JPH03293367A - Camera provided with detection device for line of sight - Google Patents

Abstract

PURPOSE:To prevent a camera from being inadvertently controlled based on information on the line of sight in the course of zooming by interrupting the detection of the line of the sight with the aid of a control means when it is detected by a zooming action detection means that a photographing lens is in the course of a zooming action. CONSTITUTION:When a start switch for detecting the line of sight is turned on, a camera controller 109 communicates with the lens controller 110 of the photographing lens 101. In the case that the lens 101 is a zoom lens, it is detected whether the lens 101 is in the course of the zooming action or not. Then, in the case that it is not in the course of the zooming action, the controller 109 transmits a start signal for the line of sight to an operation processor 9 and the line of the sight is detected. Besides, when it is discriminated to be in the course of the zooming action, the detection of the line of the sight is stopped. Therefore, the position of an object in the course of the zooming and the position of the object after the finish of the zooming generally do not coincide each other and an inadvertent focusing point happens to be selected. However, since the information for detecting the line of sight accumulated before the zooming action is reset by the processor 9, the precise focus detection point is selected.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a camera having a line of sight detection device, and more specifically, the present invention relates to a camera having a line of sight detection device. A line of sight detection device that detects the axis of the direction of the gaze point observed by an observer, the so-called line of sight or visual axis, by using a reflected image of the eyeball obtained when the surface of the observer's eyeball is illuminated. The present invention relates to a camera having a

[Prior Art] Various devices have been proposed for detecting the so-called line of sight (visual axis), which detects the position on the observation surface that an observer or photographer is observing.

For example, in JP-A-61-172552, a parallel light beam from a light source is projected onto the anterior segment of the observer's eyeball, and the corneal reflection image formed by the light reflected from the cornea and the image formation position of the pupil are used to provide visual acuity. I'm looking for an axis.

FIG. 5 is a diagram explaining the principle of the line-of-sight detection method, in which (A) is a schematic diagram of the line-of-sight detection optical system, and (B) is an output intensity diagram of the photoelectric element array 6.

In the figure, reference numeral 5 denotes a light source such as a light emitting diode that emits infrared light that confuses the viewer, and is arranged on the focal plane of the projection lens 3.

The infrared light emitted from the light source 5 is turned into parallel light by the projection lens 3, reflected by the half mirror 2, and illuminates the cornea 21 of the eyeball. At this time, a corneal reflected image d (virtual image) due to part of the infrared light reflected on the surface of the angle WA21 is transmitted through the half mirror 2, focused by the light receiving lens 4, and projected at a position d° on the photoelectric element array 6. .

Further, the light beams from the ends a and b of the iris 23 form images of the ends a and b at positions ab° on the photoelectric element array 6 via the light receiving lens 4. When the rotation angle θ of the optical axis A of the eyeball with respect to the optical axis (optical axis A) of the light receiving lens 4 is small, the end portion a of the iris 23
, b are Za and Zb, the coordinate Zc of the center position C of the pupil 24 is expressed as ZC4(Za+Zb)/2.

In addition, the two coordinates of the corneal reflection image d and the center of curvature 0 of the angle fi21
The two coordinates coincide, so the rotation angle e of the optical axis of the eyeball, where Zd is the Z coordinate of the position d of the corneal reflection image and OC is the distance between the center of curvature 0 of the cornea 21 and the center C of the pupil 24, is , OC*sinθMisakiZc-Zb substantially satisfies the relational expression (1). Therefore, in the arithmetic processing unit 9, the eyeball light is detected by detecting the position of each singular point (the corneal reflection image d and the edges a and b of the iris) projected on the photoelectric element array 6 shown in the figure (B). The rotation angle θ of axis I can be determined. At this time, equation (1) is β* OC* sinθ4 (Za'+Zb')/2-
It can be replaced with Zd' (2). However, β is a magnification determined by the position of the eyeball with respect to the light receiving lens 4.

Further, once the rotation angle θ of the optical axis of the observer's eyeball is calculated, the line of sight of the observer is determined by correcting the optical axis of the eyeball and the visual axis.

In addition, although the figure shows an example in which the observer's eyeball rotates within the Z-x plane (e.g. horizontal plane), if the observer's eyeball rotates within the X-Y plane (e.g. vertical plane) It is also detectable in the same way.

