JPH1186287A - Optical memory equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide optical memory equipment enabling verification of a recorded state in a short time. SOLUTION: Regarding an optical disk 10 having a recording layer 14 wherein information is recorded by casting light thereon in conformity with a recording-erasing signal series 20 and a superresolution reproduction film 12 which is disposed on the light incidence side of the recording layer, the emission accompanying de-excitation of excited electrons of the superresolution reproduction film 12, which occurs after reproduction light from a light source 21 is cast on the disk, is detected by a photodetector 32. By comparing an emission detection signal from this photodetector 32 with thresholds TH1 and TH2 by comparators 33 and 34, verification of a recorded state of the recording layer 14 is conducted, and by inputting a verification signal 35 to an arithmetic circuit 36 and collating it with the recording-erasing signal series 20, a re-recording- erasing signal series 37 is generated at the time of miswrite or miserase.

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 disk with light to record and reproduce information.

[0002]

2. Description of the Related Art Information is reproduced or recorded by irradiation of light.
Optical memory devices, such as optical disc devices that perform playback, have been put to practical use for various files such as audio, images, and computer data as information storage devices that have large capacity, high-speed access, and medium portability. Its development is expected.

Techniques for increasing the density of an optical memory device include shortening the wavelength of a gas laser for cutting a master for manufacturing an optical disk, shortening the wavelength of a semiconductor laser which is a light source for recording and reproduction, and increasing the numerical aperture of an objective lens. In addition, there are approaches such as thinning of an optical disk, and there are various approaches for a recordable optical disk such as mark length recording and land / groove recording.

On the other hand, in addition to these approaches, a super-resolution reproduction technique using a medium film is being studied as a technique effective for increasing the density of an optical disc. Super-resolution reproduction technology was initially proposed as a technology specific to magneto-optical disks. In super-resolution reproduction by magneto-optical recording, a magnetic film having a super-resolution function (super-resolution reproduction film) is provided on the recording light incident side with respect to the recording layer, and both are exchange-coupled or magnetostatically coupled. Use medium. Then, by raising the temperature of the super-resolution reproduction film by irradiation of the reproduction light and changing the exchange force or the magnetostatic force between the layers, a partial optical mask or an optical aperture for the reproduction light spot is formed on the super-resolution reproduction film. By effectively reducing the size of the reproduction light spot, high-resolution reproduction can be performed.

[0005] Then, not only in magneto-optical recording but also in ROM disks, after irradiating the recording layer with reproducing light, a super-resolution reproducing film whose light transmittance is changed by irradiation of the reproducing light is provided. Attempts to do so have been reported. As described above, the super-resolution reproduction technology uses a magneto-optical disk, a CD-ROM,
It is becoming clear that the present invention can be applied to all optical disks such as CD-R, WORM, and phase-change optical recording media.

Incidentally, in this type of optical memory device, verification is generally performed at the time of recording, that is, verification of the recording state is performed. In the conventional optical memory device, the verify operation at the time of recording is performed after a certain recording operation is completed. For example, in a one-beam optical memory device, after at least one rotation of the optical disk has elapsed after the formation of a recording mark array, a reproducing operation called test reproduction is performed to verify the recording state, and as a result of the verification, If an error occurs, a method of re-recording at the same or different location from the first recorded location on the optical disc has been adopted.

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. When an error occurs, recording → verify (test reproduction) → re-recording. (→ re-verify) and time for 3 to 4 rotations of the disk.

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

[0009]

As described above, in the conventional optical memory device, a long time is required for verification at the time of recording, and when an optical recording medium having a super-resolution reproduction film is used, the super-resolution There is a problem that distortion is apt to occur in the reproduction signal due to the characteristics of the reproduction film, which causes an increase in error.

An object of the present invention is to solve such a conventional problem, and an object of the present invention 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 distortion of a reproduction signal when using an optical recording medium having a super-resolution reproduction film.

[0011]

In order to solve the above-mentioned problems, the present invention firstly relates to a recording layer for recording information by irradiating 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 occurring after irradiating the optical recording medium with light is detected, and the recording state of the optical recording medium is detected using the light emission detection signal. Is verified. More specifically, the verification of the recording state can be performed 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 film, undergoes an optical change upon electronic 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, the light emission accompanying the deexcitation of the excited electrons of the super-resolution reproduction film that occurs after irradiating the optical recording medium with light is detected, and the recording state of the optical recording medium is verified using the emission detection signal. Good. A phosphor film or the like can be used as the light emitting film.

The level of the light emission detection signal obtained by detecting the light emission of the light emitting film generated after irradiating the optical recording medium with light, for example, varies depending on the recording state of the recording layer. Can be used to verify the recording state of the optical recording medium. In this way, the recording state can be verified in parallel with the recording, so that the time required for the verification is longer than the conventional verification method in which test reproduction is performed after recording to verify the recording state. It is greatly reduced.

