OPHTHALMOLOGIC APPARATUS, OPHTHALMOLOGIC PHOTOGRAPHING METHOD, AND PROGRAM

• US 20130027664A1
• Filed: 07/25/2012
• Published: 01/31/2013
• Est. Priority Date: 07/29/2011
• Status: Abandoned Application

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Kishida, Nobuyoshi
• Application Number:
  US13/558,247
• Publication Number:
  US 20130027664A1
• Time in Patent Office: Days
• US Class Current: 351/206
• CPC Class Codes: A61B 3/14 Arrangements specially adapted for eye photography apparatus or arrangements for taking photographs per se G03B

Abstract

An ophthalmologic apparatus controls a second light source according to a fundus image corrected using sensitivity as to a first wavelength band and a light quantity of a first light source when a fundus image is captured.

Claims

1. An ophthalmologic apparatus comprising:

an illumination optical system configured to have a first light source which emits light with a first wavelength band and a second light source which emits light with a wavelength band different from the first wavelength band, and to illuminate a target eye to be examined with the light from either one of light sources;

an imaging unit configured to capture as a fundus image via an imaging optical system, reflected light from a fundus of the target eye illuminated by the illumination optical system; and

a control unit configured to control the second light source according to a fundus image corrected using sensitivity as to the first wavelength band and a light quantity of the first light source when the fundus image is captured.

2. The ophthalmologic apparatus according to claim 1, further comprising:

an acquisition unit configured to acquire the sensitivity as to the light with the first wavelength band.

3. The ophthalmologic apparatus according to claim 1, further comprising:

a reflection unit configured to insert or remove a reflecting member which reflects an illumination light, on a common light path of the illumination optical system and the imaging optical system,

wherein the acquisition unit acquires the sensitivity according to a pixel value of the fundus image captured by the light radiated from the first light source while the reflecting member is inserted into the light path, and the light quantity of the first light source at that time.

4. The ophthalmologic apparatus according to claim 1, further comprising:

a storage unit configured to store a sensitivity as to the first wavelength band,

wherein the acquisition unit acquire the sensitivity stored in the storage unit.

5. The ophthalmologic apparatus according to claim 1, further comprising:

a calculation unit configured to obtain reflection characteristics of the fundus of the target eye from a value obtained by correcting a photometric value based on the pixel value of the fundus image using information indicating the sensitivity, and a light quantity of the first light source when the fundus image is captured,

wherein the control unit controls the second light source such that a predetermined light quantity is reflected from the fundus of the target eye, according to the reflection characteristics.

6. The ophthalmologic apparatus according to claim 5, wherein the calculation unit changes a size of a fundus image region from which the photometric value is obtained, according to a photographing site.

7. The ophthalmologic apparatus according to claim 5, wherein the acquisition unit acquires average pixel values of images obtained by the imaging unit, as a photometric value.

8. The ophthalmologic apparatus according to claim 1, wherein the control unit controls light quantities of the first light source based on a table in which reflection characteristics of the fundus of the target eye obtained based on the fundus images corrected using sensitivity as to the first wavelength band, and light quantities of the first light source are associated with each other, when the fundus images are captured.

9. The ophthalmologic apparatus according to claim 1, wherein the control unit controls light quantities of the second light source based on a table in which reflection characteristics of the fundus of the target eye obtained based on fundus images corrected using sensitivity as to the first wavelength band, and light quantities of the second light source are associated with each other, when the fundus images are captured.

10. The ophthalmologic apparatus according to claim 1, wherein the imaging unit captures a fundus as a moving image using the first light source as an observation light, and captures a fundus as a still image using the second light source as a photographic light.

11. The ophthalmologic apparatus according to claim 1, wherein the second wavelength band includes at least a visible wavelength band, and the first wavelength band is infrared.

12. The ophthalmologic apparatus according to claim 1, wherein the second wavelength band is 420 to 750 nm, and the first wavelength band is 850 nm band.

13. The ophthalmologic apparatus according to claim 1, wherein the imaging unit has a sensor for the first wavelength band, and a sensor for the second wavelength band which are similar to each other

14. The ophthalmologic apparatus according to claim 1, wherein the imaging unit is detachably attached to the ophthalmologic apparatus, and can be replaced with other imaging units showing different sensitivities.

15. The ophthalmologic apparatus according to claim 1, wherein the control unit performs control such that an integrated value of flash amounts of the second light source assumes a predetermined value.

16. A photographing method of a fundus comprising:

obtaining a fundus image as an image of an target eye captured by a sensor with an observation light;

acquiring a light quantity of the observation light when the fundus image is captured and sensitivity of the sensor as to the observation light;

obtaining photographing light quantity based on a pixel value of the fundus image, a light quantity of the observation light, and sensitivity of the sensor as to the observation light; and

.

imaging the fundus of the target eye with the photographic light having the photographing light quantity.

17. A storage medium storing a program for causing a computer to execute the photographing method according to claim 16.