JP2009080003A - Imaging apparatus and lens failure diagnosis system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus and a lens failure diagnosis system capable of self-diagnosing the presence of lens failure. <P>SOLUTION: The infrared imaging apparatus 1 which has a group of infrared lenses 11 and an infrared image sensor 13a for photographing an image obtained by condensing light by using the group of infrared lenses 11 and outputting a taken image with a gradient value corresponding to the intensity of condensed light, includes: a plane mirror 16 and an irradiation part 14 for irradiating the group of infrared lenses 11 with light at an incident angle of a half field angle or less with respect to an optical axis L of the group of infrared lenses 11. Furthermore, the lens failure diagnosis system includes the infrared imaging apparatus 1 and an image processing device which diagnoses the presence of the failure of the group of infrared lenses 11, based on the taken image output from the infrared image sensor 13a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an imaging apparatus and a lens abnormality diagnosis system that self-diagnose the presence or absence of lens abnormality.

An automobile safety system including an imaging device and an image processing device mounted on an automobile, such as a night vision system and a pre-crash safety system, has been put into practical use. An image pickup apparatus used for an automobile safety system is required to have high reliability. For this reason, various reliability tests of the image pickup apparatus are performed before shipment to ensure high reliability.
For example, an infrared detector that can perform self-diagnosis of an infrared imaging element abnormality at the time of component manufacture has been proposed (for example, Patent Document 1).
Japanese Patent Laid-Open No. 2005-98872

  However, the lens and infrared imaging element of the imaging device mounted on the vehicle are exposed to harsh environments such as heat, vibration, moisture, etc. There is a possibility that a defect or a failure may occur. In particular, the self-diagnosis of the lens abnormality cannot be performed by the infrared detector according to Patent Document 1.

  The present invention has been made in view of such circumstances, and a lens abnormality diagnosis system capable of self-diagnosis of a decrease in transmittance due to dirt, cracks, scratches, peeling of a coating, or the like of a lens, and the lens abnormality diagnosis An object of the present invention is to provide an imaging apparatus constituting the system.

  An image pickup apparatus according to a first invention includes a lens and an image pickup device that picks up an image obtained by condensing with the lens and outputs a picked-up image having a gradation value corresponding to the intensity of the collected light. An imaging apparatus, comprising: an irradiating unit that irradiates the lens with light having an incident angle with respect to an optical axis of the lens equal to or less than a half angle of view.

In the first invention, the light emitted from the irradiating means and transmitted through the lens is condensed on the image sensor. This is because when the incident angle of light with respect to the optical axis of the lens is equal to or smaller than the half angle of view, the light is incident on the image sensor. The imaging element outputs a captured image obtained by capturing an image when the irradiating unit is irradiating light. By referring to the captured image output by the imaging element, it is possible to diagnose the presence or absence of lens abnormality.
Note that the term “half angle of view” does not intend to limit the shape of the image sensor, and light having an incident angle equal to or greater than the half angle of view means light incident outside the image sensor. Therefore, the shape of the image sensor is not limited to a rectangle having an aspect ratio of 3: 4, a rectangle having an aspect ratio of 1:10, a square, and the like, and those skilled in the art can adopt any shape.

  An image pickup apparatus according to a second aspect of the present invention can be opened and closed, and includes a shutter that blocks external light other than light from the irradiation unit, and the irradiation unit emits light when the shutter is closed. It is characterized by being.

  In the second invention, the openable / closable shutter blocks external light incident on the lens. The irradiating means irradiates light when the shutter is closed and external light is blocked. The image pickup device picks up a focused image that is irradiated from the irradiation means with the shutter closed, passes through the lens, and outputs a picked-up image. Since the gradation value of the pixels constituting the captured image directly corresponds to the transmittance of the lens, the presence or absence of abnormality of the lens can be directly self-diagnosed by referring to the gradation value.

  The imaging apparatus according to a third aspect is characterized in that the irradiating means includes a light source and a reflecting mirror that reflects light from the light source and makes the light incident on the lens.