The present invention also relates to an optical recording medium having a recording layer for reproducing information by irradiating light and a luminous film disposed on the light incident side of the recording layer and emitting light upon irradiation with light. The optical memory device according to the present invention is characterized in that the light emission of the light emitting film that occurs after light is incident on the optical recording medium is detected, and the reproduction signal from the optical recording medium is corrected with reference to the light emission detection signal. This correction of the reproduction signal is preferably performed in accordance with the characteristics of the luminous body film with reference to the light emission detection signal.

In one embodiment, the optical recording medium serves as the luminous film as described above, which undergoes an optical change upon electron excitation by light irradiation, and emits light upon deexcitation of the excited electrons after the light irradiation, thereby achieving super-resolution reproduction. Having a membrane. In this case, the light emission accompanying the deexcitation of the excited electrons of the super-resolution reproduction film that occurs after irradiating the optical recording medium with light is detected, and the reproduction signal from the optical recording medium is corrected with reference to the light emission detection signal. do it. Also, a phosphor film or the like can be used as the light emitting film.

As described above, the light emission detection signal obtained by detecting the light emission of the luminous film generated after irradiating the light on the optical recording medium is not only the recording state of the recording layer but also the super-resolution reproduction film on the optical recording medium. When there is a film that causes a distortion of the reproduction signal as described above, the distortion due to the film can be monitored, so that the reproduction signal can be removed or reduced by using this emission detection signal. It is possible to correct. When a super-resolution reproduction film is used, more accurate correction can be performed by further correcting the reproduction signal with reference to the characteristics of the super-resolution reproduction film. By correcting the reproduction signal in this manner, reproduction information with a low error rate can be obtained.

[0017]

Embodiments of the present invention will be described below. First, an example in which a super-resolution reproducing film is used as a light emitting film will be described. The super-resolution reproduction film undergoes an optical change due to electronic excitation by light irradiation. The excited electrons emit light upon deexcitation. In this embodiment, the light emission is detected to verify the recording state (record verification).

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

When information recorded on the optical disk 10 is reproduced, reproduction light is applied from the substrate 11 side to the super-resolution reproduction film 12.
Then, the recording mark train formed in the recording layer 14 is irradiated through the intermediate layer 13. That is, the super-resolution reproduction film 1
2 is formed on the incident side of the reproduction light with respect to the recording layer 14.

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

When Tr monotonically increases with an increase in Np as in the example of FIG. 2, the transmittance is high in a portion where the number of incident photons is large near the center of the spot of the reproduction light, and the light is transmitted in the peripheral portion. Since the efficiency is low, the effective spot size of the reproduction light is small, and 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 electronically excited by light irradiation, and the film is optically changed by a change in electron density existing in at least two levels involved in the excitation. Specifically, a semiconductor material whose energy difference between two levels relating to excitation is substantially equal to 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 two levels such as a conduction band, a valence band, an impurity level, and an excitation level matches the light source wavelength. A continuous film-like semiconductor film can also be used as a super-resolution reproduction film. However, it is better to control the energy difference between levels and to control the time constant of de-excitation by using a form in which the semiconductor is finely divided and dispersed in a dielectric. Preferred 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 principle of operation of this super-resolution reproducing film is that the electron density of the lower level is reduced by the electron excitation and the electron density of the upper level is increased, so that the excitation probability is reduced, that is, the light absorption is reduced. Is to do. When the excitation probability is significantly reduced, a further decrease in the probability is small and the absorption is saturated. Therefore, the super-resolution reproduction of the present embodiment can be regarded as a transmittance change due to the absorption saturation.

FIG. 3 (a) shows the change in transmittance Tr due to absorption saturation in this super-resolution reproduction film (in this case, T
From the time point t = 0 when r is maximized), the value before the transmittance changes with de-excitation (in this case, the transmittance is minimum)
It is a figure showing a situation until it becomes. FIG. 3 (b)
2 also shows the amount of light emission at the time of deexcitation of the super-resolution reproducing film. Assuming that the life of the de-excitation is “td”, the light emission amount at the time of de-excitation becomes maximum around time td. It should be noted that the characteristics shown in FIG. 3B are not limited to the super-resolution reproduction film, but are the same for a general light-emitting film.

The two levels that cause absorption saturation in the super-resolution reproducing film in which the semiconductor fine 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 lifetime of de-excitation in a super-resolution reproduction film in which semiconductor fine particles are dispersed is several tens in a very high-speed example.
ns, and it is difficult to detect the light emission. However, by taking measures such as reducing the particle size or providing an appropriate impurity level to perform multi-step deexcitation, the recording /
Emission accompanying de-excitation can be maximized at a position sufficiently distant from the irradiation position of the reproduction light beam, and detection becomes easy. For example, when the linear velocity of the disk is 20 m / s, if the super-resolution reproduction film having a de-excitation life of 1 ms is used, the irradiation position of the recording / reproduction light beam and the detection position of the light emission due to the de-excitation are separated by about 20 mm. And a detection system based on ordinary lens condensing can be employed.

