JP3328483B2 - Camera view conversion adapter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for converting a photographing area by optically separating and synthesizing an input image from a television camera or the like.

[0002]

2. Description of the Related Art A photographing device represented by a CCD camera is
It has come to be used in various fields due to its higher resolution and lower price. In particular, demand for monitoring equipment and data input devices has shown a marked increase.

[0003] It can be assumed that a conventional general camera shoots through a substantially square window with respect to space. Therefore, for example, when photographing a space that expands in the horizontal direction,
Even if there is no spread in the vertical direction, it is necessary to photograph a wide area with a wide angle field of view based on the horizontal direction. However, shooting in a wide-angle field of view leads to lower resolution of the target object,
When high resolution is required, the cost is high, but a method has been adopted in which a plurality of cameras are used to divide the photographing region to photograph.

[0004]

As described above, when a camera is used as a monitoring or data input device, the field of view of a square window is often not optimal for practical use. For example, in the case of a camera for monitoring a floor, an image is usually taken with a wide-angle field of view in order to take a picture of a wide area. Alternatively, depending on the camera installation location, the majority of the screen may be a monitoring unnecessary area such as a ceiling. In addition, when photographing a license plate of a vehicle, the fluctuation in the vertical direction is sufficiently smaller than the fluctuation in the horizontal direction depending on the vehicle traveling position because it depends only on the plate mounting position. Therefore, in the above case, it can be said that it is desirable to widen the viewing area in the horizontal direction as an image.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem of expanding the field of view of a camera.
An object of the present invention is to provide a camera field-of-view conversion adapter that realizes inexpensive conversion of a shooting area by optically dividing and composing a camera field of view.

[0006]

In order to achieve the above-mentioned object, the present invention comprises a primary reflector at a position in front of a camera which divides a part of a camera field of view and reflects the part laterally around the camera field of view. A secondary reflecting mirror that adjusts one or both of a position and an angle for reflecting a part of the reflected camera field of view in an arbitrary direction is a position where a part of the reflected camera field of view is incident. A camera field-of-view conversion adapter is provided on the side of the camera field of view.

In the above-mentioned camera field-of-view conversion adapter, it is preferable to divide a part of the camera field of view into a plurality of sections by providing a plurality of sets of primary reflecting mirrors and secondary reflecting mirrors in order to meet various uses. .

In the above-described camera field-of-view conversion adapter, one or both of the primary reflecting mirror and the secondary reflecting mirror are positioned in an area where part or all of the visual field differs from the camera visual field and the divided camera visual field. A configuration in which one or both of the angles are adjusted is preferable for expanding the field of view.

Further, in the above-mentioned camera field-of-view conversion adapter, the camera field of view and the divided camera field of view are configured so that a part of the field of view mutually overlaps by the width of the object to be observed. It is suitable in that it can be caught without being.

According to the present invention, a part of the camera field of view is divided by providing a primary reflecting mirror which is slidable in the vertical direction and adjustable in angle, for example, in front of the camera lens of the mounted camera. To reflect. By directing this divided field of view to an arbitrary direction in space by adjusting the secondary reflector, any field of view can be optically divided and synthesized into the camera field of view without using multiple cameras, and the image area can be imaged. Can be set in any direction.

Further, by providing a plurality of sets of the primary reflecting mirror and the secondary reflecting mirror, it is possible to divide an arbitrary number of visual fields and to provide a visual field region having an arbitrary ratio.

Further, by setting the divided field of view to be different from a part of the direct field of view of the camera field of view and the whole of the divided field of view, a wide-angle field of view, ie, without lowering the resolution, is achieved. , Allowing the field of view to expand in any direction. For example, a half of the image area is divided by the primary reflecting mirror, and the fields of view divided by the adjustment of the secondary reflecting mirror are set at positions directly arranged in the horizontal direction of the field of view to obtain a wide field of view in the horizontal direction.

Furthermore, by partially overlapping the direct visual field and the divided visual field by the width of the observation target, the observation target can be observed without being separated into the direct visual field image and the divided visual field image. .

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1A and 1B are configuration diagrams showing an embodiment of the present invention, in which FIG. 1A is a perspective view, and FIG. 1B is a side view and a top view thereof. In the embodiment of the present invention, a photographing apparatus for photographing a vehicle license plate will be described as an example.

In FIG. 1, 1 is a primary reflecting mirror, 2 is a secondary reflecting mirror, 3 is a TV camera, 4 is a camera 3, and reflecting mirrors 1 and 2.
Is a movable part of the primary reflecting mirror 1, and 6 and 7 are movable parts of the secondary reflecting mirror 2. The portion excluding the TV camera 3 is a camera view conversion adapter.

