7 containing Sb and Se as main components is formed.
A recording film having a three-layer structure including 6 and a reflection film 77 containing Bi as a main component and a metal reflection film 75 containing Al or Au as a main component was formed. According to this embodiment, the interference film 76 and the reflection film 77 of the three-layer structure recording film in the RAM area are formed by the mask sputtering method, and then the metal reflection film 75 is formed on the entire surface of the disk, which is relatively easy. The optical disk of this embodiment can be manufactured.

FIG. 8 shows another embodiment of this embodiment. As shown in FIG. 8, a metal reflective film 75 containing Al or Au as a main component is formed in the ROM region, and an interference film 76 containing Sb and Se as a main component and Bi as a main component are formed in the RAM region. A reflecting film 77, a dielectric film 78 made of a mixture of zinc sulfide and silicon monoxide (hereinafter referred to as ZnS—SiO ₂ ), and a metal reflecting film 75 containing Al or Au as a main component.
To form a four-layer structure recording film. The manufacturing method of this embodiment is almost the same as that of the above embodiment, but by inserting the dielectric film 78 of low thermal conductivity between the metal reflective film 75 of high thermal conductivity and the reflective film 76, the interference layer 76 is formed. Since the converted thermal energy can be suppressed from being transferred to the metal reflective film 75 having a good thermal conductivity, there is an advantage that the thermal energy can be efficiently used and the recording sensitivity is improved.

FIG. 9 shows another embodiment of this embodiment. As shown in FIG. 9, a metal reflective film 75 containing Al or Au as a main component is formed in the ROM area, and a first dielectric film 81 made of ZnS—SiO ₂ and germanium (hereinafter , Ge) and Sb and tellurium (hereinafter represented as Te), a second dielectric film 83 made of ZnS—SiO _2, and a metal reflective film containing Al or Au as a main component. A four-layer recording film composed of 75 and 75 was formed. The manufacturing method of this embodiment is almost the same as that of the above embodiment. The above-described two embodiments are write-once (writable only once) recording films, but this embodiment uses a phase-change recording film and has an advantage that rewriting is possible.

FIG. 10 shows another embodiment of this embodiment.
As shown in FIG. 10, Al or Au is stored in the ROM area.
And a first metal film 85 containing Al or Au as a main component is formed in the RAM region.
And a first dielectric film 81 made of ZnS-SiO ₂ , and G
a phase change recording film 82 made of e-Sb-Te and ZnS-
The second dielectric film 83 made of SiO ₂ and Al or Au
A five-layer recording film was formed from the second metal film 75 containing as a main component. The manufacturing method of this embodiment is almost the same as that of the above embodiment. In the present embodiment, the first metal film 85 is newly added, which makes it easier to control the cooling rate at the time of recording / erasing, and has the advantage of improving the rewriting performance.

Next, an optical disk recording / reproducing apparatus according to the present invention will be described. FIG. 11 shows a schematic configuration diagram of an optical disk recording / reproducing apparatus according to the present invention. The recording / reproducing apparatus according to the present invention includes a spindle motor 6 for driving an optical disk 16.
4, an optical disk drive control system including a focus tracking control circuit 66, a servo motor circuit 69, a slider motor 162, and a slider motor servo circuit 160, a system controller 63, an optical head 65, an RF signal preamplifier circuit 67, and data. The demodulation circuit 68 and the laser drive circuit 161 are provided. The recording / reproducing apparatus according to the present invention is further characterized in that it further includes a data modulation circuit 61, a disk reflectance detection circuit 62, and a recording / reproduction switching circuit 163.

The optical disk 16 used in this embodiment
Is an optical disk capable of recording at 2 mW with a reflectance of 70% or more in the ROM area and 10% in the RAM area. In the optical head 65 of this embodiment, a 30 mW semiconductor laser is mounted on a CD optical head, and the maximum output laser power of the optical head is 2.1 mW, which is considerably lower than that of a normal recording type optical head. Low cost can be realized by using the optical head.

