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New features in the optical lens material
New features in the optical lens material
New features in the optical lens material
Purpose of optical glasses by wearing corrective lenses to refractive errors of the eye to restore clear vision, so the choice of lens materials and the need to consider the following refractive lens is closely related factors: 1, the geometric properties of materials: the radius of curvature surface shape;
2, physical and chemical properties of materials: refractive index oakley Polarized MINUTE 2.0 Sunglasses, Abbe number and so on.
Lens materials research and development is mainly related to access and control these factors to understand and master its features to make continuous improvement, the development of the optical lens correction.
The basic characteristics of the lens material are:
1, optical properties, calculation and control of optical properties of refractive effect;
2, mechanical and thermal properties;
3, the electrical properties of materials;
4, the chemical nature of the possible through contact with the outside world to understand the material corresponding chemical changes.
First, the optical properties:
Optical properties of the basic properties of the material, and lens seen in daily life consistent with a variety of optical phenomena, mainly in the lens surface of the light refraction and reflection, absorption of the material itself, as well as scattering and diffraction phenomena.
(1) refraction of light
Light through the lens in the lens surface before and after refraction or deviation, deviation of light by the refractive index, and incident light angle of incidence on the lens surface of the decision.
1) Refractive index:
Transparent medium of refractive index is the speed of light in vacuum c and the velocity v in the medium in the ratio, n = c / v. The ratio has no units and is always greater than 1.
Reflect the refractive power of the medium refractive index, the higher refractive index from air into the media Oakley Bottlecap Sunglasses, the more deviation from the beam. From the air to a transparent medium of refractive index n of the deviation or refraction can occur according to Snell - Descartes's law (Snell-Descartes
Law) calculated as follows: refraction of light and incident light in the same plane and the normal angle of incidence i and refraction r, respectively, by the normal and the incident light, reflected light form. The formula: sin i = n sin
r
As the speed of light with the wavelength transparent medium changes, so always refer to the value of the refractive index of a specific wavelength, said: In Europe and Japan, the reference wavelength e-line 546.07nm (mercury - green line), but in the United States and other other countries is the d-587.56nm (helium - yellow line). However, this difference did not cause the actual impact, because it merely reflects the difference between the value of the refractive index on the third decimal.
Lens used in the current market the refractive index range from 1.5 - 1.9.
2) dispersion coefficient: Abbe number
By the light-induced refractive index changes depending on the refraction will produce white light dispersion. In fact, the shorter the wavelength, the higher refractive index, the refraction from the visible light spectrum red zone extends to the blue area. Ability of the material dispersion can be described by the Abbe number, in Europe, Japan provided the e-line, in the United States and other countries require the use of d-line.
Abbe number and the material dispersion force is inversely proportional to the scope of the provisions of the lens material is usually from 30-60 Oakley Polarized Straight Jacket Sunglasses Brown, the greater the value that means less dispersion. In general, the higher refractive index, the greater the dispersion forces, while the lower Abbe number. Although all lenses are present dispersion, but in the center of the lens, this factor can be ignored only in materials with a high dispersion of the lens periphery, dispersion phenomena was readily detectable. In this case, the dispersion is shown by the edge of off-axis object with color stripes.
(2) light reflection
Light refraction at the lens surface, it would also have a reflection phenomenon. Reflected light will affect the clarity of the lens, the lens surface and in reflected light will produce interference. Generally, the higher refractive index of the lens material, the loss due to reflection of light more. Of course, for the interference of reflected light through the lens can be coated with multilayer antireflection coating and the corresponding offset.
(3) light absorption
The material itself will reduce the absorption characteristics of light transmittance of the lens of the light, this part of the amount of light loss for the non-stained glasses can be ignored, but if the stain or color lens, a large amount of light absorption, which is the type lenses are designed. Glasses of light absorption usually refers to the absorption of light inside the material, through the lens before and after the surface expressed as a percentage of light absorbed. For example, 30% of the light absorption equivalent to 30% of the flux in the reduction inside the lens. Light absorption of the material to follow Lambert (Lambert's
Law) Law, which according to the different thickness of the lens changes exponentially.
Light transmittance of the lens
Light transmittance of the lens means no light is reflected through the lenses and the amount of light absorbed. Arrived at through the lens of the eye lens front surface flux ΦΥ equivalent to the amount of incident Φ, minus lenses before and after the amount of surface reflection Φρ replica oakley sunglasses, less likely to be absorbed by the material flow Φα, that ΦΥ + Φρ + Φα = Φ. So, who's vision by wearing glasses combined effects of three aspects: the intensity of incident light and incident light spectral range, the lens on the spectral absorption and the selection and eye sensitivity to different wavelengths of visible.
