US4849623A — System and method for determining anisotropy of l…

Claim 1

Independent Claim 143 words

A method for determining the optical anisotropy of a light transmitting sheet comprising the steps of: irradiating the surface of a sample of a light-transmitting sheet with a polarized light perpendicular to the surface; directing the light transmitted through said sample to an analyzer element with the polarizing plane of the analyzer element being matched to, or maintained in a predetermined angle relative to, the polarizing plane of said irradiated polarized light, while adjusting the angle of relative rotation between said sample and said analyzer element polarizing plane; directing the analyzed light from said analyer element to a light sensor unit to generate electric signals corresponding to the light intensity detected while adjusting sais angle of relative rotation; and determining the optical anisotropy of said sample in accordance with the relation between the data of electric signals and said angle of relative rotation.

Claim 2

Independent Claim 143 words

A method for determining the optical anisotropy of a light transmitting sheet comprising the steps of: irradiating the surface of a sample of a light-transmitting sheet with a polarized light perpendicular to the surface; directing the light transmitted through said sample to an analyzer element with the polarizing plane of the analyzer element being matched to, or maintained in a predetermined angle relative to, the polarizing plane of said irradiated polarized light, while adjusting the angle of relative rotation between said sample and said analyzer element polarizing plane; directing the analyzed light from said analyer element to a light sensor unit to generate electric signals corresponding to the light intensity detected while adjusting sais angle of relative rotation; and determining the optical anisotropy of said sample in accordance with the relation between the data of electric signals and said angle of relative rotation.

Claim 3

Dependent Claim 37 words

The method of claim 1 wherein the step of determining the optical anisotropy of said sample includes calculating the difference between the refractive indices of the polarized light in first and second directions in the sample plane.

Claim 4

Dependent Claim 15 words

The method of claim 1 wherein the polarized light irradiating the sample is laser light.

Claim 5

Dependent Claim 99 words

The method of claim 1 wherein the step of determining the optical anistropy of said sample includes calculating α, β and cos δ by solving the equations: for θ=0, A.sup.2 p=β.sup.2 A.sup.2 for θ=π/2, A.sup.2 p=α.sup.2 A.sup.2 for θ=π/4, A.sup.2 p=[1/4(α.sup.2 +β.sup.2)1/2αβ cos δ]A.sup.2 where: α=the amplitude transmission factor of polarized light in an x direction. β=the amplitude transmission factor of polarized light in a y direction. A=amplitude of incident light θ=angle of incidence of linearly polarized light δ=phase difference between velocity of polarized light transmitted in x and y directions A 2 p=measured intensity of transmitted polarized light

Claim 6

Dependent Claim 11 words

The method of claim 4 wherein α 2 =β 2 .

Claim 7

Dependent Claim 9 words

The method of claim 4 wherein (β/α) 2 =0.7.

Claim 8

Dependent Claim 23 words

The method of claim 4 wherein said analyzer element has a polarizing plane perpendicular to the polarizing plane of said irradiated polarized light.

Claim 9

Dependent Claim 55 words

The method of claim 4 further comprising the step of determining the difference (n1-n2) between the indices of refraction in mutually perpendicular x and y directions in said sample plane according to the equation ##EQU3## where: λ=light wavelength d=sample sheet thickness n1=sample sheet refractive index in x direction n2=sample sheet refractive index in y direction.

Claim 10

Dependent Claim 18 words

The method of claim 8 further comprising the step of displaying the ratio α:β and the difference (n1-n2).

Claim 11

Dependent Claim 53 words

The method of claim 1 wherein said determining step further includes determining the orientation of said sample having a substantially constant thickness of taking the ratio TI (Vmin/Vmax) where V is the light intensity measured through said analyzer element, said analyzer element polarization plane matching the polarizing plane of said irradiated polarized light.