In the third invention, the light from the light source is reflected by the reflecting mirror and enters the lens.
Therefore, compared with a configuration in which light from the light source is directly incident on the lens without using a reflecting mirror, the degree of freedom of arrangement of the irradiation means is high, and the infrared imaging device can be miniaturized.

  An image pickup apparatus according to a fourth invention is characterized in that the irradiating means includes a collimator and irradiates the lens with parallel light from the collimator.

In the fourth aspect of the invention, the parallel light generated by the collimator is irradiated onto the lens and is condensed on the image sensor. The parallel light enters the lens more accurately than the non-parallel light and is condensed on the image sensor.
In particular, when the optical system is focused at infinity, the spread of light when focused on the image sensor can be minimized.

  The image pickup apparatus according to a fifth aspect is characterized in that the irradiating means irradiates light over a predetermined range including the entire surface of the lens or the central portion of the lens.

In the fifth invention, when the light from the irradiating means is irradiated on the entire surface of the lens, the light transmitted through the entire surface of the lens is condensed on the image sensor.
Therefore, the imaging device can output a captured image indicating the transmittance of the lens over the entire lens surface, that is, the presence or absence of an abnormality over the entire lens surface.
In addition, when the light from the irradiation unit is applied to a predetermined range including the central portion of the lens, the light transmitted through the predetermined range of the lens is collected on the image sensor.
Therefore, the imaging device can output a captured image indicating whether there is an abnormality in the predetermined range of the lens.

  An image pickup apparatus according to a sixth aspect of the invention is characterized by comprising diagnostic means for diagnosing the presence or absence of an abnormality of the lens based on a gradation value of a pixel constituting a picked-up image obtained by the image pickup device. .

  In the sixth invention, the diagnosis means self-diagnose the presence / absence of an abnormality related to the transmittance of the lens based on the gradation value of the pixels constituting the captured image output by the image sensor.

  According to a seventh aspect of the present invention, there is provided a lens abnormality diagnosis system, the imaging apparatus according to any one of the first to fifth aspects, an acquisition unit that acquires a captured image obtained by the imaging element, and the acquisition unit And a diagnostic device having diagnostic means for diagnosing the presence / absence of abnormality of the lens based on gradation values of pixels constituting the captured image.

  In the seventh invention, the acquisition unit of the diagnostic apparatus acquires the captured image output by the imaging device of the imaging apparatus, and the diagnostic unit is based on the gradation values of the pixels constituting the captured image acquired by the acquisition unit. Then, the self-diagnosis of the abnormality related to the transmittance of the lens is performed.

  In the lens abnormality diagnosis system according to an eighth aspect of the present invention, the diagnosis device includes a storage unit that stores a threshold value, and the diagnosis unit includes a gradation value of a pixel that constitutes a captured image acquired by the acquisition unit, and the storage The present invention is characterized in that the presence or absence of abnormality of the lens is diagnosed by comparing threshold values stored in the means.

  In the eighth invention, the storage means of the diagnostic device stores a threshold value for diagnosing the presence or absence of abnormality of the lens, and the diagnostic means stores the gradation values of the pixels constituting the captured image acquired by the acquisition means And the threshold value stored in the storage means is diagnosed to determine whether there is an abnormality in the lens. Specifically, it is determined whether or not the transmittance of the lens is equal to or higher than a predetermined transmittance.

  In the lens abnormality diagnosis system according to a ninth aspect of the present invention, the diagnostic means includes a gradation value for each of a plurality of pixels constituting a captured image obtained by the imaging device when the irradiation means is irradiating light, And a difference calculating means for calculating a difference between gradation values of each of a plurality of pixels constituting a picked-up image obtained by the image pickup device when the irradiation means is not irradiating light, and the difference calculating means Based on the calculated difference, the presence or absence of abnormality of the lens is diagnosed.

  In the ninth invention, the difference calculating means calculates a difference for each of a plurality of pixels constituting each captured image output by the image sensor. The difference calculated by the difference calculation means directly corresponds to the transmittance of the lens, and the diagnosis means diagnoses a lens abnormality based on the difference.