(4) light scattering and diffraction
1) scattering: scattering of light is spread in all directions, a phenomenon, it is generally in the solid surface and the transparent material within. In theory there is no surface scattering occurs glasses, because the process of lens grinding (polishing) to eliminate this phenomenon. However, when the lens is dirty or polluted as the outside surface obscured because oil will produce scattering. The food inside the lens while shooting is also very limited, only in occasional cases, the lens may cause yellow or milky white. Currently only a very qualified glasses have a small amount of scattered light is usually negligible.
2) diffraction: Diffraction is when waves encounter a small obstacles and change direction acts as a phenomenon. In optical glasses, the diffraction phenomenon is need to pay attention, because the diffraction lens surface will produce abnormal interference, especially in the use of improper or careless of the lens surface wear caused by the case.
Second, the mechanical properties
Mechanical properties of bulk solid materials usually reflect the characteristics of a material which provides the quality, volume and size, and material on the deformation and impact resistance.
The most common mechanical properties reflect the characteristics of the lens are:
1, the proportion;
2, hardness;
3, the coefficient of elasticity E (or Young's modulus): pressure and initial recovery after the exclusion of the pressure generated when the shape of the ratio between the corresponding deformation.
4 oakley sunglasses, the impact resistance: often used by the U.S. Food and Drug Administration (FDA) required that a drop-ball test. Drop ball test that uses a 16-gram steel ball from a height 1.27M aligned lens centers falling test.
5, anti-off point: the use by the European Committee for Standardization's "100 N" CEN static deformation test. The test is in a constant pressure to increase speeds up to 100 Newton.
Third, the thermal properties
Describes the thermal properties of the material changes on the temperature under the influence of state and characteristics.
Thermal properties include:
1, the heat transfer coefficient.
2, the specific heat: the object temperature is increased by one degree Celsius and the heat required for the same quality of water for every one degree Celsius increase in the ratio of the heat required.
3, the linear expansion coefficient: a pre-set temperature range.
4, melting point: physical constants.
5, the boiling point.
6, the lens of the stress temperature.
Fourth, the electrical properties
Electrical properties of the material that the characteristics of electromagnetic waves and electric effects, determined by the laws of physics, and sometimes need the optical properties of the lens and the electrical properties of contact. Typically materials into the following parameters to be considered:
1, dielectric strength;
2, scheduled frequency dielectric loss factor.
Five, the chemical nature of the
Reflects the chemical properties of the lens manufacturing and everyday life, the lens material properties for the chemical reaction, or in some extreme conditions cheap oakleys, the response properties of materials. For example, accelerated aging test is to test the credibility of the material. Test commonly used cold water, hot water, acids and organic solvents, but also in the international standard to determine the fire resistance of lens materials testing.
2, physical and chemical properties of materials: refractive index oakley Polarized MINUTE 2.0 Sunglasses, Abbe number and so on.
Lens materials research and development is mainly related to access and control these factors to understand and master its features to make continuous improvement, the development of the optical lens correction.
The basic characteristics of the lens material are:
1, optical properties, calculation and control of optical properties of refractive effect;
2, mechanical and thermal properties;
3, the electrical properties of materials;
4, the chemical nature of the possible through contact with the outside world to understand the material corresponding chemical changes.
First, the optical properties:
Optical properties of the basic properties of the material, and lens seen in daily life consistent with a variety of optical phenomena, mainly in the lens surface of the light refraction and reflection, absorption of the material itself, as well as scattering and diffraction phenomena.
(1) refraction of light
Light through the lens in the lens surface before and after refraction or deviation, deviation of light by the refractive index, and incident light angle of incidence on the lens surface of the decision.
1) Refractive index:
Transparent medium of refractive index is the speed of light in vacuum c and the velocity v in the medium in the ratio, n = c / v. The ratio has no units and is always greater than 1.
Reflect the refractive power of the medium refractive index, the higher refractive index from air into the media Oakley Bottlecap Sunglasses, the more deviation from the beam. From the air to a transparent medium of refractive index n of the deviation or refraction can occur according to Snell - Descartes's law (Snell-Descartes
Law) calculated as follows: refraction of light and incident light in the same plane and the normal angle of incidence i and refraction r, respectively, by the normal and the incident light, reflected light form. The formula: sin i = n sin
r
As the speed of light with the wavelength transparent medium changes, so always refer to the value of the refractive index of a specific wavelength, said: In Europe and Japan, the reference wavelength e-line 546.07nm (mercury - green line), but in the United States and other other countries is the d-587.56nm (helium - yellow line). However, this difference did not cause the actual impact, because it merely reflects the difference between the value of the refractive index on the third decimal.
Lens used in the current market the refractive index range from 1.5 - 1.9.
2) dispersion coefficient: Abbe number
By the light-induced refractive index changes depending on the refraction will produce white light dispersion. In fact, the shorter the wavelength, the higher refractive index, the refraction from the visible light spectrum red zone extends to the blue area. Ability of the material dispersion can be described by the Abbe number, in Europe, Japan provided the e-line, in the United States and other countries require the use of d-line.