Next, the principle of the verify operation at the time of recording / erasing according to the present invention will be described with reference to an example in which 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 a non-recording mark portion, is larger than the reflectance (Ra) of the amorphous portion. It is assumed that a phase change type optical recording medium is used as the optical disk 10 of FIG.
Further, it is assumed that the reflectance (Rm) of the portion in the molten state in the process of forming the amorphous portion is smaller than the reflectance (Rc) of the crystal portion.

FIGS. 4A and 4B are timing charts for explaining the verify operation at the time of recording / erasing in this embodiment. FIG. 4A shows the recording / erasing light, and FIGS. 4B and 4D show the super-resolution reproducing film 12. (C) is a miswrite detection signal which is a recording verify signal corresponding to (b),
(E) is a mis-erase detection signal which is an erase verify signal, and (f) is a signal obtained by integrating light emission detection signals.

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

Here, as shown in FIG.
It is assumed that, at the time of the second recording pulse of the recording / erasing light in FIG. When there is no miswrite, the intensity of the light incident on the super-resolution reproduction film 12 first
between the intensity Io of the light incident upon irradiation with the light of w and the intensity Trw × Rm × Io of the reflected light from the molten portion of the recording layer 14 in the process of becoming amorphous. The sum is (1 + Trw × Rm) Io. Here, Trw is the transmittance of the optical opening of the super-resolution reproduction film 12 formed when the optical disk 10 is irradiated with the light of the recording power Pw.

On the other hand, the intensity of the light incident on the super-resolution reproducing film 12 when a miswrite occurs
And the intensity Io of light incident when the recording layer 12 is irradiated with light having the recording power Pw, and the intensity Trw × Rc × of the reflected light from a portion of the recording layer 12 which is not in a molten state but in a crystalline state.
The sum of Io (1 + Trw × Rc) Io.

Since the relationship between the reflectance Rc of the crystal portion of the recording layer 14 and the reflectance Rm of the portion in the molten state in the process of forming the amorphous portion is Rc> Rm, the relationship from the super-resolution reproduction film 12 As shown in FIG. 4B, the detection signal of the reflected light has a higher signal level in the case where miswriting has occurred than the signal level detected in the case where the recording has been performed correctly. Therefore, FIG.
By performing threshold processing on 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 at the time of erasing will be described. The erasure of the recording marks in the recording layer 14 is performed by recrystallizing the amorphous portion. When the recording / erasing light shown in FIG.
It is assumed that an erase pulse that cannot be erased occurs during an erase pulse between the third recording pulse. When the erasing is completed completely, the intensity of the light incident on the super-resolution reproducing film 12 is determined by the intensity Io of the light incident when the optical disk 10 is first irradiated with the light of the erasing power Pe and the intensity of the recording layer 14. Intensity Tre x Rc x I of reflected light from the recrystallized portion of the amorphous portion
The sum of o is (1 + Tre × Rc) Io. However, Tre
Is the transmittance of the optical aperture of the super-resolution reproduction film 12 formed when the optical disk 10 is irradiated with light of the erasing power Pe.

On the other hand, the intensity of light incident on the super-resolution reproducing film 12 when a mis-erasure occurs
0, the intensity Io of the light incident upon irradiating the light with the erasing power Pe, and the intensity Tre × Ra of the reflected light from the portion of the recording layer 12 which is not recrystallized and maintains an amorphous state. ×
The sum of Io is (1 + Tre × Ra) Io.

Since the relationship between the reflectance Rc of the crystal portion of the recording layer 14 and the reflectance Ra of the portion where the amorphous portion is maintained without recrystallization is Rc> Ra, the super-resolution reproduction film 12 As shown in FIG. 4 (d), the detection signal of the reflected light from the signal becomes lower than the signal level in the case where the miserasing has occurred and the signal level in the case where the erasing has been performed correctly. Therefore, FIG.
Is subjected to threshold processing with a predetermined threshold value TH2, a mis-erase detection signal as shown in FIG. 4E can be obtained.

Here, the case where the reflectance Rc of the crystal part of the recording layer 14 is higher than the reflectance of the amorphous part Ra has been described as an example. Reflectivity R
Even when c is larger than c, the polarity of the detection signal is only reversed, so that the detection of the miswrite and the erase, that is, the verification at the time of recording / erasing can be performed in the same manner as described above.