In the above, the primary reflecting mirror 1 divides a part of the field of view of the camera 3. The movable section 5 moves the primary reflecting mirror 1 up and down to adjust the dividing position of the camera field of view. Also,
The primary reflecting mirror 1 itself is also mounted on the pedestal 4 so that the reflection angle can be adjusted. On the other hand, the secondary reflecting mirror 2 is a primary reflecting mirror 1
Is directed in an arbitrary direction in space. Movable part 6
Moves the secondary reflecting mirror 2 to the left and right, and the movable part 7 gives rotation to the secondary reflecting mirror 2. These movable parts 6 and 7 enable the secondary reflecting mirror 2 to direct the divided visual field received from the primary reflecting mirror 1 in a free direction in space.

When the vehicle license plate is photographed by the TV camera 3, the change in the vehicle passing position appears in the horizontal direction in the image, and the range is determined by the road width. Although the number attachment position varies depending on the vehicle type, it can be estimated that the number attachment position falls within a range of several tens of centimeters to about one meter from the ground. If the vehicle passing position can be limited, an angle of view of about 2 meters in the horizontal direction is sufficient, but practically, it is difficult to limit the vehicle passing. Therefore, a wide field of view in the horizontal direction is required to cover the vehicle passage area.

FIG. 2 is a view for explaining camera field-of-view division for expanding the camera field of view in the horizontal direction as described above, and is a view as seen from the side and top. In FIG. 2, k is a photographing device including the camera view conversion adapter and the TV camera 3 described in FIG. 1, i ₁ is a divided view (indirect view) divided by the primary reflecting mirror 1, and h is a direct view from the TV camera 3. Field of view,
i ₂ is a divided field of view reflected by the secondary reflecting mirror 2. In this example, the divided visual field i ₁ is directly divided below the visual field h by the movable portion 5. Also, the divided visual field i ₂ is
The tilt can be adjusted by changing the tilt of the secondary reflecting mirror 2 by the movable portion 6 and changing the reflecting direction, and is partially shifted from the direct visual field h and shifted in the horizontal direction.

FIG. 3 is a diagram showing how the direct visual field h is projected inside the camera through the camera lens in this embodiment, and α is an arbitrary value on the direct visual field projection plane. Is a point. The direct visual field h is projected on the lower half area of the CCD surface, and the arbitrary point α passes through the direct visual field h along the path indicated by the arrow in the figure.

FIG. 4 is a diagram showing how an indirect visual field (divided visual field) is projected inside the camera.
Is an arbitrary point on the indirect visual field projection plane. Indirect field of view is C
The arbitrary point β is projected on the upper half area of the CD plane, is reflected by the primary reflecting mirror 1 along the path of the arrow in the figure, and passes through the divided visual field i ₁ .

FIG. 5 is a diagram for explaining the application of the photographing device according to the present embodiment to vehicle license plate photographing, where k is the photographing device, j is the vehicle to be photographed,
h is a direct visual field from the camera, i is a divided visual field (indirect visual field) area reflected by the primary reflecting mirror and the secondary reflecting mirror, and L is an overlapping area of the direct visual field h and the divided visual field i.

In this application example, the photographing device k is installed in a space above a two-lane road on one side, and a half of the field of view of the camera is divided by a primary reflecting mirror, and the secondary reflecting mirror is adjusted to directly connect the divided field of view i to the field of view. The area h is set so as to be horizontally arranged horizontally, and one lane is covered by the divided visual field area i.
Covers the remaining lanes. If the divided visual field area i and the direct visual field area h are arranged horizontally in this way, it is possible to obtain a wide visual field in the horizontal direction while securing the resolution, and it is possible to recognize the license plate of the vehicle j in the captured image. It will be easier. The overlapping area L in FIG. 5 is an area where the direct visual field area h and the divided visual field area i overlap, and secures the same area as the width of the license plate of the vehicle j. This is necessary in order to always capture the entire license plate in either the direct visual field h or the divided visual field i. For example, in the case of a two-lane road as shown in FIG.
On the other hand, L is about 0.3 m, and it is sufficient to secure 4% of the entire visual field.

