JP3462375B2 - Optical memory device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical memory device for irradiating an optical recording medium such as an optical disc with light to record or reproduce information.

[0002]

2. Description of the Related Art Information is reproduced or recorded by irradiation of light.
An optical memory device represented by an optical disk device for reproduction is put to practical use for various files such as voice, images, computer data, etc. as an information storage device having large capacity, high speed accessibility, and medium portability, and will continue to be used in the future. Its development is expected.

Techniques for increasing the density of optical memory devices include shortening the wavelength of a gas laser for cutting a master for manufacturing an optical disc, shortening the wavelength of a semiconductor laser that is a light source for recording / reproducing, and increasing the numerical aperture of an objective lens. There are various approaches such as thinning the optical disk, and further, there are various approaches such as mark length recording and land / groove recording for recordable optical disks.

On the other hand, in addition to these approaches, a super-resolution reproducing technique using a medium film is being studied as a technique effective for increasing the density of an optical disc. The super-resolution reproduction technology was originally proposed as a technology peculiar to the magneto-optical disk. In super-resolution reproduction with magneto-optical recording, a magnetic film having a super-resolution function (super-resolution reproduction film) is provided on the recording layer on the incident side of reproduction light, and both are exchange-coupled or magneto-statically coupled. Use medium. Then, by heating the super-resolution reproducing film by irradiating the reproducing light to change the exchange force or the static magnetic force between the layers, a partial optical mask or an optical aperture for the reproducing light spot is formed in the super-resolution reproducing film. However, by effectively reducing the size of the reproduction light spot, reproduction with high resolution becomes possible.

After that, not only in magneto-optical recording but also in a ROM disk, after superimposing a reproducing light on the recording layer, a super-resolution reproducing film whose light transmittance changes by irradiation of the reproducing light is provided. Attempts to do so have been reported. In this way, the super-resolution reproduction technology is used for magneto-optical disks, CD-ROMs,
It has become clear that it can be applied to all optical disks such as CD-R, WORM, and phase change type optical recording media.

By the way, in this kind of optical memory device, generally, at the time of recording, verification, that is, verification of the recording state is carried out. In the conventional optical memory device, the verify operation during recording is performed after the recording operation is completed to some extent. For example, in a one-beam optical memory device, after at least one rotation of the optical disk has elapsed after the formation of the recording mark row, a reproducing operation called trial reproduction is performed to verify the recording state, and as a result of this verification, If an error occurs, a method has been adopted in which re-recording is performed on the same or different place as the first recorded place on the optical disc.

Therefore, even in a normal recording operation in which no error occurs, it takes time for recording → verify (test reproduction) and two rotations of the disk, and when an error occurs, recording → verify (test reproduction) → re-recording. (→ re-verify), and it took 3 to 4 rotations of the disk.

On the other hand, the verification at the time of reproduction can be generally realized by an error detection / correction function which an optical memory device has. However, when an optical recording medium having a super-resolution reproducing film is used, as will be described in detail later, the reproduced signal is likely to be distorted due to the characteristics of the super-resolution reproducing film, which causes a new error increase. Therefore, there is a difficulty that the error detection and correction capability must be stronger than ever.

[0009]

As described above, in the conventional optical memory device, it takes a long time for verifying at the time of recording, and when an optical recording medium having a super-resolution reproducing film is used, super-resolution is required. There is a problem in that the reproduced signal is likely to be distorted due to the characteristics of the reproducing film, which causes an increase in errors.

The present invention has been made to solve such conventional problems, and an object thereof is to provide an optical memory device capable of verifying a recording state in a short time. Another object of the present invention is to provide an optical memory device capable of correcting the distortion of a reproduced signal when an optical recording medium having a super resolution reproducing film is used.

[0011]

In order to solve the above-mentioned problems, the present invention firstly relates to a recording layer for recording information by irradiation of light and a light irradiation arranged on the light incident side of the recording layer. In an optical memory device using an optical recording medium having a luminous film that emits light, the light emission of the luminous film that occurs after irradiating the optical recording medium with light is detected, and the recording state of the optical recording medium is detected by using the emission detection signal. Is characterized in that More specifically, the recording state can be verified by comparing the level of the light emission detection signal with a predetermined threshold value.

According to one embodiment, the optical recording medium as the above-mentioned luminous body film undergoes an optical change upon electron excitation by light irradiation, and emits light upon deexcitation of excited electrons after the light irradiation. It has an image reproducing film. In this case, if light emission due to deexcitation of excited electrons in the super-resolution reproducing film that occurs after irradiating the optical recording medium with light is detected, and the light emission detection signal is used to verify the recording state of the optical recording medium. Good. A phosphor film or the like can also be used as the light emitter film.

The light emission detection signal obtained by detecting the light emission of the light emitting film after the light is irradiated to the optical recording medium changes its level depending on the recording state of the recording layer. Can be used to verify the recording state of the optical recording medium. By doing so, since it is possible to verify the recording state in parallel with the recording, the time required for the verification is longer than that of the conventional verify method in which the test reproduction is performed after the recording to verify the recording state. Significantly shortened.

Secondly, the present invention uses an optical recording medium having a recording layer for reproducing information by irradiation of light and a light-emitting film which is arranged on the light incident side of the recording layer and emits light upon irradiation with light. In the optical memory device described above, the light emission of the light emitting film after the light is incident on the optical recording medium is detected, and the reproduction signal from the optical recording medium is corrected by referring to the light emission detection signal. It is preferable that the correction of the reproduction signal is performed according to the characteristics of the light emitter film with reference to the light emission detection signal.

In one embodiment, the optical recording medium, as the above-mentioned light-emitting film, undergoes an optical change upon electron excitation by light irradiation, and emits light along with deexcitation of excited electrons after the light irradiation. Have a membrane. In this case, the light emission due to the deexcitation of excited electrons in the super-resolution reproducing film that occurs after the optical recording medium is irradiated with light is detected, and the light emission detection signal is referenced to correct the reproduction signal from the optical recording medium. do it. Also, a phosphor film or the like can be used as the light emitter film.

As described above, the luminescence detection signal obtained by detecting the luminescence of the luminous body film after irradiating the optical recording medium with light is not only the recording state of the recording layer but also the super-resolution reproducing film on the optical recording medium. When there is a film that causes the distortion of the reproduction signal as described above, the distortion caused by the film can be monitored. Therefore, the emission detection signal can be used to remove or reduce the distortion of the reproduction signal. It is possible to correct. When the super-resolution reproducing film is used, more accurate correction can be performed by further correcting the reproduced signal by referring to the characteristics of the super-resolution reproducing film. By correcting the reproduction signal in this way, reproduction information with a low error rate can be obtained.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. First, an example in which a super-resolution reproducing film is used as the light emitting film will be shown. The super-resolution reproducing film undergoes an optical change in association with electronic excitation by light irradiation. The excited electrons are accompanied by light emission upon deexcitation. In the present embodiment, this light emission is detected to verify the recording state (record verify).