Claim 12

Independent Claim 265 words

A system for determining the optical anisotropy of a light transmitting sheet comprising: polarized light source means; a sample of a light transmitting sheet positioned to be perpendicularly irradiated with polarized light from said light source; means for analyzing the light transmitted through said sample and emitted from the surface of said sample opposite to the irradiated surface, said analyzing means having a polarizing plane matched to, or maintained in predetermined angular relation to, the polarizing plane of the polarized light from said light source means; means for supporting said sample and said analyzing means, and for adjusting the relative rotation between said sample and said analyzing means with the polarizing plane of said analyzing means being matched to, or maintained in predetermined angular relation to, the polarizing plane of the light from said light source means; angular sensing means for establishing a reference angular position for said relative rotation; means for controllably driving said suporting and rotation adjusting means to cause said relative rotation within a predetermined angular range from said reference angular position; light sensing means for detecting the light transmitted through said analyzing means to generate electric signals corresponding to the light intensity during said relative rotation; a central processing unit for referencing the state of said angular sensing means to control said driving means, and for receiving said electric signals to determine the optical anisotropy of the sample from the relation between the data of said electric signals and the angular positions in said relative rotation; and an output device for displaying or outputting the determined optical anistropy of the sample.

Claim 13

Independent Claim 265 words

A system for determining the optical anisotropy of a light transmitting sheet comprising: polarized light source means; a sample of a light transmitting sheet positioned to be perpendicularly irradiated with polarized light from said light source; means for analyzing the light transmitted through said sample and emitted from the surface of said sample opposite to the irradiated surface, said analyzing means having a polarizing plane matched to, or maintained in predetermined angular relation to, the polarizing plane of the polarized light from said light source means; means for supporting said sample and said analyzing means, and for adjusting the relative rotation between said sample and said analyzing means with the polarizing plane of said analyzing means being matched to, or maintained in predetermined angular relation to, the polarizing plane of the light from said light source means; angular sensing means for establishing a reference angular position for said relative rotation; means for controllably driving said suporting and rotation adjusting means to cause said relative rotation within a predetermined angular range from said reference angular position; light sensing means for detecting the light transmitted through said analyzing means to generate electric signals corresponding to the light intensity during said relative rotation; a central processing unit for referencing the state of said angular sensing means to control said driving means, and for receiving said electric signals to determine the optical anisotropy of the sample from the relation between the data of said electric signals and the angular positions in said relative rotation; and an output device for displaying or outputting the determined optical anistropy of the sample.

Claim 14

Dependent Claim 29 words

The system of claim 11 wherein said supporting and rotation adjusting means rotates said sample relative to said analyzing means, said analyzing means being held in a fixed position.

Claim 15

Dependent Claim 84 words

The system of claim 11 wherein said central processing unit determines the optical anistropy of the sample by calculating α, β and cos δ through solving the equations: ##EQU4## where: α=the amplitude transmission factor of polarized light in an x direction β=the amplitude transmission factor of polarized light in a y direction A=amplitude of incident light. θ=angle of incidence of linearly polarized light δ=phase difference between velocity of polarized light transmitted to x and y directions A 2 p=measured intensity of transmitted polarized light.

Claim 16

Dependent Claim 23 words

The system of claim 13 wherein said analyzer element has a polarizing plane perpendicular to the polarizing plane of said irradiated polarized light.

Claim 17

Dependent Claim 56 words

The system of claim 13 wherein said central processing unit further determines the difference (n1-n2) between the indices of refraction in mutually perpendicular x and y directions in said sample plane according to the equation: ##EQU5## where: λ=light wavelength d=sample sheet thickness n1=sample sheet refractive index in x direction n2=sample sheet refractive index in y direction.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1992-07-17	1993-01-16	1993-07-18	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1996-07-17	1997-01-16	1997-07-18	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2000-07-17	2001-01-16	2001-07-18	$7700.00	Window Closed / Lapsed

System and method for determining anisotropy of light-transmitting sheet specimen

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