JPS62289935A - Information recording medium - Google Patents

Abstract

PURPOSE:To change array and coupling forms of molecules with an external electric signal, heat, etc., and to prolong the life of a recording surface and improve secrecy by arranging a light quantity control material which varies in light reflection factor and transmissivity with wavelength on the recording material of a recording medium. CONSTITUTION:The optical recording material 1 is formed on the holding member 2 of the card type information recording medium and the light quantity control material 3 is formed covering the surface of the material 1. This control material 3 uses a liquid crystal display element, a transmission type solid display element, and a photochromic material which controls the transmissivity of specific wavelength, and a control part 4 at an end part of the material 1 is provided with a control circuit, etc. This control material 3 is applied with an electric signal, heat, energy, etc., externally to change array and coupling forms of molecules, thereby varying the light reflection factor and transmissivity of the material 1 and making a display surface visible. Then, the life of the recording surface is prolonged and the secrecy is improved.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an improvement of an information recording medium that performs recording and reproduction using optical means.

[Conventional technology]

Conventionally, as an information recording medium for optically recording and reproducing, Japanese Patent Application Laid-Open No. 58-501422. Japanese Patent Publication No. 55-10899
As described in Publication No. 5, by drilling holes in the medium with laser light, etc., and changing the crystal structure, the reflectance or transmittance of light with surrounding areas where information is not recorded can be improved. Information was recorded and reproduced by taking advantage of the difference between the two. However, materials used for optical recording generally undergo deterioration due to natural light, and in severe cases, written information may be destroyed, so special care has been required when storing information recording media. In addition, there were other problems such as the inability to use it in applications where it would be exposed to natural light for long periods of time. moreover,
In order to perform optical reproduction, the information must be visible from the outside, so for example, if credit information such as bank deposits is recorded, anyone can easily read the information. There were problems such as the inability to maintain the confidentiality of information because it was vulnerable to outsiders.

[Problem that the invention seeks to solve]

Information recording media that perform recording and reproduction using the conventional optical means described above do not take into consideration optically covering the optical recording material when not in use or during storage, and therefore the life of the medium is shortened. There were also problems such as difficulty in maintaining confidentiality.

The present invention was made in view of the above situation, and it is an object of the present invention to provide an information recording medium that can extend the life of the recording surface and improve confidentiality.

[Means for solving the problem] The above purpose is to cause a chemical reaction using external electric signals, heat, energy, etc., and to change the molecular arrangement and bonding style, thereby increasing the light intensity of the material. This is achieved by disposing a light amount control material that changes the reflectance and transmittance for each wavelength on the optical recording material of the recording medium so as to cover the information recording surface.

[Effect]

As will be explained later in the embodiments, if the optical recording material on the optical information recording surface is covered with a light amount control material, it will block external light and protect the recording surface under normal conditions, and will protect the recording surface from external light during recording and playback. It becomes possible to make the recording surface visible by applying a predetermined electric signal, heat, or light energy. Further, by utilizing the change in transmittance depending on the wavelength of light, it is possible to selectively irradiate the recording/reproducing surface with light of a specific wavelength.

〔Example〕

Hereinafter, the information recording medium of the present invention will be described using an example (see FIG. 1).
explain. FIG. 1 is a perspective view of a card-shaped information recording medium. In the figure, 1 is an optical recording material. Optical recording material 1 has holes made with a laser beam, etc., and the crystal structure has been changed, resulting in a difference in reflectance between it and the surrounding unrecorded area. It looks like this.

Reference numeral 2 denotes a holding member, which is made of a plastic sheet or the like, and the optical recording material 1 is applied onto the holding member 2 by means such as sputtering or printing.
is formed, and the light amount control material 3 is formed so as to cover the surface of the optical recording material 10. Known materials for the light amount control material 3 include liquid crystal display elements, electrochromic elements that are transmissive solid-state display elements, photochromic elements, and PLZT. Note that the light amount control material 3 changes due to a chemical reaction caused by an external electric signal, heat, light energy, etc., or a change in the molecular arrangement or bonding style.
It has the characteristic that the reflectance and transmittance of light change depending on the wavelength. Reference numeral 4 denotes a control section.The control section 4 includes a control CPv for the light amount control material 3, a battery, and a signal connection terminal with the outside (none of which is shown). By covering the optical recording material 1 with the light amount control material 3, in normal conditions it shields external light and protects the recording surface, and during recording and reproduction, it protects the recording surface from electrical signals, heat, and light energy determined from the outside. By providing this, it is possible to make the recording surface visible, and during playback, light is applied and reflected. Further, by utilizing the change in transmittance depending on the wavelength of light, it is possible to selectively irradiate the recording/reproducing surface with light of a specific wavelength. Therefore, by providing the control unit 4 with a password verification function, it is possible to protect the confidentiality of recorded information. And the control section 4
can also be formed by being embedded in the holding member 2. Furthermore, if necessary, a waist-retaining layer such as 8fCh may be provided between each layer.

