JP6760871B2 - Image recognition system and lighting equipment - Google Patents

Description

The present invention relates to an image recognition system and a lighting device.

Conventionally, an image recognition system that recognizes a gesture by using an image captured by a camera is known. As such an image recognition system, a system that recognizes gestures by using an image captured by a stereo camera having two cameras is known (see, for example, Patent Document 1). In an image recognition system using a stereo camera, a detection target is extracted from images captured by two cameras by using shape information and brightness information, and the distance to the detection target is detected from the parallax.

Further, as an image recognition system, a system including an illumination device that irradiates an imaging region of a camera is known. As the lighting device, a device that irradiates infrared rays or visible light is used.

Japanese Unexamined Patent Publication No. 2015-219885

By the way, in general, on the projection surface facing the lighting device, the brightness becomes brightest at the position in front of the lighting device, and becomes darker as the distance from the front position increases. Therefore, in the image captured by the camera, the central portion is bright and the periphery is likely to be dark. In particular, in an illuminating device that spreads the light from a light source by a lens and irradiates it, the vicinity of the peripheral edge in the image captured by the camera tends to be darker due to the influence of the attenuation of the light intensity by the lens.

As described above, in the conventional image recognition system, the illumination distribution is non-uniform, and due to the influence of this non-uniform illuminance distribution, the detection object cannot be detected accurately, and sufficient image recognition accuracy may not be obtained. is there.

Therefore, an object of the present invention is to provide an image recognition system and a lighting device capable of improving the uniformity of the illumination distribution and improving the accuracy of image recognition.

An object of the present invention is to illuminate an image pickup apparatus, an image processing unit that detects a predetermined detection object based on an image captured by the image pickup apparatus, and an imaging region of the image pickup apparatus for the purpose of solving the above problems. The lighting device includes a lighting device, the lighting device has a light source and a lens, and is configured to irradiate the imaging region with light from the light source through the lens, and the light source emits surface light. Provided is an image recognition system having a light emitting unit that emits light, and the brightness at the central portion of the light emitting unit is smaller than the brightness at the peripheral portion of the light emitting unit.

Further, for the purpose of solving the above problems, the present invention provides an image recognition system including an image pickup device and an image processing unit that detects a predetermined detection target based on the image captured by the image pickup device. It is an illumination device used to illuminate the imaging region of the imaging apparatus, has a light source and a lens, and is configured to irradiate the imaging region with light from the light source through the lens. The light source provides a lighting device having a light emitting portion that emits surface light, and the brightness at the central portion of the light emitting portion is smaller than the brightness at the peripheral portion of the light emitting portion.

According to the present invention, it is possible to provide an image recognition system and a lighting device capable of improving the uniformity of the illumination distribution and improving the accuracy of image recognition.

It is a figure which shows the image recognition system which concerns on one Embodiment of this invention, (a) is a figure explaining the arrangement of a camera and a lighting apparatus, (b) is a schematic block diagram. It is a schematic block diagram of a lighting device. It is a figure which shows an example of a light source, (a) is a perspective view, (b) is an exploded perspective view.

[Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(Overall configuration of image recognition system)
1A and 1B are views showing an image recognition system according to the present embodiment, FIG. 1A is a diagram illustrating an arrangement of a camera and a lighting device, and FIG. 1B is a schematic configuration diagram.

As shown in FIGS. 1A and 1B, the image recognition system 1 is based on a stereo camera 2 having two left cameras 21 and a right camera 22 as image pickup devices, and images captured by both cameras 21 and 22. It is provided with an image processing unit 3 for detecting a predetermined detection object such as a finger, and a lighting device 4 for illuminating the imaging regions of both cameras 21 and 22.

The image recognition system 1 is, for example, electrically connected to an electronic device mounted on a vehicle. The image recognition system 1 determines a gesture from the image captured by the stereo camera 2, and outputs a gesture signal corresponding to the determined gesture to the electronic device. In the electronic device, the operation according to the gesture is executed. That is, the image recognition system 1 is used, for example, as an input device for operating an electronic device by a gesture.

