Light emitting apparatus, image forming apparatus, display apparatus, and image pickup apparatus
A light emitting apparatus having organic EL elements is provided. The first optical length L 1 between the emission point of the light emitting layer and the reflection surface of the first electrode, satisfies the following formula: L 1 >0, (λ/8)×(−1−2Φ 1 /π)<L 1 <(λ/8)×(1−2Φ 1 /π), where λ denotes the wavelength of the highest peak in the emission spectrum of the organic EL element, and Φ 1 denotes the phase shift at the reflection surface of the first electrode at the wavelength λ. The first electrode has a first layer and a second layer. The first layer contains Al and is connected to a transistor, and the second layer covers the first layer and contains Mo and/or W.
1. A light emitting apparatus comprising:
a substrate;
organic EL elements, the organic EL elements formed on the substrate and each having a first electrode, a light emitting layer, and a second electrode; and
transistors, the transistors formed on the substrate and each connected to the first electrode of each organic EL element, wherein
a first optical length L 1 between an emission point of the light emitting layer and a reflection surface of the first electrode, satisfies formula A, and
wherein the first electrode comprises a first layer and a second layer covering the first layer;
the first layer containing Al and connected to one of the transistors:
the second layer containing Mo and/or W:
L 1 >0,(λ/8)×(−1−2Φ 1 /π)< L 1 <(λ/8)×(1−2Φ 1 /π) Formula A
where λ denotes a wavelength of a highest peak in an emission spectrum of each organic EL element, and Φ 1 denotes a phase shift at the reflection surface of the first electrode at the wavelength λ.
2. The light emitting apparatus according to claim 1 , wherein the first electrode further comprises a third layer covering the second layer, the third layer containing a molybdenum oxide and/or a tungsten oxide, the metallic film and the oxide film formed in this order from the first layer side.
3. The light emitting apparatus according to claim 1 , wherein a second optical length L 2 between the emission point of the light emitting layer and a reflection surface of the second electrode, satisfies formula B:
L 2 >0,(λ/8)×(−1−2Φ 2 /π)< L 2 <(λ/8)×(1−2Φ 2 /π) Formula B
where Φ 2 denotes a phase shift at the reflection surface of the second electrode at the wavelength λ.
4. An image forming apparatus comprising:
the light emitting apparatus according to claim 1 ;
a photosensitive member on which the light emitting apparatus forms a latent image; and
a charging unit configured to charge the photosensitive member.
5. A display apparatus comprising:
a substrate;
organic EL elements, the organic EL elements formed on the substrate and each having a first electrode, a light emitting layer, and a second electrode; and
transistors, the transistors formed on the substrate and each connected to the first electrode of each organic EL element, wherein
a first optical length L 1 between an emission point of the light emitting layer and a reflection surface of the first electrode, satisfies formula C, and
wherein the first electrode comprises a first layer, a second layer covering the first layer and a third layer covering the second layer;
the first layer containing Al and connected to one of the transistors:
the second layer containing Mo and/or W:
L 1 >0,(λ/8)×(−1−2Φ 1 /π)< L 1 <(λ/8)×(1−2Φ 1 /π) Formula C
where λ denotes a wavelength of a highest peak in an emission spectrum of each organic EL element, and Φ 1 denotes a phase shift at the reflection surface of the first electrode at the wavelength λ.
6. The display apparatus according to claim 5 , wherein the organic EL elements include organic EL elements of different colors.
7. An image pickup apparatus comprising the display apparatus according to claim 5 and an image sensor.
8. The display apparatus according to claim 5 , wherein the second layer contains Mo.
9. The display apparatus according to claim 8 , wherein the first electrode further comprises a third layer covering the second layer, the third layer containing a molybdenum oxide, the metallic film and the oxide film formed in this order from the first layer side.
10. The display apparatus according to claim 5 , wherein the second layer contains W.
11. The display apparatus according to claim 10 , wherein the first electrode further comprises a third layer covering the second layer, the third layer containing a tungsten oxide, the metallic film and the oxide film formed in this order from the first layer side.
12. The display apparatus according to claim 5 , wherein the second layer contains Mo and W.
13. The display apparatus according to claim 12 , wherein the first electrode further comprises a third layer covering the second layer, the third layer containing a molybdenum oxide and tungsten oxide, the metallic film and the oxide film formed in this order from the first layer side.
14. The light emitting apparatus according to claim 1 ,
wherein the thickness of the second layer is 2 nm or more and 9 nm or less.
15. The light emitting apparatus according to claim 2 ,
wherein the thickness of the third layer is 1 nm or more and 5 nm or less.
16. The display apparatus according to claim 5 ,
wherein the thickness of the second layer is 2 nm or more and 9 nm or less.
17. The display emitting apparatus according to claim 9 ,
wherein the thickness of the third layer is 1 nm or more and 5 nm or less.
18. The display emitting apparatus according to claim 11 ,
wherein the thickness of the third layer is 1 nm or more and 5 nm or less.
19. The display emitting apparatus according to claim 13 ,
wherein the thickness of the third layer is 1 nm or more and 5 nm or less.