JP4239167B2 - Visual sensor - Google Patents

Description

  The present invention relates to a visual sensor that captures a peripheral image at an arbitrary viewpoint position.

  Conventionally, as a visual sensor that captures a peripheral image at an arbitrary viewpoint position, for example, an omnidirectional visual sensor that captures an omnidirectional image at an arbitrary viewpoint position is known. As shown in FIG. For example, there is a patent that includes a reflecting mirror 11 having one hyperboloid shape and a lens 12 having the other hyperboloid shape of a two-leaf hyperboloid and having a center disposed at the focal point of the other hyperboloid. It is disclosed in Document 1.

Such an omnidirectional visual sensor can pick up an omnidirectional image from its focal point by the hyperboloidal reflecting mirror 11, so that it is possible to obtain an image with less distortion that has not undergone optically complicated conversion. Yes, the captured image can be easily converted.
JP-A-6-295333

  The omnidirectional visual sensor reflects incident light b from the surroundings by the reflecting mirror 11, and further forms an image of the incident light 13 reflected by the lens 12 on the image pickup device 13 such as a CCD (Charge-Coupled Device). The omnidirectional image is picked up by the image pickup device 13. Therefore, in order to obtain the omnidirectional image without distortion by the image sensor 13, it is necessary to strictly match the central axis of the reflecting mirror 11 and the optical axis of the lens 12, and the reflecting mirror 11 and the lens 12 are arranged with high accuracy. It is required to install. However, particularly in a miniaturized omnidirectional visual sensor, it is difficult to dispose the reflecting mirror 11 and the lens 12 separately formed with high accuracy, and the omnidirectional image may be greatly distorted. There was a problem that there was.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a visual sensor capable of suppressing the occurrence of distortion in a peripheral image taken at an arbitrary viewpoint position.

In order to solve the above-described problems, the present invention provides an optical member that guides incident light from the surroundings in a predetermined direction, an imaging element that receives the incident light guided by the optical member and images a peripheral image, and A case body that houses the imaging element, and the optical member has an incident part that guides the incident light into the optical member, and has a curved shape, and the incident light from the incident part is incident on the imaging element. A reflecting portion that reflects toward the imaging device; an emitting portion that forms an image of the incident light reflected by the reflecting portion on the imaging device; and a support portion that extends from the incident portion and supports the incident portion and the emitting portion. A mounting portion provided at an end portion of the support portion and disposed in the case body for positioning with respect to the imaging element housed in the case body. Features.

  Further, the optical member has a solid structure.

  In addition, the emission part has a curved shape protruding toward the image sensor.

  The present invention relates to a visual sensor that captures a peripheral image at an arbitrary viewpoint position, and can prevent distortion of the captured image.

  Hereinafter, a visual sensor according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 1, the visual sensor mainly includes an optical member 1, a case body 2, and an image sensor 3. For example, the visual sensor is fixed to a vehicle bumper, a side mirror, or the like, and images a blind spot portion of a driver seated on a driver's seat around the vehicle as a peripheral image.

  The optical member 1 is made of, for example, a translucent resin material, and includes an incident portion 1a that guides incident light from the periphery of the optical member 1 to the inside of the optical member 1, and a front surface from the incident portion 1a that has a hyperboloid shape. The reflection part 1 b that reflects incident light toward the image sensor 3, the support part 1 c for disposing the optical member 1 on the case body 2, and the incident light reflected by the reflection part 1 b are coupled to the image sensor 3. The emitting part 1d to be imaged is formed integrally. The optical member 1 has a solid structure with no space inside, and is formed using an appropriate method such as etching, cutting or molding. By making the optical member 1 a solid structure, dimming due to surface reflection can be suppressed, and adverse effects such as lack of contrast on the peripheral image at an arbitrary viewpoint position imaged by the image sensor 3 can be suppressed. It is possible to do.

  The incident portion 1a is formed in a spherical shape centering on the focal point A of the reflecting portion 1b having a hyperboloid shape, and the surrounding incident light is incident on the reflecting portion 1b. By forming the incident portion 1a into a spherical shape, the light directed to the focal point of the reflecting portion 1b is incident perpendicularly to the surface of the incident portion, so that the incident light is incident on the incident portion 1a. It is possible to suppress the deformation of the peripheral image when the image sensor 3 captures the peripheral image due to refraction, and does not require a complicated calculation for correcting the deformation in the image processing in the image sensor 3, and can be easily performed. Image processing can be performed.

  The reflecting portion 1b is formed by a concave portion formed in one hyperboloid shape of a two-leaf curved surface and is provided with a metal film 4 made of a metal material such as aluminum (AL) in order to make the outer surface a mirror surface. It is. The reflection unit 1b reflects the incident light incident from the incident unit 1a, and particularly reflects the incident light a directed toward the focal point of the reflection unit 1b toward the imaging element 3.

  The support part 1c is formed in a cylindrical shape extending from the incident part 1a, and supports the incident part 1a and the reflecting part 1b. Further, the optical member 1 is disposed at the end of the support portion 1c on the wall portion of the case body 2 to be described later, and the mounting portion is used for positioning with respect to the image sensor 3 housed in the case body 2. 1e is formed. The optical member 1 is disposed so as to cover an opening of a case body 2 to be described later. For example, the mounting portion 1e and the wall portion of the case body 2 are bonded and fixed via an adhesive (not shown). ing.

