JPH0675149A - Visual device - Google Patents

Abstract

PURPOSE:To surely simulate eye-ball movement by a small device and to make a camera system conform to an adverse environment such as vibration as for the twin-lens view camera system. CONSTITUTION:A first wedge-like prism 23 and a second wedge-like prism 214 are arranged in front of the lens 21 of an image pickup camera 1 so that they can be independently rotated by an identical axis to the optical axis of the lens by prism holders 25 and 26 and bearings 27 and 28. A rotational angle controller 36 is actuated according to a control command from a host device 37 and motors 30 and 31 are driven to be rotated by referring to detection signals from angle sensors 34 and 35. Besides, the prisms 23 and 24 are rotated together with the holders 25 and 26 through gears 32 and 33. By the rotation of the prisms 23 and 24, the optical axis of the camera 1 is controlled in an optional direction and a visual field can be moved in a direction which is desired to be gazed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual device applied to a visual information input device for measuring the external situation of a nuclear robot or an intelligent robot.

[0002]

2. Description of the Related Art Conventionally, a method called binocular stereo is used as an imaging technique for displaying and measuring a three-dimensional solid shape. This method utilizes the fact that the images obtained by the two eyes are displaced due to parallax, and this displacement creates perspective. That is, the left and right eyes see the scene as shown in FIG.

That is, when performing three-dimensional measurement, as shown in FIG. 6, two cameras 1 corresponding to both eyes are used.
In the images 2a and 2b obtained from a and 1b, the three-dimensional coordinates are calculated on the basis of the triangulation principle from the coordinates of the point P of the object 3 to be measured in the left and right images. According to this method, only the part that can be seen by both cameras, that is, the common field of view, of the fields of view of the two cameras 1a and 1b is the measurable region.

When attempting to measure three-dimensional coordinates, FIG.
As shown in (a), if a narrow-angle lens is used to narrow the field of view, highly accurate measurement is possible.
The common field of view of b becomes small, and the whole area cannot be overlooked.

On the other hand, when an image is picked up using a wide-angle lens capable of overlooking the surroundings as shown in FIG. 7B, the common field of view becomes large and the three-dimensional measurement range becomes large, but the three-dimensional measurement accuracy decreases. .

The lenses attached to the cameras 1a and 1b are desired to have a narrow angle in terms of accuracy, but if this is the case, they can only be seen locally, and there is a dilemma that the accuracy cannot be satisfied with lenses that are viewed globally. .

The human eye is said to have a visual field of ± 100 ° to the left and right with both eyes, but the part where a person with a visual acuity of 1.0 can actually see with a 1.0 ability is It is said that it is within a few degrees at most to the eyeball. One of the reasons why a wide field of view is clearly visible despite such ability is that the eyeball moves.

[0008]

Conventionally, as a method for simulating the movement of the eyeball, as shown in FIGS. 8 (a) and 8 (b), a rotary mirror 5 for expanding the horizontal field of view in front of the lens 4 of the camera 1, a vertical mirror. There is a method of changing the direction of the visual field by providing the rotating mirror 6 which widens the directional visual field.

However, in this method, the rotating mirrors 5, 6 are
The size of is large because it is necessary to cover the field of view. Further, the flat mirror has a drawback that it is easily affected by angular shake due to vibration.

When the direction of the visual field is changed by the mirrors as described above, it is necessary to cover the visual field range of the lens 4 of the camera 1, and the mirrors 5 and 6 installed in front of the lens are inevitably set at their set positions. Since it is necessary to have a size commensurate with the size of the visual field at a corresponding position, there is a restriction on miniaturization.

The present invention has been made to solve the above problems, and provides a visual device capable of reliably simulating eye movements with a small device and adapted to a bad environment such as vibration. With the goal.

[0012]

In a binocular camera system, a visual device according to the present invention includes a first wedge-shaped prism and a second wedge-shaped prism arranged in front of a lens of an imaging camera, A mechanism for independently rotatably holding the first and second wedge-shaped prisms on the same axis as the lens optical axis, a motor for rotating the first and second wedge-shaped prisms, and driving the motor. And above first
And a controller for rotating the second wedge-shaped prism to deflect the optical axis of the camera.

