JP3078161B2 - Recording and playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus and an image processing apparatus used for the recording / reproducing apparatus. The present invention relates to a recording and reproducing apparatus that records information and reproduces the recorded information as image information, and an image processing apparatus that extracts recorded information from image information reproduced by the recording and reproducing apparatus.

[0002]

2. Description of the Related Art In recent years, the recording capacity of data in a recording apparatus tends to increase. In such a tendency, it is indispensable that the size of the recording unit is further reduced and the density thereof is further increased. For example, in a digital audio disc using optical recording, the size of a recording unit reaches about 1 μm ² .

On the other hand, recently, a scanning tunneling microscope (Sc) capable of directly observing the shape of the material surface and the electronic structure near the surface has been developed.
anning Tunneling Microscope; hereinafter abbreviated as STM)
Has been developed and has the following advantages, and is expected to be widely applied.

[0004] 1. High resolution measurement of a real space image can be performed irrespective of single crystal or amorphous.

[0005] 2. Observation can be performed with low power without damaging the recording medium due to electric current.

[0006] 3. It works not only in ultra-high vacuum but also in air and in solution.

[0007] 4. It can be used for various materials.

The STM utilizes the fact that a tunnel current flows between a probe electrode (metal probe) and a conductive substance when a voltage is applied and the distance is reduced to about 1 nm. Tunnel current is very sensitive to changes in the distance between the probe electrode and the conductive material. Therefore, surface information in the real space can be obtained by scanning the probe in the in-plane direction while performing control so as to keep the tunnel current or the average distance between the two constant. At this time, the resolution in the in-plane direction is 10 nm or less.

Applying the principle of the STM and using a material having a memory effect on voltage-current switching characteristics, for example, a thin film layer of a π-electron organic compound or chalcogenide as a recording medium, the recording unit becomes Information recording of 0.01 μm ² or less is possible.

Further, if a method of changing the surface shape of a medium using an electromagnetic wave such as an electron beam or light is used, the recording unit becomes large due to the limit of the degree of convergence of the beam, but it is equivalent to the current optical recording. Recording and reproduction of information at a recording density of

However, in a conventional recording / reproducing apparatus to which the above-described STM principle is applied, when recording / reproducing high-density information over the entire surface (recording surface) of a recording medium having a predetermined area, The unevenness present on the recording surface deteriorates the S / N ratio and error rate of the signal at the time of reproduction, which is a major obstacle to achieving a higher recording capacity. As a method for reducing physical irregularities on the surface of the recording medium, a method in which an Au thin film is grown as a single crystal on a cleavage plane such as mica to form a smooth surface can be applied.

However, in the recording medium according to such a method,
Usually, irregularities almost equal to the recording bit size with a diameter of 10 nm or less rarely occur, but steps or ridges of the atomic order still exist. The problem that the shape of the recording bit changes due to the irregularities on the atomic order and the SN ratio and the error rate of the signal at the time of reproduction are reduced still remains.

[0013] In order to solve this problem, it is necessary to perform image processing for extracting only recording information from the read image information after reading information recorded on the recording medium as image information. For example, the state of the recording medium surface on which the recording bits are not written is measured in advance, and the recording information is determined from the difference between the surface state and the surface state indicated by the reproduced image, thereby extracting the recording bits from the reproduced image. It is possible to do.

[0014]

However, in a recording / reproducing apparatus to which the principle of the conventional STM is applied, there is a problem that a signal-to-noise ratio of a reproduced signal is reduced and an error rate is increased due to unevenness existing on the surface of a recording medium. In order to solve this, as described above, a case where the state of the surface of the recording medium on which the recording bit is not written is measured in advance to create an image before recording, and the reproduced image is compared with the image before recording It is necessary to store the surface state of the recording medium before recording on the recording medium, and it is naturally necessary to store the surface state of the area required for the recording unit. Is required, the recording area used for recording is greatly restricted, and there is no point in recording information on a medium.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has been made in consideration of the above circumstances, and provides a recording method capable of efficiently extracting only recording information from image information affected by irregularities on the surface of a recording medium. It is an object to provide a playback device.