The two cameras 21 and 22 of the stereo camera 2 are arranged apart from each other. Here, the one arranged on the left side in FIG. 1A is referred to as the left camera 21, and the one arranged on the right side is referred to as the right camera 22, but the left and right in this designation do not limit the actual arrangement. However, for example, both cameras 21 and 22 may be arranged vertically in the vertical direction. The left camera 21 and the right camera 22 are mounted on the same substrate 5.

The left camera 21 and the right camera 22 include semiconductor image sensors such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal-Oxide Semiconductor), for example. The captured images of the left camera 21 and the right camera 22 are output to the image processing unit 3.

The image processing unit 3 generates a parallax image by a known stereo matching method such as block matching based on the images captured by the left camera 21 and the right camera 22, and based on the generated parallax image, a predetermined detection of a finger or the like is performed. The object is detected and the gesture is judged. The image processing unit 3 outputs a gesture signal corresponding to the determined gesture to the electronic device.

The image processing unit 3 is mounted on the control unit 6. The control unit 6 includes, for example, a CPU (Central Processing Unit) that performs calculations and processing on the acquired data according to a stored program, a RAM (Random Access Memory) that is a semiconductor memory, a ROM (Read Only Memory), and the like. It is a microcomputer that is used. In this ROM, for example, a program for operating the control unit 6 and the like are stored. The RAM is used, for example, as a storage area for temporarily storing the captured image of the stereo camera 2 and the calculation result. Further, the control unit 6 has a means for generating a clock signal inside thereof, and executes processing based on the clock signal.

(Explanation of Lighting Device 4)
The lighting device 4 has a light source 41 that irradiates infrared rays and visible light, and a lens 42, and is configured to irradiate the imaging region of the stereo camera 2 with the light from the light source 41 via the lens 42.

As shown in FIG. 2, the lens 42 is a plano-convex lens having a flat surface 42a on the light source 41 side and a curved surface 42b curved so that the side opposite to the light source 41 is convex outward. In FIG. 2, the lens 42 and the light source 41 are brought into contact with each other, but the lens 42 and the light source 41 may be separated from each other.

The lens 42 is mounted on the substrate 5 together with the left camera 21 and the right camera 22. A lens hole 5a penetrating the substrate 5 is formed in the substrate 5, and a part of the lens 42 is inserted and fixed in the lens hole 5a. In FIG. 1A, the lens 42 is provided so as not to protrude from the surface of the substrate 5 (the surface on the imaging side of the cameras 21 and 22), but the present invention is not limited to this, and the lens 42 protrudes from the surface of the substrate 5. You may be.

The lens hole 5a is formed at an intermediate position between the two cameras 21 and 22, and the lens 42 is arranged at an intermediate position between the two cameras 21 and 22. The distances from the lens 42 to the cameras 21 and 22 are made substantially equal.

By using the lens 42 in the illuminating device 4, it is possible to bring the cameras 21 and 22 closer to the irradiation position of the illuminating light, and it is possible to reduce the size of the member in which the stereo camera 2 and the illuminating device 4 are unitized. It will be possible. However, since the irradiation light from the light source 41 passes through the lens 42, the amount of peripheral light is likely to decrease in the captured image due to the influence of the attenuation by the lens 42.

Therefore, in the present embodiment, the light source 41 of the lighting device 4 has a light emitting unit 411 that emits surface light, and the brightness at the central portion of the light emitting unit 411 is made smaller than the brightness at the peripheral portion of the light emitting unit 411. .. That is, in the present embodiment, the light source 41 having a low brightness at the central portion of the light emitting unit 411 and a high brightness at the peripheral portion of the light emitting unit 411 is used.

As a result, if the brightness of the central portion and the peripheral portion of the light emitting portion 411 is appropriately adjusted in consideration of the amount of attenuation of the light intensity in the lens 42, any projection surface 7 facing the substrate 5 (shown by hatching in FIG. 1). On the surface), it is possible to make the illuminance distribution uniform and suppress a decrease in the amount of peripheral light in the captured image.