Next, an embodiment of an optical disk device having the above-described verify function at the time of recording / erasing will be described. FIG. 5 shows a configuration of a recording / reproducing system of the optical disk device. As described above, the optical disk 10 includes the super-resolution reproduction film 12 and the intermediate layer 1 on the disk substrate 11.
3, a configuration in which 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 sequence 20, and the recording / erasing light shown in FIG. The recording / erasing light is guided to a first objective lens 23 via a beam splitter 22, and is irradiated on the optical disk 10 as a minute spot 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 obtained by dividing the light receiving surface into a plurality (for example, two or four), and outputs a plurality of output signals corresponding to each of the divided surfaces to an arithmetic circuit (not shown) which will be described later. The arithmetic circuit generates a reproduced signal and an error signal for focusing and tracking.

On the other hand, in order to perform verification at the time of recording / erasing, a second objective lens 31, a second photodetector 32, first and second comparators 33 and 34, and an arithmetic circuit 36 are provided.
Is provided. First and second comparators 33 and 3
Numeral 4 is for generating a verify signal sequence 35 by detecting a miss write and a miss erase, respectively. The arithmetic circuit 36 generates a re-recording / erasing signal sequence 37 for performing re-recording / erasing on the optical disk 10 from the verifying 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 disk 1 immediately after recording / erasing is performed.
The reflected light from 0 (light emitted at the time of de-excitation of the super-resolution reproducing film 12) is collected by the second objective lens 31, and this light is detected as an electric signal by the second photodetector 32. The light emission detection signal from the second photodetector 32 is
The signals are input to the second comparators 33 and 34.

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

The outputs of the first and second comparators 33 and 34 are combined to form a write / erase verify signal sequence 35 which is a result of verifying the write / erase state, and is input to an arithmetic circuit 36. The arithmetic circuit 36 controls the recording / erasing signal sequence 20
The re-recording / erasing signal sequence 37 is generated by collating the recording / erasing verify signal sequence 35 with the recording / erasing verify signal sequence 35. Specifically, for example, from the recording / erasing verify signal sequence 35, a place on the optical disc 10 where a miswrite or miserasure has occurred is recognized, and re-recording / re-erasing for re-recording / re-erasing at these places or other places. An erasure signal sequence 37 is generated.

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

In this case, for example, 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. Obtainable. FIG. 4 (f) obtained by integrating in this manner.
By setting the first and second thresholds TH1 and TH2 for the first and second comparators 33 and 34 for the signal of the above, even if the amount of light emission at the time of de-excitation of the super-resolution reproducing film 12 is weak, a mis-illustration, a mis-erase Can be reliably detected.

Although the case where the super-resolution reproducing film is used as the luminous film disposed on the light incident side of the recording layer has been described above, the same applies to the case where the luminous film other than the super-resolution reproducing film is used. Detects and records miswrites and erases based on the principle of
Verification of the erased state can be performed.

That is, light emission due to transition between levels such as a conduction band, a valence band, an impurity level, and an exciton level, an F center, a transition metal ion, and a rare earth metal ion without exhibiting super-resolution characteristics. Use anything that exhibits luminescence, such as luminescence generated when electrons excited to a certain level de-excit to a lower energy level, such as luminescence due to the localized center of an organic compound having π or π electrons. Can be.

Next, the operation of correcting the reproduced signal will be described. The optical disc 10 having the super-resolution reproduction film 12 used in the present embodiment has an advantage that the recording mark having a narrow pitch can be identified and reproduced, as compared with the case without the super-resolution reproduction film, but it has an advantage in that it depends on the recording state. Distortion (fluctuation) is likely to occur in the reproduced signal. This occurs for the following reasons.

When reproducing the information recorded on the optical disk 10 by irradiating the reproducing light with the intensity Io in the same manner as when detecting the above-described miswrite and mis-erase, the light incident on the super-resolution reproducing film 12 is considered. Is (1 + Trr ×) when a recording mark portion (amorphous portion) of the recording layer 14 is being reproduced.
Ra) Io, and (1 + Trr × Rc) Io when reproducing a non-recorded mark portion (crystal portion). That is, the number of photons incident on the super-resolution reproduction film 12 is modulated depending on the recording state of the recording layer 14. Here, Trr is the transmittance of the optical opening formed by light irradiation of the super-resolution reproduction film 12 when the optical disk 10 is irradiated with reproduction 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 spot of the reproduction light mainly irradiates the recording mark portion M indicated by oblique lines, the optical aperture (the portion of the super-resolution reproduction film 12 where the transmittance is high) Aa As shown in FIG. 6B, when the spot of the reproduction light mainly irradiates the area other than the recording mark section, the optical opening Ac is large. Modulation. Such modulation of the optical aperture of the super-resolution reproduction film 12 distorts the reproduction signal and causes a reduction in the CNR (carrier noise ratio) of the reproduction signal.

This will be described with reference to FIG.
The effective photon number of the light incident on 2 is different for a recorded mark portion, such as Na, and for a non-recorded mark, Nc. Actually, the optical disc 1 as in this embodiment
As a result of superimposing the super-resolution reproducing film 12 with respect to 0 and attempting a super-resolution reproducing operation with a constant reproducing power, a mark with a narrow pitch can be discriminated and reproduced as compared with the case without the super-resolution reproducing film. However, the noise level was higher than that without the super-resolution reproduction film.

