JP2005107460A - Lens focus system and the same method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a user to automatically perform focusing to a position where an interested object exists through a viewfinder in optical equipment such as a camera and binoculars. <P>SOLUTION: When the user gazes an object substantially existing in an infinite distant place through the viewfinder at the time of starting use of the equipment, a reference value of user's interpupillary distance is measured. After that, the user gazes an object 42 set as an object of observation or photography through the viewfinder, the interpupillary distance X<SB>2</SB>changes according to distance between the object 42 and the viewfinder. Distance X<SB>3</SB>from the viewfinder to the object 42 is calculated based on the interpupillary distance X<SB>2</SB>. The focusing is automatically performed according to the calculated value of distance X<SB>3</SB>. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The subject of the present disclosure relates to a dual lens focus system for an optical device that correlates the lens of the device to the orientation of each pupil of the user when the user looks at an object to be photographed.

  The pupil position of both eyes of the user assigned to the viewfinder is determined (measured), and then the stereoscopic lens is moved so that the lens of the optical device is focused on the target object viewed by the eyes. There are several stereo optical devices. In general, a stereoscopic viewing apparatus gives a three-dimensional effect to an object by capturing the object from two slightly different viewpoints and then viewing them side by side. Examples of such an optical device include binoculars, a binocular microscope, and a stereo camera. For binoculars and binocular microscopes, the lens is usually focused by manually adjusting the lens toward or away from the object being viewed. For dual lens cameras that provide autofocus, it can be very important that the photographer can focus the camera quickly and properly, especially on the object that is the photographic target.

  However, unfortunately, as Applicants have noticed in connection with such optical devices, such focusing can be performed regardless of whether the object is stationary or moving. This can be a problem when there are multiple other objects in the scene that are not intended to be adjusted. In this case, if the optical device is a digital camera, such a camera normally captures images continuously while changing the focus adjustment position of the lens. Each image is then analyzed to determine which is the image with the highest average difference between adjacent pixels (high contrast), which is a time consuming task, especially from the widest range. It can take up to 2 seconds or more to find a focused exposure (image). When the optical device is a video camera, such a camera always shifts the focus adjustment position slightly to determine whether or not the camera is in focus. In short, in many cases, regardless of the optical device used, it can be a problem for the user of the device to focus on the correct object appropriately and when needed.

  The content disclosed herein includes an optical device with an automatic lens focus system based on interpupillary distance (pupil spacing).

  The lens focus system disclosed herein includes a viewfinder that allows the user to apply both eyes when staring through the viewfinder in order to stare and visualize the object to be focused. Since the convergence angle of the pupil increases as the object approaches the viewfinder, a pupil orientation sensor that measures the interpupillary distance can be connected to the viewfinder. . The system further includes first and second stereoscopic lenses that are movable back and forth along an axis (optical axis) so as to focus on the object stereoscopically. Such movement of the lens can be done automatically using each actuator that is electrically actuated so that each lens moves along an axis. The system further comprises a microprocessor provided with the correlation between the pupil distance and the distance from the viewfinder to the object, and the corresponding lens movement required to focus the lens on the object. Can do. Further, the microprocessor may be able to move each lens along an axis to move the lens actuator almost instantly to focus the lens on the object.

  The focus system described herein can be advantageous in situations where the object is present at multiple locations separated in the perspective direction within the scene. In particular, as an example applied to a camera, the present system can eliminate the situation where the focus of the stereoscopic lens of the camera is determined by the direction in which the user's eyes are looking at the object, and thus the focus is out of focus. . Since the eye and the lens respond to each other, it is possible to determine the delay due to focusing and whether or not the lens is correctly focused. This rapid focus capability allows users to quickly focus from scene to scene and from object to object, regardless of where the object is in each scene, while focusing clearly on any object. Can move.

  First, referring to FIGS. 1 to 4, a stereo camera (hereinafter simply referred to as “camera”) 10 is shown. The camera 10 corresponds to the pupils 14 and 16 of the user's eyes 13 and 15 looking at the selected object through the viewfinder lenses 18 and 20 as a stereo photographing lens focus system (see through the eyes 13 and 15). A viewfinder 12 can be provided. Second, the camera 10 includes two side-by-side (parallelly arranged) camera lenses (stereoscopic lenses) 22 and 24 that can move back and forth so as to focus on the selected object. Can do. Such movement of the lenses 22, 24 can be performed by an appropriate drive system such as two independent electric actuators 26, 28, and stepping motors can be used as the electric actuators 26, 28.