  The lens abnormality diagnosis system according to a tenth aspect of the invention is characterized in that the diagnostic device includes means for issuing a warning when diagnosing that there is an abnormality in the lens.

  In the tenth invention, when the diagnostic device determines that the lens is abnormal, it issues a warning to notify the user of the imaging device that the lens is abnormal.

  According to the present invention, it is possible to obtain a captured image for diagnosing a lens abnormality by providing an irradiation unit that irradiates the lens with light having an incident angle equal to or smaller than a half field angle. Can be diagnosed.

(Embodiment 1)
Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
FIG. 1 is a schematic diagram showing an infrared imaging device 1 according to Embodiment 1 of the present invention.
In the figure, reference numeral 11 denotes an infrared lens group composed of a plurality of infrared lenses, and the infrared lens group 11 is fixedly fitted inside a lens barrel 12 made of aluminum. An infrared imaging unit 13 is disposed on the back side of the infrared lens group 11. For convenience of drawing and explanation, the infrared lens group 11 is shown as a single lens having optical performance equivalent to that of the condensing optical system composed of the plurality of infrared lenses.

  The infrared lens group 11 is a sintered body obtained by sintering, for example, zinc sulfide raw material powder by a hot press method, and has transparency to infrared rays of 8 to 12 μm band. In order to improve the environmental resistance of the infrared lens group 11, the front surface of the infrared lens group 11 may be covered with a DLC (diamond like carbon) film. The DLC film is an amorphous carbon thin film having a structure similar to diamond.

  The infrared imaging unit 13 is a matrix of elements that image the front of the vehicle with infrared rays having a wavelength of 7 to 14 μm, that is, photoelectrically convert an image formed by the infrared lens group 11 into luminance signals, such as thermopile, pyroelectric element, and bolometer. A substantially rectangular infrared imaging element 13a is provided. In the infrared imaging element 13a, the optical axis L of the infrared lens group 11 passes through the center thereof, and the distance between the principal point of the infrared lens group 11 and the infrared imaging unit 13 in the direction of the optical axis L is the infrared ray in order to focus at infinity. They are arranged so as to be substantially equal to the focal length of the lens group 11. Since the depth of field becomes deeper as the focus is adjusted farther, the subject in the distance range of about 50 m to infinity is taken from the infrared imaging apparatus 1 without adjusting the focus by adjusting the focus to infinity. Will be able to. The aspect ratio of the infrared imaging element 13a is 4/3. The infrared imaging unit 13 performs imaging processing continuously or intermittently, generates, for example, 30 pieces of captured image data per second, and outputs them to the signal processing unit 18. In addition, each pixel which comprises a captured image is arranged in two dimensions, and captured image data contains the data which show the brightness | luminance of each pixel shown as a position of each pixel, and a gradation value.

  The signal processing unit 18 is controlled by a control unit 17 formed of a microcomputer, and AD-converts analog captured image data into digital captured image data. More specifically, each pixel constituting the image is converted into digital captured image data represented by a gradation value such as 256 gradations (1 Byte). Then, the image processing unit performs various correction processes on the AD-converted captured image data, and outputs the captured image data to an external device via the output unit 19.

  The infrared imaging device 1 also includes an irradiation unit 14 (irradiation unit) for diagnosing the presence or absence of abnormality of the infrared lens group 11, a shutter 15, a plane reflecting mirror 16 (irradiation unit), and a shutter drive unit 15a. .

  The irradiation unit 14 includes a light source 14a that emits infrared rays having a predetermined intensity, and a collimator lens 14b. The light source 14a has, for example, a filament that generates heat when energized, and is disposed at the focal point of the collimator lens 14b. The light source 14 a is turned on and off by the control unit 17.