Accordingly, 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 incident photon number Np and transmittance Tr shown in FIG. 2)
It is desirable to correct according to

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

At the time of reproducing information recorded on the optical disk 10, a reproduction light having a constant power Pr is generated from the light source 21. The 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 disk 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 obtained by dividing the light receiving surface into a plurality (for example, two or four), and outputs a plurality of output signals corresponding to the respective divided surfaces to an arithmetic circuit 25 (not shown). And 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, a detailed description will be omitted.

On the other hand, in order to correct the reproduced signal, the second
, An objective lens 31, a second photodetector 32, and a correction circuit 41 are provided. The correction circuit 41 corrects the reproduced signal sequence 25 from the arithmetic circuit 25 with reference to the light emission detection signal 40 from the second photodetector 32 for light emission at the time of de-excitation of the super-resolution reproduction film 12. is there.

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

The correction circuit 41 determines the characteristics of the super-resolution reproduction film 12 (the number of incident photons Np and the transmittance Tr of the super-resolution reproduction film 12).
), The distortion of the reproduction signal sequence 26 due to 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 sequence 43 in which the waveform of the reproduced signal sequence 26 has been corrected is output.

It should be noted that, even when correcting the reproduced signal,
When the amount of light emission at the time of de-excitation of the super-resolution reproducing film 12 is weak, a period of ± Δt seconds from a point of time td seconds after the reproducing light generated from the light source 21 passes the reproducing power Pr. It is desirable to integrate the amount of light emission of. Specifically, the second
After integrating the light emission detection signal 40 from the photodetector 32 over a period of 2ΔT of ± Δt seconds centering on the above time,
The data is input to the correction circuit 41. Here, Δt is a time width in which the transmittance changes due to light emission at the time of deexcitation of the super-resolution reproduction film 12, as shown in FIG.

FIG. 8 is a diagram showing another embodiment of an optical disk device having a function of correcting a reproduced signal, and 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, for example, the relationship between the number Np of incident photons and the transmittance Tr shown in FIG. 2 is stored in advance as a table. In this embodiment,
The correction circuit 41 refers to the light emission detection signal 40 in accordance with the characteristic data stored in the ROM 42 and reproduces the reproduced signal sequence 2.
5 is corrected.

Hereinafter, an example that further embodies the above-described embodiment will be described. [Embodiment 1] The optical disk used in this embodiment has basically the configuration shown in FIG. 1. A polycarbonate substrate provided with a tracking groove is used as a disk substrate 11, and a super-resolution reproduction film 12 is formed thereon. A semiconductor fine particle-dispersed super-resolution reproducing film also having a function of a light emitting film, and a 150 nm thick ZnS-Si film as a first optical interference film as an intermediate layer 13.
O ₂ film, 15 nm thick GeSbTe phase change recording layer as the recording layer 14, 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 reflection film Was formed. Lamination and initialization after the film is formed on the substrate 11 are performed according to a usual method.

The semiconductor fine particle-dispersed super-resolution reproducing film is a fine particle of ZnTe having a band gap corresponding to 550 nm,
It has a structure uniformly dispersed in the SiO ₂ matrix, and absorbs and transitions light of a wavelength of 650 nm between a defect level formed near the valence band and an exciton level below the conduction band. It is adjusted so that a change in absorptivity, that is, a change in light transmittance occurs. In the super-resolution reproducing film, when the intensity of incident light is high, the number of electrons at the defect level is reduced by excitation, the absorptance is reduced, and the transmissivity is increased. The lifetime of de-excitation from the exciton level is adjusted to 10 ns or more due to the effect of atomization, and a sufficient change in transmittance is obtained. At the time of recording / erasing, the incident light intensity is very high compared to that at the time of reproduction, so the transmittance is high in most parts of the light spot,
In the recording / erasing process, this is equivalent to the absence of the super-resolution reproducing film.

In this embodiment, as the film other than the super-resolution reproducing film 12 of the optical disk 10, the same film as that of an ordinary phase change type medium is used, and the absorption rate is not particularly adjusted. However, a translucent film may be inserted between the super-resolution reproducing film 12 and the first optical interference film, or an absorptivity adjusting film structure may be used by using a translucent film instead of the reflective film. In the ordinary 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).

In the case where the optical disk 10 having the above configuration was used, verification was performed in the following procedure. FIG.
In the optical disk device having the configuration shown in FIG.
0 by a spindle motor (not shown) with a linear velocity of 10 m /
s and the wavelength 6 used as the light source 21
The first photodetector 2 is driven by driving a semiconductor laser of 50 nm.
Focusing and tracking servo are performed based on a focusing error signal and a tracking error signal from an arithmetic circuit connected to the output of the optical disk 10, and a light beam is irradiated on a predetermined track of the optical disk 10.