FIG. 6 is a schematic diagram of main parts when a line of sight detection device is arranged in a single-lens reflex camera. The object light transmitted through the photographic lens 101 is reflected by the flip-up mirror 102 and forms an image near the focal plane of the focusing plate 104. Furthermore, the focus plate 104
The subject light diffused by the camera is guided to the photographer's eye point X via the condenser lens 105, the pentagonal roof prism 106, and the eyepiece lens 1.

The line-of-sight detection optical system includes an illumination optical system consisting of a light source 5 such as an infrared emitting diode that is insensitive to the photographer (observer) and a light projecting lens 3, and a light receiving optical system consisting of a photoelectric element array 6 and a light receiving lens 4. It is arranged above the eyepiece lens 1 which also serves as a dichroic mirror. Infrared light emitted from the infrared light emitting diode 5 is reflected by the dichroic mirror surface 1a and illuminates the photographer's eyeball. Further, a part of the infrared light reflected by the eyeball is re-reflected by the dichroic mirror surface 1a and is focused onto the photoelectric element array 6 via the light receiving lens 4. Image information of the eyeball obtained on the photoelectric element array 6 (
The arithmetic processing unit 9 calculates the direction of the photographer's line of sight from FIG.

In this way, if it is possible to know which point on the focus plane the photographer is observing in an eye reflex camera, for example, if the camera has a focus detection device that can detect the focus of multiple points on the viewfinder screen, For example, when a photographer attempts to perform automatic focus detection by selecting one point that matches the main subject, that is, the subject that the photographer is trying to photograph, from among points where focus can be detected,
It is effective to save the time and effort of selecting and inputting one of the points as the point being observed by the casual photographer, select that point for automatic fishing, and perform automatic focus detection.

[Problem to be solved by the invention] However, it is common for single-lens reflex cameras these days to be used with a zoom lens attached, and when the photographer zooms, the position of the subject within the viewfinder screen also moves. As a result, the position of the subject during zooming often does not match the position of the subject after zooming is completed. Therefore, the movement of the line of sight during zooming does not reflect the position of the line of sight after zooming, and if the line of sight data during zooming is used to control the camera, for example to select the focus detection point, the wrong point may be selected. There was a drawback that it could be stored away.

Furthermore, in order to select a plurality of focus detection points or to determine an exposure value from photometric values of a plurality of areas, it is necessary to detect the position of one or more main subjects intended by the photographer. In order to detect the position of the main subject intended by the photographer more accurately than the movement of the line of sight, it must be statistically detected from multiple line of sight information, so it is necessary to accumulate the line of sight information at the same time as detecting the line of sight. However, if a zooming operation is performed while this information is being stored, the main subject's position will be updated with the accumulated line-of-sight information for the main subject's position before zooming, which is different from the main subject's position after zooming. Since detection is performed, there is a drawback that the position of the main subject may be incorrect.

Therefore, even when performing a zooming operation, the present invention
It is an object of the present invention to provide a camera having a line-of-sight detection device that can control the camera based on correct line-of-sight information, for example, select an accurate focus detection point.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes an illumination means for illuminating the eyeballs of an observer, and a light receiving means for receiving reflected light from the eyeballs illuminated by the illumination means. and an arithmetic means for calculating the line of sight of the observer from the reflected image of the eyeball received by the light receiving means, and the detecting device further detects whether or not the lens is in a zooming operation. The camera is configured to include a zooming operation detection means for detecting a zooming operation, and a control means for stopping the line of sight inspection during the zooming operation.

Further, in the invention according to claim 2, the calculation means is configured to include means for resetting the line of sight detection information accumulated before the zooming operation when the zooming operation detection means detects that the zooming operation has been performed. .

[Function] Since the present invention is configured as described above, when the photographer performs zooming, the zooming detection means detects this and the control means stops line of sight detection. However, the position of the subject during zooming and the position after zooming generally do not match, and an incorrect focal point may be selected. According to the present invention, this can be prevented. It is clear that when the zooming operation is not in progress, the calculation means calculates the line of sight based on the reflected image reflected from the eyeball illuminated by the zero-stage illuminator.

In the invention as set forth in claim 2, when the zooming operation detection means detects that a zooming operation has been performed, the calculation means resets the line of sight detection information accumulated before the zooming operation. According to the present invention, even if a plurality of focus detection points are selected, the position of the main subject after zooming is completed can be accurately detected.