FIG. 12 shows the relationship between the reflectance and the recording power. As shown in FIG. 12, when the reflectivity (%) of the optical disk is plotted on the horizontal axis and the recording power (mW) is plotted on the vertical axis, the recording power, which is the output power of the laser for recording and recording, decreases as the disk reflectance decreases. The recording power increases as the disc reflectance increases. For example, if the disc reflectance is 40% or less, recording can be performed with a laser power of 5 mW or less, and further, if the disc reflectance is 10%,
Recording can be performed with a recording power of 2 mW. By the way, since the CD optical heads currently on the market are produced at a very low price, if the CD optical head can be used for recording, a low-priced recording / reproducing apparatus can be provided. Since the optical utilization efficiency of the optical head for CD is about 7%, the conventionally used semiconductor laser is mounted on the semiconductor laser of 30 mW after using the optical disk having the optical reflectance of 10% or less. A recording power of 2 mW can be obtained without changing the optical system only by changing the optical system, and a low-cost recording / reproducing apparatus can be realized. Further, a semiconductor laser of 70 mW is required to obtain a recording power of 5 mW, and such a semiconductor laser is still expensive at present, but it is close to the fact that the high output of the semiconductor laser is being actively promoted. It is easy to predict that the price will be very low in the future. Therefore, a recording power of 5 mW can be obtained without changing the optical system by simply replacing the conventionally used semiconductor laser with a semiconductor laser of 70 mW after using an optical disk having a light reflectance of 40% or less. Therefore, a low-priced recording / reproducing device can be realized. On the other hand, the normal recording type optical head emits a high output laser power, so that the utilization efficiency is about 30%.
Inevitably, a high-priced semiconductor laser must be used, which inevitably increases the cost of the entire device.

The operation of the optical disk recording / reproducing apparatus according to the present invention will be described. In FIG. 11, the ROM area and the RAM area of the optical disc 16 are discriminated from each other by discriminating the intensity level of the light detected by the optical head 65 in the disc reflectivity detection circuit 62, and the discriminating signal is transmitted to the system. It is sent to the controller 63. The system controller 63 controls the focus tracking control circuit 66 and the RF signal preamplifier circuit 67 corresponding to the ROM area and the RAM area based on the discrimination signal. That is, since the reflectances of the ROM area and the RAM area are 7 times different, appropriate reproduction is performed by switching or changing the focus gain, the tracking gain, and the preamplifier gain so as to cope with the change of the reflectances. Also, as a RAM area,
When a recording film whose reflectance increases after recording is used, R
It is necessary to reverse the tracking polarity in the AM area and switch the tracking polarity at the same time as the focus gain and the tracking gain. On the other hand, needless to say, switching of the tracking polarities becomes unnecessary when the type of recording film of the RAM area in which the reflectance decreases after recording is used.

Since each circuit is switched between the ROM area and the RAM area, the objective lens (not shown) of the optical head 65 is normally pulled to the focusing position, and the tracking servo operates normally.
Therefore, the RF signal output level of the RF signal preamplifier circuit 67 also becomes an appropriate value, and the data demodulation circuit 68 can obtain predetermined data and clock signals.

Next, the case of recording data in the RAM area will be described. When recording data in the RAM area, the recording data is sent to the data modulating circuit 61 via the system controller 63, the recording data is EFM-modulated by the data modulating circuit 61, and the system controller 61 also performs a recording / reproducing switching circuit. 163 is switched to the recording mode, and the EFM signal is transferred to the recording / reproducing switching circuit 1
It is sent to the laser drive circuit 161 via 63. Information is recorded on the optical disk 16 by the laser drive circuit 161 changing the laser intensity of the optical head based on the EFM signal.

In the RAM area of the optical disk 16, A
TIP (Absolute Time In Preg)
signal is recorded, and the ATIP signal is demodulated by the system controller 63 from the optical head 65 via the data demodulation circuit 68. The ATIP
System controller 63 based on data based on signals
Determines the recording address and sends a rotation control signal to the motor servo circuit 69 to control the spindle motor 64.

In the above embodiment, the EFM is set in the RAM area.
Although the modulation signal is recorded, the data modulation circuit 61 is not limited to this, and the data modulation circuit 61 is a 1-7RLL modulation signal, a 2-7RL
It is possible to support various digital modulations such as an L modulation signal, an 8-9RLL modulation signal, and a multilevel modulation signal. Further, although the ATIP signal is used in the above-described embodiment, the present invention is not limited to this. A method of forming a header signal composed of concave and convex pits in the recording address signal, and the header signal for rotation control are used. A CAV control method or the like can be adopted.

