TW501126B - Optical recording medium - Google Patents

Abstract

The purpose of the present invention is to perform multi-level recording of five or more levels on a recording layer by changing at least either of the irradiation time or the irradiation power of a laser beam. To accomplish the goal, virtual recording cells 40 are assumed in grooves 16 on the dye recording layer 12 of an optical recording medium 10. At least either of the irradiation time or the irradiation power of a laser beam is modulated at five or more levels every virtual recording cells 40 in accordance with the information to be recorded. Recording marks 48A to 48G having different sizes of five or more levels are formed, light reflection on the virtual recording cells 40 are modulated at multi levels, thereby changes the reflecting levels of a read laser beam during reproduction at five or more levels. The difference between the starting temperature and the finishing temperature of weight reduction of a dye used for the recording layer 12 by thermal decomposition (TG) in the inert gas is made to range over 100 DEG C or more. The weight reduction by the thermal decomposition of the dye begins at 300 DEG C or less, and continues to 350 DEG C or more.

Description

Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 501126 A7 B7 __ V. Description of the Invention (1) Technical Field The present invention is related to the information provided for recording, and at least one of the irradiation time and power of the laser beam The optical recording medium is irradiated with the multi-level conversion, and the above-mentioned data is optically recorded on the optical recording medium. The prior art optical recording media used a multi-step change in the length of the reproduced signal (the length of the reflection signal modulation section) to record data. Compared with this method, the depth of the reproduced signal (the modulation factor of the reflection signal) was used. Multi-level conversion, each signal of the same length is recorded by most data, and its related research has already existed. With this optical recording method, compared with the single bit data of 2 値, it can record most data in the depth direction, which can increase the signal amount per unit length. Therefore, the linear recording density can be improved, and a light recording method for a hologram and a multilayer recording layer has been proposed. Here, the multi-level recording of data by using the change in the depth of the reflectance is called multi-level recording. Problems to be Solved by the Invention In such a multi-level recording, it is necessary to shorten the recording marks in order to increase the recording density. However, when the recording mark is shrunk to be smaller than the beam diameter of the laser beam used for recording and reading, multi-level recording is difficult. For example, Japanese Patent Laid-Open No. 10- 1 3 4 3 5 3 states that the paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X29? Mm) Z4I ~ ~. # Ί _ ^ ^ -I ^ ^. (Please read the precautions on the back before filling in this page} 501126 A7 B7 V. Description of the Invention (2) It contains multi-level recording for adjusting the laser light amount. This is when the optical recording medium is a pigment film 'phase change film The reproduction signal is formed due to the difference between the reflection of the recorded portion and the unrecorded portion. Therefore, the method disclosed in JP-A No. 10—13 4 3 53 is related to the presence or absence of recording at the recording stage and not at the recording stage. For multi-level recording. More specifically, in the phase change film, there is an intermediate state between the unrecorded and unrecorded pigment films. This is done by using a pigment film and a phase change film as an optical recording medium to adjust the amount of laser light. The order recording is mainly due to the change of the laser power, which mainly records the change in the width of the mark. The light collecting beam is generally distributed in Gauss, and the film is a pigment film, and the phase change film is to exceed a certain threshold. Make a record. Of the laser power The change makes the spot size of the recordable light-collecting beam change, and the width of the recording mark changes accordingly. If the recording mark length is shortened to be shorter than the diameter of the light-collecting beam in order to increase the recording density, it is necessary to adjust the thunder. The method of changing the mark width of the radio power is difficult to record in multiple steps, especially in the order of 5 or more. That is, it is difficult to change the reflection power during reproduction to change more than 5 orders. The diameter of the collecting beam is represented by κ λ / NA (K: constant, λ: laser wavelength, NA: number of openings of the lens). The reader for CD is: 1 = 780 nm, NA = 〇 · 45, with a diameter of about 1.6 micrometers. At this time, when the recording mark length is less than 1.6 micrometers, it is difficult to make multi-level or higher-level recordings using the current method of changing laser power. For example, Japanese Unexamined Patent Publication No. 1 1 8 2 8 4 6 reveals, enter !! _% 1_ (Please read the precautions on the back before filling out this page), 11 The paper size of the paper is applicable to China National Standard (CNS) A4 (210X 297 mm) _ 5-501126 A7 B7 V. Description of the invention (3) When the amount of light incident on the recording layer is given in a digital amount, the optical absorbance of the reactant in the recording layer is changed in a digital amount. (Please first (Please read the notes on the reverse side and fill in this page) However, the optical recording medium speculates that the absolute change in the absorbance of the laser exposure (number of times) is very small and is not practical. Also, JP-A-Sho 6 1-2 1 Publication