[0016]

According to the recording / reproducing apparatus of the present invention, when a probe electrode is two-dimensionally scanned relative to a recording surface of a recording medium, a physical distance is established between the probe electrode and the recording medium. In a recording / reproducing apparatus that records information on the recording medium using a signal generated by the interaction and reproduces the recorded information as image information, a pixel of two-dimensional image data is determined using a predetermined prediction parameter. Predicting means for determining a predicted pixel value of the pixel from a pixel value of a pixel in the vicinity of the pixel, and generating predicted image data composed of a predicted pixel having the predicted pixel value; Learning means for optimizing prediction parameters using the pixel values; and using the prediction parameters optimized by the learning means to obtain again each predicted pixel value of the image data by the prediction means. Ri, characterized by binarizing the two-dimensional image data.

According to another aspect of the present invention, there is provided a recording / reproducing apparatus comprising:
When the probe electrode is two-dimensionally scanned relative to the recording surface of the recording medium, information is recorded and recorded on the recording medium using a signal generated by physical interaction between the probe electrode and the recording medium. In a recording / reproducing apparatus that reproduces information obtained as image information, a predicted pixel value of a pixel of two-dimensional image data is obtained from a pixel value of a pixel in the vicinity of the pixel using a predetermined prediction parameter. A prediction unit that generates predicted image data composed of predicted pixels having values, a learning unit that optimizes a prediction parameter using each pixel value of the image data and each predicted pixel value of the predicted image data, and a learning unit. By using the optimized prediction parameters, each prediction pixel value of the image data is obtained again by the prediction means, thereby binarizing the two-dimensional image data.

In any of the recording / reproducing apparatuses described above,
The creation of the prediction image data by the prediction unit and the optimization of the prediction parameter by the learning unit may be performed before recording, and when recording information is not recorded or reproduced, an area that is not recorded is used. May be performed.

As a specific configuration example, an absolute value of a difference between each predicted pixel value obtained by the prediction means and each pixel value of image data is calculated, and if the absolute value is smaller than a predetermined threshold value, Create a binary image having “0” as the pixel value if the absolute value is larger than a predetermined threshold value 2
Value image creating means, binary image storing means for storing the binary image created by the binary image creating means, and the pixel value of the binary image created by the binary image creating means being '0' For example, if the pixel value of the image data is “1” and the pixel value of the binary image is “1”, a predicted pixel value of the predicted image data is selected to generate a composite image, and the generated composite image is output to the prediction unit. And a binary image reconstructing unit comprising a composite image creating unit, wherein the prediction unit uses the composite image instead of the two-dimensional image data when the composite image is input from the composite image creating unit, New prediction image data is created by using the prediction parameters optimized by the learning means, and the binary image creation means creates a new binary image from the new prediction image data created by the prediction means, The binary image reconstruction means is equivalent to a binary image storage means. The binary image is reconstructed by calculating the logical sum of the pixel value of the stored binary image and the pixel value of the new binary image created by the binary image creating means. When the values of all the pixels of the binary image sent from the means are “0”, the reconstructed binary image is output to the outside.

[0020]

In the image processing apparatus of the present invention, image data before recording can be predicted from image data after recording by using optimized prediction parameters obtained by the learning means. The prediction parameter is a calculation parameter used when calculating the value of the pixel to be predicted from the values of the pixels around the pixel to be predicted, and is valid for the entire area of the recording medium.

In the present invention, since the pixel value is predicted using the above-described prediction parameters, the bits recorded on the recording medium can be efficiently extracted.

The binary image forming means subtracts the predicted image data before recording from the image data after recording to obtain difference data indicating the difference from the predicted image data before recording from the image data after recording. By binarizing the difference data, desired recording information (binary image) can be obtained.