FIG. 1 shows a sectional structure of an optical disk according to an embodiment of the present invention. The optical disc 10 includes a super-resolution reproducing film 12, an intermediate layer 13, and a recording layer 14 on a disc substrate 11.
The protective layer 15 is sequentially formed.
The intermediate layer 13 and the protective layer 15 are provided as needed. It is assumed that a recording mark string corresponding to recording information is formed on the recording layer 14.

When reproducing the information recorded on the optical disk 10, reproduction light is transmitted from the substrate 11 side to the super-resolution reproduction film 12.
And the recording mark train formed in the recording layer 14 is irradiated through the intermediate layer 13. That is, the super-resolution reproducing film 1
Reference numeral 2 is formed on the recording layer 14 on the incident side of the reproduction light.

Here, the super-resolution reproducing film 12 will be described in detail. FIG. 2 is a diagram showing general characteristics of the super-resolution reproducing film, and shows the relationship of the transmittance Tr of the film with respect to the number Np of photons incident on the film. In this example, the transmittance Tr is low when the number Np of incident photons is small, and is high when Np is large. On the contrary, depending on the material of the super-resolution reproducing film, Tr is high when Np is small and Np is small.
There is also a characteristic that Tr becomes low as the value becomes large. In short, the essential characteristic of the super-resolution reproducing film is that the transmittance changes with the number of incident photons.

When Tr increases monotonically with an increase in Np as in the example of FIG. 2, the transmittance is high in the portion where the number of incident photons is large near the central portion of the reproduction light spot, and is transmitted in the peripheral portion. Since the rate is low, the effective spot size of the reproducing light is small, and the recording marks can be formed on the recording layer at a narrow pitch.

The super-resolution reproducing film used in this embodiment is
Basically, the film is optically excited by light irradiation, and the film is optically changed by a change in electron density existing in at least two levels related to the excitation. Specifically, a semiconductor material in which the energy difference between the two levels related to excitation is substantially the same as the light source wavelength of the optical memory device is used. The level to be used is not particularly limited as long as the energy difference between the two levels such as the conduction band, valence band, impurity level, and excitation level matches the light source wavelength. A continuous film-shaped semiconductor film can also be used as a super-resolution reproducing film, but it is better to control the energy difference between levels and the time constant control of deexcitation by using a form in which the semiconductor is made into fine particles and dispersed in the dielectric. It is preferable from the point. Further, the super-resolution reproducing film may have a structure in which a quantum size effect can be expected, such as a quantum well structure in which semiconductors are stacked.

The operating principle of this super-resolution reproducing film is that the electron density in the lower level is decreased by the electron excitation and the electron density in the upper level is increased, so that the excitation probability is decreased, that is, the light absorption is decreased. To do. When the excitation probability is significantly reduced, further reduction in probability is small and absorption saturation occurs. Therefore, the super-resolution reproduction of this embodiment can be regarded as a change in transmittance due to absorption saturation.

FIG. 3A shows a change in the transmittance Tr of this super-resolution reproducing film due to absorption saturation (in this case, T at absorption saturation).
The value before the change in transmittance due to deexcitation from the time point t = 0 when r is maximized) (in this case, the minimum transmittance)
It is the figure which showed the mode until it became. In addition, FIG.
In addition, the amount of light emission at the time of deexcitation of the super-resolution reproducing film is also shown. Assuming that the life of deexcitation is “td”, the amount of light emission at the time of deexcitation becomes maximum around time td. The characteristics shown in FIG. 3B are not limited to the super-resolution reproducing film, and are the same for general light emitting films.

The two levels causing absorption saturation in the super-resolution reproducing film in which semiconductor particles are dispersed can be selected from a valence band, a conduction band, an exciton level, an impurity level and the like. In addition, the life of deexcitation in a super-resolution reproducing film in which semiconductor particles are dispersed is several tens in a very high-speed example.
It is on the order of ns, and it is difficult to detect luminescence, but recording / recording can be performed by devising measures such as reducing the size of fine particles or providing an appropriate impurity level for multistage deexcitation.
Light emission due to deexcitation can be maximized at a position sufficiently distant from the irradiation position of the reproduction light beam, which facilitates detection. For example, when the disc linear velocity is 20 m / s, if a super-resolution reproducing film with a de-excitation lifetime of 1 ms is used, the recording / reproducing light beam irradiation position and the emission detection position due to de-excitation should be separated by about 20 mm. Therefore, it is possible to employ an ordinary detection system by condensing a lens.

Next, the principle of the verify operation at the time of recording / erasing according to the present invention will be described by taking the case where a super-resolution reproducing film is used as a light emitting film as shown in FIG. In the present embodiment, it is assumed that the recording mark of the recording layer 14 is formed of an amorphous portion, and the reflectance (Rc) of the crystal portion which is the non-recording mark portion is higher than the reflectance (Ra) of the amorphous portion. A phase change type optical recording medium is used as the optical disc 10 in FIG.
Further, it is assumed that the reflectance (Rm) of the molten portion in the process of forming the amorphous portion is smaller than the reflectance (Rc) of the crystalline portion.

FIG. 4 is a timing chart for explaining the verify operation at the time of recording / erasing in this embodiment. (A) is recording / erasing light, (b) and (d) are super-resolution reproducing films 12. A detection signal of reflected light from the optical disc, (c) is a miswrite detection signal which is a recording verify signal corresponding to (b),
(E) is a miserase detection signal which is an erase verify signal, and (f) is a signal obtained by integrating light emission detection signals.

First, the verify operation during recording will be described. As shown in FIG. 4A, it is assumed that the optical disc 10 is irradiated with recording / erasing light that changes in a pulse shape between the recording power Pw and the erasing power Pe from the substrate 11 side. Power P
A pulse of w is called a recording pulse, and a pulse of power Pe is called an erasing pulse. The super-resolution reproducing film 12 changes its transmittance upon incidence of light to form an optical aperture (a portion with high transmittance),
The recording layer 14 is irradiated with light through this optical opening.
Recording is performed by forming a recording mark by amorphizing the crystal part of the recording layer 14. The intensity of light incident on the super-resolution reproducing film 12 is the sum of the intensity of light initially incident and the intensity of light reflected from the recording layer 14.

Here, as shown in FIG.
At the time of the second recording pulse of the recording / erasing light of (a), it is assumed that so-called miswrite occurs in which recording cannot be performed by mistake. When there is no miswriting, the intensity of the light incident on the super-resolution reproducing film 12 is first determined by the recording power P on the optical disk 10.
The intensity Io of the incident light when irradiated with the light of w and the intensity Trw × Rm × Io of the reflected light from the portion in the molten state in the process in which the crystal part of the recording layer 14 becomes amorphous. The sum is (1 + Trw × Rm) Io. However, Trw is the transmittance of the optical aperture of the super-resolution reproducing film 12 formed when the optical disk 10 is irradiated with the light of the recording power Pw.