No. 1 8 3 5 discloses a light recording method in which the light intensity or the number of times of irradiation with a light-color-developing material is changed, and recording is performed at a color-developing density state at an arbitrary step. However, this optical recording method has a problem in that when the laser light is irradiated for reading, the color development density state cannot be read at a level of 5 or more. The present inventors have found that even under the condition that the recording mark is shorter than the diameter of the collected light beam, it is possible to perform multi-level recording of 5 steps or more with changes in laser irradiation time or irradiation power. Optical recording media using mainly pigment-based materials as recording materials have so far been preferred in which the pigment can be rapidly decomposed during recording. This is because the recorded part is clearly distinguished from the unrecorded part, so the signal quality is good. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. However, if the decomposition of the pigment material is rapid in the multi-level records, when the specific laser irradiation time or irradiation power is exceeded, the pigment will start to completely decompose. Order recording control. The present inventors have found that by limiting the thermal decomposition characteristics of pigment materials, multi-level recording can be performed well. The present invention has been made in consideration of the above-mentioned matters, and an object thereof is to provide an optical recording medium with good signal quality that can be obtained by performing multi-level recording using an optical recording medium such as CD-R which is generally widely used. This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -6-501126 A7 B7 V. Description of the invention (4) Means to solve the problem (Please read the precautions on the back before filling this page) The inventors have repeatedly carefully studied optical recording media, found a recording method for multi-level recording, and confirmed that with this method, high-density multi-level recording of 5 levels or more can be performed on the optical recording medium. In addition, when a pigment that is thermally decomposed over a wide range of 1000 ° C or more is used, the laser irradiation time can be recorded well regardless of the length. It is also known that when using a pigment whose thermal decomposition starts below 300 ° C, it can record the local sensitivity. That is, the above-mentioned object can be achieved by the present invention described below. Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs and the Consumer Cooperative (1) A transparent substrate has a recording layer containing pigment as the main component, and a laser beam is irradiated onto the recording layer to form a recording mark to record the data, and the laser beam is illuminated An optical recording medium capable of reading recorded data on a recording mark is characterized in that an arbitrary unit length of a relative movement direction of a laser beam and the recording layer and a unit width in a vertical direction thereof are determined on the recording layer, and become a continuous setting In the virtual recording element in the moving direction, the recording layer in the virtual recording element can form recording marks of different sizes according to modulation of at least one of 5 times of the irradiation time and irradiation power of the laser beam, thereby The area ratio and light transmittance of the recording mark to the virtual recording element can be used to make a multi-level or higher-level recording of data at least based on the area ratio to modulate the light reflectance, and the heat of the pigment used in the recording layer in an inert gas The temperature difference between the weight loss start temperature and the initial 20% weight caused by decomposition (TG) is more than 100 ° C. (2) It is characterized in that the weight loss caused by the thermal decomposition of the above-mentioned pigments starts at less than 300 ° C and lasts to 3500 t: the light recording medium of (1) above.

This paper size is applicable to the China National Standard (CNS) A4 specification (210 X 297 mm)-Z 501126 A7 B7 V. Description of the invention (5) (Please read the precautions on the back before filling this page). The size of the recording mark refers to the amount of change in the material constituting the recording layer when it is irradiated with a laser beam to decompose and change its refractive index, or when the change in the thickness direction causes a change in light transmittance. The optical recording medium of the invention may be configured as follows. (3) It is characterized in that the unit length of the above-mentioned virtual recording element is set to be approximately equal to the light gH of (1) or (2) of the length of the 5-record mark formed by irradiating the laser beam with the above maximum irradiation time Recording media. (4) It is characterized in that a groove for laser light guide is set along the recording layer, the virtual recording element is set in the groove, and the unit width is approximately equal to (1), (2) or (3) The optical recording medium 0 (5) is characterized in that the above-mentioned unit length of the above-mentioned virtual recording element is the light of any one of (1) to (4) below the waist diameter of the above-mentioned read laser beam Recording media. (6) It is characterized in that in one part of the above-mentioned recording layer, the data has been previously recorded in a multi-level light recording medium of any one of (1) to (5). The system (7) is characterized in that at least one of the above-mentioned virtual recording element and the multi-level recording part is recorded with any one of the optical recording media (1) to (6) presenting information that it is a multi-level