FIG. 6 is a diagram for explaining the setting of the overlapping area L at the time of photographing the license plate. X is a test object for setting the overlapping area. When setting this area, an object X having the same width as the license plate is placed on the road so as to directly cover the corner of the viewing area h, and the secondary reflecting mirror of the photographing apparatus k is adjusted. In the figure, the divided visual field region i is moved in the direction indicated by the dashed arrow, and the secondary reflecting mirror is fixed with the object X in both the direct visual field region h and the divided visual field region i.

FIG. 7 is a diagram showing a photographing result in the above embodiment, wherein the upper part shows the photographing area by the camera, and the lower part shows the image acquiring result by the photographing. j is the vehicle to be photographed, h is the direct visual field from the camera, i is the divided visual field reflected by the primary reflecting mirror and the secondary reflective mirror, and L is the overlapping area of the direct visual field h and the divided visual field i. is there. On an actual TV monitor,
As shown in the lower part of the figure, the visual field can be observed in a vertically divided state, and a wide visual field in the horizontal direction can be secured.

When license plate recognition is assumed for the overlapping area, there is no particular need to delete it.
At this point, the conversion of the viewing area, which is the object of the present invention, has been achieved.

If a plurality of sets of the primary reflecting mirror and the secondary reflecting mirror are provided, an arbitrary number of visual field divisions can be made, and a visual field region having an arbitrary ratio can be provided.

Further, the field of view may be divided by dividing the image into left and right, and the field of view may be arbitrarily enlarged in the vertical direction.

[0029]

According to the present invention, a part of the camera field of view is optically divided and set in an arbitrary direction for conversion.
The angle of view according to the purpose of use can be set at low cost, and T
When monitoring or inputting data with a V camera,
An effective imaging device can be realized.

Further, when a plurality of sets of the primary reflecting mirror and the secondary reflecting mirror are provided, an arbitrary number of visual field divisions can be performed, and a visual field region with an arbitrary ratio can be provided.

In the case where the divided visual field is set so that the direct visual field of the camera visual field and the divided visual field are partially or entirely different from each other, the wide-angle visual field is not required, that is, the resolution is reduced. Without doing so, it is possible to expand the field of view in any direction.

Further, when a part of the direct visual field and a part of the divided visual field overlap each other by an observation object width,
In particular, the observation target can be observed without being directly separated into the visual field image and the divided visual field image.

[Brief description of the drawings]

FIGS. 1A and 1B are device configuration diagrams showing an embodiment of the present invention, in which FIG. 1A is a perspective view, and FIG. 1B is a side view and a top view.

FIG. 2 is a diagram illustrating camera field-of-view division in the embodiment.

FIG. 3 is a diagram showing how a direct field of view is projected inside a camera in the embodiment.

FIG. 4 is a diagram showing how an indirect visual field (divided visual field) is projected inside the camera in the embodiment.

FIG. 5 is a diagram illustrating application to vehicle license plate photography in the embodiment.

FIG. 6 is a diagram for explaining the setting of an overlapping area during license plate photographing in the embodiment.

FIG. 7 is a diagram showing a photographing result in the embodiment.

[Explanation of symbols]

1 ... The primary reflector 2 ... secondary reflector 3 ... TV camera 4 ... base 5 ... movable portions 6 movable part 7 ... movable part h ... direct viewing or direct vision area i ... dividing the viewing area (indirect field area) i ₁ … Divided field of view reflected by primary reflecting mirror i ₂ … Divided field of view or divided field area reflected by secondary reflecting mirror k… Imaging device with camera field conversion adapter attached to TV camera L… Direct field of view and divided field of view Of overlapping area X: Test target for setting overlapping area

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-111799 (JP, A) JP-A 8-111798 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 5/222-5/257 H04N 7/18

Claims (4)

(57) [Claims] 1. A primary reflecting mirror which divides a part of a camera field of view and reflects sideward around the camera field of view is provided at a position in front of the camera, and reflects a part of the reflected camera field of view in an arbitrary direction. A secondary reflecting mirror having one or both of a position and an angle that can be adjusted is provided at a position where a part of the reflected camera field of view is incident and at a side of the periphery of the camera field of view. View conversion adapter. 2. The camera field-of-view conversion adapter according to claim 1, wherein a plurality of sets of a primary reflecting mirror and a secondary reflecting mirror are provided to divide a part of the camera field of view into a plurality. 3. The position and / or angle of one or both of the primary mirror and the secondary mirror are adjusted in a region where a part or all of the visual field differs from the camera field of view and the divided camera field of view. The camera view conversion adapter according to claim 1 or 2, wherein 4. The camera field-of-view conversion adapter according to claim 3, wherein the camera field of view and the divided camera field of view partially overlap each other by an observation target width.