1. A liquid crystal display comprising:
a liquid crystal panel;
two polarizing films provided on both surfaces of the liquid crystal panel; and
two compensation films provided between the liquid crystal panel and each of the polarizing films,
wherein an angle (\u03b8p) formed by two polarizing axes of the polarizing films and an angle (\u03b8r) formed by two optical axes of the compensation films satisfy the Formula as follows:
\u22122\xb0\u2266\u03b8r\u2212\u03b8p\u22662\xb0.
2. The liquid crystal display as set forth in claim 1, wherein
the two polarizing films comprise a first polarizing film provided on one surface of the liquid crystal panel and having a first polarizing axis and a second polarizing film provided on the other surface of the liquid crystal panel and having a second polarizing axis; and
the two compensation films comprise a first compensation film provided between the liquid crystal panel and the first polarizing film and having a first optical axis and a second compensation film provided between the liquid crystal panel and the second polarizing film and having a second optical axis.
3. The liquid crystal display as set forth in claim 2, wherein the angle (\u03b8r) formed by the first optical axis and the second optical axis is between 88\xb0 and 92\xb0.
4. The liquid crystal display as set forth in claim 2, wherein the first optical axis and the second optical axis are disposed on facing two of four quadrants divided by the first polarizing axis and the second polarizing axis when a crossing of the first polarizing axis and the second polarizing axis matches a crossing of the first optical axis and the second optical axis.
5. The liquid crystal display as set forth in claim 4, wherein the first polarizing axis and the second polarizing axis perpendicularly intersect each other.
6. The liquid crystal display as set forth in claim 2, wherein the angle (\u03b8p) formed by the first polarizing axis and the second polarizing axis are between 88\xb0 and 92\xb0.
7. The liquid crystal display as set forth in claim 6, wherein the first optical axis and the second optical axis are disposed on facing two of four quadrants divided by the first polarizing axis and the second polarizing axis when a crossing of the first polarizing axis and the second polarizing axis matches a crossing of the first optical axis and the second optical axis.
8. The liquid crystal display as set forth in claim 7, wherein the first optical axis and the second optical axis perpendicularly intersect each other.
9. The liquid crystal display as set forth in claim 2, wherein
in the respective first and second compensation films, if one surface of each of the first and second compensation films is defined as an x-y plane, the optical axis of the each compensation film is defined as a z\u2032-axis, a surface perpendicular to the optical axis and passing an x-axis is defined as an x-y\u2032 plane, a first retardation value (Ro\u2032) of each of the compensation films is defined as (nx\u2212ny\u2032)xd, and a second retardation value (Rth\u2032) of each of the compensation films is defined as (nx+ny\u2032)2\u2212nz\u2032xd, the first retardation value and the second retardation value satisfy the Formula as follows:
0.92\u2266Rth\u2032Ro\u2032\u22664.75
where n represents a refractive index of the respective axes and d represents a z-axis directional thickness of each of the compensation films.
10. The liquid crystal display as set forth in claim 9, wherein the first retardation value is a retardation value for the x-y\u2032 plane, and the second retardation value is a retardation for the z\u2032-axis of each of the compensation films.
11. The liquid crystal display as set forth in claim 10, wherein the first retardation value is between 40 nm and 100 nm, and the second retardation value is between 110 nm and 200 nm.
12. The liquid crystal display as set forth in claim 2, wherein in the respective first and second compensation films, an angle (\u03b2) between the optical axis and the z-axis of each of the compensation films is between 10\xb0 and 25\xb0.
13. The liquid crystal display as set forth in claim 12, wherein the x-y\u2032 plane of the first compensation film is titled to a line parallel to the first polarizing axis by the angle (\u03b2), and the x-y\u2032 plane of the second compensation film is titled to a line parallel to the second polarizing axis by the angle (\u03b2).
14. The liquid crystal display as set forth in claim 1, wherein the liquid crystal panel comprises:
a first substrate;
a second substrate opposite to the first substrate; and
a liquid crystal provided between the first substrate and the second substrate, the liquid crystal being a twisted nematic liquid crystal.
15. The liquid crystal display as set forth in claim 14, wherein:
dielectric anisotropy of the twisted nematic liquid crystal is between 7 and 13.
16. The liquid crystal display as set forth in claim 14, wherein a retardation value of the twisted nematic liquid crystal is between 400 nm and 480 nm.
17. The liquid crystal display as set forth in claim 14, further comprising
a first alignment layer provided between the first substrate and the liquid crystal and aligned in the same direction as the first polarizing axis; and
a second alignment layer provided between the second substrate and the liquid crystal and aligned in the same direction as the second polarizing axis.
18. The liquid crystal display as set forth in claim 1, wherein each of the compensation films is made of a thermoplastic resin.
19. The liquid crystal display as set forth in claim 9, wherein each of the compensation films satisfies the Formula as follows:
nx>ny\u2032\u2267nz\u2032.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for selecting a femoral implant based on models of a femoral neck andor a femoral head of a patient, comprising:
a) detecting reference points on the femoral neck andor femoral head of the patient;
b) registering the femoral neck andor femoral head based on three-dimensional reference point spatial positions of the detected reference points;
c) producing a femoral neck model andor femoral head model from the three- dimensional reference point spatial positions;
d) ascertaining a base size of a femoral implant model based on the femoral head model;
e) producing the femoral implant model based on the base size of the femoral implant model;
f) positioning the femoral implant model at a position in or on the femoral head model;
g) ascertaining, using a processor, an implant value that indicates how many or what proportion of the ascertained reference point spatial positions are outside the femoral implant model;
h) determining if the implant value exceeds a predetermined limit value; and
i) if the implant value exceeds the limit value, repositioning the femoral implant model and performing steps g) to i), or if the implant value does not exceed the limit value, determining an appropriate size and position of the femoral implant.