  The lens barrel 12 includes a cylindrical main body portion 12a that holds the infrared lens group 11, and a holding portion 12b that is integrally formed on the outer peripheral surface of the main body portion 12a and holds the collimator lens 14b and the light source 14a. . The holding portion 12b has a posture in which the collimator lens 14b faces the front and obliquely inside. Specifically, the optical axis of the collimator lens 14b and the optical axis L of the infrared lens group 11 are in the same plane, and each light The collimator lens 14b is held in such a posture that the angle θ formed by the axis L is equal to or less than the half angle of view α.

The shutter 15 has a plate shape that can be opened and closed, and is provided on the front side of the infrared lens group 11. Opening and closing of the shutter 15 is controlled by the control unit 17. The control unit 17 gives a shutter drive signal to the shutter drive unit 15a, and the shutter drive unit 15a opens and closes the shutter 15 when receiving the shutter drive signal. When the shutter 15 is opened, external light is incident on the infrared lens group 11, and when the shutter 15 is closed, the external light incident on the infrared lens group 11 is blocked.
Although a mechanical plain shutter is taken as an example, a shutter having another configuration may be used as long as external light can be blocked.

  The shutter 15 is provided to block outside light that hinders the lens abnormality diagnosis, but infrared rays are also emitted from the shutter 15 itself, and the infrared rays may hinder the lens abnormality diagnosis. Therefore, it is preferable to perform a self-diagnosis of lens abnormality while keeping the intensity of infrared rays emitted from the shutter 15 constant. When the intensity of infrared rays emitted from the shutter 15 is constant and known, the presence or absence of lens abnormality can be diagnosed in consideration of the influence of the infrared rays. In order to keep the infrared intensity constant, for example, the shutter 15 is formed of a metal having high thermal conductivity so that the surface temperature of the shutter 15 is uniform, and is constant by a thermocouple temperature detector and a Peltier element (not shown). Control to temperature.

  Furthermore, since the shutter 15 that blocks external light is necessary not only for lens abnormality diagnosis but also for periodically offset correcting sensitivity variations of the infrared imaging device 13a, the shutter 15 is used for lens abnormality diagnosis. You may comprise so that it may be shared by the object for offset correction.

  On the surface of the shutter 15 on the infrared lens group 11 side, a plane reflecting mirror 16 for reflecting the infrared ray irradiated from the irradiation unit 14 and making it incident on the infrared lens group 11 is fixed. The planar reflecting mirror 16 is fixed in such a posture that the reflecting surface is substantially perpendicular to the optical axis L. Accordingly, the infrared light irradiated from the irradiation unit 14 is incident on the plane reflecting mirror 16 at the incident angle θ, is reflected at the reflecting angle θ, and the infrared light reflected by the planar reflecting mirror 16 is incident on the infrared lens group 11 at the incident angle θ. To do.

  FIG. 2 is a schematic diagram illustrating a configuration of an obstacle detection system including the infrared imaging device 1. The obstacle detection system (lens abnormality diagnosis system) according to the first embodiment of the present invention detects two obstacles in front of a vehicle by issuing two infrared imaging devices 1 constituting a stereoscopic infrared imaging device, and issues a warning. An image processing device (diagnostic device) 3 having an obstacle detection function and a lens abnormality diagnosis function for diagnosing the presence or absence of abnormality of the infrared lens group 11 is provided.

  The infrared imaging device 1 is juxtaposed inside the front grill. One infrared imaging device 1 is arranged on the right side in the vehicle width direction when viewed from the driver's seat side. The other infrared imaging device 1 is arranged on the left side in the vehicle width direction and at a position where the height from the road surface is equal to the one infrared imaging device 1. Moreover, each infrared imaging device 1 is fixed in a posture such that the optical axis L direction is substantially parallel. By capturing a common imaging target with the two infrared imaging devices 1, the parallax of the imaging target in both images can be calculated, and the distance to the imaging target can be obtained based on the principle of triangulation.

  FIG. 3 is a block diagram illustrating a configuration of the image processing apparatus 3. The image processing apparatus 3 includes a control unit 31, an image memory 32, a RAM 33, an input unit 34, a video output unit 35, a communication interface unit 36, and a storage unit 37.