recording medium. (8) It is characterized in that a groove for laser light guide is provided along the above-mentioned recording layer, and a part of the groove is interrupted from any of the optical recording media of (1) to (7). The paper size applies the Chinese National Standard (CNS) A4 Specifications < 210 x 297 mm) -8-501126 A7 B7 V. Description of the invention (6) (Please read the notes on the back before filling out this page} In the present invention, when the recording mark is smaller than the recording beam diameter, multi-level adjustment By recording the irradiation time or irradiation power of the laser and limiting the pigments constituting the recording layer, the reflectance can be controlled in multiple steps. That is, the recording mark can be adjusted by adjusting at least one of the laser irradiation time and the irradiation power. The size of the multi-level recording can be changed according to the area ratio of the recording mark in a certain area. The multi-level recording can be made. Moreover, the effect is particularly significant when the multi-level recording is more than 5 levels. This recording method is particularly useful. On an optical recording medium having a recording film with organic pigments. Embodiments of the invention A few examples of embodiments of the present invention will be described in detail with reference to the drawings. The optical recording medium 10 related to the morphological example is a CD-R using a pigment on the recording layer 12 and a transparent substrate 14 made of a transparent base material, and is coated on one side of the transparent substrate 14 (No. The above recording layer 12 formed by the pigment of the laser light guide groove 16 on the top of the figure 1) is formed on the recording layer 12 with gold, silver or the like formed by sputtering and vacuum evaporation. Light-reflective films 18 such as alloys, and a protective layer 20 covering the outside of the light-reflective films 18. The above-mentioned transparent substrates 14 can be optionally used for various materials of conventional optical recording media. Applicants include, for example, , Polycarbonate resin, polymethyl methacrylate resin, epoxy resin, polyolefin resin, polyester resin, etc. On the transparent substrate 14, information such as the above-mentioned groove 16 or the address signal of the table is formed. Concave and convexity (preset grooves or pits). This paper size applies to Chinese National Standard (CNS) A4 (210X297 mm) _ g _ 501126 A7 ______ Β7 V. Description of the invention (7) (Please read the precautions on the back before reading (Fill in this page) The recording layer 12 on the transparent substrate 14 is based on organic pigments. The organic pigment can be a cyanine pigment, a full-base alkali pigment, a complex pigment, an anthraquinone pigment, a metal azo pigment, a phthalocyanine pigment, a naphthol cyanine pigment, etc. Among these pigments, It is preferable that the temperature difference between the initial weight loss start temperature at the time of thermal decomposition (TG) in inert gas and the initial 20% of the weight be greater than 100 ° C. In addition, the weight loss caused by the decomposition of the pigment is 3 It starts below 0 ° C, and lasts to more than 3 50 t. The decomposition temperature of the pigment can be borrowed from alkyl, alkoxy, aryl, halogen atom, alkylcarbonyl, alkylsulfonyl, alkylsulfonyl The introduction of various polar groups such as amine, amine, and nitro groups, and ionic pigments can be controlled by changing the composition of counter ions. The solvents used in the printing of organic pigment coating solutions by employees of the Intellectual Property Bureau of the Ministry of Economic Affairs can be butyl acetate, cellosolve acetate and other esters; methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone and other ketones; dichloride Pinane, 1,2-dichloroethane, chloroform and other chlorinated hydrocarbons; dimethylformamide and other chloramines; cyclohexane and other hydrocarbons; tetrahydrofuran, ether, dioxane and other ethers ; Alcohols such as ethanol, n-propanol, isopropanol, n-butanol, diacetone alcohol; Fluorine solvents such as 2, 2, 3, 3-tetrafluoropropanol; ethylene glycol monomethyl ether, ethylene glycol Glycol ethers such as alcohol monoethyl ether and propylene glycol monomethyl ether, etc. These solvents may be used alone or in combination in consideration of the solubility of organic pigments. Various additives such as singlet oxygen inhibitors, antioxidants, UV absorbers, plasticizers, and lubricants can be added to the coating liquid according to the purpose. A protective layer 20 is provided on the light reflecting film 18 for physical and chemical protection of the organic pigment recording layer 12 and the light reflecting film 18. The protective layer 20 can also be used to improve the transparent substrate 14 without any organic pigment recording. The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) -10—501126 A7 —B7 V. Description of the invention (8 ) (Please read the precautions on the back before filling in this page) The layer side is resistant to damage and moisture. The material of the protective layer 20 is generally a UV curable resin. This ultraviolet curable resin is directly or dissolved in an appropriate solvent to prepare a coating solution, and then coated on a transparent substrate 14 and cured by ultraviolet irradiation to form a protective layer 20. Various additives such as an antistatic agent, an antioxidant, and an ultraviolet absorber can be added to these coating liquids according to the purpose. The protective layer 20 has a thickness of about 0.1 to 100 m. Multi-level recording is performed on the optical recording medium 10 thus prepared, using the optical recording device 30 as shown in FIG. 2. For example, the recording light of a semiconductor laser 36 in the wavelength range of 770 