Visual axis detection apparatus and optical apparatus provided therewith

• US 6,035,054 A
• Filed: 01/07/1997
• Issued: 03/07/2000
• Est. Priority Date: 10/29/1992
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Odaka, Yukio, Matsushima, Hiroshi
• Primary Examiner(s): Couso, Jose L.
• Assistant Examiner(s): Bella, Matthew C.
• Application Number:
  US08/779,908
• Time in Patent Office: 1,155 Days
• Field of Search: 382/117, 382/118, 351/205, 351/200, 351/210, 351/211, 351/206, 396/51
• US Class Current: 382/117
• CPC Class Codes: G03B 13/02 Viewfinders
• CPC Class Codes: G03B 2213/025 Sightline detection

Abstract

The invention relates to a visual axis detection apparatus and the like which is constituted by light receiving device for receiving image of an observer'"'"'s eye, read-out device for reading out the photoelectric conversion signals from the light receiving device, information processing device for extracting a plurality of characteristic information on the basis of the signals read out by the read-out device and outputting information regarding the direction of the observer'"'"'s visual axis and restricting device for giving a restriction to the read-out area of the light receiving device.

Claims

1. An apparatus comprising:

light receiving means for receiving an image of an observer'"'"'s eye and for outputting photoelectric conversion signals;

read-out means for reading out photoelectric conversion signals from a read-out area of said light receiving means in a first read out step and in a second read out step, said read out means including means for changing photoelectric conversion signals into digital signals;

limitation means for limiting the read-out area of said light receiving means, said limitation means determining a position of a pupil in the image of the observer'"'"'s eye based on digital signals read out by said read-out means in a first read-out step, to limit the read-out area of said light-receiving means in a second read-out step to within an area smaller than the entire read-out area, said smaller area corresponding to an area lying around a center of the pupil, such that said read-out means changes the photoelectric conversion signals from the entire read-out area into digital signals in the first read-out step, and changes only photoelectric conversion signals from said smaller area to digital signals in the second read-out step; and

information processing means for extracting characteristic information including a plurality of characteristics on the basis of photoelectric conversion signals read out by said read-out means, and for outputting information regarding the direction of the observer'"'"'s visual axis.

2. An apparatus according to claim 1, wherein said read-out means repeatedly executes the read-out a plural number of times, and said limitation means is actuated at a second time that the read-out is executed or thereafter.

3. An apparatus according to claim 1, wherein said limitation means defines the read-out area on the basis of an area having a predetermined length from the pupil'"'"'s center.

4. An apparatus according to claim 1, wherein said limitation means defines the read-out area on the basis of an average length having a certain multiple of the radius of the pupil.

5. An apparatus according to claim 1, wherein said light receiving means includes an area type solid-state imaging element.

6. An apparatus according to claim 1, wherein the characteristic information relates to one or more of Purkinje images, a pupil'"'"'s edge portions, and lowest luminance positions.

7. An apparatus according to claim 1, wherein said information processing means has a function to determine whether a proper information can be formed in regard to the visual axis direction or not, and when any proper information cannot be formed, a restriction is returned to its initial value by said limitation means.

8. A visual axis detection apparatus comprising:

illuminating means for illuminating an observer'"'"'s eyeball;

light receiving means for receiving an eyeball image of the observer, detecting a distribution of luminous intensity in a two-dimensional direction, and outputting photoelectric conversion signals;

read-out means for reading out photoelectric conversion signals which are output from a read-out area of said light receiving means, said read-out means including means for changing photoelectric conversion signals into digital signals, and limitation means for determining a position of a pupil in the eyeball image based on digital signals output by said read-out means in a first read-out step, to limit the read-out area of said light-receiving means within an area smaller than the entire read-out area in a second read-out step, said smaller area corresponding to an area lying around a center of said pupil, such that said read-out means chances the photoelectric conversion signals from the entire read-out area into digital signals in the first read-out step, and changes only photoelectric conversion signals from said smaller area to digital signals in the second read-out step

cornea reflection image detection means for detecting a cornea reflection image of a light source from the observer'"'"'s eyeball image; and

means for detecting the observer'"'"'s visual axis by a positional relationship between the pupil portion and the cornea reflection image.