Next, another embodiment of the optical disk recording / reproducing apparatus according to the present invention will be described. The recording / reproducing apparatus of the present embodiment has the same configuration as the recording / reproducing apparatus of the above-mentioned embodiment.
The reproduction of the OM area and the recording / reproduction of the RAM area can be performed. In this embodiment, a read-only ROM area having a reflectance of 70% or more and a writable RAM area having a reflectance of 40% or less are provided. Using an optical disc, the ROM area stores game software, and the RAM area stores information such as a game progress or result and a player name.

FIG. 13 shows an operation flowchart of this embodiment. As shown in FIG. 13, at the start of the game, first,
The lead-in signal of the ROM area is read (S1), and then the TOC information of the ROM area is read (S2).
Next, information such as the progress of the game or the player name recorded in the RAM area is read (S3), and this information is displayed in a menu (S4). For example, when the game is played for the first time, the player name is input, and when the game is continued in the middle of the game, the player name and the continuation are selected (S5). The game is started by this menu selection (S5). At the end of the game (S7), information such as the progress or result of the game and the player name is recorded in the RAM area (S8) and the system ends (S9).

By thus recording the information about the game software on the same optical disc, it is possible to continue playing from the middle of the game using another device by carrying only the optical disc. It is possible to improve the usability of the game software by using a new function such that the result of the play can be recorded for each player on the disc itself on which the game software is recorded.

Further, since this recording / reproducing apparatus can be realized at a low price as described above, it is very suitable for home game use. In addition, in this embodiment,
By making the ROM area of the optical disc the same as the game CD-ROM, there is an advantage that even a player without a normal recording function can enjoy the game software. In this case, the new features mentioned above cannot be used.

The third embodiment of the optical disk recording / reproducing apparatus according to the present invention will be described below. The recording / reproducing apparatus of the present embodiment has the same configuration as the recording / reproducing apparatus of the above-mentioned embodiment, and is capable of reproducing in the ROM area and recording / reproducing in the RAM area, and is a reproduction-only ROM having a reflectance of 70% or more. Area and a writable RAM area having a reflectance of 40% or less are used, the program software is stored in the ROM area, and the program software is first stored in the RAM area.
It stores the ID number information of the CPU device or the like installed the second time.

FIG. 14 shows an operation flowchart of this embodiment. As shown in FIG. 14, at the start of installation,
The lead-in signal of the ROM area is read (S11),
Next, the TOC information in the ROM area is read (S1
2). Next, I of the CPU device etc. which installed the program software recorded in the RAM area for the first time.
D number information and the like are read (S13). Since the above-mentioned ID number information is not recorded in the RAM area at the time of the first installation, the flow proceeds to the first installation flow (S14), and the CPU or system installed by the CPU or system is installed in the RAM area. ID of
The number information is recorded (S15), the installation is started (S16), and then the installation is finished (S2).
2). As a result of reading the information recorded in the RAM area,
When the ID number information or the like is detected, the process proceeds to the second and subsequent installation flows (S17), and the ID number of the CPU or system recorded in the RAM area is compared with the ID number of the CPU or system to be installed. Yes (S18). If the ID numbers match (S
19), installation starts (S16), and then
The installation is finished (S22). However, if the ID numbers do not match (S20), the disc is ejected (S21) so that the disc cannot be installed.

According to this embodiment, there is an advantage that the program software can be prevented from being copied and that the same CPU or system can be installed immediately when the system goes down. There is also an advantage that the recording / reproducing apparatus can be provided at a low price.

Next, an application device of the optical disk recording / reproducing device according to the present invention will be described. FIG. 15 is a schematic block diagram of an applied device using the optical disk recording / reproducing device according to the present invention. In the present embodiment, a read-only ROM area having a reflectance of 70% or more and a writing R having a reflectance of 40% or less are possible.
Using an optical disc having an AM area, map information is stored in the ROM area, and new information about the map is recorded in the RAM area. The optical disc recording / reproducing apparatus 31 of the present embodiment has the same configuration as the recording / reproducing apparatus of the above-mentioned embodiment, and is capable of reproducing the ROM area and recording / reproducing the RAM area.