to 790 nanometers, 6 30 to 6 600 nanometers' is irradiated on the organic pigment recording layer 12 with a suitable laser beam to modify the organic pigment, The regeneration method reads the difference between the laser light reflections of the deteriorated and undegraded organic pigments. The above-mentioned optical recording device 30, which is a CD-R burner, is printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, which is a mandrel servo device 31 driven by a spindle motor 3 2 at a certain linear or angular speed ( The disc 10 is rotated, and the laser beam from the laser 36 is used to record information on the recording layer 12 of the optical recording medium 10 (disc) 10 formed as described above. The laser 36 is in accordance with the information to be recorded, and the laser driver 38 controls the laser beam irradiation time of 40 in each virtual recording element (details described later) in the first and third pictures, such as laser pulses. number. Reference numeral 42 in FIG. 2 is a recording optical system including an objective lens 4 2A and a half mirror 4 2 B. The objective lens 4 2 A is controlled by a focus tracking servo device 4 4 so that the laser beam is focused on the recording layer 12. And this paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm). ^ 501126 A7 B7 __ V. Description of the invention (9) (Please read the precautions on the back before filling this page) 'Objective 4 2A and The half mirror 4 2 B is controlled by the conveying servo device 46 and is synchronized with the rotation of the disc 10, and moves from the inner peripheral side to the outer peripheral side at a selected speed. The above-mentioned mandrel servo device 3 1, the laser driver 3 8 ′, the focus tracking servo device 4 4, and the conveyance servo device 46 are controlled by the control device 50. The information (information) to be recorded in the recording layer 12 is controlled by Device 50 0 inputs. Next, the above-mentioned virtual record element 40 and the record mark recorded in the record element 40 will be described. The virtual recording element is limited to the unit width in the radial direction and the unit length in the rotation direction of the optical recording medium. The unit width is below the beam waist diameter of the laser beam, and the width of the track pitch, groove width, etc. of the disc 10 can be selected. 0 The virtual record element of this embodiment is printed by the consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. As shown in Figure 1, in the groove 16 described above, the length (circumferential length) shorter than the beam diameter (beam waist diameter) D and the groove 1 are defined in the rotation direction of the disc 10, that is, the circumferential direction. 6 Equal width, continuously virtual in the circumferential direction, and irradiated by the laser beam of each virtual record element 40, according to the information to be recorded, the model record marks 4 8 A to 4 8 G illustrated in Figure 3 are formed . Here, the laser beam emitted from the above-mentioned laser 36 is located at a beam diameter D of the recording layer 12 which is larger than the above-mentioned virtual recording element 40. Depending on the material selection of the recording layer 12, it can be applied to the laser. In the center of the laser beam, recording marks of different diameters 4 8 A to 4 8 G are formed according to the laser irradiation time. (Because the laser beam is circular, the optical recording medium is rotated on the side of the laser recording paper to apply to China. National Standard (CNS) A4 specification (210X297 mm) -12-501126 A7 _ B7 V. Description of the invention (10) The beam is irradiated, and the recording mark becomes oval with the irradiation time). In any case, the focused laser beam is generally Gaussian distributed and recorded on the recording layer 12 only when the irradiation energy of the laser beam exceeds a certain valve. Therefore, changing the irradiation time of the laser beam can be recorded. The spot size of the laser beam to be recorded by the layer 12 varies, whereby, for example, 7th-order recording marks 4 8 A to 4 8 G in FIG. 3 can be formed. Here, the pigments constituting the recording layer 12 are limited as described above, and corresponding to the irradiation time of the laser beam, they cannot be rapidly decomposed or deteriorated, and therefore, good multi-level recording can be performed. The size of each of the recording marks 4 8 A to 4 8 G is set such that the light reflectance of the reflected light can be divided into 7 steps when the virtual recording element 40 is irradiated with the reading laser beam. The light reflectance is that the smaller the recording mark is, the larger it is. The virtual recording element formed with no recording mark has the highest reflectance, and the virtual recording element with the largest recording mark 4 8 G has the smallest reflectance. More specifically, the light reflectance is set in consideration of the area ratio of each of the recording marks 4 8 A to 4 8 G to the virtual recording element 40 and the light transmittance of the recording mark itself. The light transmittance of the recording marks 4 8 A to 4 8 G itself varies with the material constituting the recording layer 12 due to the irradiation of the laser beam, and its refractive index changes, or the amount of change in the thickness direction of the recording layer 12 It's different. When the transmittance of the formed recording mark portion is zero, it may be disregarded. In the above embodiment, the irradiation time of the laser beam is changed by more than 5 orders, and multi-level recording is performed on the recording layer 12. However, the present invention is not limited to this, and the irradiation power or irradiation time of the laser beam may also be changed. And irradiation power (please read the precautions on the back before filling this page)