[0013]

The optical axis of the camera is deflected by the first wedge prism. The optical axis is deflected in the direction in which the wedge prism has the largest wall thickness. Therefore, when the first wedge-shaped prism is rotated, its optical axis rotates around the original camera optical axis while keeping the deflection angle constant.

The optical axis of the camera deflected by the first wedge prism is further deflected by the second wedge prism. When the first and second wedge-shaped prisms are rotated so that the maximum thickness portions thereof are in the same direction, the deflection directions of both prisms coincide with each other, and the deflection amount of the optical axis becomes maximum. If the direction of one prism is reversed 180 degrees from this state,
The deflections are canceled out so that the optical axis becomes parallel to the optical axis of the original camera, which is approximately the same condition as when the two wedge prisms are not used.

As described above, the first wedge-shaped prism functions to rotate the optical axis while deflecting it around the optical axis of the camera at a constant angle, and the second wedge-shaped prism determines the magnitude of the deflection angle. Act on. Therefore, the optical axis of the camera can be controlled in any direction by independently controlling the rotation angles of the first and second wedge-shaped prisms in any direction under the control of the control device, and the field of view in the direction of interest can be controlled. Can be moved.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a visual device capable of simulating eye movement according to the present invention. In FIG. 1, 1 (1
Reference numerals a, 1b) are cameras, which are provided with a lens 21 and a simulation mechanism 22 for simulating eye movement on the front surface of the camera body 20. The simulation mechanism 22 is installed in each of the left and right cameras 1a and 1b, but since it has the same configuration, only one of the cameras will be described in detail below with reference to FIG.

In FIG. 2A, reference numeral 11 denotes a housing, and the camera main body 20 is provided in the housing 11 via a camera fixing base 12.
Is installed. Then, the front plate 13 is attached to the front surface of the housing 11. A circular window is formed in the center of the front plate 13, and in the window portion, the first wedge-shaped prism 23 and the second wedge-shaped prism 23 are arranged so as to face the front surface of the lens 21 of the camera 1. Wedge prism 24
Is provided. The wedge-shaped prisms 23, 24 are rotatably supported by bearings 27, 28 via ring-shaped holders 25, 26. These bearings 27 and 28 are
It is fixed to the window portion of the front plate 13 by the fixing bracket 29.

The fixed base 12 has a camera body 2 attached thereto.
The prism driving motors 30 and 31 are fixed by U-shaped stoppers 14 and 15 so as to be positioned above and below 0, and prism rotation gears 32 and 33 are attached to the rotation shafts thereof. The gears 32 and 33 are provided on the holder 25,
It engages with a thread groove provided on the outer peripheral surface of 26, and drives the motors 30 and 31 to rotate the holders 25 and 26 together with the prisms 23 and 24. In this case, the motor 3
The rotating shaft of No. 1 is led out to the outside through a through hole 16 provided in the front plate 13, and a prism rotating gear 33 is attached to the tip end thereof.

Further, the motors 30 and 31 have an angle sensor 3 for detecting the rotation angles of the prisms 23 and 24.
4, 35 are attached. These angle sensors 34, 35
Is equipped with an N-rotation potentiometer (not shown), and from the rotation angles of the motors 30 and 31, 0 of the prisms 23 and 24 can be obtained.
Rotation angle is detected from ° to 360 °. That is, the motor 30,
Since the speed reduction ratio of the rotation transmitted from 31 to the holders 25 and 26 via the prism rotation gears 32 and 33 is known in advance, the rotation angles of the prisms 23 and 24 can be calculated from the rotation angles of the rotation shafts of the motors 30 and 31. You can ask. In this case, the angle sensors 34 and 35 are provided with 5-rotation potentiometers, for example, when the reduction gear ratios of the prism rotation gears 32 and 33 are "5". Since the N-rotation potentiometer has a variable resistance structure, the output voltage 0v is the reference origin.