As shown in FIG. 15, this applied device is an optical disk recording / reproducing device 31 and a CPU device 3 with a built-in memory.
2, a display device 33, a position detecting device 34 such as GPS, and a traveling state detecting device 35. This applied device is suitable for use as a car navigation. That is, since the map information changes drastically, it can be rewritten while driving the latest information. For example, when a new road not found on the map is found, its position is stored in the memory, and when the information is completed, it is recorded in the RAM area of the optical disc. It is also possible to record information such as a place to go again such as a restaurant or a park.

[0040]

As described above, according to the present invention, in an optical disk having a read-only ROM area and a writable RAM area, the recording sensitivity of the RAM area can be improved, so that an optical head with a low power output can be used. Information can be recorded, and as a result, there is an effect that the recording / reproducing apparatus can be supplied at a low price. Further, since it is possible to provide a low-priced recording / reproducing apparatus, there is an effect that the application of the ROM / RAM mixed disk is greatly expanded.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the structure of an optical disc according to the present invention.

FIG. 2 is a cross-sectional view showing the structure of the optical disc of FIG. 1 taken along the line AA ′.

FIG. 3 is a sectional view showing an embodiment of a boundary area in the optical disc of the embodiment of FIG.

4 is a cross-sectional view showing another embodiment of the boundary area in the optical disc of the embodiment of FIG.

5 is a cross-sectional view showing another embodiment of the boundary region in the optical disc of the embodiment of FIG.

FIG. 6 is a plan view showing another embodiment of the structure of the optical disc according to the present invention.

FIG. 7 is a sectional view showing the first embodiment of the optical disc of the example of FIG.

FIG. 8 is a sectional view showing a second embodiment of the optical disc of the embodiment of FIG.

FIG. 9 is a cross-sectional view showing a third embodiment of the optical disc of the example of FIG.

FIG. 10 is a sectional view showing a fourth embodiment of the optical disc of the embodiment of FIG.

FIG. 11 is a block diagram showing the configuration of an embodiment of a recording / reproducing apparatus using the optical disc according to the present invention.

FIG. 12 is a characteristic diagram showing the relationship between disc reflectance and recording power.

FIG. 13 is an operation flowchart showing a second embodiment of the recording / reproducing apparatus according to the present invention.

FIG. 14 is an operation flowchart showing the third embodiment of the recording / reproducing apparatus according to the present invention.

FIG. 15 is a system block diagram showing the structure of another embodiment of the recording / reproducing apparatus according to the present invention.

[Explanation of symbols]

 1 Metal Reflective Layer 2 Interference Layer 3 Reflective Layer 4 Polycarbonate Substrate 5 ROM Pit 7 Land 8 Groove 11 ROM Area 12 RAM Area 61 Data Modulation Circuit 62 Reflectance Detection Circuit 63 System Controller 65 Optical Head 66 Focus Tracking Control Circuit 67 RF Signal Preamplifier Circuit 68 Data demodulation circuit 163 Recording / reproduction switching circuit

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Yoshihiko Noro, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa, Ltd.Inside the Hitachi Media Visual Media Laboratory (72) Inventor Takashi Takeuchi, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi Media Co., Ltd. Video Media Research Laboratory (72) Inventor Kyoji Kodera 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture

Claims (15)

