Display device and display unit using the same

• US 20040145303A1
• Filed: 09/26/2003
• Published: 07/29/2004
• Est. Priority Date: 10/04/2002
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Yamada, Jiro, Tamura, Shinichiro, Asai, Nobutoshi
• Granted Patent: US 7,224,114 B2
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 59/876 comprising a resonant cavity structure, e.g. Bragg reflector pair

Abstract

Provided are a display device and a display unit having higher light extraction efficiency. An optical distance L₁ between a maximum light-emitting position of a light-emitting layer and a first end portion satisfies L₁=tL₁+a₁ and (2tL₁)/λ=−Φ₁/(2π)+m₁. An optical distance L₂ between the maximum light-emitting position and a second end portion satisfies L₂=tL₂+a₂ and (2tL₂)/λ=−Φ₂/(2π)+m₂. In the formulas, tL₁ and tL₂ represent a theoretical optical distance between the first end portion and the maximum light-emitting position and a theoretical optical distance between the second end portion and the maximum light-emitting position, respectively, a₁ and a₂ represent correction amounts based upon a light-emitting distribution in the light-emitting layer, λ represents a peak wavelength of the spectrum of light desired to be extracted, Φ₁ and Φ₂ represent a phase shift of reflected light generated in the first end portion and a phase shift of reflected light generated in the second end portion, respectively, and each of m₁ and m₂ is 0 or an integer.

Claims

1. A display device, comprising:

a light-emitting layer between a first electrode and a second electrode; and

a resonator structure resonating light generated in the light-emitting layer between a first end portion and a second end portion,

wherein an optical distance L₁ between the first end portion and a maximum light-emitting position of the light-emitting layer satisfies Mathematical Formula 1, and

an optical distance L₂ between the second end portion and the maximum light-emitting position of the light-emitting layer satisfies Mathematical Formula 2.

L₁=tL₁+a₁ (2tL₁)/λ

=−

Φ

₁/(2π

)+m₁ 

 

[Mathematical Formula 1]

(where tL₁ represents a theoretical optical distance between the first end portion and the maximum light-emitting position, a₁ represents a correction amount based upon a light-emitting distribution in the light-emitting layer, λ

represents a peak wavelength of the spectrum of light desired to be extracted, Φ

₁ represents a phase shift of reflected light generated in the first end portion, and m₁ is 0 or an integer.)

L₂=tL₂+a₂ (2tL₂)/λ

=−

Φ

₂/(2π

)+m₂ 

 

[Mathematical Formula 2]

(where tL₂ represents a theoretical optical distance between the second end portion and the maximum light-emitting position, a₂ represents a correction amount based upon a light-emitting distribution in the light-emitting layer, λ

represents a peak wavelength of the spectrum of light desired to be extracted, Φ

₂ represents a phase shift of reflected light generated in the second end portion, and m₂ is 0 or an integer.)

2. A display device according to claim 1, wherein

the correction amount a₁ satisfies Mathematical Formula 3, and the correction amount a₂ satisfies Mathematical Formula 4.

a₁=b(log_e(s)) 

 

[Mathematical Formula 3]

(where b is a value within a range of 2 n≦

b≦

6 n in the case where the light-emitting distribution in the light-emitting layer extends from the maximum light-emitting position to the first electrode, or a value within a range of −

6 n≦

b≦

−

2 n in the case where the light emitting distribution extends from the maximum light-emitting position to the second electrode, s represents a physical value (1/e decay distance) relating to the light-emitting distribution in the light-emitting layer, n is an average refractive index between the first end portion and the second end portion in the peak wavelength λ

of the spectrum of light desired to be extracted.)

a₂=−

a₁ 

 

[Mathematical Formula 4]

3. A display device according to claim 1, further comprising:

an organic layer including the light emitting layer between the first electrode and the second electrode.

4. A display unit, comprising:

a display device comprising a light-emitting layer between a first electrode and a second electrode, and a resonator structure resonating light generated in the light-emitting layer between a first end portion and a second end portion,

wherein an optical distance L₁ between the first end portion and a maximum light-emitting position of the light-emitting layer satisfies Mathematical Formula 5, and

an optical distance L₂ between the second end portion and the maximum light-emitting position of the light-emitting layer satisfies Mathematical Formula 6.

L₁=tL₁+a₁ (2tL₁)/λ

=−

Φ

₁/(2π

)+m₁ 

 

[Mathematical Formula 5]

(where tL₁ represents a theoretical optical distance between the first end portion and the maximum light-emitting position, a₁ represents a correction amount based upon a light-emitting distribution in the light-emitting layer, λ

represents a peak wavelength of the spectrum of light desired to be extracted, Φ

₁ represents a phase shift of reflected light generated in the first end portion, and m₁ is 0 or an integer.)

L₂=tL₂+a₂ (2tL₂)/λ

=−

Φ

₂/(2π

)+m₂ 

 

[Mathematical Formula 6]

(where tL₂ represents a theoretical optical distance between the second end portion and the maximum light-emitting position, a₂ represents a correction amount based upon a light-emitting distribution in the light-emitting layer, λ

represents a peak wavelength of the spectrum of light desired to be extracted, Φ

₂ represents a phase shift of reflected light generated in the second end portion, and m₂ is 0 or an integer.)

5. A display unit according to claim 4, wherein

the correction amount al satisfies Mathematical Formula 7, and the correction amount a₂ satisfies Mathematical Formula 8.

a₁=b(log_e(s)) 

 

[Mathematical Formula 7]

(where b is a value within a range of 2 n≦

b≦

6 n in the case where the light-emitting distribution in the light-emitting layer extends from the maximum light-emitting position to the first electrode, or a value within a range of −

6 n≦

b≦

−

2 n in the case where the light emitting distribution extends from the maximum light-emitting position to the second electrode, s represents a physical value (1/e decay distance) relating to the light-emitting distribution in the light-emitting layer, n is an average refractive index between the first end portion and the second end portion in the peak wavelength λ

of the spectrum of light desired to be extracted.)

a₂=−

a₁ 

 

[Mathematical Formula 8]

6. A display unit according to claim 4, further comprising:

an organic layer including the light emitting layer between the first electrode and the second electrode.