9. A visual axis detection apparatus according to claim 8, wherein said limitation means designates an area having a certain multiple of the radius of said pupil.

10. A visual axis detection apparatus according to claim 8, further comprising determining means for determining whether or not said means for detecting the observer'"'"'s visual axis is able to detect the observer'"'"'s visual axis, wherein said limitation means resets an initial value in accordance with the result of said determining means.

11. A visual axis detection apparatus comprising:

light receiving means formed by a plurality of photoelectric conversion elements receiving reflection light reflected by an observer'"'"'s eyeball;

first storage means for storing information from said light receiving means;

characteristic point position detecting means for detecting positional information of a plurality of characteristic points of the eyeball in accordance with information stored in said first storage means;

second storage means for storing positional information detected by said characteristic point position detecting means;

detecting means for detecting the visual axis on the basis of the positional information stored in said second storage means; and

detection area limitation means which is arranged in said characteristic point position detecting means for limiting the detection area to a plurality of different areas of said light receiving means each of which respectively corresponds to one of the plurality of characteristic points when the characteristic points of the eyeball are detected.

12. A visual axis detection apparatus according to claim 11, wherein the characteristic points relate to one or more of Purkinje images, a pupil'"'"'s edge portions, and lowest luminance positions.

13. An optical apparatus comprising:

control means for controlling at least one predetermined function;

light receiving means for receiving an image of a user'"'"'s eye, and for outputting photoelectric signals;

read-out means for reading out photoelectric signals from a read-out area of said light receiving means in a first read out step and in a second read out step, said read out means including means for changing photoelectric conversion signals into digital signals;

limitation means for limiting the read-out area of said light receiving means, said limitation means determining a position of a pupil in the image of the user'"'"'s eye based on digital signals read out by said read-out means in a first read-out step, to limit the read-out area of said light-receiving means in a second read-out step to within an area smaller than the entire read-out area, said smaller area corresponding to an area lying around a center of the pupil, such that said read-out means chances the photoelectric conversion signals from the entire read-out area into digital signals in the first read-out step, and changes only photoelectric conversion signals from said smaller area to digital signals in the second read-out step; and

information processing means for extracting characteristic information including a plurality of characteristics on the basis of photoelectric signals read out by said read-out means, and for outputting information regarding the direction of the user'"'"'s visual axis from said plurality of characteristics for use of control by said control means; and

limitation means for giving a restriction to the read-out area of said light receiving means.

14. An optical apparatus according to claim 13, wherein said read-out means repeatedly executes the read-out plural times, and said limitation means is actuated at a second time that the read-out is executed or thereafter.

15. An optical apparatus according to claim 13, wherein said apparatus further includes an imaging optical system.

16. An optical apparatus according to claim 15, wherein said apparatus further comprises focal point detecting means for executing the focal point detection with respect to a plurality of areas of the imaging fields of said optical imaging system, respectively, and said predetermined function is to operate said focal point detecting means.

17. An optical apparatus according to claim 15, wherein said apparatus further comprises photometric means for separating the imaging field of said imaging optical system into a plurality of areas, and executing the photometry for each of the areas independently, and said function is to determine the exposure value of said imaging optical system by providing weight for the photometric values of said photometric means.

18. A visual axis detection apparatus comprising:

means for illuminating an eye;

an image forming optical system for forming an image of said illuminated eye on a photoelectric conversion element array having a plurality of photoelectric conversion elements; and

signal processing means for obtaining a direction of a visual axis of said eye based on a signal from each of said plurality of photoelectric conversion elements, said signal processing means detecting a position of a center of a pupil and a position of a cornea reflection image, in said image of said eye by using said signals to obtain said direction of the visual axis from these positions;

wherein when said position of the center of said pupil is detected,

then a number of said elements using the signals therefrom is set to be smaller than a number of all elements of said photoelectric conversion element; and

when said position of said cornea reflection image is detected,

then a number of said elements using the signals therefrom is set to be smaller than the number of elements when said position of the center of said pupil is detected.