However, since the predicted image data before recording does not always match the image data before recording, the binary image created by the binary image creating means is stored in the binary image storing means. Then, if the pixel value of the binary image created by the binary image creating means is “0”, the pixel value of the image data is changed to “1” by the composite image creating means. For example, by selecting a predicted pixel value of the predicted image data and generating a composite image, a composite image close to the image data before recording is generated. Subsequently, the predicting means similarly predicts the image data before recording from the composite image data, and the binary image creating means subtracts the predicted image data from the composite image data before recording, thereby obtaining the post-recording image data. The difference data indicating the difference from the predicted image data before recording can be obtained from the image data, and the obtained difference data is binarized to obtain a binary image. In the binary image obtained in this way, when the predicted image data before recording matches the image data before recording, the values of all the pixels are “0”, and thus all the binary image The above operation is repeated until the pixel value becomes '0'.

In each pixel of the binary image obtained at each repetition of the above operation, those having a pixel value of "1" correspond to the pixels on which information is recorded, and those having a pixel value of "0". These correspond to pixels for which no information is recorded. Therefore, every time the above operation is performed,
A binary image reconstructing unit obtains a logical sum of a pixel value of the binary image stored in the binary image storage unit and a pixel value of a new binary image created by the binary image creating unit. By reconstructing the binary image in this way, a binary image corresponding to the recording information can be finally obtained.

In the recording / reproducing apparatus of the present invention, the image processing means is configured in the same manner as the above-described image processing apparatus, and the learning means optimizes the prediction parameters using the surface state image data before recording. Without storing the surface state image data before recording, the surface area that has undergone a state change by the recording operation is extracted and binarized.

However, also here, the predicted surface state image data before recording does not always match the surface state image data before recording. When predicting a pixel value of a pixel in a recording bit area in which a recording bit as a recording unit of information is written from a pixel value of a neighboring pixel, when the neighboring pixel is also in the recording bit area, the prediction unit Since the predicted pixel value is predicted from the pixel values of the neighboring pixels, the predicted pixel value at this time is not the pixel value of the pixel before recording. However, the surface state image data before recording can be predicted from the pixel value of the pixel at the boundary portion of the recording bit area. From the surface state image data including such a recording bit area and its predicted image, the binary image creating unit performs processing from the pixel which gives '1' to the pixel value of the boundary portion where the surface state image data before recording could be predicted. The composite image creating means creates composite image data in which the boundary portion is replaced with surface state image data before recording. By repeating the above process using the composite image data as an input image of the prediction means, the binary image creation means can generate a binary image consisting of pixels having a value "1" given to a pixel value of a new boundary portion of the recording bit area. The images are sequentially created, and the synthesized image creating means sequentially creates synthesized image data in which a newly formed boundary portion is replaced with surface state image data before recording. When the values of all the pixels of the binary image become “0”, it means that all the pixel values of the pixels in the recording bit area have been replaced with the pixel values of the pixels of the surface state image data before recording. By taking the logical sum of the pixel values of the binary image obtained up to this point by the image reconstructing means, a binary image whose recording bit area corresponds to "1" can be obtained.

In the recording / reproducing apparatus provided with the scanning control means and the learning control means, even when a part of the surface of the recording medium is already used for recording, the recording / reproducing operation is not performed by the apparatus. The learning control unit compares the difference data with a predetermined threshold value from among a plurality of areas on the surface of the recording medium arbitrarily selected by the scanning control unit, and the unused data is used. Can be found, and learning of prediction parameters is performed at any time using the pixel value of the pixel of the surface state image data corresponding to this region and its predicted pixel value.

[0028]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a recording / reproducing apparatus according to one embodiment of the present invention.

The main body of the recording / reproducing apparatus 101 of the present invention comprises a structure 113 supporting a fine movement control mechanism 117 for finely moving the probe electrode 116 and a coarse movement control mechanism 112 for coarsely moving the recording medium 111; The large coarse movement control mechanism 114 on which is mounted, and the seismic isolation table 115 on which the large coarse movement control mechanism 114 is mounted.