On the other hand, when miswriting occurs, the intensity of light incident on the super-resolution reproducing film 12 is as follows.
Intensity Io of light that is incident when the light of recording power Pw is applied to the recording layer 12 and intensity Trw × Rc × of reflected light from a portion of the recording layer 12 that is in a crystalline state without being in a molten state.
It is the sum of Io (1 + Trw × Rc) Io.

Since the relationship between the reflectance Rc of the crystalline portion of the recording layer 14 and the reflectance Rm of the molten portion in the process of forming the amorphous portion is Rc> Rm, the super resolution reproducing film 12 As for the detection signal of the reflected light, the signal level when miswriting occurs as shown in FIG. 4B becomes larger than the signal level detected when the recording is correctly performed. Therefore, FIG.
By thresholding the detection signal of (b) with a predetermined threshold value TH1, a miswrite detection signal as shown in FIG. 4 (c) can be obtained.

Next, the verify operation during erase will be described. The recording mark on the recording layer 14 is erased by recrystallizing the amorphous portion. When the recording / erasing light shown in FIG.
Assume that a miserasure that cannot be erased occurs during the erase pulse between the second recording pulses. When the erasing can be completed completely, the intensity of the light incident on the super-resolution reproducing film 12 is the intensity Io of the light incident when the optical disc 10 is first irradiated with the light having the erasing power Pe, and the intensity of the recording layer 14. Intensity of reflected light from the recrystallized portion of the amorphous portion Tre × Rc × I
The sum of o is (1 + Tre × Rc) Io. However, Tre
Is the transmittance of the optical aperture of the super-resolution reproducing film 12 formed when the optical disk 10 is irradiated with light having the erasing power Pe.

On the other hand, when the miserasure occurs, the intensity of the light incident on the super-resolution reproducing film 12 is as follows.
The intensity Io of light that is incident when the light having the erasing power Pe of 0 is irradiated, and the intensity Tre × Ra of the light reflected from the portion of the recording layer 12 that holds the amorphous state without being recrystallized. ×
The sum of Io (1 + Tre × Ra) is Io.

Since the relationship between the reflectance Rc of the crystalline portion of the recording layer 14 and the reflectance Ra of the portion which is kept in the amorphous state without being recrystallized is Rc> Ra, the super-resolution reproducing film 12 is obtained. The detection signal of the reflected light from is smaller than the signal level in the case where the erase can be correctly performed, as shown in FIG. 4D. Therefore, FIG. 4 (d)
By performing threshold processing on the detection signal of No. 2 with a predetermined threshold value TH2, a miserase detection signal as shown in FIG. 4E can be obtained.

Here, the case where the reflectance Rc of the crystalline portion of the recording layer 14 is higher than the reflectance of the amorphous portion Ra is taken as an example, but conversely, the reflectance Ra of the amorphous portion is equal to that of the crystalline portion. Reflectance R
Even if it is larger than c, the polarities of the detection signals are only reversed, so that miswriting and miserasing can be detected, that is, verification at the time of recording / erasing can be performed in the same manner as described above.

Next, an embodiment of the optical disk device having the above-mentioned verify function at the time of recording / erasing will be described. FIG. 5 shows the structure of the recording / reproducing system of this optical disk device. As described above, the optical disc 10 includes the super-resolution reproducing film 12 and the intermediate layer 1 on the disc substrate 11.
3, the recording layer 14 and the protective layer 15 are sequentially formed.

When recording / erasing the optical disk 10,
A light source (for example, a semiconductor laser) 21 is driven by the recording / erasing signal series 20, and the recording / erasing light shown in FIG. 4A is generated. The recording / erasing light is guided to the first objective lens 23 via the beam splitter 22, and is irradiated as a minute spot on the optical disc 10 from the substrate 11 side by the objective lens 23.

The reflected light from the optical disk 10 passes through the first objective lens 23 in the direction opposite to the incident light, is guided to the first photodetector 24 by the beam splitter 22, and is detected as an electric signal. The first photodetector 24 is, for example, a divided photodetector in which the light-receiving surface is divided into a plurality of portions (for example, 2 or 4), and a plurality of output signals corresponding to the respective division surfaces are provided to an arithmetic circuit (not shown) described later. The input signal is input, and the arithmetic circuit generates a reproduction signal and an error signal for focusing and tracking.

On the other hand, in order to perform verification at the time of recording / erasing, the second objective lens 31, the second photodetector 32, the first and second comparators 33 and 34, and the arithmetic circuit 36.
Is provided. First and second comparators 33 and 3
Reference numeral 4 is for detecting a miswrite and a miss erase, respectively, to generate a verify signal sequence 35. The arithmetic circuit 36 generates a re-recording / erasing signal sequence 37 for re-recording / erasing the optical disc 10 from the verification signal sequence 35 and the recording / erasing signal sequence 20 which are the comparison results of the comparators 33 and 34.

Next, the verify operation at the time of recording / erasing in this embodiment will be described. In order to perform the verify operation at the time of recording / erasing, the optical disc 1 immediately after recording / erasing is performed.
Reflected light from 0 (light emitted when the super-resolution reproducing film 12 is deexcited) is condensed by the second objective lens 31, and this light is detected by the second photodetector 32 as an electric signal. The emission detection signal from the second photodetector 32 is the first,
It is input to the second comparators 33 and 34.

The first comparator 33 is a super-resolution reproduction which occurs td seconds after the recording / erasing light generated from the light source 21 passes the recording power Pw (a time near the maximum light emission amount). The emission detection signal from the photodetector 32 based on the emission at the time of deexcitation of the film 12 is compared with the threshold value TH1,
If the signal level of the detection signal is equal to or higher than the threshold value TH1, the miswrite detection signal is output. Similarly, the second comparator 34 compares the light emission detection signal from the photodetector 32 with the threshold value TH2, and outputs the miserase detection signal if the detection signal is less than or equal to the threshold value TH2.

The outputs of the first and second comparators 33 and 34 are combined into a recording / erasing verify signal sequence 35 which is the verification result of the recording / erasing state and is input to the arithmetic circuit 36. The arithmetic circuit 36 is provided with a recording / erasing signal sequence 20.
And the recording / erasing verify signal series 35 are collated with each other to generate a re-recording / erasing signal series 37. Specifically, for example, the recording / erasing verify signal sequence 35 is used to recognize the locations on the optical disc 10 where miswriting or miserasing has occurred, and re-recording / erasing for re-recording / re-erasing at these locations or other locations. The erase signal series 37 is generated.

When the amount of light emitted from the super-resolution reproducing film 12 at the time of de-excitation is weak, td seconds after the recording / erasing light generated from the light source 21 passes the recording power Pw. On the other hand, it is desirable to integrate the light emission amount over a period of ± Δt seconds. Specifically, after the detection signals from the second photodetector 32 are integrated over the period of 2ΔT of ± Δt seconds centering on the above-mentioned time point, the first and second comparators 33 and 3 are then integrated.
Make sure to enter 4. Here, Δt is a time width in which the transmittance changes due to light emission during deexcitation of the super-resolution reproducing film 12, as shown in FIG. 3B.

