Method and display element with reduced thermal stress
OwnerZhanjun Gaoinventor
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Abstract
The invention relates to a flexible display device comprising properly selected layers so that the thermal stress in the display can be reduced to avoid failure. The flexible display comprises in order a substrate layer, a conductive layer, a flexible light-emitting layer, a conductive layer, and a superstrate layer wherein the display is balanced such that the layer most subject to damage by stress is substantially stress-free. In addition, the invention provides methods of constructing such a balanced flexible display.
Claims28
A flexible display comprising in order
- a substrate layer,
- a conductive layer,
- a flexible light-emitting layer,
- a conductive layer, and
- a superstrate layer
- wherein the display is balanced such that the layer most subject to damage by stress is substantially stress-free.
A flexible display comprising in order
- a substrate layer,
- a conductive layer,
- a flexible light-emitting layer,
- a conductive layer, and
- a superstrate layer
- wherein at least one of the substrate or superstrate has a predetermined curvature such that when the device reaches a stead state operating temperature, the layer most subject to damage by stress is substantially stress-free, and the display become essentially flat.
A method of providing flexible display comprising:
- determining the layer most subject to damage by stress in the flexible display comprising in order
- a substitute layer,
- a conductive layer,
- a flexible light-emitting layer,
- a conductive layer, and
- a superstrate layer,
- determining the stead state operating temperature of the display, and
- selecting the materials for each layer with their thickness, Young's moduli, Poisson's ratios, coefficients of thermal expansion so that the said layer most subject to damage by stress (the j-th layer) satisfies Equation (11) and therefore, is stress-free, wherein Equation (11) is given as
- {
- σ
- x
- T
- σ
- y
- T
- σ
- xy
- T
- }
- j
- =
- [
- Q
- ]
-
- [
- {
- ɛ
- x
- 0
- ɛ
- y
- 0
- ɛ
- xy
- 0
- }
- +
- h
- j
-
- {
- k
- x
- k
- y
- k
- xy
- }
- -
- Δ
-
-
- T
-
- {
- α
- x
- α
- y
- α
- xy
- }
- j
- ]
- =
- 0
- (
- 11
- )
A method of providing flexible display comprising in order
- a substitute layer,
- a conductive layer,
- a flexible light-emitting layer,
- a conductive layer, and
- a superstrate layer
- determining the stead state operating temperature of the display,
- selecting the materials for each layer with their thickness, Young's moduli, Poisson's ratios, coefficients of thermal expansion so that the said layer most subject to damage by stress (the j-th layer) satisfies Equation (11) and therefore, is stress-free, wherein Equation (11) is given as
- {
- σ
- x
- T
- σ
- y
- T
- σ
- xy
- T
- }
- j
- =
- [
- Q
- ]
-
- [
- {
- ɛ
- x
- 0
- ɛ
- y
- 0
- ɛ
- xy
- 0
- }
- +
- h
- j
-
- {
- k
- x
- k
- y
- k
- xy
- }
- -
- Δ
-
-
- T
-
- {
- α
- x
- α
- y
- α
- xy
- }
- j
- ]
- =
- 0
- (
- 11
- )
- selecting said substrate and said superstrate with pre-existing curvature given in Equation (7)
- {
- k
- x
- k
- y
- k
- xy
- }
- =
- {
- [
- A
- ]
- -
- 1
-
- [
- B
- ]
- -
- [
- B
- ]
- -
- 1
-
- [
- D
- ]
- }
-
- {
- [
- A
- ]
- -
- 1
-
- {
- N
- x
- T
- N
- y
- T
- N
- xy
- T
- }
- -
- [
- B
- ]
- -
- 1
-
- {
- M
- x
- T
- M
- y
- T
- M
- xy
- T
- }
- }
- (
- 7
- )
- but in opposite direction so that said display is balanced in such a way that the layer most subject to damage by stress has essentially no stress, and the said display become essentially flat when the device reaches a stead state operating temperature.
Dependencies are inferred from the claim text.