The structure 113 is for supporting each structural part, and is made of an Invar alloy. A coarse movement control mechanism 112 is attached to the bottom surface of the structure 113, and a recording medium 111 is placed on the coarse movement control mechanism 112. In the recording medium 111, information is actually written, and squarylium-bis-6-octylazulene, which has a memory effect on current-voltage switching characteristics, is formed on a graphite substrate by the Langmuir-Blodgett method (LB).
Method) is used to accumulate eight layers. Note that the recording medium 111 is in a non-recording state (off state) in an initial state. The coarse movement control mechanism 112 has a parallel spring using an elastic hinge.
This is for performing coarse movement control in the axial direction and the Y-axis direction. A fine movement control mechanism 117 is mounted inside the upper surface of the structure 113 so that the probe electrode 116 faces the recording medium 111. The probe electrode 116
It is used for recording and reproducing information. The probe electrode 116 is made of a tungsten needle whose tip is mechanically polished or electrolytically polished in order to improve the recording / reproducing resolution. The material of the probe electrode 116 is Pt-Ir, Pt
Etc., and the processing method is not limited to this. The fine movement control mechanism 117 is composed of a cylindrical piezoelectric element,
The probe electrode 116 is moved in the in-plane direction (X,
This is for moving in the direction (Y direction) and the direction between the recording medium 111 and the probe electrode 116 (Z direction). During normal operation, the distance between the tip of the probe electrode 116 and the surface of the recording medium 111 is such that a tunnel current flows.

The large coarse movement mechanism 114 includes a fine movement control mechanism 117.
And control of a size outside the control range of the coarse movement control mechanism 112. The anti-vibration table 115 is for preventing external vibrations from being transmitted to the recording / reproducing apparatus 101, thereby preventing a malfunction of the recording / reproducing apparatus 101 due to external vibrations.

The electrical and control system of the recording / reproducing apparatus 101 includes a voltage applying apparatus 119 and a probe current amplifier 120
, An arithmetic unit 121 and an XY controller 118.

The voltage application device 119 stores information in the recording medium 1.
A bias voltage for performing recording, reproduction, and erasing is set to −10 between the probe electrode 116 and the recording medium 111.
It is given at an arbitrary magnitude in the range of V to + 10V.

The probe current amplifier 120 is connected to the probe electrode 116 and detects a tunnel current flowing through the probe electrode 116 by a bias voltage.
The detected tunnel current is converted into a voltage signal, amplified, and output to the arithmetic unit 121.

The XY controller 118 controls the fine movement control mechanism 117 and the coarse movement control mechanism 112 to arbitrarily displace the probe electrode 116 with respect to the recording medium 111.

The arithmetic unit 121 includes the probe current amplifier 1
20 is input, and a voltage application device 119 is provided.
And the XY controller 118. Arithmetic unit 12
1 is an XY controller 118 and a voltage application device 11
9, an A / D converter for converting a voltage signal sent from the probe current amplifier 120 into a digital signal and quantizing the digital signal, a tunnel signal converted into a digital signal, or a movement of the probe electrode 116 in the Z direction. The image processing apparatus stores a reproduced image having a pixel value of a voltage applied to the fine movement control mechanism 117 via the XY controller 118, and extracts only a recording bit area from the reproduced image.

In the present recording / reproducing apparatus, in addition to the operation of the normal STM, the probe electrode 116 is moved to an arbitrary position in the space on the recording medium 111, and -10 V is applied even when feedback is applied or feedback is cut off.
A bias voltage of an arbitrary magnitude can be applied in a range of up to +10 V.

The actual recording / reproducing operation of the recording / reproducing apparatus 101 will not be described in detail here, but the recording on the recording medium 111 is larger than the threshold voltage of the recording medium 111 at which the memory effect occurs. This is performed by applying a voltage of +10 V to the recording medium 111 as a recording voltage.
In the area where the memory effect has occurred, when reproduction is performed with a bias voltage lower than the threshold value after application of the recording voltage, for example, in a constant current mode in the STM, an image having an upward convexity appears. It can correspond to the recording bit ('1') of '1' or '0').