[Claims] 1. In an optical disc having a read-only ROM area in which information can be recorded and only optically reproduced and a writable RAM area in which information can be optically recorded and reproduced, the reflectance of the ROM area is 70% or more. , The RAM
An optical disk having a reflectance of writing light in an area of 40% or less. 2. The aluminum (A
1) or a metal reflective film containing gold (Au) as a main component is formed, and an interference film containing antimony (Sb) and selenium (Se) as main components and bismuth (Bi) as a main component in the RAM region. The optical disc according to claim 1, wherein a two-layer structure recording film including a reflective film is formed. 3. The ROM area is a lead-in section or TOC conforming to a CD or a CD-ROM format.
The optical disc according to claim 1 or 2, further comprising a read section, a program section, and a lead-out section. 4. The optical disk according to claim 3, wherein the RAM area is provided on an outer peripheral portion and / or an inner peripheral portion of the ROM area. 5. The aluminum (A
1) or a metal reflective film containing gold (Au) as a main component is formed, and an interference film containing antimony (Sb) and selenium (Se) as main components and bismuth (Bi) as a main component in the RAM region. Reflective film and aluminum (Al) or gold (A
The optical disc according to claim 1, wherein a three-layer structure recording film including a metal reflection film containing u) as a main component is formed. 6. The aluminum (A
1) or a metal reflective film containing gold (Au) as a main component is formed, and an interference film containing antimony (Sb) and selenium (Se) as main components and bismuth (Bi) as a main component in the RAM region. The optical disc according to claim 1, wherein a four-layer structure recording film including a reflective film, a dielectric film made of an inorganic material, and a metal reflective film containing aluminum (Al) or gold (Au) as a main component is formed. 7. The aluminum (A
1) or a metal reflection film containing gold (Au) as a main component, and a first metal film, a first dielectric film, a phase change recording film, a second dielectric film, and a second metal film in the RAM area. The optical disk according to claim 1, wherein a recording film having a five-layer structure composed of is formed. 8. The aluminum (A
1) or a metal reflective film containing gold (Au) as a main component is formed, and the RAM area has a four-layer structure recording including a first dielectric film, a phase change recording film, a second dielectric film, and a metal film. The optical disc according to claim 1, wherein a film is formed. 9. An optical disk recording / reproducing apparatus having a read-only ROM area capable of recording and optically reproducing information and a writable RAM area capable of optically recording / reproducing information, wherein at least information is recorded / reproduced. An optical disk, a focus tracking control circuit, an RF signal preamplifier circuit, a disk reflectance detection circuit, a laser drive circuit, a recording / reproduction switching circuit, a data modulation circuit, and a system controller are provided, and the optical disk is the RO.
An optical disk is used, wherein the reflectance of the M area is 70% or more and the reflectance of the writing light in the RAM area is 40% or less, and the ROM area and the RAM area are provided with the disk reflectance detection circuit. The focus tracking control circuit and the RF signal preamplifier circuit are controlled by the system controller according to the determination signal.
When writing data in the RAM area while controlling according to the cases of the M area and the RAM area. A recording / reproducing apparatus for an optical disk, wherein the data modulating circuit, the recording / reproducing switching circuit, and the laser driving circuit are operated to record information by the optical head. 10. An optical disk recording / reproducing apparatus having a read-only ROM area capable of recording information and optically reproducing only, and a writable RAM area capable of optically recording / reproducing information, wherein a game is provided in the ROM area. Software is stored and information such as the progress or result of the game and the player name is stored in the RAM area. At the start of the game, the lead-in signal and TOC information of the ROM area are read and recorded in the RAM area. By reading the above information, it has a function of selecting the progress of the game based on the information, and at the end of the game, it has a function of storing information such as the progress or result of the game and the player name in the RAM area. An optical disk recording / reproducing apparatus characterized by the above. 11. An optical disc having a read-only ROM area capable of recording information and optically reproducing only and a writable RAM area capable of optically recording and reproducing information, wherein the reflectance of the ROM area is 70% or more. , The RAM
The optical disc recording / reproducing apparatus according to claim 10, wherein an optical disc having a writing light reflectance of 40% or less is used. 12. An optical disk recording / reproducing apparatus having a read-only ROM area capable of recording and optically reproducing information and a writable RAM area capable of optically recording / reproducing information, wherein a program is stored in the ROM area. It has a function of storing the software and writing the ID number information of the CPU device etc. in which the program software is first installed into the RAM area, and the second and subsequent installations are the CPU devices installed in the first time. An optical disk recording / reproducing apparatus having a function that cannot be installed in a device other than the above. 13. An optical disc having a read-only ROM area for recording and optically reproducing information and a writable RAM area for optically recording and reproducing information, wherein the ROM area has a reflectance of 70% or more. , The RAM
The optical disc recording / reproducing apparatus according to claim 12, wherein an optical disc having a reflectance of writing light in the area of 40% or less is used. 14. An optical disk recording / reproducing apparatus having a read-only ROM area capable of recording information and optically reproducing only and a writable RAM area capable of optically recording / reproducing information, wherein a map is provided in the ROM area. An optical disk recording / reproducing apparatus having a function of storing information and recording new information about a map in the RAM area. 15. An optical disc having a read-only ROM area in which information can be recorded and only optically reproduced and a writable RAM area in which information can be optically recorded and reproduced, and the reflectance of the ROM area is 70% or more. , The RAM
15. The optical disc recording / reproducing apparatus according to claim 14, wherein an optical disc having a writing light reflectance of 40% or less is used.