In this case, when the light emission detection signal from the photodetector 32 at the time of recording shown in FIG. 4B is integrated for ± Δt seconds, a signal as shown in FIG. 4F is obtained. Obtainable. FIG. 4 (f) obtained by integrating in this way
By setting the first and second threshold values TH1 and TH2 for the signal of the above, even if the amount of light emission at the time of deexcitation of the super-resolution reproducing film 12 is weak, the mis-illustration and the mis-erasure are performed. Can be reliably detected.

The case where the super-resolution reproducing film is used as the light-emitting film disposed on the light-incident side of the recording layer has been described above, but the same applies when a light-emitting film other than the super-resolution reproducing film is used. Detects and writes miswrites and miserases on the principle of
The erased state can be verified.

That is, even if the super-resolution characteristic is not exhibited, light emission due to transition between levels such as conduction band, valence band, impurity level, exciton level, F center, transition metal ion, rare earth metal ion Use anything that emits light, such as light emission from a localized center of an organic compound with or π electrons, which occurs when an electron excited to a certain level is deexcited to a lower energy level. You can

Next, the correction operation of the reproduced signal will be described. The optical disc 10 having the super-resolution reproducing film 12 used in the present embodiment has an advantage that the recording marks of a narrow pitch can be discriminated and reproduced as compared with the case where the super-resolution reproducing film is not provided. Distortion (fluctuation) is likely to occur in the reproduced signal. This happens for the following reasons.

In the same way as when detecting miswrite and miserase described above, when reproducing the information recorded on the optical disk 10 by irradiating the reproducing light with the intensity Io, the light incident on the super-resolution reproducing film 12 is irradiated. Is (1 + Trr ×) when the recording mark portion (amorphous portion) of the recording layer 14 is being reproduced.
Ra) Io, and (1 + Trr × Rc) Io when reproducing the non-recorded mark portion (crystal portion). That is, the number of incident photons on the super-resolution reproducing film 12 is modulated depending on the recording state of the recording layer 14. Here, Trr is the transmittance of the optical aperture formed by the light irradiation of the super-resolution reproducing film 12 when the optical disk 10 is irradiated with the reproducing light.

When the recording mark portion (amorphous portion) of the recording layer 14 has a lower reflectance than the non-recording mark portion (crystal portion),
As shown in FIG. 6A, when the reproducing light spot illuminates the recording mark portion M mainly indicated by the oblique line, the optical aperture portion (a portion in the super-resolution reproducing film 12 having a high transmittance) Aa is As shown in FIG. 6 (b), the optical aperture Ac is large when the spot of the reproduction light is mainly illuminating other than the recording mark portion. Will be subject to modulation. Such modulation of the optical aperture of the super-resolution reproducing film 12 distorts the reproduced signal and becomes a factor of lowering the CNR (carrier noise ratio) of the reproduced signal.

This will be described with reference to FIG. 2. The super-resolution reproducing film 1
The number of effective photons of the incident light on 2 is Na for the recording mark portion and Nc for the non-recording mark. In fact, the optical disc 1 as in this embodiment
As a result of stacking the super-resolution reproducing film 12 with respect to 0 and attempting the super-resolution reproducing operation with a constant reproducing power, it is possible to discriminate and reproduce the narrow pitch mark as compared with the case without the super-resolution reproducing film. However, the noise level was higher than that without the super-resolution reproducing film.

Therefore, in order to improve the quality of the reproduction signal, the reproduction signal is converted into the characteristics of the super-resolution reproduction film 12 (specifically,
(Relationship between the number Np of incident photons and the transmittance Tr shown in FIG. 2)
It is desirable to correct it in accordance with.

Next, an embodiment of the optical disk device having the above-mentioned reproduction signal correcting function will be described. Figure 7
Shows the structure of the recording / reproducing system of this optical disk device. As described above, the optical disc 10 has a structure in which the super-resolution reproducing film 12, the intermediate layer 13, the recording layer 14, and the protective layer 15 are sequentially formed on the disc substrate 11.

When reproducing the information recorded on the optical disk 10, the light source 21 generates reproduction light having a constant power Pr. This reproduction light is guided to the first objective lens 23 via the beam splitter 22, and is irradiated as a minute spot on the optical disc 10 from the substrate 11 side by the objective lens 23.

The reflected light from the optical disk 10 passes through the first objective lens 23 in the direction opposite to the incident light, is guided to the first photodetector 24 by the beam splitter 22, and is detected as an electric signal. The first photodetector 24 is, for example, a divided photodetector in which the light-receiving surface is divided into a plurality (for example, 2 or 4), and a plurality of output signals corresponding to the respective divided surfaces are input to an arithmetic circuit 25 (not shown). This arithmetic circuit 2
5, a reproduction signal sequence 26 and an error signal for focusing and tracking are generated. Since these processes are well known, detailed description will be omitted.

On the other hand, in order to correct the reproduction signal, the second
The objective lens 31, the second photodetector 32, and the correction circuit 41 are provided. The correction circuit 41 corrects the reproduction signal series 25 from the arithmetic circuit 25 with reference to the emission detection signal 40 from the second photodetector 32 with respect to the emission during the deexcitation of the super-resolution reproduction film 12. is there.

Next, the correction operation of the reproduced signal in this embodiment will be described. When correcting the reproduction signal, the reflected light from the optical disk 10 immediately after reproduction is condensed by the second objective lens 31, and this light is detected as an electric signal by the second photodetector 32. That is, the emitted light at the time of deexcitation of the super-resolution reproducing film 12, which is generated td seconds after the reproduction light generated from the light source 21 passes the reproduction power Pr (a time near the maximum emission amount), is emitted. It is detected by the detector 32. The light emission detection signal 40 from the photodetector 32 is input to the correction circuit 41 as a reference signal.

The correction circuit 41 has characteristics of the super-resolution reproducing film 12 (number of incident photons Np of the super-resolution reproducing film 12 and transmittance Tr.
From the above), the distortion of the reproduction signal sequence 26 caused by the modulation of the optical aperture of the super-resolution reproduction film 12 due to the presence or absence of the recording mark portion of the recording layer 14 is estimated, and the distortion is removed or reduced. A reproduced signal series 43 in which the waveform of the reproduced signal series 26 is corrected is output.

Even when the reproduction signal is corrected,
When the amount of light emitted during de-excitation of the super-resolution reproducing film 12 is weak, the reproducing light generated from the light source 21 has a period of ± Δt seconds after td seconds after passing the reproducing power Pr. It is desirable to integrate the luminescence amount of. Specifically, the second
After the light emission detection signal 40 from the photodetector 32 is integrated over a period of 2ΔT of ± Δt seconds centered on the above time point,
Input to the correction circuit 41. Here, Δt is a time width in which the transmittance changes due to light emission during deexcitation of the super-resolution reproducing film 12, as shown in FIG. 3B.

