Organic EL panel translucent substrate, control method for refractive index anisotropy of organic EL panel translucent substrate, manufacturing method for organic EL panel translucent substrate, organic EL panel, and organic EL device

1. An organic EL panel translucent substrate satisfying at least one of the following conditions (B) to (E):

(B)

with respect to light having a wavelength of 550 nm incident from a direction at an angle of 45° to the in-plane direction of the organic EL panel translucent substrate, a numerical value (Rth/Rip) obtained by dividing the Rth represented by equation (II) by the Rip represented by equation (I) is 5.0 or less, where

Rip =( nx−ny )· d   (I)

Rth ={( nx+ny )/2− nz}·d   (II)

where nx, ny, and nz respectively represent refractive indices in an X-axis direction, a Y-axis direction, and a Z-axis direction in the organic EL panel translucent substrate, the X-axis direction is an axial direction in which an in-plane refractive index is largest, the Y-axis direction is an axial direction that is perpendicular to the X-axis direction in the plane, and the Z-axis direction is a thickness direction that is perpendicular to the X axis and the Y axis,

d represents a thickness (nm) of the organic EL panel translucent substrate;

(C)

with respect to light incident from a direction perpendicular to the in-plane direction of the organic EL panel translucent substrate,

the in-plane retardation Rip represented by equation (I) in a wavelength range from 380 to 780 nm to the Rip at a wavelength of 550 nm is in a range from 95 to 110%, and

the thickness direction retardation Rth represented by equation (II) in a wavelength range from 380 to 780 nm to the Rth at a wavelength of 550 nm is in a range from 90 to 115%;

(D)

at a measurement wavelength, a luminance at an angle in a range from 2 to 90° to the in-plane direction of the organic EL panel translucent substrate to a luminance at an angle of 90° to the in-plane direction of the organic EL panel translucent substrate is in a range from 85 to 110%, and

a chromaticity change Δu′v′ at an angle in a range from 2 to 90° to the in-plane direction of the organic EL panel translucent substrate is in a range from 0 to 0.02, provided that the measurement wavelength is in a range from 380 to 780 nm;

(E)

at an angle in a range from 2 to 90° to the in-plane direction of the organic EL panel translucent substrate, in a case where the angle to the in-plane direction of the organic EL panel translucent substrate is the same, the Rip and the Rth in a wavelength range from 380 to 780 nm to the Rip and the Rth at a wavelength of 550 nm are respectively in a range from 90 to 120%.

2. The organic EL panel translucent substrate according to claim 1 , wherein the substrate is a flexible translucent substrate.

3. The organic EL panel translucent substrate according to claim 1 , wherein the substrate is for an organic EL lighting panel.

4. The organic EL panel translucent substrate according to claim 1 , wherein the substrate is for an organic EL display panel.

5. An organic EL panel comprising:

the organic EL panel translucent substrate according to claim 1 .

6. The organic EL panel according to claim 5 , wherein the panel is substantially optically isotropic in the in-plane direction and the thickness direction.

7. The organic EL panel according to claim 6 satisfying at least one of the following conditions (B′) to (E′):

(B′)

with respect to light having a wavelength of 550 nm incident from a direction at an angle of 45° to the in-plane direction of the organic EL panel, a numerical value (Rth′/Rip′) obtained by dividing the Rth′ represented by equation (II′) by the Rip′ represented by equation (I′) is 5.0 or less, where

Rip ′=( nx′−ny′ )· d′   (I′)

Rth ′={( nx′+ny′ )/2− nz′}·d′   (II′)

nx′, ny′, and nz′ respectively represent refractive indices in an X-axis direction, a Y-axis direction, and a Z-axis direction in the organic EL panel, the X-axis direction is an axial direction in which the in-plane refractive index of the organic EL panel is the greatest, the Y-axis direction is an axial direction that is perpendicular to the X-axis direction in the plane, and the Z-axis direction is a thickness direction that is perpendicular to the X axis and the Y axis,

d′ represents a thickness (nm) of the organic EL panel;