  The input unit 34 is connected to the output unit 19 of the infrared imaging device 1 via the cable 7 and inputs captured image data output from the infrared imaging device 1. The captured image data input to the input unit 34 is sequentially stored in the image memory 32 in units of one frame.

  The video output unit 35 is connected to the display device 4 via the cable 8, for example, an in-meter display, a navigation display, a head-up display, and the like. The video output unit 35 appropriately transmits the input captured image data to the display device 4 and causes the display device 4 to display the captured image obtained by the infrared imaging device 1.

  An alarm device 5 is connected to the communication interface unit 36 via an in-vehicle LAN cable 6 compliant with CAN (Controller Area Network), and an alarm signal according to the control of the control unit 31 is transmitted via the communication interface unit 36. The alarm device 5 is configured to be transmitted.

The alarm device 5 includes a buzzer, a speaker, and the like, and when a pedestrian that may contact or collide is detected in the obstacle detection process, the alarm device 5 outputs a message to that effect by a sound, a warning sound, etc. , “Danger” is displayed.
Further, when it is diagnosed that there is an abnormality in the infrared lens group 11 in the lens abnormality diagnosis process described later, the alarm device 5 outputs that effect by voice, warning sound, etc., and the display device 4 displays “lens abnormality”. Etc. are displayed.

  The image memory 32 is SRAM, flash memory, SDRAM or the like, and temporarily stores captured image data input from the infrared imaging device 1 via the input unit 34.

The storage unit 37 stores in advance a threshold value for determining whether the infrared lens group 11 has a normal transmittance. The threshold value is a value obtained by measurement in advance when the infrared imaging device 1 is manufactured. Specifically, the infrared rays irradiated from the irradiation unit 14 with the shutter 15 closed are transmitted through a normal infrared lens group 11 before starting to be used without being contaminated or scratched and condensed on the infrared imaging element 13a. In this case, the maximum gradation value of the captured image output from the infrared imaging element 13a is measured, the measured maximum gradation value is multiplied by a predetermined ratio, for example, 0.8, and the value obtained by multiplication is set as a threshold value. To do. The maximum gradation value is a maximum value of gradation values of a plurality of pixels constituting the captured image.
More preferably, the threshold value is set by measuring the maximum gradation value in a state where the surface temperature of the shutter 15 is maintained at a predetermined temperature at the time of lens abnormality diagnosis. This is because the influence of infrared rays emitted from the shutter 15 on the lens abnormality diagnosis is eliminated by setting the surface temperature of the shutter 15 to be the same at the time of setting the threshold and at the time of lens abnormality diagnosis.

  The control unit 31 reads captured image data stored in the image memory 32 in units of frames, and executes an obstacle detection process for detecting an obstacle ahead of the vehicle based on the read captured image data. The control unit 31 also performs a lens abnormality diagnosis process described later at a predetermined timing.

Next, the operation of the infrared imaging device 1 and the image processing device 3 according to the present invention when performing lens abnormality self-diagnosis processing will be described.
FIG. 4 is a flowchart showing a processing procedure of the control unit 17 on the infrared imaging device 1 side related to the self-diagnosis of the infrared lens group 11.

  The control unit 17 of the infrared imaging device 1 provides the shutter drive signal to the shutter drive unit 15a, thereby closing the shutter 15 (step S11) and turning on the light source 14a (step S12). When the shutter 15 is closed, the surface temperature of the shutter 15 is preferably heated or cooled to a predetermined temperature when the threshold is set. This is because the influence of infrared rays emitted from the shutter 15 on the diagnosis of lens abnormality is excluded.

  Next, the control unit 17 captures the image condensed by the infrared lens group 11 with the infrared imaging element 13a (step S13), and outputs captured image data obtained by imaging to the image processing device 3 (step S14). ).

  Then, the control unit 17 turns off the light source 14a (step S15), and provides the shutter drive signal to the shutter drive unit 15a, thereby opening the shutter 15 (step S16) and ends the process.