FIG. 8 is a diagram showing another embodiment of an optical disk device having a reproduction signal correction function, in which a ROM 42 is provided in addition to the configuration of FIG. In the ROM 42, characteristic data of the super-resolution reproducing film 12, specifically, the relationship between the number Np of incident photons and the transmittance Tr shown in FIG. 2, for example, is stored in advance as a table. In this embodiment,
The correction circuit 41 refers to the light emission detection signal 40 according to the characteristic data stored in the ROM 42 and reproduces the reproduction signal sequence 2
Correction of 5 is performed.

Examples of further embodying the above-described embodiment will be described below. [Embodiment 1] The optical disk used in this embodiment basically has the structure shown in FIG. 1, and a polycarbonate substrate provided with a tracking groove is used as a disk substrate 11, and a super-resolution reproducing film 12 is formed thereon. Semiconductor fine particle dispersed super-resolution reproducing film also having a function of a light emitting film, and ZnS-Si having a thickness of 150 nm which is the first optical interference film as the intermediate layer 13.
O ₂ film, 15 nm thick GeSbTe phase change recording layer as the recording layer 14, and 25 nm thick ZnS—SiO ₂ film having the function of the second optical interference film as the protective layer 15 and 100 nm thick AlMo film as the reflecting film. The laminated film of was formed. Bonding and initialization after film formation on the substrate 11 are performed according to a usual method.

The semiconductor fine particle-dispersed super-resolution reproducing film is obtained by atomizing ZnTe having a band gap of 550 nm.
It has a structure in which it is uniformly dispersed in the SiO ₂ matrix, and absorbs light of wavelength 650 nm between the defect level formed near the valence band and the exciton level below the conduction band. It is adjusted so that a change in absorptivity, that is, a change in light transmittance occurs. When the intensity of incident light is high, the number of electrons in the defect level of the super-resolution reproducing film is reduced by excitation, and the absorptance is lowered and the transmittance is increased. The lifetime of deexcitation from the exciton level is adjusted to 10 ns or more due to the effect of atomization, and a sufficient transmittance change amount is obtained. Since the incident light intensity during recording / erasing is much higher than during reproduction, the transmittance is high in most of the light spot.
This is equivalent to the absence of a super-resolution reproducing film in the recording / erasing process.

Further, in the present embodiment, as the film other than the super-resolution reproducing film 12 of the optical disk 10, the film which is very similar to the ordinary phase change medium is used, and the absorptance is not adjusted. However, an absorptance adjusting film structure may be used by inserting a semitransparent film between the super-resolution reproducing film 12 and the first optical interference film, or by using a semitransparent film instead of the reflecting film. In the normal film structure of this embodiment, the reflectance (Ra) of the recording mark portion (amorphous portion) is lower than the reflectance (Rc) of the non-recording mark portion (crystal portion).

For the case of using the optical disk 10 having the above-mentioned structure, the verification was carried out in the following procedure. Figure 5
In the optical disc device having the configuration shown in FIG.
0 by a spindle motor (not shown)
The wavelength 6 used as the light source 21 while rotating at s
The first photodetector 2 is driven by driving a 50 nm semiconductor laser.
Focusing and tracking servo are performed based on the focusing error signal and the tracking error signal from the arithmetic circuit connected to the output of the optical disc 4, and a light beam is irradiated onto a predetermined track of the optical disc 10.

Next, the semiconductor laser as the light source 21 is driven in accordance with the test data (recording / erasing signal series 20) to record a predetermined record mark row on the track of the optical disk 10 and reproduce the recorded information. . In the case of this embodiment, the recording power Pw is 12 to 14 mW and the erasing power Pe is
Was set to 7 mW and overwriting was performed with a pulse wave. The reproducing power Pr was set to 1 mW.

Under this condition, the verify operation at the time of recording / erasing as shown in the description of FIG. 5 was performed. However, by inputting the detection signal from the second photodetector 32 to the comparators 33 and 34 without performing the above-mentioned integration and comparing them with the threshold values TH1 and TH2, the recording / erasing verification signal sequence 35 is obtained. Generated.

FIG. 9 shows the relationship between the recording power Pw and the number of write error occurrences during recording detected as the recording / erasing verify signal series 35. For comparison, FIG. 9 also shows, as a conventional example, the result of examining the number of write error occurrences by reproducing the recorded area after the recording. From this result, it can be seen that the detected number of write error occurrences in the present embodiment is the same as that in the conventional example. In this example, since the detection signal from the photodetector 32 was not integrated (integration of the light amount) as described above, the signal intensity was weak, but the number of write error occurrences was the same as that in the conventional example, and thus, the above-described It was confirmed that the verification at the time of recording / erasing using the light emission at the time of de-excitation according to the embodiment of the present invention is sufficiently possible.

[Embodiment 2] In the present embodiment, a semiconductor fine particle dispersed super-resolution reproducing film, which also functions as a light emitting film disposed on the light incident side of the recording layer, is provided with CdSe in a SiO ₂ base material.
Example 1 except that a finely divided and dispersed product was used.
An optical disk having the same configuration as that of was used. Although the exciton level of CdSe corresponds to 680 nm, the exciton level is shifted to the short wavelength side due to atomization and irradiation with light having a wavelength of 650 nm causes a transition from the valence band to the exciton level. Thus, the super-resolution reproducing film is adjusted. The lifetime of deexcitation from the exciton level is 10 n due to the effect of atomization.
It is adjusted to s or more, and a sufficient transmittance change amount is obtained.

For the case of using the optical disc 10 having the above-mentioned structure, the verification was carried out in the following procedure. Figure 5
In the optical disc device having the configuration shown in FIG.
0 by a spindle motor (not shown)
The wavelength 6 used as the light source 21 while rotating at s
The semiconductor laser 21 of 50 nm is driven to perform focusing and tracking servo based on the focusing error signal and the tracking error signal from the arithmetic circuit connected to the output of the first photodetector 24, and the predetermined track of the optical disc 10 is obtained. A light beam was irradiated on the top.

Next, the semiconductor laser as the light source 21 is driven in accordance with the test data (recording / erasing signal series 20) to record a predetermined record mark train on the track of the optical disk 10 and reproduce the recorded information. . In the case of this embodiment, the recording power Pw is 12 to 14 mW and the erasing power Pe is
Was set to 7 mW and overwriting was performed with a pulse wave. The reproducing power Pr was set to 1 mW.

Under this condition, the verify operation at the time of recording / erasing as shown in the description of FIG. 5 was performed. However, in the present embodiment, the detection signals from the second photodetector 32 are integrated for ± Δt seconds as described above to increase the signal strength, and then input to the comparators 33 and 34 to input the threshold values TH1 and TH.
By comparing with 2, the recording / erasing verify signal series 35 was generated.

FIG. 10 shows the relationship between the recording power Pw and the number of write error occurrences during recording detected as the recording / erasing verify signal series 35. For comparison, FIG. 10 also shows, as a conventional example, the result of examining the number of times of writing error by reproducing the recorded area after the recording is completed. From this result, it can be seen that the detected number of write error occurrences in the present embodiment is the same as that in the conventional example. In this example as well, the number of write errors occurred is the same as that of the conventional example, and it was confirmed that the verification at the time of recording / erasing using the light emission at the time of de-excitation according to the embodiment of the present invention described above can be sufficiently performed. Was done.