Next, the semiconductor laser as the light source 21 was driven in accordance with the test data (recording / erasing signal sequence 20), a predetermined record mark sequence was recorded on the track of the optical disk 10, and the recorded information was reproduced. . 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 by a pulse wave was performed. The reproduction power Pr was 1 mW.

Then, under this condition, the verify operation at the time of recording / erasing as shown in the description of FIG. 5 was performed. However, the detection signal from the second photodetector 32 is input to the comparators 33 and 34 without performing the above-described integration, and is compared with the threshold values TH1 and TH2, thereby forming the write / erase verify signal sequence 35. 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 sequence 35. FIG. 9 also shows, as a conventional example, the result of examining the number of write error occurrences by reproducing the area recorded after the end of recording for comparison. From this result, it can be seen that the number of write error occurrences detected in the present embodiment matches the conventional example. In this example, as described above, since the integration of the detection signals from the photodetector 32 (integration of the amount of light) was not performed, the signal intensity was weak, but the number of write error occurrences was the same as in the conventional example. It has been confirmed that verification at the time of recording / erasing using light emission at the time of de-excitation according to the embodiment of the present invention is sufficiently possible.

[Example 2] In this embodiment, a semiconductor fine particle dispersed super-resolution reproduction film which also functions as a luminous film disposed on the light incident side of the recording layer is made of CdSe in a SiO ₂ base material.
Example 1 was repeated except that a fine powder of
An optical disk having the same configuration as that of the above was used. The exciton level of CdSe is equivalent to 680 nm, but the exciton level is shifted to the shorter wavelength side by micronization and irradiation with light having a wavelength of 650 nm causes a transition from the valence band to the exciton level. The super-resolution reproduction film is adjusted as described above. The lifetime of deexcitation from the exciton level is 10n due to the effect of micronization.
s or more, and a sufficient transmittance change amount is obtained.

In the case where the optical disk 10 having the above configuration was used, verification was performed in the following procedure. FIG.
In the optical disk device having the configuration shown in FIG.
0 by a spindle motor (not shown) with a linear velocity of 10 m /
s and the wavelength 6 used as the light source 21
A 50 nm semiconductor laser 21 is driven to perform focusing and tracking servo based on a focusing error signal and a tracking error signal from an arithmetic circuit connected to the output of the first photodetector 24, and to perform a predetermined track on the optical disc 10. The top was irradiated with a light beam.

Next, the semiconductor laser as the light source 21 was driven in accordance with the test data (recording / erasing signal sequence 20), a predetermined record mark sequence was recorded on the track of the optical disk 10, and the recorded information was reproduced. . 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 by a pulse wave was performed. The reproduction power Pr was 1 mW.

Then, 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 signal from the second photodetector 32 is integrated by ± Δt seconds as described above to increase the signal strength, and then input to the comparators 33 and 34 to output the threshold values TH1 and TH.
By comparison with No. 2, a recording / erasing verify signal sequence 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 sequence 35. FIG. 10 also shows, as a conventional example, a result of examining the number of write errors by reproducing a recorded area after the end of recording for comparison. From this result, it can be seen that the number of write error occurrences detected in the present embodiment matches the conventional example. Also in this example, the number of times of occurrence of the write error coincides with that of the conventional example, and it is confirmed that the verifying at the time of recording / erasing using the light emission at the time of de-excitation according to the above-described embodiment of the present invention is sufficiently possible. Was done.

[0072] [Example 3] In this embodiment, as the light emitter layer disposed on the light incident side of the recording layer, 3.5MgO · 0.5MgF ₂ · GeO ₂ is a phosphor: use the Mn ²⁺ An optical disk having the same configuration as in Example 1 was used except for the above. In the case where this optical disk 10 is used,
Verification was performed in 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. Performs focusing and tracking servo based on the focusing error signal and tracking error signal from the arithmetic circuit,
A light beam is irradiated on 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 2
The second harmonic was used.

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

Then, 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 signal from the second photodetector 32 is integrated by ± Δt seconds as described above to increase the signal strength, and then input to the comparators 33 and 34 to output the threshold values TH1 and TH.
By comparing with No. 2, a recording / erasing verify signal sequence 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 write / erase verify signal sequence 35 was examined, the number of write error occurrences detected was determined by reproducing the recorded area after the end of recording. According to the conventional example and the conventional example where the number of write error occurrences was checked,
It has been confirmed that verification at the time of recording / erasing using light emission at the time of de-excitation according to the above-described embodiment of the present invention is sufficiently possible.