  The viewfinder 12 includes a pupil orientation sensor 30 that measures the interpupillary distance between the pupils of both eyes in the viewfinder 12 while observing the object through the viewfinder lenses 18 and 20 while observing the object. It can be arranged for each of the pupils 14 and 16 of both eyes. When the interpupillary distance changes because the eye is pointed at the second object, the sensor 30 follows the change in the orientation of each pupil, and this second is when the user is looking at the second object. The interpupillary distance associated with focusing on the object can be determined again. Each pupil orientation sensor 30 can be configured as shown most clearly in FIG. Specifically, the pupil 14 generates a line of sight 50 that passes through the viewfinder lens 18 and then toward the dichroic mirror 52. At the same time, the infrared source 54 irradiates the cornea with infrared rays, and the infrared rays reflected by the cornea are directed to the dichroic mirror 52, and then reflected by the dichroic mirror 52 and pass through the condenser lens 56, and the US Patent No. 5 of Ohmori et al. , 515, 131, to a gazing point detection sensor 58 such as an imaging position detection device. The light reflected by the cornea and the entire image of the eyeball pass through the condenser lens 56, and this entire image of the cornea is formed on the gazing point detection sensor 58. From this cornea image, the center position of the pupil 14 and the position of the reflected light are taken in and correlated with the second pupil direction sensor 30 that measures the other pupil 16, whereby the interpupillary distance can be calculated.

One method of customizing the focus system calibration with respect to each user's individual pupil orientation is implemented in the manner shown in FIGS. In this method, the user starts using the device as he / she looks into the viewfinder 12, and the user looks at a distant object to emulate the infinite distance gaze position of the user's pupil line of sight (FIG. 5). This provides a basic interpupillary measurement X ₁ . Thereafter, until the lens is recalibrated for another user, the lens is focused according to the direction in which the eye is looking, and moved along the axis of each lens 22, 24 according to microprocessor calculations as described below. Is appropriately performed.

In particular, the camera 10 determines the interpupillary distance X ₁ (FIG. 5) or X ₂ (FIG. 6) related to the distance X ₃ (FIG. 6) from the viewfinder to the object 42 and the lens focus according to this distance. A microprocessor 32 can be provided that correlates the lens positioning required to align the object with the object. Such a correlation between the interpupillary distance and the distance to the object can be performed by applying an algorithm or look-up table as described in connection with FIG. The interpupillary distance is electrically sent to the microprocessor 32. Since the visual line angle and the distance to the object are determined by the interpupillary distance, such an angle and the object distance are calculated only by inputting the interpupillary distance to the algorithm or the lookup table. Thereafter, the positions of the correlated lenses 22, 24 are calculated and the microprocessor 32 reads the last lens position. If the last lens position is inappropriate, the microprocessor 32 almost instantly activates the electric actuators 26, 28 through the electrical connections 38, 39 and the lenses 22, 24 through the mechanical connections 46, 41 to each track set 34. , 36 is moved back and forth, and finally placed in an appropriate location where the dual lens is focused on the object 42 that the eyes 13 and 15 are looking at.

FIG. 6 schematically shows the gaze direction (the direction of the line of sight, the direction of the pupil) of the eyes 13 and 15 with respect to the distance X ₃ from the camera lenses 22 and 24 to the object. Specifically, the interpupillary distance X ₂ and the resulting angles α ₁ and α ₂ can be sent from the two pupil orientation sensors 30 to the microprocessor 32. Thereafter, an algorithmic microprocessor application (program) calculates the value of X ₃ determined according to the formula X ₃ = X ₂ ((tan α ₁ ) (tan α ₂ )) / (tan α ₁ + tan α ₂ ). When the value of X ₃ has been determined, the microprocessor 32 may focus the dual lens as described above moves the lens 22 and 24 to fit the object 42.

  FIG. 7 schematically shows outdoor binoculars 60 that can be useful outdoors for sightseeing or the like. The binoculars 60 can incorporate the stereoscopic lens focus system described above. In particular, as described above, the binoculars can include one pupil orientation sensor 30 for measuring the distance between the pupils of the user's pupils 14 and 16 in each of the lens barrels 62 and 64. The interpupillary distance and angle measurements obtained as described above can be sent to the microprocessor 32, which determines the distance to the object that the user's eyes are looking at. The microprocessor 32 can then correlate this object distance to the position where the lenses 66, 68 need to be finally placed to focus accordingly and, if necessary, through the electrical connections 74, 76. Activating the electric actuators 70 and 72, moving the lenses 66 and 68 back and forth on the track sets 82 and 84 through the mechanical connections 78 and 80, and finally placing them in proper positions with proper focusing. Can do. When the lenses 66 and 68 are out of focus, initially, a distant object to be seen may be blurred. However, when the lens 66 and 68 is out of focus, the lenses 66 and 68 are described above. As the object moves back and forth, the object in the distance is focused.

  FIG. 8 is an embodiment of a flowchart of the focusing step. Specifically, in step 90, the reference value of the interpupillary distance is determined by the user looking at infinity. In step 92, this distance is measured and the value is sent to the microprocessor. Thereafter, in step 94, the user looks at an object to be viewed that is closer to infinity. Then, in step 96, the interpupillary distance corresponding to the object that is closer than infinity is measured and this value is sent to the microprocessor, which then distances the lens or viewfinder to the object. Is calculated (step 98). Finally, in step 100, the lens moves along the axis corresponding to the line of sight of the user looking at the object to focus on the object.