1, 1T Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs, Consumer Cooperatives The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) _ 13-501126 A7 _ ΒΊ _ V. Description of the invention (11) 〇 (Please read the back first Please note this page before filling in this page) The above-mentioned embodiment of the optical recording medium 10 is a CD-R disc, but the present invention is not limited to this, other optical recording media are applicable at once. In addition, the above-mentioned embodiment is an optical recording medium 10 related to recording without information such as data. However, the present invention is not limited to this, and an optical recording medium in which information is recorded in multiple stages of 5 or more is also applicable. Furthermore, when the recording mark is formed by the optical recording device 30, the size of the virtual recording frame 40 set on the recording layer 12 is not limited to the embodiment, and may be any length below the waist diameter of the laser beam. . For optical recording media without grooves 16, the size of the virtual recording element 40 can be arbitrarily set, and can be set. The irradiation energy and the maximum irradiation time of the laser beam exceed the valve that can change from 12 to the recording layer. The record mark formed at this time is approximately equal to the virtual record element 40. The above laser beam is made circular at the position of the recording layer 12, or as shown in FIG. 4, for example, in addition to the objective lens 4 2 A, a beam shaping prism 4 2 C is added to change the beam shape into optical recording. The moving direction of the medium 10 is short or oval or linear in a direction perpendicular to the medium. At this time, because the record of the consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, the number of printed records is shorter, the virtual record element can be shorter. That is to say, the recording density can be improved. The light § 3 recording medium 1 0 is provided with a plurality of pits with different reflectances in accordance with the modulation order of the signal as shown in FIG. A part of the multi-level recording is made as described above, so that the recording marks of the plurality of pits 5 2 and / or the part of the multi-level recording have individual identification information of the optical recording medium, and the multi-level recording uses the optical recording medium. Identification information-14-This paper size applies Chinese National Standard (CNS) A4 specification (2i × 297mm) 501126 A7 B7 V. Description of invention (12) (Please read the precautions on the back before filling this page) 'Used Specific information for determining the power of the laser beam used to reproduce the recording of the optical recording medium, and by reading the specific information during reproduction and / or recording of the optical recording medium, it is surely identified as a multi-level recording light The recording medium can also be individually identified. Since the power order of the laser beam can be determined according to the order of the pits recorded in advance, multi-level recording and reproduction can be performed more reliably. Or, as indicated by the reference numerals 5 and 6, the laser light guide groove portion is interrupted, and the groove interruption portion is provided to achieve the same effect. These methods can be used individually or in combination. Examples Hereinafter, the present invention will be described by comparing Examples 1 to 3 and Comparative Examples 1 and 2 of the present invention. The examples and comparative examples were used. The recording layer 12 used a CD-R type optical recording medium of a pigment as the optical recording medium 10, and a multi-level recording experiment was performed. Example 1 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economy The cyanine pigment A of the following chemical formula was dissolved in a fluoroalcohol to prepare a coating solution for forming a recording layer at 2%. The number of revolutions of one side of the coating solution was changed from 2 0 r pm to 5 0 0 0 r pm. The surface was spin-coated on the surface to be injection-molded with a thread-shaped preset groove formed on the surface (track pitch: 1 · 6 μm). , Preset groove width: 0 · 3 5 micrometers, preset groove depth: 0.18 micrometers), polycarbonate (Teijin Kasei Co., Ltd .: Panlite AD 5 5 03) diameter of 120 mm, Preset of transparent substrate with thickness of 1.2 mm -15- This paper size applies to Chinese National Standard (CNS) A4 specification (210X297 mm) 501126 A7 B7 V. Description of invention (13) (Please read the precautions on the back first (Fill in this page) Recording with ditch-side laser beam exposure. The reproduction system rotates at the same fixed linear velocity, and irradiates the recording layer with a laser beam of 1 milliwatt, detects the reflected light, and reproduces. The recording and evaluation equipment used was D D U (recording wavelength: 7 8 4 nm) manufactured by PULSTECH, and the laser beam at the time of recording was 14 mW. At this time, the recording linear velocity is 4 -8 m / s, and the recording clock frequency is 4 megahertz (250 nanoseconds). The laser irradiation time during recording was (1) 50 nanoseconds, 2) 8 0 nanoseconds, (3) 1 1 0 nanoseconds, (4) 1 4 0 nanoseconds, (5) 1 7 0 nanoseconds, (6) Multi-level recording is performed at 200 nanoseconds. Each record a single signal on the disc. The signals recorded in this way were read and measured with a digital oscilloscope made by LeCroy LC — 5 3 4 E L. The jitter 値 was measured, and the change caused by the difference in the irradiation time of the laser beam during recording was small, which was good. Printed by the Consumers' Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. The jitter tester used in the past considers the recording surface of the previous dual-recording method to form an organic pigment recording layer about 200 nanometers thick from the bottom of the preset groove. The transparent substrate used here is a person who previously recorded the discrimination signal for multi-level recording of the optical recording medium and information about the power and irradiation time of the laser beam. [Chemical Formula 1]