If the reduction ratio of the prism rotation gears 32 and 33 is "1", the angle sensors 34 and 35 are
A one-turn absolute encoder or an incremental encoder can be used. Further, in order to make the origin clear, for example, a pin may be provided on the side of the holder 25, 26, the position of this pin may be detected by a sensor such as a limit switch, and the reference origin may be detected by the output of this sensor. .

The detection signals of the angle sensors 34 and 35 are
It is sent to the rotation angle control device 36 provided in the camera body 11 and shown in FIG. The rotation angle control device 36 is connected to a host device 37 such as an electronic computer or a remote control device using a man-machine interface. The rotation angle control device 36 operates according to a control command from the host device 37 so that the first and second wedge prisms 23 and 24 have a predetermined rotation angle based on the detection signals of the angle sensors 34 and 35. The rotation of the motors 30 and 31 is controlled. Thereby, the optical axis of the camera 1 is controlled in an arbitrary direction, and the visual field is moved in the desired direction. Next, the operation of the above embodiment will be described.

FIG. 3 shows the movement of the first wedge prism 23. The wedge prism 23 has a function of deflecting an incident light beam according to the refractive index.
Therefore, the wedge prism 23 is attached to the lens 21 of the camera 1.
The optical axis of the camera 1 is deflected by placing it in front of the camera.
The optical axis is deflected in the direction in which the wedge prism 23 has the thickest wall thickness. When the wedge prism 23 is rotated, its optical axis rotates around the original optical axis of the camera while keeping the deflection angle constant. That is, when the first wedge-shaped prism 23 is rotated, the optical axis of the camera 1 rotates in a conical shape with respect to the original optical axis.

The second wedge prism 24 has the same shape as the first wedge prism 23. When the first wedge-shaped prism 23 and the second wedge-shaped prism 24 are arranged in series as shown in FIG. 4, the optical axis of the camera is further deflected by the second wedge-shaped prism 24. The action of deflection is the second because the wedge-shaped prism shapes are the same.
In principle, the deflection by the wedge-shaped prism 24 also works in the same manner as the first wedge-shaped prism 23. However, this deflection depends on the rotation position of the first wedge prism 23 and the second position.
The action changes depending on the relative relationship of the rotational positions of the wedge-shaped prism 24.

As shown in FIG. 4 (a), when the wedge prisms 23 and 24 are rotated so that the maximum thickness portions are in the same direction, the deflection direction of the first wedge prism 23 is The deflection directions of the second wedge-shaped prism 24 coincide with each other, and the deflection amount of the optical axis becomes maximum. If Figure 4
As shown in (b), when the direction of the second wedge-shaped prism 24 is reversed by 180 ° with the first wedge-shaped prism 23 kept as it is, the deflection is canceled and the optical axis becomes parallel to the optical axis of the original camera. And approximately two wedge-shaped prisms 23,
The conditions are the same as when 24 is not used. That is, when the rotation angle of the first wedge prism 23 is fixed and the second wedge prism 24 is rotated, the optical axis changes in the radial direction.

As described above, as shown in FIG. 5, the first wedge-shaped prism 23 functions to rotate the optical axis while deflecting the optical axis around the optical axis of the camera 1 at a constant angle, and the second wedge-shaped prism 24. It acts to determine the magnitude of the deflection angle.
That is, the movement of the optical axis on the surface orthogonal to the original camera optical axis is represented by (θ, φ), θ is determined by the rotation angle of the first wedge prism 23, and φ is the second wedge. Prism 2
Determined by the rotation angle of 4.

The rotation angle control device 36 independently controls the rotation angle of the first wedge-shaped prism 23 and the rotation angle of the second wedge-shaped prism 24 in an arbitrary rotation direction based on a control command from the host device 37. To do. As a result, the optical axis of the camera 1 can be controlled in an arbitrary direction, and the visual field can be moved in a desired direction.