[Embodiment 3] In this embodiment, a phosphor 3.5MgO.0.5MgF ₂ .GeO ₂ : Mn ²⁺ is used as a light emitting film disposed on the light incident side of the recording layer. An optical disk having the same configuration as that of Example 1 was used except for the above. When using this optical disk 10,
The verification was performed according to the following procedure. In the optical disk device having the configuration shown in FIG. 5, the optical disk 10 was rotated at a linear velocity of 10 m / s by a spindle motor (not shown), and light having a wavelength of 430 nm was generated and connected to the output of the first photodetector 24. Focusing and tracking servo are performed based on the focusing error signal and the tracking error signal from the arithmetic circuit,
A light beam is irradiated onto a predetermined track of the optical disc 10. As the light having a wavelength of 430 nm, a semiconductor laser oscillated in the infrared region is used as the light source 21, and the output light
The next harmonic was used.

Next, the semiconductor laser as the light source 21 is driven in accordance with the test data (recording / erasing signal series 20) to record a predetermined record mark train on the track of the optical disk 10 and reproduce the recorded information. . In the case of this embodiment, the recording power Pw is 10 mW and the erasing power Pe is 6 m.
As W, overwriting with a pulse wave was performed. The reproducing power Pr was set to 1 mW.

Under this condition, the verify operation at the time of recording / erasing as shown in the description of FIG. 5 was performed. However, in the present embodiment, the detection signals from the second photodetector 32 are integrated for ± Δt seconds as described above to increase the signal strength, and then input to the comparators 33 and 34 to input the threshold values TH1 and TH.
By comparing with 2, the recording / erasing verify signal series 35 was generated.

When the relationship between the recording power Pw and the number of write error occurrences at the time of recording detected as the record / erase verify signal series 35 was examined, the detected write error occurrence number was found by reproducing the recorded area after the end of recording. It agrees with the conventional example and the conventional example in which the number of write error occurrences was examined,
It was confirmed that the above-described embodiment of the present invention can sufficiently perform the verification at the time of recording / erasing using the light emission at the time of deexcitation.

[Embodiment 4] Using the same optical recording medium as in Embodiment 1, correction of the reproduction signal was carried out according to the following procedure. In the optical disc apparatus having the configuration shown in FIG. 7, the optical disc 10 is rotated at a linear velocity of 10 m / s by a spindle motor (not shown), and the semiconductor laser having a wavelength of 650 nm used as the light source 21 is driven to drive the first photodetector. Focusing and tracking servo are performed based on the focusing error signal and the tracking error signal from the arithmetic circuit connected to the output of 24,
A predetermined beam on the optical disc 10 was irradiated with a light beam.

Next, the semiconductor laser as the light source 21 is driven in accordance with the test data (recording / erasing signal series 20) to record a predetermined record mark train on the track of the optical disc 10, and then the recorded information is reproduced. . In this embodiment, the recording power Pw is 12 mW and the erasing power Pe is 7 m.
Mark pitch of 0.67μ in W overwrite mode
m-0.33 μm (0.4 μm in bit pitch-
0.2 μm), and single-frequency overwrite recording was performed for each track. Recording was performed multiple times for each track, and the CNR and erasing rate were measured.

As a result of a recording / reproducing test performed on an optical disk having no super-resolution reproducing film prepared as a comparative example, the CNR was 54d when the mark pitch was 0.67 μm.
B, the erasure ratio was -33 dB, which was a sufficient value for practical use.
When the pitch was 0.6 μm or less, both the CNR and the erasing ratio deteriorated rapidly. In the phase change medium without the absorption rate adjustment as in this comparative example, the increase in the overwrite jitter also causes a large intersymbol interference between the adjacent marks, and the mark pitch of 0 when the super-resolution reproduction is not performed. 0.58 μm (bit pitch:
0.35 μm) was the limit of the linear density. As a supplement, even in the absence of the super-resolution reproducing film, it was possible to reduce the linear density up to the mark pitch of 0.5 μm (bit pitch: 0.3 μm) in the optical disk whose absorptance was adjusted.

Then, reproduction from the optical disc on which the recording marks were formed as described above was performed in the following procedure. When performing super-resolution reproduction, since the number of incident photons (Np in FIG. 2) on the super-resolution reproduction film 12 during reproduction is important, the reproduction power Pr was first changed to select the optimum power. If there is no super-resolution reproducing film, a reproducing operation is performed while changing the reproducing power Pr for a recording mark row with a mark pitch of 0.4 μm for which sufficient CNR cannot be obtained even in the absorptance adjusting film structure. Was selected as the optimum playback power. The CNR at this time is higher than that of an optical disc having a conventional structure without a super-resolution reproducing film (including the absorptance adjusting film structure), and the super-resolution reproducing film 1 used in the practice of the present invention.
It has been clarified that No. 2 sufficiently functions to reduce intersymbol interference.

However, looking at only the signal level, although it was possible to identify and reproduce the mark row with a narrow pitch, the noise level was high and the CNR value was not sufficient for practical use. First
Looking at the reproduction signal series 26 generated by passing the detection signal from the photodetector 24 of FIG. 7 through the arithmetic circuit 25, as shown in FIG. 7, although the recording signal is a sine wave of a single frequency, The signal from the non-recording mark portion (crystal portion) with high reflectance is promoted more than the signal from the recording mark portion (amorphous portion) with low reflectance, and the noise at the rising and falling portions is significant. there were. The cause of the noise in the reproduction signal series 26 is that the optical aperture formed in the super-resolution reproduction film 12 is modulated depending on the recording state (presence or absence of the recording mark portion) as described above.

On the other hand, the light emitted when the super-resolution reproducing film 12 is deexcited is condensed by the first objective lens 31, and the second photodetector 32 is collected.
The light emission detection signal 40 obtained by the detection is a signal that reflects the presence or absence of the recording mark portion on the recording layer 14, and the correction circuit 41 refers to the light emission detection signal 40 to determine the waveform of the reproduction signal series 26. to correct. Specifically, let Ia ^* and Ic ^* be the effective incident light intensities on the super-resolution reproducing film 12 when reproducing light spots are incident on the amorphous portion and the crystal portion of the recording layer 14, respectively. , These can be approximated as Ia ^* = (1 + Tr1 × Ra) Io Ic ^* = (1 + Tr2 × Rc) Io. Here, Io is the light source 21
Intensity of the reproduction light from Ra, Rc is the reflectance of the amorphous portion and the crystal portion of the recording layer 14, and Tr1 and Tr2 are the super-resolution reproduction after the reproduction light of the intensity Io is reflected at the reflectances Ra and Rc. Super-resolution reproducing film 12 when incident on the film 12
And the transmittance of each of these can be obtained in advance.