19. An apparatus according to claim 18 in which

said elements using said signals therefrom when said position of center of said pupil is detected are a plurality of elements lying in an area which is larger than said pupil but which is limited in said photoelectric conversion element array and

said elements using said signals therefrom when said position of said cornea reflection image is detected are a plurality of elements lying in an area which is smaller than said pupil in said photoelectric conversion element array.

20. An apparatus according to claim 19 in which:

said illuminating means illuminates said eye with lights from two light sources, and

said signal processing means detects positions of two cornea reflection images corresponding to each of said two light sources in said image of said eye,

wherein said direction of the visual axis is obtained based on a difference between an intermediate position between said two cornea reflection images and a position of the center of said pupil.

21. An apparatus according to claim 20 in which:

analog signals from each of said plurality of elements of said photoelectric conversion element array are converted to digital signals to store each of said digital signals into a memory, and

the direction of said visual axis is obtained by using each of said digital signals of said plurality of elements stored in said memory.

26. Equipment having a visual detection apparatus of any of claim 18 to 25,

where in a function thereof is controlled according to said obtained direction of the visual axis.

27. An equipment according to claim 26 including a finder having an eyepiece.

28. A camera having a visual detection apparatus of any of claims 18 to 25,

wherein a function thereof is controlled according to said obtained direction of the visual axis.

29. An equipment according to claim 28 including a finder having an eyepiece.

22. A visual axis detection apparatus comprising;

means for illuminating an eye;

an image forming optical system for forming an image of said illuminated eye on a photoelectric conversion element array having a plurality of photoelectric conversion elements; and

signal processing means for obtaining a direction of a visual axis of said eye based on a signal from each of said plurality of elements of said photoelectric conversion array,

wherein said signal processing means detects a position of a center of a pupil and a position of a cornea reflection image, in said image of said eye by using said signals to obtain said direction of the visual axis from these positions;

wherein said signal processing means determines said elements using said signals therefrom when said position of the center of said pupil is detected and said elements using said signals therefrom when said position of said cornea reflection image is detected, based on a result of detection of said position of the center of said pupil in said image of said eye,

wherein a number of said elements when said position of the center of said pupil is detected is smaller than a number of all elements of said photoelectric conversion element and a number of said elements when said position of said cornea reflection image is detected is smaller than a number of said elements when said position of the center of said pupil is detected, and

wherein,

when said direction of the visual axis is obtained after said elements used in each detection of said position of the center of said pupil and detection of said position of said cornea reflection image are determined,

said position of said center of said pupil is detected based on outputs of said elements for detecting said position of the center of said pupil in said photoelectric conversion element array and

said position of said cornea reflection image is detected based on outputs of said elements for detecting said position of said cornea reflection image in said photoelectric conversion element array.

23. An apparatus according to claim 22 in which:

said elements using said signals therefrom when said position of the center of said pupil is detected are a plurality of elements lying in an area which is larger than said pupil but which is limited in said photoelectric conversion element array, and

said elements using said signals therefrom when said position of said cornea reflection image is detected are a plurality of elements lying in an area which is smaller than said pupil in said photoelectric conversion element array.

24. An apparatus according to claim 23 in which:

said illuminating means illuminates said eye with lights from two light sources, and

said signal processing means detects positions of cornea reflection images corresponding to each of said two light sources in said image of said eye,

wherein said direction of the visual axis is obtained based on a difference between an intermediate position between said two cornea reflection images and the position of the center of said pupil.

25. An apparatus according to claim 24 in which:

analog signals from each of said plurality of elements of said photoelectric conversion element array are converted to digital signals to store said digital signals into a memory and

a direction of said visual axis is obtained by using said digital signals of each of said plurality of elements stored in said memory.