It is embodiment of the front view of the stereo camera provided with the stereo (binocular) lens focus system of a binocular optical device. FIG. 2 is a schematic top view embodiment taken along line 2-2 of FIG. FIG. 3 is a schematic top view embodiment of a cross-section along line 3-3 of FIG. 1. FIG. 4 is a schematic side view embodiment along line 4-4 of FIG. 2; FIG. 4 is a schematic top view embodiment of a user's eye looking at infinity. It is embodiment of the schematic top view of the eye of the user who is staring at the target object in a position near infinity. It is embodiment of the typical top view of the binoculars provided with the stereoscopic vision lens focus system. 6 is an embodiment of a flowchart for a focus step that activates focus of a stereoscopic lens focus system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Stereo camera 12 Viewfinder 13, 15 User's eyes 14, 16 Pupil 18, 20 Viewfinder lens 22, 24 Camera lens 26, 28, 70, 72 Electric motor (motor)
30 Pupil orientation sensor 32 Microprocessor 34, 36 Track set 38, 39, 74, 76 Electrical line 41, 46, 78, 80 Mechanical connection 50 Line of sight 52 Dichroic mirror 54 Infrared source 56 Condensing lens 58 Gaze point detection sensor 66, 68 lenses

Claims (10)

A lens focus system for an optical device,
a) a binocular viewfinder;
b) a pupillary direction sensor operatively linked to the binocular viewfinder and generating a sensor signal indicating the direction of the pupil;
c) first and second stereoscopic lenses movable back and forth along an axis;
d) The inter-pupil distance related to the distance from the viewfinder to the object and the lens positioning operation necessary to focus on the object corresponding to the distance from the viewfinder to the object And a microprocessor
The microprocessor is coupled to the first and second stereoscopic lenses for moving the first and second stereoscopic lenses along the axis in accordance with a microprocessor control for focusing on the object. A lens focus system characterized by   The lens focus system according to claim 1, further comprising a lens driving unit operatively connected to the first and second lenses and responsive to a change in the sensor signal.   3. The lens focus system according to claim 2, wherein the microprocessor operates the lens driving unit. A stereo camera capable of focusing on the object according to each direction in which the pupils of both eyes of the user look at the object,
a) a viewfinder, the viewfinder corresponding to each pupil of both eyes of the user when the user is looking at the object through the viewfinder;
b) first and second stereoscopic lenses that are movable back and forth along an axis to focus on the object;
c) a pupil orientation sensor for each of the pupils of both eyes, which measures the distance between the pupils of both eyes when the pupils of both eyes are staring at the object;
d) The interpupillary distance related to the distance from the viewfinder to the object and the lens operation necessary to focus on the object corresponding to the distance from the viewfinder to the object And a microprocessor
The microprocessor is coupled to the first and second stereoscopic lenses for moving the first and second stereoscopic lenses along the axis in accordance with a microprocessor control for focusing on the object. A stereo camera characterized by   5. The actuator according to claim 4, further comprising an actuator for moving the first and second stereoscopic lenses along the axis for each of the first and second stereoscopic lenses. Stereo camera.   6. The stereo camera according to claim 5, wherein the microprocessor activates each of the actuators so that each of the first and second stereoscopic lenses moves along the axis almost instantaneously. An optical device,
An optical device including an automatic lens focusing system based on interpupillary distance. a) a viewfinder, the viewfinder corresponding to each of the pupils of both eyes of the user when the user is looking at an object through the viewfinder;
b) a pupillary orientation sensor for each pupil that measures the distance between the pupils when each of the pupils is staring at the object;
c) first and second stereoscopic lenses movable back and forth along an axis to focus on the object;
d) The interpupillary distance related to the distance from the viewfinder to the object and the lens operation necessary to focus on the object corresponding to the distance from the viewfinder to the object And a microprocessor
The microprocessor is coupled to the first and second stereoscopic lenses for moving the first and second stereoscopic lenses along the axis according to a microprocessor control for focusing on the object. The optical device according to claim 7, wherein A method of focusing a stereoscopic lens of the optical device on an object in front of the optical device,
a) measuring the user's interpupillary distance when a user of the optical device is gazing at the object;
b) The measured interpupillary distance is the distance from the optical device to the object and the movement of the stereoscopic lens necessary to focus the object on the object at such distance. Comparing each with a known interpupillary distance that is reflected respectively;
c) determining a distance from the optical device to the object reflected by the measured interpupillary distance, and further determining a movement of the stereoscopic lens corresponding to the distance;
and d) moving the stereoscopic lens of the optical device by an amount necessary to adjust the focus of the stereoscopic lens to the object. A method of focusing a stereoscopic lens of a dual lens optical device operated by a user on an object,
a) a step of looking at infinity;
b) measuring and recording a first interpupillary distance while staring at infinity;
c) staring at an object closer than infinity;
d) measuring and recording a second interpupillary distance while gazing at an object closer than infinity;
e) determining a distance from the stereoscopic lens to the object based on the second interpupillary distance;
f) moving the stereoscopic lens to focus on the object.

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