Therefore, in the two-eye visual system shown in FIG. 1, the simulation mechanism 22 is provided to the two cameras 1a and 1b.
Attaching allows you to control the gazing point for both left and right eyes. Even when reading a character, humans face the direction of the character on both sides. By controlling the visual system so that the object to be watched is displayed in the center of the screen, it is possible to reduce the processing of unnecessary parts.

For example, when a walking robot is autonomously guided to walk, it is important whether or not the ground to be landed next is flat. In such a case, the walking robot is equipped with the twin-lens vision system according to the present invention, the next landing position of the robot is calculated, and the rotation angles of the prisms 23 and 24 are set to the motors 30 and 31 so that the position comes to the center of the screen. You can control with.

As described above, according to the present invention, the wedge prisms 23 and 24 may be installed just before the lens 21, and the interval between the two prisms 23 and 24 can be narrowed. The wedge prisms 23 and 24 need only be slightly larger than the aperture of the lens 21, and can be designed with a mechanism similar to that of a conventional electric zoom lens, which facilitates miniaturization.

Further, in the conventional mirror system, rotation of the optical axis of 1 ° corresponds to 0.5 ° of the mirror axis, so that high precision control of the rotation direction is required. This is because the ray reflected by the mirror is determined by the physical formula that it is twice the rotation angle of the mirror and cannot be changed. In contrast, the method according to the invention is variable,
Since the maximum deflection angle can be controlled by rotating the prisms 23 and 24 by ± 90 °, the rotation of the optical axis 1 ° is 1 * 90/45 = 2 ° even if the deflection angle is ± 45 °.

This can be realized by rotating the prisms 23 and 24 by 2 °, and the control accuracy of the rotation angle becomes 4 times less than in the mirror system. In other words, the accuracy required for the resolution of the angle sensors 34, 35 can be reduced. By using a prism that reduces the deflection angle, this magnification can be further increased, so that an optimum design can be performed according to the purpose that the mirror system does not have. Further, in the present invention, unlike the method of swinging the mirror, since the disk-shaped object is controlled to rotate,
Easy to adapt to bad environment such as vibration.

[0033]

As described above in detail, according to the present invention,
It is possible to reliably simulate the eye movement with a small device, and it is possible to perform stable operation without being easily affected by vibration.

[Brief description of drawings]

FIG. 1 is a perspective view of a visual device capable of simulating eye movement according to an embodiment of the present invention.

FIG. 2 is a diagram showing details of a simulation mechanism portion in the embodiment.

FIG. 3 is a diagram showing the movement of a first wedge-shaped prism.

FIG. 4 is a diagram showing the movement of a second wedge-shaped prism.

FIG. 5 is a diagram showing the overall operation of the first and second wedge-shaped prisms.

FIG. 6 is a diagram showing a captured image obtained by the binocular view method.

FIG. 7 is an explanatory diagram of a visual field obtained by the binocular vision method.

FIG. 8 is a diagram showing a conventional method of rotating a mirror to change the direction of the visual field.

[Explanation of symbols]

1, 1a, 1b ... Camera, 11 ... Housing,
12 ... Fixed base, 13 ... Front plate, 14, 15 ... Stoppers, 16 ... Through hole, 21 ... Lens, 22 ... Simulated mechanism, 23 ... First wedge-shaped prism, 24
... Second wedge prism, 25,26 ... Ring holder, 27, 28 ... Bearing, 29 ... Fixing metal fitting,
30, 31 ... Motor, 32, 33
... Gears, 34, 35 ... Angle sensor, 36 ... Rotation angle control device, 37 ... Upper device.

Claims (1)

[Claims] 1. A twin-lens camera system, comprising a first wedge-shaped prism and a second wedge-shaped prism arranged in front of a lens of an imaging camera, and the first and second wedge-shaped prisms, respectively. A mechanism for independently rotatably holding the same optical axis as the lens optical axis, a motor for rotating the first and second wedge prisms, and a motor for driving the motor to drive the first and second wedge prisms. And a control device for rotating the optical axis of the camera to deflect the optical axis of the camera.