Incidentally, the recording / reproducing apparatus 101 of this embodiment
Here, as described above, the image processing apparatus is incorporated in the arithmetic unit 121. As described above, the recording bit, which is the minimum unit of the recording information, appears as an upwardly convex area on the image, but in an actual image, the influence of irregularities on the recording medium surface is further superimposed. The image processing apparatus uses a general threshold value logic to prevent the influence of unevenness on the surface of a recording medium from a reproduced image in which a pixel value is a value corresponding to a tunnel current value or a displacement amount of the probe electrode 116 in the Z direction. A recording bit area image (binary image) in which recording information is extracted by a method different from binarization and the recording information is used as a pixel value
Is output.

FIG. 2 is a block diagram showing the configuration of the image processing apparatus.

A predictor 212 used in the image processing device
Predicts the value of each pixel of a two-dimensional image from the value of each pixel in the vicinity thereof, and has a learning function of adjusting a prediction parameter based on a comparison between an input image input and a predicted image predicted. ing. First, the predictor 212 will be described. FIG. 3 is a principle diagram showing a learning process of the predictor 212, and FIG. 4 is an embodiment of the learning process.

Since the learning process is for learning irregularities on the surface of the recording medium 111, it is necessary that no recording bit is written, and the surface of the micro motion control mechanism 117 can be used for scanning at the time of shipment. This is performed as follows.

In the learning process, a reproduced image 302 obtained from the recording / reproducing apparatus 101 (however, an image of the surface in a non-recorded state at the time of shipment as described above, for example, an image shown in FIG. 4A) Input. For example, the predictor 21
2 is composed of an adaptive AR model, the adjusted prediction parameter is a linear coefficient, and the adjustment method is
Mean square error 30 between reproduced image 302 and predicted image 304
Achieved with the steepest descent method based on 5. Also, if the predictor is configured by a neural network, the adjusted prediction parameter is a coupling coefficient (weight) between the units.
The adjustment method is also achieved by the steepest descent method based on the mean square error 305 between the reproduced image 302 and the predicted image 304. Through such a learning process, the predictor 212 can output the predicted image shown in FIG. 4B with respect to the input image shown in FIG. Can be expected to fall within a certain range.

The image processing device includes an input image storage unit 211,
A prediction unit 210 including a predictor 212 and a prediction image storage unit 213; a pixel processing unit 220 including an absolute value circuit 221, a comparison circuit 222, output limiting circuits 223, 224, and a synthesis unit 225; It comprises a binary image synthesizing section 232 and an image reconstructing section 230 comprising a pixel value totaling section 233.

The input image storage unit 211 stores the recording / reproducing device 1
01 or the pixel processing unit 2 as described later.
20 is temporarily stored as an input image to be output to the predictor 212, and the value of each pixel constituting the input image is sequentially stored in the absolute value circuit 2 of the pixel processing unit 220.
21 and the output limiting circuit 223. Predictor 21
2 outputs the predicted image predicted from the input image to the predicted image storage unit 213 as described above. Predicted image storage unit 213
Temporarily stores the predicted image predicted by the predictor 212 and sequentially outputs the value of each pixel constituting the predicted image to the absolute value circuit 221 and the output limiting circuit 224 of the pixel processing unit.

The absolute value circuit 221 is provided in the input image storage 21
The difference between the value of each pixel of the input image from No. 1 and the value of each pixel of the predicted image from the predicted image storage unit 213, that is, the prediction error is obtained, and the absolute value of the prediction error is output to the comparison circuit 222. The comparison circuit 222 compares the absolute value of the difference data output from the absolute value circuit 221 with a preset threshold value, and if the absolute value of the difference data is larger than the threshold value, “1”.
Is output to the output limiting circuits 223 and 224 and the binary image storage unit 231 and the pixel value totaling unit 233 of the image reconstructing unit 230 if the value is smaller. Output limiting circuits 223, 22
Reference numeral 4 has three terminals of an input terminal, an output terminal and an output limiting terminal. If the input of the output limiting terminal is "1", the input is output from the output terminal as it is to the input terminal, and the input of the output limiting terminal is " If it is 0 ', the circuit does not output anything from the output terminal regardless of the value of the input. Output limiting circuit 223
Inputs the value of each pixel of the input image from the input image storage unit 211 to the input terminal, inverts the binary output of the comparison circuit 222 to the output limiting terminal, and combines the value of each pixel whose output has been limited to the combining unit. 225. The output limiting circuit 224 inputs the value of each pixel of the predicted image from the predicted image storage unit 213 to an input terminal, inputs the binary output of the comparison circuit 222 to the output limiting terminal as it is, and outputs Combining the value into the combining unit 2
25. The synthesizing unit 225 includes an output limiting circuit 223
Then, each pixel value of the output of the output limiting circuit 224 is added and output to the input image storage unit 211 of the prediction unit 210.
Therefore, this output forms a composite image composed of pixels of the input image or the predicted image in the input image storage unit 211.