(Explanation of Specific Example of Light Source 41)
As the light source 41, it is necessary to use a light source whose distribution of brightness in the light emitting unit 411 can be controlled. As such a light source 41, for example, those shown in FIGS. 3A and 3B can be used.

As shown in FIGS. 3A and 3B, the light source 41 has a three-layer structure in which a first light source 43 and two second light sources 44 and 45 are laminated.

The first light source 43 has a first substrate 43a and a first light emitting unit 43b provided on the first substrate 43a. Here, the first light emitting unit 43b is formed in a circular shape. A wiring 43c for supplying a drive current is connected to the first light emitting unit 43b. The wiring 43c is composed of a wiring pattern formed on the first substrate 43a.

The second light sources 44 and 45 have second substrates 44a and 45a arranged on the irradiation side of the first light emitting unit 43b and second light emitting units 44b and 45b provided on the second substrates 44a and 45a. There is. One of the two light sources 44 and 45, the second light source 44, is arranged on the first light source 43 side, and the other second light source 45 is arranged on the lens 42 side. As the second substrates 44a and 45a, transparent substrates that transmit light from the first light emitting unit 43b and the second light emitting units 44b and 45b are used.

The second light emitting units 44b and 45b have a larger outer diameter than the first light emitting unit 43b, and are formed in an annular shape along the peripheral edge of the first light emitting unit 43b when viewed from the irradiation side of the second light emitting units 44b and 45b. In the present embodiment, the second light emitting portions 44b and 45b are formed in an annular shape coaxial with the first light emitting portion 43b when viewed from the lens 42 side. Wiring 44c for supplying a drive current is connected to the second light emitting units 44b and 45b. The wirings 44c and 45c are composed of wiring patterns formed on the second substrates 44a and 45a.

In this light source 41, the brightness of the first light emitting unit 43b is made smaller than the brightness of the second light emitting units 44b and 45b, respectively. Further, as the second light sources 44 and 45 are farther from the first light source 43, the inner and outer diameters of the second light emitting units 44b and 45b are larger, and the brightness of the second light emitting units 44b and 45b is increased. In the present embodiment, the outer diameter of the first light emitting unit 43b and the inner diameter of the second light emitting unit 44b are made equal, and the outer diameter of the second light emitting unit 44b and the inner diameter of the second light emitting unit 45b are made equal.

As described above, in the light source 41, the first light emitting unit 43b, the second light emitting unit 44b, and the second light emitting unit 45b are sequentially arranged from the central portion to the peripheral portion of the light emitting unit 411 when viewed from the irradiation side. .. Further, in the light source 41, the relationship of (brightness of the first light emitting unit 43b) <(brightness of the second light emitting unit 44b) <(brightness of the second light emitting unit 45b) is established. As a result, it is possible to realize a light source 41 in which the brightness of the light emitting unit 411 gradually increases from the central portion to the peripheral portion. Further, in this light source, it is possible to easily prevent the light emitting units 43b and 44b from being hidden by the wirings 43c, 44c and 45c that supply the drive current to the light emitting units 43b, 44b and 45b, and the wiring layout is easy. ..

The portion of the second light sources 44, 45 on the central side of the second light emitting portions 44b, 45b may be transparent second substrates 44a, 45a that transmit the light of the light emitting portions 43b, 44b, or the second light source. It may be a through hole penetrating the substrates 44a and 45a.

An organic EL (electroluminescence) panel can be used as the first light source 43 and the second light sources 44 and 45. Further, as the first light source 43 and the second light sources 44 and 45, a panel light source in which a light guide plate and a light emitting diode are combined can also be used. Although the case where two second light sources 44 and 45 are used has been described here, the number of the second light sources is not limited to this, and may be one or three or more.

(Actions and effects of embodiments)
As described above, in the image recognition system 1 according to the present embodiment, the light source 41 has a light emitting unit 411 that emits surface light, and the brightness at the central portion of the light emitting unit 411 is at the peripheral portion of the light emitting unit 411. Is less than the brightness of. This makes it possible to improve the uniformity of the illumination distribution on the projection surface 7 by canceling out the influence of the attenuation of the light intensity on the lens 42 and the influence of the decrease in the light intensity due to the distance from the illumination device 4. , It becomes possible to improve the accuracy of image recognition.