R: The size of this paper is based on the Chinese National Standard (CNS) A4 (210 X 297 mm) _ 16-501126 A7 B7 V. Description of the invention (14) (Please read the notes on the back before filling this page} Second, On the organic pigment recording layer, a sputtered light reflection layer having a thickness of about 100 nm was formed on the organic pigment recording layer. Then the number of revolutions was changed on the light reflection layer from 300 rpm to 4000 rpm by spin coating. Coated UV-curable resin (Dai Nihon Ink Chemical Industry Co., Ltd .: SD 3 1 8). After coating, a high-pressure mercury lamp was irradiated with ultraviolet rays from above to form a protective layer with a thickness of 10 microns. The optical recording medium thus obtained was used as Multi-level recording. Multi-level recording is an optical recording medium rotating at a fixed linear speed. The irradiation time is changed to 6 levels. If the jitter 値 is less than 10%, the recording can be judged to be good. The thermal decomposition temperature of the cyanine pigment A The measurement was performed with a measuring device of Model 205 manufactured by TA Instrument. When the temperature was raised at 10 ° C / min in nitrogen, the decomposition start temperature was 230 ° C, and the initial weight was 20%. Temperature (decomposition termination temperature) 4 8 0 ° C. That is, the weight loss of cyanine pigments due to thermal decomposition starts below 300 ° C and continues to more than 3 50. Example 2 Example 1 printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs The pigment was changed to a mixture of cyanine A and phthalocyanine B with a ratio of 1: 1 (Molar ratio), and the coating solvent was changed to an ethyl cellosolvant with a fluorine-containing alcohol. An optical recording medium was produced in the same manner as in Example 1 and multilevel recording was performed. The power of the laser beam during gS recording is 13 milliwatts. At this time, the recording linear velocity is 4 · 8 m / s, the clock frequency of recording is 4 megahertz (250 nanoseconds), and the laser during recording. The irradiation time is (1) 50 nanoseconds, (2) 70 nanoseconds, (3) 90 nanoseconds, (4) 1 1 0 nanoseconds, (5 cns) < 210x297 ^^) ΤγΓ. 1 501126 A7 _ B7 __ V. Description of the invention (15)) 130 nanoseconds, (6) 1500 nanoseconds. (Please read the notes on the back before filling out this page.) Each single signal is recorded on one circle of the disc. The signal thus recorded was read and measured with a digital oscilloscope L C — 5 3 4 E L manufactured by LeCroy to measure the jitter 测定, and the change caused by the difference in laser beam irradiation time during recording was small, which was good. The thermal decomposition of the pigment mixture was measured, and it was found that the decomposition initiation temperature was 230 ° C, and the decomposition termination temperature was 480 ° C. That is, the weight loss of the pigment mixture caused by thermal decomposition starts below 300 ° C and continues above 350 ° C. Example 3 An optical recording medium was produced in the same manner as in Example 2 except that the pigment of Example 2 was changed to a 1: 1 (mole ratio) mixture of cyanine A and phthalocyanine C, and multi-level recording was performed. The laser beam power during recording was 13 mW. At this time, the recording linear velocity was 4 · 8 m / s, the clock frequency was 4 MHz (250 nanoseconds), and the laser irradiation time during recording was (1) 50 nanoseconds each. (Ministry of Economic Affairs Printed by the Intellectual Property Bureau's Consumer Cooperatives 2) 70 nanoseconds, (3) 90 nanoseconds, (4) 110 nanoseconds, (5) 130 nanoseconds, and (6) 150 nanoseconds. Each single signal is recorded one turn on the disc. To make such a record, read the recorded signal with LeCroy digital oscilloscope L C-5 3 4 E L to measure the jitter. It is known that the change caused by the difference in laser beam irradiation time during recording is small, which is good. The thermal decomposition of the pigment mixture was measured, and it was found that the decomposition initiation temperature was 230 ° C, and the decomposition termination temperature was 5 4 7 ° C. That is, due to the thermal decomposition of this paper, the Chinese national standard (CNS) A4 specification (210X297 mm) is applicable ~ " 501126 A7 B7 ^^ ------- ----- V. Description of the invention (16) The weight loss of the pigment mixture started below 300 ° C and continued to 30 °. 〇 or more. (Please read the precautions on the back before filling in this page.) Comparative Example 1 Except that the pigment was changed to cyanine B with the following chemical formula, and the coating solvent was changed to ethyl cellosolve, the optical recording medium was produced in the same manner as in Example 1. Order recording: The laser beam power during recording is 14 mW. At this time, the recording linear velocity is 4.8 m / s, the clock frequency is 4 MHz (250 nanoseconds), and the laser irradiation time during recording is (1) 70 nanoseconds, ( 2) 80 nanoseconds, (3) 90 nanoseconds, (4) 100 nanoseconds, (5) 110 nanoseconds, and (6) 120 nanoseconds. Each single signal is recorded one turn on the disc. [Chemical Formula 2]

Μ: Metal R: The consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs printed the signal for recording, and measured the jitter with a digital oscilloscope B C 5 3 4 EL manufactured by LeCroy, which has nothing to do with the difference in laser beam irradiation time during recording. The jitter is not good.