Therefore, the correction circuit 41 uses the reproduction signal sequence 26
Bottom (the part corresponding to the intensity of the reflected light from the amorphous part)
For 1 / Io (1 + Tr1 × Ra), and 1 / Io (1 + Tr2) for the peak of the reproduction signal series 26 (the portion corresponding to the intensity of the reflected light from the crystal part).
× Rc), and 1 / Io (1 + Tr1 × Ra) and 1 / I for the intermediate intensity part between the bottom and the peak.
A correction signal having a correction coefficient composed of an arithmetic mean value of o (1 + Tr2 × Rc) was obtained by calculation, and the reproduction signal series 26 was corrected by this correction signal.

The reproduced signal sequence 43 corrected by the correction circuit 41 in this way has a waveform with almost the same single frequency and little distortion as the recorded signal. This reproduction signal series 4
By sending 3 to a reproduction signal processing system (not shown) to identify and reproduce the original information, good reproduction with a low error rate is possible even for a narrow pitch recording mark row, and a mark pitch of 0.33 μm is sufficient. It became clear that stable operation was established.

[Embodiment 5] Next, as shown in FIG.
An example of correcting the reproduction signal series 26 according to the characteristic data (relationship between the number Np of incident photons Np and the transmittance Tr of FIG. 2) of the super-resolution reproduction film 12 stored in the OM 42 will be described.
In this embodiment, 1 / Io is applied to the bottom of the reproduction signal series 26 (the portion corresponding to the intensity of the reflected light from the amorphous portion).
For the correction coefficient of (1 + Tr1 × Ra), the peak of the reproduction signal series 26 (the portion corresponding to the reflected light intensity from the crystal part), the correction coefficient of 1 / Io (1 + Tr2 × Rc), and the bottom and the peak. 1 / Io for medium strength part
(1 + Tr1 × Ra) and 1 / Io (1 + Tr2 × Rc)
The point where the correction signal having the correction coefficient consisting of the arithmetic mean value of is calculated and the reproduction signal series 26 is corrected by this correction signal is the same as in the fourth embodiment.
The transmittances Tr1 and T obtained from the characteristics stored in 42
The difference from Example 4 is that r2 is used.

More specifically, since the number of photons incident on the super-resolution reproducing film 12 is modulated depending on the recording state of the recording layer 14 as described above, the level of the reproducing signal series 26 also depends on this. Then, the original level depends only on the change in the reflectance from the recording layer 14. Therefore,
In the arithmetic circuit 41, R corresponding to the level of the reproduction signal series 26
When the address of the OM 42 is generated, the data of the transmittance corresponding to the level of the reproduction signal series 26, that is, the number of incident photons to the super-resolution reproduction film 12 is read from the ROM 42.

That is, in the fourth embodiment, the relationship between the incident photon number Np and the transmittance Tr shown in FIG. 1 is linearly approximated and used, whereas in the present embodiment, the actual relationship between Np and Tr is used. By correcting the reproduced signal series 26 by using it, it becomes possible to more accurately reproduce the original signal waveform as the corrected reproduced signal series 43.

In the embodiment described above, the case where the phase change type optical recording medium in which the super-resolution reproducing film or another light emitting film is arranged on the light incident side of the recording layer is used is explained. An optical recording medium in which a super-resolution reproducing film or another luminescent film is arranged on the light incident side of the recording layer can be applied to the case where an optical recording medium other than the phase change type is used.

Further, in the above-mentioned embodiment, the semiconductor fine particle dispersed type super-resolution reproducing film is used as the super-resolution reproducing film, but it can be applied as long as the super-resolution reproducing film emits light by light. Further, the present invention can be applied to DVD-ROM, WORM, CD-R and the like.

[0089]

As described above, according to the present invention, in an optical memory device using an optical recording medium having a light-emitting film on the light-incident side of a recording layer, which emits light upon irradiation with light, the optical recording medium is exposed to light. Detects the light emission of the phosphor film that occurs after irradiation,
Since the recording state of the optical recording medium is verified by using the light emission detection signal, it is possible to verify the recording state in parallel with the recording, and the verifying time is significantly longer than that of the conventional verifying method. It can be shortened.

Further, according to the present invention, the light emission of the luminous body film which occurs after the light is incident on the same optical recording medium is detected, and the luminous body detection film is referred to, or the luminous body film is a super-resolution reproducing film. In this case, by further correcting the reproduction signal by referring to the characteristics of the super-resolution reproduction film, it is possible to remove or reduce the distortion of the reproduction signal and obtain reproduction information with a low error rate.

[Brief description of drawings]

FIG. 1 is a sectional view showing a basic configuration of an optical recording medium in an optical memory device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the relationship between the number of incident photons and the transmittance of the super-resolution reproducing film on the optical disc.

FIG. 3 is a characteristic diagram showing a change with time in the transmittance of the super-resolution reproducing film of the optical disc and a change in the amount of light emitted during deexcitation.

FIG. 4 is a timing chart for explaining a verify operation at the time of recording / erasing in the same embodiment.

FIG. 5 is a configuration diagram of a recording / reproducing system of the optical memory device having a verify function at the time of recording / erasing according to the same embodiment.

FIG. 6 is a diagram showing the principle of super-resolution reproduction.

FIG. 7 is a configuration diagram of a recording / reproducing system of an optical memory device having a reproduction signal correcting function in the embodiment.

FIG. 8 is another configuration diagram of the recording / reproducing system of the optical memory device having the reproduction signal correcting function in the embodiment.

FIG. 9 is a graph showing the relationship between the number of write errors and the recording power in Example 1 of the present invention and a conventional example.

FIG. 10 is a diagram showing the relationship between the number of write errors and the recording power in Example 2 of the present invention and a conventional example.

[Explanation of symbols]

10 ... Optical disc 11 ... Optical disc substrate 12 ... Super resolution reproducing film 13 ... Middle layer 14 ... Recording layer 15 ... Protective layer 20 ... Recording / erasing signal series 21 ... Semiconductor laser 22 ... Beam splitter 23 ... First objective lens 24 ... First photodetector 25 ... Arithmetic circuit 26 ... Reproduction signal sequence 31 ... First objective lens 32 ... Second photodetector 33 ... Comparator for detecting mislight 34 ... Miss erase detection comparator 35 ... Record / erase verify signal series 36 ... Arithmetic circuit 40 ... Emission detection signal 41 ... Correction circuit 42 ... ROM storing characteristic data of super-resolution reproducing film 43 ... Reproduced signal sequence after correction

Continuation of front page (56) Reference JP-A-4-246586 (JP, A) JP-A-2-76126 (JP, A) JP-A-2-192049 (JP, A) JP-A-5-12673 (JP , A) Japanese Patent Laid-Open No. 7-201096 (JP, A) Patent 3455658 (JP, B2) "Information content, 200 times DVD, Toshiba, new technology in optical memory", Nikkei Sangyo Shimbun, March 4, 1997 (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B ^7/ 00-7/30

Claims (5)