Although the embodiments and modifications of the present invention have been described above, these embodiments and modifications are merely examples and do not limit the invention according to the claims. These novel embodiments and modifications can be implemented in various other embodiments, and various omissions, replacements, changes, etc. can be made without departing from the gist of the present invention. Moreover, not all combinations of features described in these embodiments and modifications are essential as means for solving the problems of the invention. Further, these embodiments and modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

1 ... Image recognition system 2 ... Stereo camera 21 ... Left camera (imaging device)
22 ... Right camera (imaging device)
3 ... Image processing unit 4 ... Lighting device 41 ... Light source 411 ... Light emitting unit 42 ... Lens 43 Substrate 43 ... First light source 43a ... First substrate 43b ... First light emitting unit 44, 45 ... Second light source 44a, 45a ... Second Substrates 44b, 45b Second light emitting unit

Claims (5)

Two imaging devices arranged apart from each other ,
An image processing unit that detects a predetermined detection target based on the images captured by the two imaging devices, and
A lighting device for illuminating the imaging region of the imaging device is provided.
The lighting device has a light source and a lens arranged at an intermediate position between the two image pickup devices, and is configured to irradiate the imaging region with light from the light source through the lens.
The light source has a light emitting portion that emits surface light, and the brightness at the central portion of the light emitting portion is smaller than the brightness at the peripheral portion of the light emitting portion.
Image recognition system. Imaging device and
An image processing unit that detects a predetermined detection target based on the image captured by the image pickup device, and
A lighting device for illuminating the imaging region of the imaging device is provided.
The lighting device has a light source and a lens, and is configured to irradiate the imaging region with light from the light source via the lens.
The light source is a first light source having a first substrate and a surface-emitting first light emitting unit provided on the first substrate, and is arranged on the irradiation side of the first light emitting unit from the first light emitting unit. A second light source having a second substrate that transmits the light of the above and a second light emitting unit that emits surface light provided on the second substrate, and the second light emitting unit is the first light emitting unit. The outer diameter is larger than that of the first light emitting portion, and the first light emitting portion is formed in an annular shape along the peripheral edge of the first light emitting portion when viewed from its own irradiation side, and the brightness of the first light emitting portion is smaller than the brightness of each of the second light emitting portions. ,
Image recognition system. The light source is configured by stacking the first light source and a plurality of the second light sources.
The farther the second light source is from the first light source, the larger the inner and outer diameters of the second light emitting unit and the larger the brightness of the second light emitting unit.
The image recognition system according to claim 2 . Two imaging devices arranged apart from each other ,
Based on the captured image of the two imaging devices, a predetermined image processing section for detecting a detection target, is used in an image recognition system comprising a lighting device for illuminating the imaging area of the imaging device,
It has a light source and a lens arranged at an intermediate position between the two imaging devices, and is configured to irradiate the imaging region with light from the light source via the lens.
The light source has a light emitting portion that emits surface light, and the brightness at the central portion of the light emitting portion is smaller than the brightness at the peripheral portion of the light emitting portion.
Lighting device. Imaging device and
A lighting device used in an image recognition system including an image processing unit that detects a predetermined detection object based on an image captured by the image pickup device, and illuminates the image pickup region of the image pickup device.
It has a light source and a lens, and is configured to irradiate the imaging region with light from the light source through the lens.
The light source is a first light source having a first substrate and a surface-emitting first light emitting unit provided on the first substrate, and is arranged on the irradiation side of the first light emitting unit from the first light emitting unit. A second light source having a second substrate that transmits the light of the above and a second light emitting unit that emits surface light provided on the second substrate, and the second light emitting unit is the first light emitting unit. The outer diameter is larger than that of the first light emitting portion, and the first light emitting portion is formed in an annular shape along the peripheral edge of the first light emitting portion when viewed from its own irradiation side, and the brightness of the first light emitting portion is smaller than the brightness of each of the second light emitting portions. ,
Lighting device.

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