_ This paper size applies the CNS M specification (21GX297 male 1 ^ -19V 501126 A7 B7 V. Description of the invention (17) The thermal decomposition of the phthalocyanine B pigment is determined, and the decomposition start temperature is 3 1 9 ° C, decomposition termination temperature was 4 1 4 ° C. Comparative Example 2 An optical recording medium was produced in the same manner as in Example 1 except that the pigment was changed to phthalocyanine C of the following chemical formula and the coating solvent was changed to methylcyclohexane. [Chemical Formula 3] (Please read the precautions on the back before filling in this page)

Μ: Metal R: σ C (CH3) 3 When the record is printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, the laser beam power is 14 mW. At this time, the recording linear velocity was 4 · 8 m / s, the clock frequency was 4 MHz (250 nanoseconds), and the laser irradiation time during recording was (1) 70 nanoseconds, ( 2) 8 0 nanoseconds, (3) 9 0 nanoseconds, (4) 1 0 0 nanoseconds, (5) 1 1 0 nanoseconds, (6) 1 2 0 nanoseconds. Each single signal is recorded one turn on the disc. The signal recorded in this way is a digital oscilloscope LC made by LeCroy. A paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) 20-501126 A7 B7 V. Description of the invention (18) 5 3 4 EL reading to determine the jitter 値It has nothing to do with the difference of the laser beam irradiation time during recording, and the jitter is not good. (Please read the precautions on the back before filling in this page.) Measure the thermal decomposition of the phthalocyanine pigment. It is known that the decomposition start temperature is 5 1 0 t, and the decomposition end temperature is 5 4 6 ° C. Example 4 The pigment of Example 1 was changed to a phthalocyanine pigment made by Ciba Corporation ~ Super Green〃, and the solvent for the cloth was changed to dimethylcyclohexane. The depth was about 100 nm, and the width was about 600 nm. A transparent substrate with a predetermined groove is formed to form an organic pigment layer with a thickness of about 100 nanometers in the predetermined groove portion to prepare an optical recording medium. Using the optical recording medium thus prepared, multi-level recording was performed under the same conditions as in Example 1, and the jitter 测定 was measured. The change in the jitter 値 caused by the difference in the irradiation time of the laser beam during recording was small and good. The thermal decomposition of the pigment was measured, and it was found that the decomposition initiation temperature was about 2 6 3 ° c, and the decomposition termination temperature was about 8 2 0 ° C. That is, the weight loss of pigments caused by thermal decomposition starts below 300 ° C and continues above 350 ° C. Printed in Example 5 by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs The pigment in Example 1 was changed to a phthalocyanine pigment a YDN-0 2 〃 manufactured by Yamada Chemicals, and the coating solvent was changed to methylcyclohexane, 2-methoxyethanol. The mixed solvent of methyl ethyl ketone and tetrahydrofuran is adjusted to a concentration of 1.5% by weight on a transparent substrate having a predetermined groove having a depth of approximately 160 nm and a width of approximately 650 nm. 1 2 0 nm organic pigment recording layer 'An optical recording medium was produced. -21-This paper size applies to China National Standard (CNS) A4 (210X297 mm) 501126

AB V. Description of the invention (19) (Please read the precautions on the back before filling out this page) Using the optical recording medium thus prepared, make multi-level recording under the same conditions as in Example 1 and measure the jitter 値. The variation in the jitter 値 caused by the difference in the irradiation time of the beams is small and good. When the thermal decomposition of the pigment was measured, it was found that the decomposition initiation temperature was about 2 4 2 ° C, and the decomposition termination temperature was about 8 60 ° C. That is to say, the weight loss of pigments due to thermal decomposition starts below 300 ° C and continues above 350 tons. Table 1 shows the thermal decomposition characteristics of the pigments, the laser irradiation time during recording, and the radon of the recorded signals. Table 1 Example Comparative Example 1 2 3 4 5 5 6 Thermal decomposition start temperature fc) 230 230 230 263 242 319 510 Thermal decomposition end temperature (° c) 480 480 547 820 860 414 547 Shake laser irradiation time (1) 6.4 6.9 7.4 7.2 6.7 9.7 10.5 Dynamic laser irradiation time (2) 6.5 7.1 