The binary image storage unit 231 includes a comparison circuit 222
Is stored until one image is formed, and the binary value is output to the binary image forming unit 232 at an appropriate reading speed. Each pixel value of the binary image stored in the binary image storage unit 231 is updated to a newly input pixel value for each image. When the binary output of the comparison circuit 222 forms one image, the pixel value summing unit 233 includes “1” included in the one image.
Is calculated, and when the number of pixels of '1' becomes 0,
An output start signal is output to the binary image forming unit 232. The binary image synthesizing unit 232 stores the binary output of the binary image storage unit 231. Each time a new pixel value is input, the value of each pixel to be stored is updated to a logical sum of the input pixel value and the value already stored. Upon receiving the output start signal from the pixel value summing unit 233, the stored binary image is output as a recording bit area image which is the final output image of the image processing apparatus.

Next, the operation of the image processing apparatus will be described.

The predictor 212 outputs a predicted image for an input image based on the prediction parameters adjusted as described above. As the input image of the predictor 212, a reproduced image from the recording / reproducing device 101 is given as an initial value.

The absolute value circuit 221 calculates the absolute value of the difference (difference data) between the input image and the predicted image for each pixel, and the comparison circuit 222 checks the magnitude relationship between the absolute value of the difference data and the threshold value. . Therefore, the output of the comparison circuit 222 is a binary image in which the pixel whose absolute value of the difference data is larger than the threshold value is “1” in the binary image storage unit 231.

The output of the comparing circuit 222 is output to the output limiting terminals of the output limiting circuits 223 and 224. Since the output limiting terminal of the output limiting circuit 223 is an inverted input, the output of the comparing circuit 222 is If the output is “1”, the pixel of the predicted image is output to the combining unit 225, and if the output of the comparison circuit 222 is “0”, the pixel of the input image is
It is output to the combining unit 225. Therefore, the composite image in the input image storage unit 211 is an input image in which pixels whose absolute values of the difference data are larger than the threshold value are replaced with pixels of the predicted image. The prediction unit 210 and the pixel processing unit 220 create a predicted image and a composite image using the composite image as a new input image.

A binary image is sent to the image reconstructing section 230 every time the predictor 212 outputs a predicted image.
The value image synthesizing unit 232 calculates the sum of the sets of the binary images, and the pixel value summing unit 233 calculates the sum of the pixel values. When all the pixel values of the pixels of the binary image are “0”, the binary image synthesizing unit 232 receives the output start signal from the pixel value summing unit 233 and records the binary image obtained by performing the set sum. Finally output as a bit area image.

FIG. 5 shows a specific example of this operation. For simplicity, the reproduced image shown in FIG. 5A is one-dimensional data. The predictor 212 outputs a predicted image as shown in FIG. 5B with respect to the reproduced image shown in FIG. An image shown in FIG. 5C is generated based on the absolute values of these difference data. Based on this, the comparison circuit 122 creates a binary image shown in FIG. , 224 and the synthesis unit 225
The combined image shown in (e) is combined. The combined image shown in FIG. 5 (e) is obtained by converting the pixel of the binary image shown in FIG. 5 (d) corresponding to the pixel of the reproduced image shown in FIG. ) Are replaced with the pixels of the predicted image shown in FIG. The above process is performed again using the synthesized image shown in FIG. 5E synthesized as described above as an input image.
The binary image and the composite image shown in (h) and (i) are obtained. FIG.
The above process is performed again using the binary image shown in (h) as an input image to obtain a binary image shown in FIG. In this binary image, since the values of the pixels are all 0, the composite image and the binary image obtained by performing the above process again are shown in FIG.
And the binary image shown in FIG. 5 (l). The binary image synthesizing unit 232 calculates the logical sum of each pixel of the binary images shown in FIGS. 5D and 5H obtained as described above and obtains the binary image shown in FIG. Create a value image. FIG. 5 shows the final image processing device.
The binary image shown in (m) is output as a recording bit area image.

