Optical recording medium, erasure apparatus and erasure method thereof

1. An optical recording medium comprising:

a substrate;

an organic pigment recording layer formed on the substrate; and

a photocatalyst layer in physical contact with the organic pigment recording layer;

wherein the photocatalyst layer is configured to demonstrate oxidation in response to being irradiated with light having a first wavelength such that the oxidation of the photocatalyst layer causes erasure of data recorded in the organic pigment recording layer.

2. The optical recording medium according to claim 1 , wherein the photocatalyst layer is configured to demonstrate oxidation when irradiated with ultraviolet rays of a short wavelength.

3. The optical recording medium according to claim 1 , wherein the organic pigment recording layer is configured to record data in response to being irradiated by light having a second wavelength, and wherein the second wavelength is different from the first wavelength.

4. The optical recording medium according to claim 1 , wherein the organic pigment recording layer is configured to allow read out of data in response to receiving the light having the first wavelength.

5. An erasure apparatus that erases information recorded in an optical recording medium the erasure apparatus comprising:

a first optical irradiation system configured to emit light having a first wavelength at the optical recording medium, wherein the optical recording medium includes an organic pigment recording layer and a photocatalyst layer in physical contact with the organic pigment recording layer, and wherein the light having the first wavelength is configured to cause oxidation of the photocatalyst layer and erasure of data recorded in the organic pigment recording layer; and

a control system configured to cause the first optical irradiation system to irradiate the optical recording medium with the light having the first wavelength.

6. The erasure apparatus according to claim 5 , wherein the control system is configured to receive an irradiation instruction from a user to erase the optical recording medium and cause the first optical irradiation system to emit the light having the first wavelength in response to receiving the irradiation instruction, and wherein the first optical irradiation system is configured to irradiate the optical recording medium with the light having the first wavelength to erase the information recorded in the organic pigment recording layer.

7. The erasure apparatus according to claim 5 , wherein the control system is configured to cause irradiation of the optical recording medium with the light having the first wavelength in response to the optical recording medium being read a predetermined number of times.

8. The erasure apparatus according to claim 5 , further comprising a reading control device configured to:

determine whether data can be read from the organic pigment recording layer after irradiation of the photocatalyst layer with the light having the first wavelength; and

cause another instance of irradiation of the photocatalyst layer with the light having the first wavelength in response to a determination that data can be read from the organic pigment recording layer after a previous irradiation of the photocatalyst layer with the light having the first wavelength.

9. The erasure apparatus according to claim 5 , wherein the duration of the irradiation of the photocatalyst layer is adjustable.

10. The erasure apparatus according to claim 5 , further comprising a second optical irradiation system configured to emit light having a second wavelength to write data to the organic pigment recording layer.

11. The erasure apparatus according to claim 5 , further comprising a second optical irradiation system configured to emit light having a second wavelength to read data from the organic pigment recording layer.

12. The erasure apparatus according to claim 5 , further comprising a second optical irradiation system configured to emit light having the first wavelength to read data from the organic pigment recording layer such that each instance of reading data from the organic pigment recording layer causes a gradual erasure of the organic pigment recording layer.

13. An erasure method for erasing information recorded in an optical recording medium the erasure method comprising:

providing the optical recording medium, wherein the optical recording medium includes an organic pigment recording layer configured to store data and a photocatalyst layer in physical contact with the organic pigment recording layer; and

irradiating the optical recording medium with light having a first wavelength such that the photocatalyst layer demonstrates oxidation, and wherein the oxidation of the photocatalyst layer causes erasure of data stored on the organic pigment recording layer.

14. The erasure method according to claim 13 , further comprising irradiating the optical recording medium with light having a second wavelength to write data to the organic pigment recording layer, wherein the second wavelength is different from the first wavelength.

15. The erasure method according to claim 13 , further comprising irradiating the optical recording medium with light having a second wavelength to read data from the organic pigment recording layer.

16. The erasure method according to claim 13 , further comprising irradiating the optical recording medium with the light having the first wavelength to read data from the organic pigment recording layer such that each instance of reading data from the organic pigment recording layer causes a gradual erasure of the organic pigment recording layer.

17. The erasure method according to claim 13 , further comprising modifying a duration of the irradiation of the optical recording medium with the light having the first wavelength.

18. The erasure method according to claim 13 , further comprising:

determining whether data can be read from the organic pigment recording layer after irradiating the photocatalyst layer with the light having the first wavelength; and

causing another instance of irradiation of the photocatalyst layer with the light having the first wavelength in response to a determination that data can be read from the organic pigment recording layer after a previous irradiation of the photocatalyst layer with the light having the first wavelength.