FIG. 5 is a flowchart showing a processing procedure of the control unit 31 on the image processing apparatus 3 side related to the self-diagnosis of the infrared lens group 11.
The control unit 31 of the image processing device 3 acquires captured image data output from the infrared imaging device 1 (step S31). Next, the control unit 31 calculates the maximum gradation value of the captured image based on the acquired captured image data (step S32). The maximum gradation value is the maximum value of the gradation value of each pixel constituting the captured image. The maximum gradation value indicates the intensity of light emitted from the irradiation unit 14, transmitted through the infrared lens group 11, and condensed on the infrared imaging element 13a. Show.

  Next, the control unit 31 reads the threshold value from the storage unit 37 (step S33), and determines whether or not the maximum gradation value calculated in step S32 is less than the threshold value (step S34). That is, it is determined whether or not the transmittance of the infrared lens group 11 is in the normal range.

  If it is determined that the maximum gradation value is less than the threshold value (step S34: YES), the control unit 31 issues a warning that the infrared lens group 11 is abnormal (step S35) and ends the process. When it determines with the maximum gradation value being more than a threshold value (step S34: NO), the control part 31 complete | finishes a process noting that there is no abnormality in the infrared lens group 11. FIG.

  In the obstacle detection system configured as described above, the irradiation unit 14 is turned on with the shutter 15 closed, and an image that passes through the infrared lens group 11 and is condensed on the infrared imaging element 13a is captured. Thus, captured image data necessary for self-diagnosis of the presence or absence of abnormality of the infrared lens group 11 can be obtained.

  Further, the image processing apparatus 3 can diagnose the presence or absence of abnormality of the infrared lens group 11 based on the maximum gradation value of the captured image data. Since the maximum gradation value corresponds to the transmittance of the infrared lens group 11, it is diagnosed whether or not the transmittance of the infrared lens group 11 is normal by comparing the maximum gradation value with a threshold value. be able to.

  Furthermore, since the irradiation unit 14 includes a collimator lens 14b and converts the infrared light from the light source 14a into parallel light and enters the infrared lens group 11, the irradiation unit 14 more accurately emits light from the light source 14a than when the collimator lens 14b is not provided. Can be condensed on the infrared imaging device 13a.

  Furthermore, since the irradiation unit 14 is held by the lens barrel 12 and the infrared rays emitted from the irradiation unit 14 are reflected and incident on the infrared lens group 11, the irradiation unit 14 is arranged on the infrared imaging element 13a. Compared with the case where it is arranged on the front side, the infrared imaging device 1 can be miniaturized.

  Furthermore, the infrared ray for diagnosing lens abnormality is configured to be incident on a part of the infrared lens group 11, but the substantially entire surface of the infrared lens group 11 or the central portion of the surface of the infrared lens group 11 and the central portion. You may comprise so that the infrared rays for lens diagnosis may enter into the predetermined range including a periphery.

  FIG. 6 is a schematic diagram showing an infrared imaging device 101 according to a modification of the present invention. The infrared imaging device 101 according to the modified example is configured to irradiate lens diagnosis infrared rays on substantially the entire front side.

  The irradiation unit 114 includes a light source 14a and a collimator lens 114b, and a planar reflecting mirror 116 having a wedge-shaped side section is provided on the shutter 15. The collimator lens 114b has a diameter substantially equal to that of the infrared lens group 11, and is fixed to the holding portion 112b of the barrel 112 so as to face obliquely inside. The infrared light flux from the collimator lens 114 b is parallel light having a diameter substantially equal to the diameter of the infrared lens group 11.

  The plane reflecting mirror 116 is fixed in such a posture that the infrared ray from the collimator lens 114b is reflected and the reflected infrared ray is incident on the entire front side of the infrared lens group 11 at an incident angle θ.

  In the infrared imaging device 101 according to the first modified example, infrared rays for lens diagnosis are incident on substantially the entire surface of the infrared lens group 11, and the infrared rays transmitted through the infrared lens group 11 are condensed on the imaging element. The presence or absence of dirt, cracks, scratches, etc. on the entire surface of the infrared lens group 11 can be diagnosed.