[Example] Figures 1 to 4 are diagrams showing examples of the present invention, and Figure 1 (
8) is a schematic diagram of an eye reflex camera, FIG. 2B is a perspective view of a main part of a focus detection device, and FIG. In each figure, reference numeral 1 denotes an eyepiece lens, and a dichroic mirror 18 for transmitting visible light and reflecting infrared light is installed obliquely, and also serves as a light splitter. 4 is a light receiving lens, 5a, 5b
, 5c is an infrared light emitting diode which is an illumination light source,
6 is an image sensor with a two-dimensional array of photoelectric elements,
It is arranged so as to be conjugate with the vicinity of the pupil of the eye at a predetermined position with respect to the light receiving lens 4 and the eyepiece lens 1. 9
is an arithmetic processing unit. In addition, in Fig. 2, infrared light emitting diodes 5a, 5b, and 5c for illumination are used in pairs to detect the distance between the camera and the observer's eyeballs, and depending on the posture of the camera (5a , 5b; horizontal position), (5
b, 5a vertical position) is selected.

In each figure, a detection means for detecting the attitude of the camera is not shown, but an attitude detection means using a mercury switch or the like is effective.

Furthermore, 101 is a photographing lens (zoom lens), 102 is a flip-up mirror, 103 is a display element, 104 is a focusing plate,
105 is a condenser lens, 106 is a pentagonal roof prism, 107 is a submirror, 108 is a multi-point focus detection device, and 109 is a camera control device 110, which is a control device and has a zoom encoder lens drive for detecting zooming operations, and a memory function.

The explanation of the multi-point focus detection device 108 is not particularly necessary for understanding this embodiment, so it will be kept briefly. Figure 1 (A
) and CB), the photographing lens 10
1, a field mask 120 having a plurality of slits each determining a focus detection area, and a lens member 121 acting as a field range for the image in each slit are arranged in close proximity to each other. A set 122 of re-imaging lenses and a set 123 of photoelectric element arrays are arranged in order according to the number of slits. A set of a slit, a field lens, a reimaging lens, and a set of photoelectric element arrays each constitute a well-known focus detection system. In addition, the mirror shown in the multi-point focus detection device 108 of the same figure (^) is omitted in the same figure (B). A part of the subject light transmitted through the photographic lens 101 is reflected by the flip-up mirror 102 and forms an image near the focusing plate 104. The object reflected on the diffusing surface of the focusing plate 104 is a condenser lens 105 and a penta roof prism 106.
, guided to eyepoint E through the eyepiece. The photographer performs framing while observing the subject image projected on the focus plate 104, but at this time, the photographer's line of sight is moving around the subject to be photographed. Here, the display element 103
For example, this is a two-layer type guest-host type liquid crystal element that does not use a polarizing plate, and displays a focus detection area within the field of view of the finder.

In addition, a part of the subject light transmitted through the photographic lens 101 is
The multi-point focus detection device 1 is transmitted through the flip-up mirror 102 and reflected by the sub-mirror 107, and is placed at the bottom of the camera body.
Guided to 08. In the multi-point focus detection device 108,
Based on the focus detection area signal output from the camera control device 109, the focus adjustment state of the corresponding area is detected.

The visual field detection device according to this embodiment includes a line-of-sight detection optical system made up of members designated by numbers 1.4-6, and an arithmetic processing device 9 that calculates the line-of-sight of the photographer. Infrared light emitted from the infrared light emitting diodes 5a and 5b enters the eyepiece 1, is partially reflected by the dichroic mirror 1a, and illuminates the eyeball of an observer (not shown) located near the appointment. Further, the infrared light reflected by the eyeball is reflected by the dichroic mirror 1a, and is converged by the light receiving lens 4 to form an image on the image sensor 6.

FIG. 3 is an explanatory diagram of the principle of the line of sight detection method, FIG. 3(A) is a schematic diagram of the line of sight detection optical system, and FIG. 3(B) is a 6-output intensity diagram of the image sensor. In the same figure, 5a and 5b are light sources such as light emitting diodes that emit infrared light that is insensitive to the observer, and each light source is arranged approximately symmetrically in two directions with respect to the optical axis A, so as to avoid the observer's eyeballs. It has divergent lighting.

The infrared light emitted from the light source 5b illuminates the cornea 21 of the eyeball. At this time, a corneal reflection image d, which is a part of the infrared light reflected on the surface of the cornea 21, is focused by the light receiving lens 4 and re-imaged at a position d' on the image sensor 6.