[Embodiment 4] Using the same optical recording medium as in Embodiment 1, the reproduction signal was corrected according to the following procedure. In the optical disk device having the configuration shown in FIG. 7, the optical disk 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 form the first optical detector. Focusing and tracking servo are performed based on a focusing error signal and a tracking error signal from an arithmetic circuit connected to the output of 24.
A light beam was irradiated on 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 sequence 20), a predetermined record mark sequence is recorded on the track of the optical disk 10, and the recorded information is reproduced. . In the case of this embodiment, the recording power Pw is 12 mW and the erasing power Pe is 7 m
In overwrite mode of W, mark pitch 0.67μ
m to 0.33 μm (at a bit pitch of 0.4 μm to
0.2 μm), and a single frequency overwrite recording was performed for each track. Recording was performed a plurality of times for each track, and the CNR and erasure rate were measured.

As a result of performing a recording / reproducing test on an optical disk having no super-resolution reproducing film produced in advance as a comparative example, the CNR is 54d when the mark pitch is 0.67 μm.
B, the erasure ratio was -33 dB, which is a practically sufficient value.
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 adjustment of the absorptivity as in this comparative example, the intersymbol interference between adjacent marks is large due to the increase of the overwrite jitter, and the mark pitch is 0 when super-resolution reproduction is not performed. .58 μm (bit pitch:
0.35 μm) was the limit of linear density. As a supplement, even if there is no super-resolution reproducing film, it is possible to reduce the mark density to a line density of 0.5 μm (bit pitch: 0.3 μm) on an optical disk whose absorption rate has been adjusted.

Then, reproduction from the optical disk on which the recording marks were formed as described above was performed in the following procedure. When super-resolution reproduction is performed, the number of photons incident on the super-resolution reproduction film 12 during reproduction (Np in FIG. 2) is important. Therefore, the reproduction power Pr was first changed to select the optimum power. When there is no super-resolution reproducing film, the reproducing operation is performed while changing the reproducing power Pr on a recording mark array having a mark pitch of 0.4 μm, where a sufficient CNR cannot be obtained even in the configuration of the absorptivity adjusting film. Was selected as the optimum reproduction power. At this time, the CNR is higher than that of an optical disc having a conventional structure without a super-resolution reproducing film (including the absorption adjusting film structure).
2 has been found to function sufficiently to reduce intersymbol interference.

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

On the other hand, the light emitted when the super-resolution reproducing film 12 is de-excited is condensed by the first objective lens 31, and the second light detector 32
Is a signal reflecting the presence or absence of a recording mark portion on the recording layer 14. The correction circuit 41 refers to the light emission detection signal 40 to change the waveform of the reproduced signal sequence 26. to correct. More specifically, if the effective incident light intensity on the super-resolution reproduction film 12 when the spot of the reproduction light is incident on the amorphous portion and the crystal portion of the recording layer 14, respectively, it is assumed that Ia ^* and Ic ^*. , These can be approximated as Ia ^* = (1 + Tr1 × Ra) Io Ic ^* = (1 + Tr2 × Rc) Io. Here, Io is the light source 21
Ra and Rc are the reflectivities of the amorphous portion and the crystalline portion of the recording layer 14, and Tr1 and Tr2 are the super-resolution reproduction light after the reproduction light of intensity Io is reflected at the reflectances Ra and Rc. Super-resolution reproduction film 12 when incident on film 12
, Which can be determined in advance.

Therefore, the correction circuit 41 outputs the reproduction signal sequence 26
Bottom (part corresponding to the reflected light intensity from the amorphous part)
, The correction coefficient of 1 / Io (1 + Tr1 × Ra), and the peak of the reproduced signal sequence 26 (the portion corresponding to the intensity of light reflected from the crystal part) is 1 / Io (1 + Tr2).
× Rc), and 1 / Io (1 + Tr1 × Ra) and 1 / I
A correction signal having a correction coefficient consisting of an arithmetic mean value of o (1 + Tr2 × Rc) was obtained by calculation, and the reproduction signal sequence 26 was corrected using the correction signal.

The reproduced signal sequence 43 corrected by the correction circuit 41 in this way has a waveform with a single frequency and almost the same distortion as that of the recording signal, which has almost no distortion. This reproduced signal sequence 4
3 is sent to a reproduction signal processing system (not shown) to discriminate and reproduce the original information, thereby enabling good reproduction with a low error rate even for a narrow pitch recording mark row. It became clear that stable operation was established.

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

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

That is, in the fourth embodiment, the relationship between the number Np of incident photons and the transmittance Tr shown in FIG. By correcting the reproduced signal sequence 26 by using this, it is possible to more accurately reproduce the original signal waveform as the corrected reproduced signal sequence 43.

In the embodiment described above, a case is described in which a phase-change optical recording medium in which a super-resolution reproducing film or another luminous film is arranged on the light incident side of the recording layer is used. As long as the optical recording medium has a super-resolution reproducing film or another luminous film disposed on the light incident side of the recording layer, the present invention can be applied to the case where an optical recording medium other than the phase change type is used.