(C′)

with respect to light incident from a direction perpendicular to the in-plane direction of the organic EL panel, the in-plane retardation Rip′ represented by equation (I′) in a wavelength range from 380 to 780 nm to the Rip′ at a wavelength of 550 nm is in a range from 95 to 110%, and

the thickness direction retardation Rth′ represented by equation (II′) in a wavelength range from 380 to 780 nm to the Rth′ at a wavelength of 550 nm is in a range from 90 to 115%;

(D′)

at a measurement wavelength, a luminance at an angle in a range from 2 to 90° to the in-plane direction of the organic EL panel to a luminance at an angle of 90° to the in-plane direction of the organic EL panel is in a range from 85 to 110%, and

a chromaticity change at an angle in a range from 2 to 90° to the in-plane direction of the organic EL panel is in a range from 0 to 0.02, provided that the measurement wavelength is in a range from 380 to 780 nm;

(E′)

at an angle in a range from 2 to 90° to the in-plane direction of the organic EL panel,

in a case where the angle to the in-plane direction of the organic EL panel translucent substrate is the same, a luminance/luminosity factor (a numerical value obtained by dividing a luminance by a luminosity factor) in a wavelength range from 380 to 780 nm to the luminance/luminosity factor at a wavelength of 550 nm is in a range from 85 to 110%.

8. An organic EL device comprising:

the organic EL panel according to claim 5 .

9. An organic EL panel translucent substrate formed of a resin, wherein

the substrate is substantially optically isotropic in an in-plane direction and a thickness direction, and

wherein the resin contains a polymer showing negative birefringence and a polymer showing positive birefringence.

10. The organic EL panel translucent substrate according to claim 9 formed by at least one of the following methods (1) to (5):

(1) lamination of a polymer film showing negative birefringence and a polymer film showing positive birefringence;

(2) mixture of a polymer showing negative birefringence and a polymer showing positive birefringence;

(3) random copolymerization of a polymer showing negative birefringence and a polymer showing positive birefringence;

(4) block copolymerization of a polymer showing negative birefringence and a polymer showing positive birefringence; and

(5) graft copolymerization of a polymer showing negative birefringence and a polymer showing positive birefringence.

11. An organic EL device comprising:

the organic EL panel translucent substrate according to claim 9 .

12. The organic EL panel translucent substrate according to claim 9 , wherein the substrate is a flexible translucent substrate.

13. The organic EL panel translucent substrate according to claim 9 , wherein the substrate is for an organic EL lighting panel.

14. The organic EL panel translucent substrate according to claim 9 , wherein the substrate is for an organic EL display panel.

15. A control method for refractive index anisotropy of an organic EL panel translucent substrate, comprising:

controlling refractive index anisotropy of a resin in an organic EL panel translucent substrate formed of the resin to control refractive index anisotropy in an in-plane direction and a thickness direction of the organic EL panel translucent substrate,

wherein the control is performed such that the organic EL panel translucent substrate becomes substantially optically isotropic in its in-plane direction and thickness direction.

16. A manufacturing method for an organic EL panel translucent substrate, wherein refractive index anisotropy in an in-plane direction and a thickness direction of an organic EL panel translucent substrate is controlled by the method according to claim 15 .