In the above embodiment, the learning process is performed at the time of shipping. However, after the shipping, the learning process is performed at any time in order to accurately predict even if the surface condition of the recording medium 111 changes with time. It is conceivable to update the prediction parameters by using The prediction parameter is updated when the recording / reproducing apparatus 101 does not perform the recording / reproducing operation, for example, before the recording / reproducing apparatus 101 is turned on before the recording / reproducing operation is performed, or the recording / reproducing apparatus 101 is turned off. For example, after the previous recording / reproducing operation, it is necessary to use an area of the recording medium 111 where the recording bit is not written.

For this purpose, a scanning control unit is newly provided in the arithmetic unit 121 and a learning control unit is newly provided in the prediction unit 210 of the image processing apparatus. The scanning control unit is for obtaining a reproduced image by automatically scanning the probe electrode 116 over an arbitrary area of the recording medium 111 when the recording / reproducing apparatus is in a predetermined state, for example, after power is turned on. The learning control unit operates in conjunction with the scanning control unit, and controls the learning function of the predictor 212 based on the reproduced image obtained by the scanning control unit as follows.

The reproduced images of the area on the surface of the recording medium 111 randomly selected by the scanning control unit are sequentially sent to the image processing device. The image processing device performs the above-described processing. At this time, the learning control unit outputs the output of the absolute value circuit 221,
That is, the difference between the pixel values of the pixels of the reproduced image and the predicted image is monitored. After confirming that this difference is smaller than a preset value, that is, that no recording bit exists in this area, the learning control unit uses the pixel value of the pixel having the difference and the pixel values of its neighboring pixels. Predictor 21 for learning process
2

In the embodiment described above, the recording / reproducing apparatus has been described as the STM for detecting the tunnel current generated between the probe and the recording medium. However, the configuration which characterizes the present invention is not limited to this. Instead, an atomic force microscope (AFM) that detects an atomic force between the probe and the recording medium may be used.

[0058]

The present invention has the following effects because it is configured as described above.

In the recording / reproducing apparatus, the recording bit area is extracted by taking the difference between the surface condition image data after recording and the surface condition image data before recording predicted from this image data. The recording can be reproduced with high accuracy even if the surface has irregularities. In addition, since the prediction of the surface state image data before recording only needs to have a prediction parameter,
There is no need to use extra recording area on the recording medium surface,
There is an advantage that there is no need to have any other storage means and no burden is placed on the apparatus itself.

In the recording / reproducing apparatus provided with the scanning control means and the learning control means, the learning of the prediction parameters can be performed at any time by using an unused area on the surface of the recording medium. However, the recording can be accurately reproduced.

Since the image processing apparatus can handle general image data, it can be used particularly when detecting a change with respect to the background, for example, when counting cells.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an image processing apparatus according to an embodiment of the present invention.

FIG. 3 is a principle diagram showing a learning process of a predictor.

FIG. 4 is a diagram showing one embodiment of a learning process.

FIG. 5 is a diagram illustrating a specific example of the operation of the image processing apparatus.