FIG. 2 shows an example in which a liquid crystal display element or an electronic chromic material (for example, WOs, etc.) whose transmittance can be controlled by electric signal i is used as the light amount control material 3 shown in FIG. Transparent electrodes 5 are formed on both sides of the first light amount control material 7, and the transparent electrodes 5
Transmittance is controlled by applying a control signal to the light amount control material 7. In this case, the first light amount control material 7 made of liquid crystal or electrochromic material can be used as a display panel if necessary, and can also be used as an information display panel, thereby achieving miniaturization and multifunctionality. This is an effect of this embodiment. If a ferroelectric liquid crystal is used as the first light amount control material 7, any state of transmittance from the maximum to the minimum can be maintained without applying power from the control section 4, so that power consumption can be reduced. In addition, intermediate transmittance can be easily controlled with liquid crystals and electrochromic materials. Therefore, 1. For example, when the information recording medium of this embodiment is used in a machine with different light source intensities for recording and reproduction, it is possible to keep the light intensity irradiated to the recording surface constant by controlling the transmittance, and the recording A wide range of playback equipment compatibility can be achieved.

FIG. 3 shows a second light amount control material 8, which is a photochromic material whose transmittance can be controlled by the energy of external light, as the light amount control material 3.
An example using t- is shown below. As an example of a photochromic material, soda glass containing a small amount of Ce, Eu or Zr is known. This kind of photochromic glass is highly sensitive to ultraviolet light, and turns black after being exposed to ultraviolet light for a few seconds, blocking out light.

Therefore, according to this embodiment, when exposed to external light containing ultraviolet rays, the recording surface can be automatically blackened to block the light from reaching the recording surface, and the recording surface can be protected from external light without the need for a special control unit. can. In this case, for recording and reproducing information, it is necessary to use a light source (such as an LED or a laser) that does not emit light with a wavelength in the ultraviolet region.

FIG. 4 shows a case where the optical recording material 1 has multiple layers.

The optical recording materials 10 and 9 are selected to be sensitive to light having different wavelengths λ1 and λ2, respectively. These materials are preferably those that record using a change in one hue. The light amount control material 3 placed on these materials allows wavelengths λl,
By selectively transmitting one wavelength of λ3 and blocking the other wavelength, reflected light from other than the selected reproduction surface υ can be suppressed to a minimum, and the 8/N ratio of the signal can be improved.

Furthermore, since the wavelength of the light can be selected by the light amount control material 3 during reproduction, a plurality of specific wavelength light sources are not required on the reproduction device side, and a simple white light source is sufficient. Therefore, the device can be constructed simply and at low cost.

The embodiments shown in FIGS. 1 to 4 are all examples applied to card-shaped information recording media, but it goes without saying that the same configuration as the above embodiments can also be applied to disk-shaped information recording media as shown in FIG. I'll go. The same applies to other modified examples having shapes such as sheets and rolls. Sara K,
As shown in FIG. 6, optical recording material 1 is placed on both sides of the holding member 2.
The present invention can also be applied to double-sided media on which the light amount control material 3 is placed on each side.

In this way, in the information recording medium of each embodiment, the optical information recording surface is shielded from external light when recording and reproduction is not performed by disposing the light amount control material on the recording medium so as to cover the information recording surface. Therefore, the deterioration of the recording material due to natural light can be reduced, and the life of the recording surface can be extended by 50%. In addition, since the secrecy of optical information can be significantly enhanced by shielding the light amount with the -5° control material, it can also be used for purposes such as recording credit information. Furthermore, when a liquid crystal display element or a transmissive solid-state display element is used as the light amount control material, it can also be used as an information display panel if necessary, allowing for miniaturization and multifunctionalization. Furthermore, a recording medium in which optical recording materials are formed in multiple layers can also be covered with a light amount control material.

〔Effect of the invention〕

As described above, the information recording medium of the present invention has the effect of extending the life of the recording surface and improving confidentiality.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the information recording medium of the present invention having a guard-like shape, FIG. 4 is a sectional view of the optical recording material shown in FIG. 1 in a two-layered state, and FIG. 5 is a sectional view of the state in which the optical recording material shown in FIG. FIG. 6 is a cross-sectional view of the holding member shown in FIG. 1, with optical recording materials disposed on both sides and light amount control materials disposed on the outside of each. 1.9.10... Optical recording material, 2... Holding member, 3
... Light amount control material, 7... First light amount control material, 8...
Second light amount control material.

Claims (1)

[Claims] 1. In a device that uses optical means to perform recording and reproduction on an optical recording material on a holding member, chemical reactions may be caused by external electrical signals, heat, energy, etc., molecular alignment, By changing the bonding mode, the reflectance and transmittance of the light of the optical recording material can be changed for each wavelength, and the recording surface can be made visible by applying a predetermined electrical signal, heat, or optical energy from the outside. 1. An information recording medium, characterized in that a light amount control material is disposed on the optical recording material of the recording medium so as to cover the information recording surface. 2. The information recording medium according to claim 1, wherein a liquid crystal display element is used as the light amount control material. 3. The information recording medium according to claim 1, wherein a transmissive solid surface element is used as the light amount control material. 4. The information recording medium according to claim 1, wherein the light amount control material is a photochromic material capable of controlling the transmittance of light of a specific wavelength.