Similarly, the infrared light emitted from the light source 5a is transmitted to the cornea 21 of the eyeball.
to illuminate. At this time, a corneal reflection image e formed by a portion of the infrared light reflected on the surface of the cornea 21 is focused by the light receiving lens 4 and re-imaged at a position e° on the image sensor 6.

Also, the light flux from the ends a and b of the iris 23 is transmitted to the light receiving lens 4.
Images of the ends a and b are formed at positions a' and b' on the image sensor 6 through the image sensor 6.

When the rotation angle θ of the optical axis I of the eyeball with respect to the optical axis (optical axis A) of the light-receiving lens 4 is small, and if the Z coordinates of the ends a and b of the iris 23 are Za and Zb, then the center position C of the pupil 24 is Coordinate Z
c is expressed as Zc 4 (Za+Zb)/2.

Also, the center of curvature of the cornea 21 at the two coordinates of the midpoint of the corneal reflection images d and e is Z 1! fiZo, so the Z coordinates of the corneal reflection image occurrence positions d and e are Zd, Ze, and cornea 2.
If the distance between the center of curvature 0 of 1 and the center C of the pupil 24 is oC, then the rotation angle θ of the eyeball optical axis I is: OC* sin θ4Zc − (Zc + Ze) / 2
The relational expression (3) is approximately satisfied. Therefore, in the arithmetic processing unit 9, the image sensor is
By detecting the position of each singular point (corneal reflection images d, e and iris ends a, b) projected onto a part of the eyeball 6, the rotation angle θ of the eyeball optical axis i can be determined. At this time (3)
The formula is β* OC* sin θ4 (Za'+Zb')
/2-(Zd'+Ze')/2(4) However, β is the magnification determined by the position of the eyeball with respect to the light-receiving lens 4, and is substantially equal to the interval IZd''-Ze'l of the corneal reflection image. It is a function.

Once the rotation angle θ of the observer's eyeball is calculated, the observer's line of sight is determined by correcting the optical axis and visual axis of the eyeball.
The calculation for determining the observer's line of sight as described above is performed as described in (4) above.
It is executed by the software of the microcomputer of the arithmetic processing unit 9 based on the formula.

FIG. 4 is a flowchart of line-of-sight detection of a camera having a line-of-sight detection device according to the present invention. When a line of sight detection start switch (not shown) attached to the camera body or the photographic lens 101 is turned on (#1), the camera control device 109 communicates with a part of the memory of the lens control device 110 of the photographic lens 101. , it is determined whether or not the photographing lens 101 is a zoom lens (#2). When it is determined that the photographic lens 101 is a zoom lens (#3), the camera control device 109 communicates with a part of the zoom encoder of the lens control device 110 to determine whether the photographic lens is in zooming operation or not. Detection is performed (#4). Photography lens 1
When it is determined that 01 is not in zooming operation, the camera control device 109 sends a line-of-sight detection start signal to the arithmetic processing unit 9, and line-of-sight detection (data S (i)) is performed (#6). Furthermore, if the photographing lens 101 is not a zoom lens (#5), the camera control device 109 immediately sends a line-of-sight detection start signal to the arithmetic processing unit 9, and line-of-sight detection (data 5(i)) is performed (#6). . Here, in the arithmetic processing unit 9, a threshold value n of the number of sight line detections is set in advance.
is set, and when n = 1 (#7), the position of the main subject is calculated immediately (#6) when the line of sight is detected (#11), where the number of times n is calculated from the movement of the line of sight. This is a value of 1 or more determined based on the time required to extract the main subject.

Furthermore, if the number of times n is greater than 1 (#7), and if the number of gaze detections i is smaller than the predetermined number n (#8), the gaze detection data s (i) is stored in the data 5 ( i) (#9). Furthermore, the arithmetic processing unit 9 counts up the number of gaze detections i and (
#10) The position p of the main subject is calculated based on the data 5(i) stored in a part of the memory (#11). Also, if the number of gaze detections i is equal to the predetermined number n (#8)
The data S stored in the arithmetic processing unit 9 up to that point is s
(j-1)-s (j) (where j takes a value from 2 to n) (#12), and the latest line of sight detection data 5(i) is processed as data S (n) by the arithmetic processing unit. 9
(#13). Then, the position P of the main subject is calculated based on the replaced and stored data 5(1) (#11).