17. An organic EL panel translucent substrate manufactured by the method according to claim 16 .

18. A control method for refractive index anisotropy of an organic EL panel translucent substrate, comprising:

controlling refractive index anisotropy of a resin in an organic EL panel translucent substrate formed of the resin to control refractive index anisotropy in an in-plane direction and a thickness direction of the organic EL panel translucent substrate,

wherein the control is performed such that the organic EL panel translucent substrate becomes substantially optically isotropic in its in-plane direction and thickness direction, and

wherein the control is performed such that the refractive index anisotropy in the in-plane direction and the refractive index anisotropy in the thickness direction of the organic EL panel translucent substrate satisfy at least one of the following conditions (A) to (E):

(A)

with respect to light having a wavelength of 550 nm incident from a direction perpendicular to an in-plane direction of the organic EL panel translucent substrate, in-plane retardation Rip represented by equation (I) is 30 nm or less and thickness direction retardation Rth represented by equation (II) is 80 nm or less

Rip =( nx−ny )· d   (I)

Rth ={( nx+ny )/2− nz}·d   (II)

where nx, ny, and nz respectively represent refractive indices in an X-axis direction, a Y-axis direction, and a Z-axis direction in the organic EL panel translucent substrate, the X-axis direction is an axial direction in which an in-plane refractive index is largest, the Y-axis direction is an axial direction that is perpendicular to the X-axis direction in the plane, and the Z-axis direction is a thickness direction that is perpendicular to the X axis and the Y axis,

d represents a thickness (nm) of the organic EL panel translucent substrate;

(B)

with respect to light having a wavelength of 550 nm incident from a direction at an angle of 45° to the in-plane direction of the organic EL panel translucent substrate, a numerical value (Rth/Rip) obtained by dividing the Rth represented by equation (II) by the Rip represented by equation (I) is 5.0 or less;

(C)

with respect to light incident from a direction perpendicular to the in-plane direction of the organic EL panel translucent substrate,

the in-plane retardation Rip represented by equation (I) in a wavelength range from 380 to 780 nm to the Rip at a wavelength of 550 nm is in a range from 95 to 110%, and

the thickness direction retardation Rth represented by equation (II) in a wavelength range from 380 to 780 nm to the Rth at a wavelength of 550 nm is in a range from 90 to 115%;

(D)

at a measurement wavelength, a luminance at an angle in a range from 2 to 90° to the in-plane direction of the organic EL panel translucent substrate to a luminance at an angle of 90° to the in-plane direction of the organic EL panel translucent substrate is in a range from 85 to 110%, and

a chromaticity change Δu′v′ at an angle in a range from 2 to 90° to the in-plane direction of the organic EL panel translucent substrate is in a range from 0 to 0.02, provided that the measurement wavelength is in a range from 380 to 780 nm;

(E)

at an angle in a range from 2 to 90° to the in-plane direction of the organic EL panel translucent substrate,

in a case where the angle to the in-plane direction of the organic EL panel translucent substrate is the same, the Rip and the Rth in a wavelength range from 380 to 780 nm to the Rip and the Rth at a wavelength of 550 nm are respectively in a range from 90 to 120%.

19. A control method for refractive index anisotropy of an organic EL panel translucent substrate, comprising:

controlling refractive index anisotropy of a resin in an organic EL panel translucent substrate formed of the resin to control refractive index anisotropy in an in-plane direction and a thickness direction of the organic EL panel translucent substrate, wherein

the refractive index anisotropy in the in-plane direction and thickness direction of the organic EL panel translucent substrate is controlled by use of a polymer showing negative birefringence and a polymer showing positive birefringence as the resin.

20. The method according to claim 19 , wherein the refractive index anisotropy in the in-plane direction and thickness direction of the organic EL panel translucent substrate is controlled by at least one of the following methods (1) to (5):

(1) lamination of a polymer film showing negative birefringence and a polymer film showing positive birefringence;

(2) mixture of a polymer showing negative birefringence and a polymer showing positive birefringence;

(3) random copolymerization of a polymer showing negative birefringence and a polymer showing positive birefringence;

(4) block copolymerization of a polymer showing negative birefringence and a polymer showing positive birefringence; and

(5) graft copolymerization of a polymer showing negative birefringence and a polymer showing positive birefringence.

21. A manufacturing method for an organic EL panel translucent substrate, wherein refractive index anisotropy in an in-plane direction and a thickness direction of an organic EL panel translucent substrate is controlled by the method according to claim 19 .