2. The method according to claim 1, wherein detecting reference points includes detecting anatomical landmarks as the reference points.
3. The method according to claim 1, further comprising repeating steps f) to i) using at least one other femoral implant model that is different from the femoral implant model based on the base size.
4. The method according to claim 3, where using at least one other femoral implant model includes using a model that is larger in size than the femoral implant model produced in step e).
5. The method according to claim 3, wherein using at least one other femoral implant model includes using a femoral implant model that exhibits a larger inner diameter than the femoral implant model produced in step e).
6. The method according to claim 1, wherein ascertaining the base size of the femoral implant model includes using a diameter of the produced femoral head model as a base value of an inner diameter of the femoral implant, and using the inner diameter of the femoral implant as the base size of the femoral implant model.
7. The method according to claim 6, wherein producing the femoral implant model includes using as a starting value the inner diameter of the femoral implant model, wherein the starting value deviates from the base value of the inner diameter of the femoral implant by a predetermined value.
8. The method according to claim 7, wherein the starting value of the inner diameter of the femoral implant model is smaller than the base value by a predetermined value.
9. The method according claim 1, further comprising selecting the femoral implant based on the number or proportion of the ascertained reference point spatial positions that are outside an inner diameter of the femoral implant model.
10. The method according to claim 1, wherein producing the femoral head model from the three-dimensional reference point spatial positions includes ascertaining a shape or surface from the reference point spatial positions to form the femoral head model.
11. The method according to claim 1, further comprising ascertaining a femoral neck axis model from the reference point spatial positions.
12. The method according to claim 11, wherein ascertaining the femoral neck axis model includes ascertaining the neck axis model as an intersecting straight line of at least two planes, wherein the planes run anteriorly, superiorly, posteriorly and inferiorly through the patient.
13. The method according to claim 12, further comprising ascertaining from the reference point spatial positions a plane through a line connecting the femoral neck and the femoral head in the models of the femoral neck and the femoral head.
14. The method according to claim 13, wherein ascertaining from the reference point spatial positions the plane through the line connecting the femoral neck and the femoral head in the models of the femoral neck and the femoral head includes using the reference point spatial positions of a connection between the femoral neck and the femoral head.
15. The method according to claim 11, wherein repositioning the femoral implant model includes shifting the femoral implant model in a direction that is perpendicular to the femoral neck axis model.
16. The method according to claim 15, wherein shifting the femoral implant model in a direction that is perpendicular to the femoral neck axis model includes anteriorly, superiorly, posteriorly or inferiorly shifting the femoral implant model in a direction that is perpendicular to the femoral neck axis model.
17. The method according to claim 11, wherein repositioning the femoral implant model includes changing the position of the femoral neck axis model relative to the femoral implant model in the femoral neck model.
18. The method according to claim 1, wherein repositioning the femoral implant model includes shifting the femoral implant model in all degrees of freedom relative to the femoral head model.
19. The method according to claim 1, further comprising ascertaining and outputting a number of appropriate shapes and sizes of the femoral implant.
20. The method according to claim 1, further comprising ascertaining and outputting a size and shape of the femoral implant.
21. A computer program embodied on a computer readable storage medium for selecting a femoral implant based on models of a femoral neck andor a femoral head of a patient, comprising:
a) code that detects reference points on the femoral neck andor femoral head of the patient;
b) code that registers the femoral neck andor femoral head based on three-dimensional reference point spatial positions of the detected reference points;
c) code that produces a femoral neck model andor femoral head model from the three-dimensional reference point spatial positions;
d) code that ascertains a base size of a femoral implant model based on the femoral head model;
e) code that produces a femoral implant model based on the base size of the femoral implant model;
f) code that positions the femoral implant model at a position in or on the femoral head model;
g) code that ascertains an implant value that indicates how many or what proportion of the ascertained reference point spatial positions are outside the femoral implant model;
h) code that determines if the implant value exceeds a predetermined limit value; and
i) code that repositions the femoral implant model and performing steps g) to i) if the implant value exceeds the limit value, or determines an appropriate size and position of the femoral implant if the implant value does not exceed the limit value.
22. A device for selecting a femoral implant based on models of a femoral neck andor a femoral head of a patient, comprising:
a detection unit for detecting reference points on the femoral neck andor femoral head of the patient;
a navigation system operatively connected to the detection unit and comprising at least one camera for detecting the position of a reference star arranged on the femoral neck; and
a computational unit operatively connected to the navigation system and operative to:
a) register the femoral neck andor femoral head based on three-dimensional reference point spatial positions of the detected reference points;
b) produce a femoral neck model andor femoral head model from the three- dimensional reference point spatial positions;
c) ascertain a base size of a femoral implant model based on the produced femoral head model;
d) produce a femoral implant model based on the base size of the femoral implant model;
e) ascertain an implant value that indicates how many or what proportion of the ascertained reference point spatial positions are outside the femoral implant model;
f) determine if the implant value exceeds a predetermined limit value; and
g) determine an appropriate size and position of the femoral implant if the implant value does not exceed the limit value.
23. The device according to claim 22, wherein the camera is an infrared camera,
24. The device according to claim 22, further comprising an output device operatively connected to the navigation system, said output device operative to graphically display the femoral neck model, the femoral head model and the femoral implant model.