  The emitting portion 1d is formed on the surface of the support portion 1c facing the imaging device 3, has a curved shape protruding toward the imaging device 3, and is incident toward the focal point A of the reflecting portion 1b and is reflected by the reflecting portion 1b. The incident light “a” reflected toward the image 3 is imaged on the image sensor 3. In addition, the center of the emitting portion 1d is located at the focal point B of the other hyperboloid of the two-leaf curved surface paired with the reflecting portion 1b, and the optical axis of the emitting portion 1d and the central axis of the reflecting portion 1b coincide with each other. It is formed.

  The case body 2 is made of, for example, a dark resin material such as black, and accommodates an image sensor 3 described later. The case body 2 includes a bottom surface portion 2a on which the image pickup device 3 is disposed, a wall portion 2b extending from the bottom surface portion 2a, and a support portion 1c of the optical member 1 disposed on the adhesive, and a bottom surface portion 2a. And a cylindrical shape provided with an opening 2c that is covered with the optical member 1.

  The imaging device 3 is made of, for example, a CCD or a CMOS, and is disposed on the bottom surface portion 2a of the case body 2 so as to face the reflection portion 1b and the emission portion 1d of the optical member 1, and receives light from the emission portion 1d. The incident light a is converted into a predetermined image signal to capture the peripheral image. The image signal is output to display means (not shown) electrically connected to the image pickup device 3, and the peripheral image is visualized and displayed by controlling the display means based on the image signal.

  The visual sensor includes an optical member 1 that guides incident light from the surroundings in a predetermined direction, and an imaging element 3 that receives the incident light guided by the optical member 1 and picks up the peripheral image. Reference numeral 1 denotes an incident part 1a that guides the incident light into the optical member 1, a reflection part that has a hyperboloid shape and reflects the incident light from the incident part 1a toward the image sensor 3, and is reflected by the reflection part 1b. The exit portion 1d that forms an image of the incident light on the image pickup device 3 is integrally formed. In addition, the emission portion 1 d has a curved shape that protrudes toward the image sensor 3.

  With the above configuration, the visual sensor is configured to integrally reflect the incident light toward the image sensor 3 by integrally forming the incident portion 1a, the reflection portion 1b, and the emission portion 1d with a translucent resin material. The optical member 1 can be disposed in the case body 2 in a state where the central axis of the part 1b and the optical axis of the emitting part 1d that forms the incident light reflected by the reflecting part 1b on the image pickup device 3 coincide with each other. Therefore, when the optical member 1 is mounted, it is possible to prevent the peripheral image captured by the image sensor 3 from being distorted when the central axis of the reflecting portion 1b does not coincide with the optical axis of the emitting portion 1d. It becomes.

  In addition, the visual sensor integrally forms the incident portion 1a, the reflecting portion 1b, and the emitting portion 1d with a translucent resin material, so that the incident light a is separated from the optical member 1 as in the prior art. Since it is not necessary to dispose a dedicated lens for forming an image on the image pickup device 3, a space for disposing the lens in the case body 2 can be eliminated. It becomes possible to reduce the size as compared with the installation. Further, since the lens is not necessary, the number of parts can be reduced, and the manufacturing cost of the visual sensor can be reduced.

  In addition, the optical sensor is formed by forming the optical member 1 with a solid structure, and can reduce the dimming due to the surface reflection by reducing the places where the surface reflection occurs. It is possible to suppress adverse effects such as lack of contrast on the peripheral image.

  In addition, although the said visual sensor which is embodiment of this invention formed the optical member 1 by the solid structure, in Claim 1 of this invention, the optical member is hollow provided with space inside. It may be formed by a structure.

  In the visual sensor according to the embodiment of the present invention, the reflecting portion 1b of the optical member 1 is formed in a hyperboloid shape. However, in the present invention, the reflecting portion of the optical member may be a curved surface shape. For example, it may be formed of a curved surface such as a spherical surface, an elliptical surface, or an elliptical paraboloid.

Sectional drawing which shows the visual sensor which is embodiment of this invention. Sectional drawing which shows the conventional omnidirectional vision sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical member 1a Incident part 1b Reflective part 1c Support part 1d Output part 1e Support part 2 Case body 3 Imaging element

Claims (3)

An optical member that guides incident light from the surroundings in a predetermined direction, an image pickup device that receives the incident light guided by the optical member and picks up a peripheral image, and a case body that houses the image pickup device ,
The optical member includes an incident part that guides the incident light into the optical member, a reflection part that has a curved shape and reflects the incident light from the incident part toward the imaging element, and is reflected by the reflection part. An exit portion that forms an image of the incident light on the image sensor; a support portion that extends from the entrance portion and supports the entrance portion and the exit portion; and a case body that is provided at an end of the support portion. And a mounting portion for positioning with respect to the imaging element housed in the case body and integrally formed. The visual sensor according to claim 1, wherein the optical member has a solid structure. The visual sensor according to claim 1, wherein the emitting portion has a curved shape protruding toward the imaging element.

Images