Abbe number and the material dispersion force is inversely proportional to the scope of the provisions of the lens material is usually from 30-60 Oakley Polarized Straight Jacket Sunglasses Brown, the greater the value that means less dispersion. In general, the higher refractive index, the greater the dispersion forces, while the lower Abbe number. Although all lenses are present dispersion, but in the center of the lens, this factor can be ignored only in materials with a high dispersion of the lens periphery, dispersion phenomena was readily detectable. In this case, the dispersion is shown by the edge of off-axis object with color stripes.
(2) light reflection
Light refraction at the lens surface, it would also have a reflection phenomenon. Reflected light will affect the clarity of the lens, the lens surface and in reflected light will produce interference. Generally, the higher refractive index of the lens material, the loss due to reflection of light more. Of course, for the interference of reflected light through the lens can be coated with multilayer antireflection coating and the corresponding offset.
(3) light absorption
The material itself will reduce the absorption characteristics of light transmittance of the lens of the light, this part of the amount of light loss for the non-stained glasses can be ignored, but if the stain or color lens, a large amount of light absorption, which is the type lenses are designed. Glasses of light absorption usually refers to the absorption of light inside the material, through the lens before and after the surface expressed as a percentage of light absorbed. For example, 30% of the light absorption equivalent to 30% of the flux in the reduction inside the lens. Light absorption of the material to follow Lambert (Lambert's
Law) Law, which according to the different thickness of the lens changes exponentially.
Light transmittance of the lens
Light transmittance of the lens means no light is reflected through the lenses and the amount of light absorbed. Arrived at through the lens of the eye lens front surface flux ΦΥ equivalent to the amount of incident Φ, minus lenses before and after the amount of surface reflection Φρ replica oakley sunglasses, less likely to be absorbed by the material flow Φα, that ΦΥ + Φρ + Φα = Φ. So, who's vision by wearing glasses combined effects of three aspects: the intensity of incident light and incident light spectral range, the lens on the spectral absorption and the selection and eye sensitivity to different wavelengths of visible.
(4) light scattering and diffraction
1) scattering: scattering of light is spread in all directions, a phenomenon, it is generally in the solid surface and the transparent material within. In theory there is no surface scattering occurs glasses, because the process of lens grinding (polishing) to eliminate this phenomenon. However, when the lens is dirty or polluted as the outside surface obscured because oil will produce scattering. The food inside the lens while shooting is also very limited, only in occasional cases, the lens may cause yellow or milky white. Currently only a very qualified glasses have a small amount of scattered light is usually negligible.
2) diffraction: Diffraction is when waves encounter a small obstacles and change direction acts as a phenomenon. In optical glasses, the diffraction phenomenon is need to pay attention, because the diffraction lens surface will produce abnormal interference, especially in the use of improper or careless of the lens surface wear caused by the case.
Second, the mechanical properties
Mechanical properties of bulk solid materials usually reflect the characteristics of a material which provides the quality, volume and size, and material on the deformation and impact resistance.
The most common mechanical properties reflect the characteristics of the lens are:
1, the proportion;
2, hardness;
3, the coefficient of elasticity E (or Young's modulus): pressure and initial recovery after the exclusion of the pressure generated when the shape of the ratio between the corresponding deformation.
4 oakley sunglasses, the impact resistance: often used by the U.S. Food and Drug Administration (FDA) required that a drop-ball test. Drop ball test that uses a 16-gram steel ball from a height 1.27M aligned lens centers falling test.
5, anti-off point: the use by the European Committee for Standardization's "100 N" CEN static deformation test. The test is in a constant pressure to increase speeds up to 100 Newton.
Third, the thermal properties
Describes the thermal properties of the material changes on the temperature under the influence of state and characteristics.
Thermal properties include:
1, the heat transfer coefficient.
2, the specific heat: the object temperature is increased by one degree Celsius and the heat required for the same quality of water for every one degree Celsius increase in the ratio of the heat required.
3, the linear expansion coefficient: a pre-set temperature range.
4, melting point: physical constants.
5, the boiling point.
6, the lens of the stress temperature.
Fourth, the electrical properties
Electrical properties of the material that the characteristics of electromagnetic waves and electric effects, determined by the laws of physics, and sometimes need the optical properties of the lens and the electrical properties of contact. Typically materials into the following parameters to be considered:
1, dielectric strength;
2, scheduled frequency dielectric loss factor.
Five, the chemical nature of the
Reflects the chemical properties of the lens manufacturing and everyday life, the lens material properties for the chemical reaction, or in some extreme conditions cheap oakleys, the response properties of materials. For example, accelerated aging test is to test the credibility of the material. Test commonly used cold water, hot water, acids and organic solvents, but also in the international standard to determine the fire resistance of lens materials testing.
Event Info
| Location: | Albania, SDFSDF |
| Address: | New features in the optical lens material |
| Date, time | Apr 3 2012 at 02:01am |
| End date | Apr 3 2012 at 08:05am |
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