Further, the calculated position information of the main subject is stored in the arithmetic processing unit 9
The data is then sent to the camera control device 109. During this time, if the photographer releases the line-of-sight detection start switch or turns on the shutter release switch, the camera control device 109 sends a line-of-sight detection stop signal to the arithmetic processing unit 9 to stop line-of-sight detection ($14). If the shutter release switch is turned on, the camera control device 10
9 displays the focus detection area corresponding to the detected position P of the main subject in the finder using the display element 103, receives focus adjustment information of the focus detection area from the multi-point focus detection device 108, and further displays the focus detection area corresponding to the detected position P of the main subject. Focus adjustment information is sent to the lens control device 110 to adjust the focus of the photographic lens 101.

Furthermore, when the line-of-sight detection is not canceled (#14), if the photographing lens 101 is not a zoom lens (#15), the line-of-sight detection is continued (#6).

In addition, if the photographing lens 101 is a zoom lens (
$15), the camera control device 109 again adjusts the lens lIJm
Communication is performed with a part of the zoom encoder of the device 110 to detect whether or not the photographing lens is in zooming operation (#4). If it is determined that the zoom lens 101 is in the zooming operation, the line of sight detection is stopped and the data 5 (
j) (where j takes a value from 1 to n) is deleted (#16), and the number of gaze detections i is set to 1 (
#17). Then, the camera control device 109 again communicates with a portion of the zoom encoder of the lens control device 110 to detect whether or not the photographic lens is in zooming operation (#4).

Note that although the figure shows an example in which the observer's eyeball rotates within the 2-X plane (e.g., horizontal plane), when the observer's eyeball rotates within the X-Y plane (e.g., vertical plane) It is also detectable in the same way.

According to this embodiment, since it is also equipped with a discriminating means for discriminating whether or not the lens is a zoom lens, it can be applied to any lens system, and if it is not a zoom lens, it can be conveniently shifted to line of sight detection. be.

[Effects of the Invention] As described above, since the present invention is equipped with a line-of-sight detection device, the observer or photographer can determine which position on the observation surface the observer or photographer is observing, as in the conventional device. It can be easily inspected. At the same time, a zooming operation detection means is also provided, and when the control means detects that the zooming operation is in progress, the control means stops line of sight detection, thereby preventing erroneous camera control from being carried out based on line of sight information during zooming.

Further, according to the invention as set forth in claim 2, when the detection means detects that the zooming operation of the zoom lens has been performed, the calculation means resets the line of sight detection information accumulated before the zooming operation. This has the effect of accurately detecting the position of the main subject after zooming.

[Brief explanation of the drawing]

Figure 341 is a diagram showing an embodiment applicable to a single-lens reflex camera of the present invention, in which (A) is an overall schematic diagram, (B) is an exploded perspective view of the focus detection device, and Figure 2 is an exploded perspective view of the line of sight detection device. Figure 3 (A) is a schematic diagram showing the principle of the line-of-sight detection device, (B) is a diagram showing the output intensity on the image sensor, and Figure 4 is a diagram showing the line-of-sight detection device. 5.6 is a diagram showing a conventional example, FIG. 5(A) is a schematic diagram of a visual line detection optical system, FIG. 5(B) is an output intensity diagram of a photoelectric element array, and FIG. FIG. 2 is a schematic diagram of main parts of a camera. 5...Light source 6...Image sensor-9
... Arithmetic processing device 109 ... Camera control device 1
10...Lens control device and other 4 people 2nd figure Zb Ze' Zd Zd ``h''zb''

Claims (1)

[Scope of Claims] 1. Illumination means for illuminating the eyeballs of an observer; light receiving means for receiving reflected light from the eyeballs illuminated by the illumination means;
A line-of-sight detection device includes a calculation means for calculating the line of sight of the observer from the reflected image of the eyeball received by the light receiving means, and the detection device further detects whether or not the lens is in a zooming operation. a zooming motion detection means for
1. A camera having a line-of-sight detection device, characterized in that the camera is equipped with a control means for stopping line-of-sight detection during a zooming operation. 2. The calculation means according to claim 1 is a camera having a line-of-sight detection device, which also includes means for resetting line-of-sight detection information accumulated before the zooming operation when the zooming operation detection means detects that a zooming operation has been performed. .