[Explanation of symbols]

 Reference Signs List 101 recording / reproducing device 111 recording medium 112 coarse movement control mechanism 113 structure 114 large coarse movement control mechanism 115 anti-vibration table 116 probe electrode 117 fine movement control mechanism 118 XY controller 119 voltage application device 120 probe current amplifier 121 arithmetic unit 210 prediction unit 211 Input image storage unit 212 Predictor 213 Predicted image storage unit 220 Pixel processing unit 221 Absolute value circuit 222 Comparison circuit 223, 224 Output limiting circuit 225 Synthesis unit 230 Image reconstruction unit 231 Binary image storage unit 232 Binary image synthesis unit 233 Pixel value total unit 302 Reconstructed image 304 Predicted image 305 Mean square error 401 Input image 402 Predicted image 403 Absolute value of pixel difference 501 Reconstructed image 502, 506, 510 Predicted image 503, 507, 511 Absolute value of difference data 504, 5 8,511,512 binary image, 505, 509 synthetic image

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-161552 (JP, A) JP-A-63-161553 (JP, A) JP-A-2-72491 (JP, A) JP-A-4- 47470 (JP, A) JP-A-6-259546 (JP, A) JP-A-6-290269 (JP, A) JP-A-7-93832 (JP, A) JP-A-7-244873 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) G06T 5/00 G11B 9/00 G11B 20/10 321 G11B 20/18 560 H01J 37/28

Claims (5)

(57) [Claims] When a probe electrode is two-dimensionally scanned relative to a recording surface of a recording medium, a signal generated by a physical interaction between the probe electrode and the recording medium is used. In a recording / reproducing apparatus that records information in a pixel and reproduces the recorded information as image information, a prediction pixel value of a pixel of two-dimensional image data is calculated using a predetermined prediction parameter. A prediction unit that obtains predicted image data including predicted pixels having the predicted pixel values, and a prediction parameter obtained by using the pixel values of the image data and the predicted pixel values of the predicted image data. Learning means for optimizing, using the prediction parameters optimized by the learning means,
A recording / reproducing apparatus, wherein the two-dimensional image data is binarized by re-calculating each predicted pixel value of the image data by the prediction means. 2. When a probe electrode is two-dimensionally scanned relative to a recording surface of a recording medium, information is generated on the recording medium by utilizing a signal generated by a physical interaction between the probe electrode and the recording medium. Recording and reproducing the recorded information as image information, using a predetermined prediction parameter to calculate a predicted pixel value of a pixel of two-dimensional image data as a pixel value of a pixel in the vicinity of the pixel. And predicting means for generating predicted image data composed of predicted pixels having the predicted pixel value, and optimizing the prediction parameter by using each pixel value of the image data and each predicted pixel value of the predicted image data. Learning means to be converted, using the prediction parameters optimized by the learning means,
A recording / reproducing apparatus, wherein the two-dimensional image data is binarized by re-calculating each predicted pixel value of the image data by the prediction means. 3. The recording / reproducing apparatus according to claim 1, wherein the creation of predicted image data by the prediction means and the optimization of prediction parameters by the learning means are performed before recording. Recording and playback device. 4. The recording / reproducing apparatus according to claim 1, wherein the generation of the predicted image data by the prediction unit and the optimization of the prediction parameter by the learning unit are performed when recording information is not recorded or reproduced. Recording / reproducing apparatus characterized in that the recording / reproducing apparatus is performed using an unrecorded area. 5. The recording / reproducing apparatus according to claim 1, wherein an absolute value of a difference between each of the predicted pixel values obtained by the prediction unit and each of the pixel values of the image data is calculated. A binary image creating means for creating a binary image having a pixel value of "0" if the absolute value is smaller than a predetermined threshold, and "1" if the absolute value is larger than the predetermined threshold; A binary image storage unit that stores the binary image created by the binary image creation unit; and a pixel value of the binary image created by the binary image creation unit is “0”. If the pixel value of the image data is
If the pixel value of the value image is '1', a synthesized image is created by selecting the estimated pixel value of the estimated image data, and then the synthesized image is output to the estimating unit. The prediction means comprises: receiving the composite image from the composite image creating means, using the composite image instead of the two-dimensional image data; Generating new predicted image data using the prediction parameters optimized in the step (a), wherein the binary image generating means generates a new binary image from the new predicted image data generated by the predicting means The binary image reconstructing means includes a pixel value of the binary image stored in the binary image storing means and a pixel value of a new binary image created by the binary image creating means. Find the logical sum of And outputting the reconstructed binary image to the outside when all the pixel values of the binary image sent from the binary image creating means are '0'. Recording and playback device.