7.6 7.3 6.9 9.9 11.0 値 Laser irradiation time (3) 6.8 7.4 8.0 7.5 7.3 10.2 11.4 Laser irradiation time (4) 7.1 7.8 8.5 7.8 7.5 10.7 11.4 11.4 % Laser Irradiation Time (5) 7.2 8.3 8.7 8.1 7.9 10.9 11.6 Laser Irradiation Time (6) 7.5 8.4 9.0 8.5 8.0 11.4 12.3 Printed by Intellectual Property Bureau Employee Consumer Cooperative of the Ministry of Economic Affairs The effect of printing is mainly on pigments The optical recording medium of the recording layer of the component should be used for recording. The irradiation time of the laser beam is converted to irradiation for multi-level recording at a level of 5 or more. The characteristics of the recording medium are: the paper size applies the Chinese national standard ( CNS) A4 specification (210X297 mm) _ 22-501126 A7 _ ^ __ B7 _ V. Description of the invention (20) The use of pigments in the air due to thermal decomposition (TG) between the weight loss start temperature and the end temperature T 1 billion billion above the range, it can be achieved by good multilevel recording. Brief Description of Drawings Fig. 1 is a side view showing a part of a main part of an optical recording medium according to an embodiment of the present invention. Fig. 2 shows a block diagram of an optical recording device for recording information on the optical recording medium using a laser beam. Fig. 3 is a schematic diagram showing the relationship between the recording mark and the virtual recording element and its light reflectance when the recording mark is formed on the recording layer with the recording device. Fig. 4 is a drawing showing a case where the laser beam irradiated to the virtual recording element has other shapes. The sketchy side view. (Please read the notes on the back before filling out this page) Symbols printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 1 0 Optical recording media 1 2 Recording layer 1 4 Transparent substrate 1 6 Groove 1 8 Light reflecting film 2 0 Protective layer 3 0 Optical Recording Device 3 2 Mandrel The paper size of this mandrel applies to Chinese National Standard (CNS) A4 (210X297 mm) -23- 501126 A7 B7 V. Description of Invention (21) Printed by the Consumer Cooperative of Intellectual Property Bureau, Ministry of Economic Affairs 3 4 Disc 3 6 Laser 3 8 Laser driver 4 0 Virtual recording element 4 2 Recording optical element 4 2 A Object 4 Standing 4 2 B Semi-reflective Δ ± 1. 1 See 4 2 C Beam shaping edge 4 4 Focusing servo Electric 4 6 Conveying servo 4 8 A to 4 8 G 4 9 5 2 Pit 5 6 Groove interruption D Beam diameter 5 4 Record mark (Please read the precautions on the back before filling this page) This paper size is applicable to China Standard (CNS) A4 specification (210 > < 297 mm) 24-

Claims (1)

501126 A8 Β8 C8 D8 VI. Patent application scope 1. An optical recording medium is a transparent substrate with a recording layer containing pigment as its main component. Information can be recorded by irradiating the recording layer with a laser beam to form a recording mark. The reading laser beam illuminates the recording mark. The optical recording medium for reading the recorded information is characterized in that: in the recording layer, an arbitrary unit length and a vertical direction are defined in a relative moving direction of the laser beam and the recording layer In the unit width of the direction, a virtual recording element is continuously set in the moving direction, and in the recording layer of the virtual recording element, the modulation corresponding to at least one of the irradiation time and the irradiation power of the laser beam is changed to 5 or more steps to form Record marks of different sizes, whereby the area ratio and transmittance of the record mark to the virtual record element modulate the light reflectance based on at least the area ratio, and can be used as a multi-level record of information of level 5 or higher, and used for the record The temperature difference between the temperature at which the pigment of the layer starts to lose weight due to thermal decomposition (TG) in an inert gas is greater than 100 ° C, and the temperature difference between the weight and the initial weight is 20%. 2. The optical recording medium according to item 1 of the scope of patent application, wherein the weight loss of the above-mentioned pigment due to thermal decomposition starts below 300 t and continues above 35 CTC. (Please read the precautions on the back before filling out this page). Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. This paper size is applicable to China National Standards (CNS) A4 (210X297 mm) -25-