Display device and an optical device provided with same

• US 6,738,577 B1
• Filed: 12/09/1999
• Issued: 05/18/2004
• Est. Priority Date: 12/10/1998
• Status: Expired due to Fees

• Current Assignee: Minolta Corporation Limited (Konica Minolta Inc.)
• Original Assignee: Minolta Corporation Limited (Konica Minolta Inc.)
• Inventors: Maeda, Yasuo, Ishii, Noriyuki, Fujino, Akihiko, Yokota, Satoshi, Akesaka, Makoto, Seki, Reiji
• Primary Examiner(s): Fuller, Rodney
• Assistant Examiner(s): Smith, Arthur A
• Application Number:
  US09/457,374
• Time in Patent Office: 1,622 Days
• Field of Search: 396/287, 396/296, 396/373, 396/374, 396/384, 396/290, 396/291, 396/292, 396/383, 345/76
• US Class Current: 396/287
• CPC Class Codes: G03B 13/02 Viewfinders

Abstract

A display device 70 having an organic luminescent element arranged at an object image-forming position of a finder optical system. Frames are formed by parts 31b, 32b, 33b of the negative electrode formed of non-transparent material, an organic electroluminescent material is laminated thereon on the eyepiece side, and a positive electrode formed of transparent material is superimposed thereon on the eyepiece side. Since the non-transparent negative electrodes 31b, 32b, 33b shield the light, the frames are recognized as black frames. When the periphery is dark, a voltage is applied between the electrodes causing the organic electroluminescent material to luminesce, such that the frame itself becomes brighter in display and is readily visible.

Claims

1. A display device for placement in an optical path of an object viewer for viewing an object, comprising:

a first electrode which is made of a transparent material;

a second electrode which is made of a non-transparent material and which forms a display mark of a shape of the second electrode;

a luminescent material provided between said first and second electrodes, said luminescent material emitting light forming the shape of said second electrode when electricity is provided to said electrodes, the second electrode covering only a portion of the luminescent material provided between the first and second electrodes; and

a connection line which is made of a transparent material and electrically connects said second electrode to an exterior portion of said display device,

wherein the non-transparent material blocks light in the shape of the second electrode in the optical path when light comes from the object.

2. A display device according to claim 1, wherein said display device is shaped in the form of a rectangle, and said connection line connects said second electrode to a longer side of the rectangle.

3. An optical device, comprising:

an object viewer for observing an object and having an optical path within the object viewer;

an eye piece lens disposed at one end of the optical path;

a luminescent element disposed in the optical path of said object viewer such that light coming from the object is passed through said luminescent element so at to reach the eye piece lens, said luminescent element having electrodes and a luminescent material provided between the electrodes and emitting light when electricity is supplied to the electrodes;

wherein one of the electrodes of the luminescent element is made of a non-transparent material and forms a display mark; and

wherein the luminescent material emits light forming the shape of said one of the electrodes when the luminescent element is supplied with electricity and the non-transparent material blocks light forming the shape of said one of the electrodes when light comes from the object.

4. An optical device according to claim 3, wherein said one of the electrode is disposed on the object side of the luminescent material.

5. An optical device according to claim 3, wherein the luminescent material is a thin film of an organic electroluminescent material.

6. An optical device according to claim 3, wherein the optical device is a camera for taking a photograph.

7. The optical device of claim 3, further comprising a luminance detector for detecting an object brightness and a controller for controlling supply of the electricity to said electrodes in response to the detection result.

8. A finder for a camera having an optical path within the finder for viewing a photographic object, said finder comprising an eye piece lens disposed at one end of the optical path and a luminescent element disposed in the optical path of the finder such that an image of the photographic object is viewed through the luminescent element and the eye piece lens, said luminescent element comprising electrodes and a luminescent material provided between the electrodes and emitting light when electricity is supplied to the electrodes;

wherein one of the electrodes of the luminescent element is made of a non-transparent material and forms a display mark; and

wherein the luminescent material emits light forming the shape of said one of the electrodes when the luminescent element is supplied with electricity and the non-transparent material blocks light forming the shape of said one of the electrodes when light comes from the object.

9. A finder of a camera according to claim 8, wherein said one of the electrodes is disposed on the photographic object side of the luminescent material.

10. A finder of a camera according to claim 8, wherein said luminescent material is a thin film of an organic electroluminescent material.

11. An optical device, comprising:

an object viewer for observing an object and having an optical path therein;

a luminescent element comprising a first portion disposed in the optical path of the object viewer being configured such that light coming from the object passes through the luminescent element and a second portion disposed outside the optical path, each of the first and second portions comprising electrodes and a luminescent material provided between the electrodes and emitting light when electricity is provided to the electrodes; and

first and second drive circuits for independently supplying electricity to the first and second portions, respectively.

12. An optical device according to claim 11, wherein the luminescent material is a thin film of an organic electroluminescent material.

13. An optical device according to claim 11, wherein the optical device is a camera for taking a photograph.

14. The optical device of claim 11, further comprising a selector for selecting one of the first portion and the second portion, and a power supply circuit for supplying electricity to the selected portion.