Further, in the above-described embodiment, the semiconductor fine particle-dispersed super-resolution reproducing film is used as the super-resolution reproducing film. However, the present invention can be applied as long as the super-resolution reproducing film emits light by light. Further, the present invention can be applied to a DVD-ROM, a WORM, a 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 luminous film which emits light upon irradiation with light on the light incident side of the recording layer, light is applied to the optical recording medium. Detecting the luminescence of the luminous body film that occurs after irradiation,
Since the recording state of the optical recording medium is verified using the light emission detection signal, it is possible to verify the recording state in parallel with the recording, and the time required for the verification is greatly reduced as compared with the conventional verification method. Can be shortened.

Further, according to the present invention, the light emission of the luminous film occurring after the light is incident on the same optical recording medium is detected, and the luminous film is referred to as the super-resolution reproducing film by referring to the luminescence detection signal. In this case, by further correcting the reproduction signal with reference to the characteristics of the super-resolution reproduction film, distortion of the reproduction signal can be removed or reduced, and reproduction information with a low error rate can be obtained.

[Brief description of the 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 a relationship between the number of incident photons and the transmittance of a super-resolution reproducing film in the optical disc.

FIG. 3 is a characteristic diagram showing a time change of a transmittance and a time change of a light emission amount at the time of de-excitation in a super-resolution reproducing film of the optical disc.

FIG. 4 is a timing chart for explaining a verify operation at the time of recording / erasing in the 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 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 the optical memory device having a reproduced signal correction function according to the embodiment;

FIG. 8 is another configuration diagram of a recording / reproducing system of the optical memory device having a reproduced signal correction function according to the embodiment.

FIG. 9 is a diagram showing the relationship between the number of write errors and the recording power in the first embodiment of the present invention and the 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 the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Optical disk 11 ... Optical disk substrate 12 ... Super-resolution reproduction | regeneration film 13 ... Intermediate layer 14 ... Recording layer 15 ... Protective layer 20 ... Recording / erasing signal series 21 ... Semiconductor laser 22 ... Beam splitter 23 ... 1st objective lens 24 ... First photodetector 25 arithmetic circuit 26 reproduced signal sequence 31 first objective lens 32 second photodetector 33 mis-write detection comparator 34 mis-erase detection comparator 35 recording / erasing verify signal Sequence 36 arithmetic circuit 40 emission detection signal 41 correction circuit 42 ROM storing characteristic data of the super-resolution reproduction film 43 reproduction signal sequence after correction

Claims (6)

[Claims] 1. An optical recording medium having a recording layer on which information is recorded by irradiation of light, a light-emitting film disposed on the light incident side of the recording layer and emitting light upon irradiation with light, Light emission detection means for detecting light emission of the luminous body film occurring after irradiating light, and verification means for verifying a recording state of the optical recording medium using a light emission detection signal output from the light emission detection means. An optical memory device characterized by the above-mentioned. 2. A recording layer on which information is recorded by irradiation of light, and a recording layer disposed on the light incident side of the recording layer, wherein an optical change is caused by electron excitation by light irradiation, and the removal of excited electrons after the light irradiation. An optical recording medium having a super-resolution reproduction film that emits light in response to excitation; and an emission detection unit that detects light emission accompanying de-excitation of excited electrons in the super-resolution reproduction film that occurs after irradiating the optical recording medium with light. An optical memory device comprising: a light emission detection signal output from the light emission detection means; and a verification means for verifying a recording state of the optical recording medium. 3. The optical memory according to claim 1, wherein said verifying means verifies a recording state of said optical recording medium by comparing a level of said light emission detection signal with a predetermined threshold value. apparatus. 4. An optical recording medium having a recording layer for reproducing information by irradiating light, a light emitting film disposed on the light incident side of the recording layer and emitting light upon irradiation with light, Light emission detection means for detecting light emission of the luminous body film occurring after light is incident thereon, and correction means for correcting a reproduction signal from the optical recording medium with reference to a light emission detection signal output from the light emission detection means. An optical memory device, comprising: 5. A recording layer for reproducing information by irradiation of light and a recording layer disposed on a light incident side of the recording layer, wherein an optical change is caused by electron excitation by the light irradiation, and the removal of excited electrons after the light irradiation. An optical recording medium having a super-resolution reproduction film that emits light in response to excitation; and an emission detection unit that detects light emission accompanying de-excitation of excited electrons in the super-resolution reproduction film that occurs after irradiating the optical recording medium with light. An optical memory device comprising: a correction unit that corrects a reproduction signal from the optical recording medium with reference to a light emission detection signal output from the light emission detection unit. 6. The optical memory device according to claim 5, wherein said correction means corrects a reproduction signal from said optical recording medium in accordance with characteristics of said super-resolution reproduction film with reference to said emission detection signal. .