(57) [Claims] 1. Recording is performed by forming an amorphous mark in a crystal part by irradiation of recording light, and reproduction is performed based on a difference in reflectance between the crystal part and the amorphous mark by irradiation of reproduction light. Recording layer on which the erasing is performed by recrystallizing the amorphous mark by erasing the erasing light, and a light emitter film which is arranged on the light incident side of the recording layer and emits light upon irradiation with the light. An optical memory device for recording / reproducing / erasing information with respect to an optical recording medium having, by irradiating the optical recording medium with recording light or erasing light,
First light detecting means for detecting reflected light reflected from the recording layer, and the light emission that is arranged behind the first light detecting means and occurs after the recording light or the erasing light is irradiated onto the optical recording medium. A second light detecting means for detecting light emission of the body film, and a light emission detecting signal of the second light detecting means between a signal level when miswriting occurs and a signal level when correctly recorded. By comparing with the threshold value TH1 corresponding to the level or the threshold value TH2 corresponding to the level between the signal level when the miserasure occurs and the signal level when the correct erasing can be performed, An optical memory device, comprising: a verifying unit for verifying. 2. Recording is performed by forming an amorphous mark in a crystal part by irradiation of recording light, and reproduction is performed based on a difference in reflectance between the crystal part and the amorphous mark by irradiation of reproduction light. The recording layer is erased by recrystallizing the amorphous mark by irradiation of the erasing light, and the recording layer is arranged on the light incident side of the recording layer, and an optical change is caused by electronic excitation by the light irradiation. An optical memory device for recording / reproducing / erasing information on / from an optical recording medium having a super-resolution reproducing film which emits light upon deexcitation of excited electrons after the light irradiation. By irradiating recording light or erasing light to the
A first photo-detecting means for detecting reflected light reflected from the recording layer; and the super-light arranged after the first photo-detecting means, the super-light occurring after irradiating the optical recording medium with recording light or erasing light. The second light detecting means for detecting the light emission accompanying the deexcitation of the excited electrons of the resolution reproducing film, and the light emission detection signal of the second light detecting means are correctly recorded as the signal level when the mislight occurs. Compared with the threshold value TH1 corresponding to the level between the signal level in the case of mis-erasing and the threshold value TH2 corresponding to the level between the signal level in the case of miserasure and the signal level in the case of correct erasing. The optical memory device is provided with a verifying means for verifying at the time of recording / erasing. 3. Recording is performed by forming an amorphous mark in a crystal part by irradiation of recording light, and reproduction is performed based on a difference in reflectance between the crystal part and the amorphous mark by irradiation of reproduction light. Recording layer on which the erasing is performed by recrystallizing the amorphous mark by erasing the erasing light, and a light emitter film which is arranged on the light incident side of the recording layer and emits light upon irradiation with the light. An optical memory device for recording / reproducing / erasing information on / from an optical recording medium, comprising: first light for detecting reflected light reflected from the recording layer by irradiating the optical recording medium with reproducing light. A detection unit; an arithmetic circuit that generates a reproduction signal sequence from the detection signal of the first light detection unit; and an arithmetic circuit that is arranged behind the first light detection unit and occurs after the reproduction light is irradiated onto the optical recording medium. Second light detection for detecting light emission of the light emitter film From the light emission detection signal of the second light detecting means, the reflectance Ra of the reproduction light by the amorphous mark and the reproduction light are incident on the phosphor film after being reflected by the amorphous mark through the phosphor film. The correction coefficient including the transmittance Tr1 of the luminous body film and the reflectance Rc of the reproduction light by the crystal part and the reproduction light when the reproducing light is reflected by the crystal part through the luminous body film and then enters the luminous body film. An optical memory device, comprising: a correction signal based on an arithmetic mean value of correction coefficients including the transmittance Tr2 of FIG. 4. Recording is performed by forming an amorphous mark in a crystal part by irradiation of recording light, and reproduction is performed based on a difference in reflectance between the crystal part and the amorphous mark by irradiation of reproduction light. The recording layer is erased by recrystallizing the amorphous mark by irradiation of the erasing light, and the recording layer is arranged on the light incident side of the recording layer, and an optical change is caused by electronic excitation by the light irradiation. An optical memory device for recording / reproducing / erasing information on / from an optical recording medium having a super-resolution reproducing film which emits light upon deexcitation of excited electrons after the light irradiation. First light detection means for detecting reflected light reflected from the recording layer by irradiating reproduction light to the recording layer, and an arithmetic circuit for generating a reproduction signal sequence from a detection signal of the first light detection means, The light is arranged behind the first light detecting means and The second photodetector means for detecting the light emission accompanying the deexcitation of the excited electrons of the super-resolution reproduction film, which occurs after the recording medium is irradiated with the reproduction light, and the light emission detection signal of the second photodetector means The reflectance Ra of the reproduction light by the crystalline mark and the transmittance Tr1 of the super-resolution reproduction film when the reproduction light is incident on the super-resolution reproduction film after being reflected by the amorphous mark through the super-resolution reproduction film. The correction coefficient including and the reflectance Rc of the reproduction light by the crystal part and the transmittance T of the super-resolution reproduction film when the reproduction light is incident on the super-resolution reproduction film after being reflected by the crystal part through the super-resolution reproduction film.
An optical memory device, comprising: a correction signal based on an arithmetic mean value of correction coefficients including r2 and correcting the reproduction signal sequence. 5. Amorphous mer in the crystal part upon irradiation with recording light.
Recording is performed by forming
Based on the difference in reflectance between the crystalline part and the amorphous mark
Playback is performed, and the amorphous marks are reconnected by erasing the erasing light.
A recording layer which is erased by crystallization, and the recording
It is placed on the light-incident side of the layer and is accompanied by electron excitation by light irradiation.
An optical change occurs, which is accompanied by the deexcitation of excited electrons after the light irradiation.
The optical recording medium having a super-resolution reproducing film that emits a large amount of light
It is an optical memory device that records, reproduces, and erases information by
The recording layer by irradiating the optical recording medium with reproduction light.
And a reproduction signal sequence generated from the detection signal of the first photodetector.
And an arithmetic circuit for forming the optical recording medium, the optical circuit being disposed behind the first photodetector.
Excitation of the super-resolution reproduction film that occurs after irradiation of reproduction light on the body
Second light detection means for detecting light emission accompanying electron deexcitation
And the light emission detection signal of the second light detecting means and the ROM.
The transmission corresponding to the number of incident photons to the stored super-resolution reproducing film.
From the excess rate data, the reflectance of the reproduction light due to the amorphous mark
Ra and reproducing light pass through the super-resolution reproducing film and are reflected by the amorphous mark.
Super-resolution when incident on the super-resolution reproducing film after being reflected
The correction coefficient including the transmittance Tr1 of the reproduction film and the crystal part
Therefore, the reflectance Rc of the reproduction light and the reproduction light pass through the super-resolution reproduction film.
Incident on the super-resolution reproducing film after being reflected by the crystal part
Of the correction coefficient including the transmittance Tr2 of the super-resolution reproducing film at
A correction signal based on the arithmetic mean value is obtained, and the reproduction signal sequence is
And a correction means for correcting
Mori device.