  In the first embodiment, as an example, an infrared imaging device that captures an image of a subject using infrared light is illustrated. However, the present invention is applied to an imaging device that captures an image of a subject using visible light or light of other wavelengths. You may do it.

  In the first embodiment, a collimator lens is provided. However, when a light source capable of irradiating parallel light is provided, the collimator lens is unnecessary. For example, it is possible to provide a semiconductor laser as a light source. When the light source is provided, a collimator lens is not necessary.

  Furthermore, although the image processing apparatus performs lens abnormality diagnosis processing, the infrared imaging apparatus may be configured to perform lens abnormality diagnosis.

(Embodiment 2)
As in the first embodiment, the obstacle detection system according to the second embodiment includes an infrared imaging device 201, an image processing device 3, a display device 4, an alarm device 5, and the like.
FIG. 7 is a schematic diagram showing an infrared imaging device 201 according to Embodiment 2 of the present invention. The infrared imaging device 201 according to the second embodiment includes an infrared lens group 11, a lens barrel 12, an infrared imaging unit 13, an irradiation unit 14, a control unit 17, and a signal processing unit 18 similar to the infrared imaging device according to the first embodiment. The output unit 19 is provided.
However, in the infrared imaging device 201 according to Embodiment 2, a shutter 215 used for offset correction of the infrared imaging element 13a is disposed between the infrared lens group 11 and the imaging element. In this case, since the infrared rays from the light source 14a are also blocked by closing the shutter 215, it is impossible to diagnose the presence or absence of lens abnormality after blocking outside light using the shutter 215 as described in the first embodiment. .
The infrared imaging apparatus 201 according to the second embodiment enables self-diagnosis of the lens abnormality without closing the shutter 215, and the processing procedure of the plane reflecting mirror 216 and the control unit 31 is implemented. Different from the infrared imaging apparatus according to the first embodiment. Below, the said difference is mainly demonstrated.

  A flat plate-like reflecting mirror support 216 c that supports the flat reflecting mirror 216 is extended to the front side in the optical axis L direction at the front end portion of the lens barrel 12. The flat reflecting mirror 216 is rotatably supported at the tip of the reflecting mirror support 216c by a rotating shaft 216a, and the flat reflecting mirror 216 is folded toward the reflecting mirror support 216c as indicated by a two-dot chain line. The closed state and the open state in which the reflecting mirror faces the infrared lens group 11 as shown by the solid line can be taken.

  The plane reflecting mirror 216 is driven to rotate by the reflecting mirror driving unit 216b. The reflecting mirror driving unit 216b includes, for example, a stepping motor that rotates the planar reflecting mirror 216, a motor driving unit that drives the stepping motor, and the like. The operation of the reflecting mirror driving unit 216b is controlled by the control unit 17. Yes.

  FIG. 8 is a flowchart showing a processing procedure of the control unit 17 on the infrared imaging apparatus 201 side related to the self-diagnosis of the infrared lens group 11 in the second embodiment.

  The control unit 17 of the infrared imaging device 201 opens the planar reflecting mirror 216 by supplying a reflecting mirror driving signal to the reflecting mirror driving unit 216b (step S51), and turns on the light source 14a (step S52). Next, the control unit 17 captures an image collected by the infrared lens group 11 with the infrared imaging element 13a in a state where the light source 14a is turned on (step S53), and outputs captured image data obtained by the imaging. (Step S54).

Then, the control unit 17 turns off the light source 14a (step S55), and picks up an image collected by the infrared lens group 11 with the infrared imaging element 13a in a state where the light source 14a is turned off (step S56). Captured image data obtained by imaging is output (step S57).
Note that the captured image data when the light source 14a is turned on and off in steps S53 and S56 is preferably data when the captured image is stable, for example, when the vehicle is stopped. This is because it takes time to turn on and off the light source 14a and the imaging process, and therefore accurate difference data cannot be obtained when the captured image is not stable. Therefore, for example, a receiving unit that receives a vehicle speed sensor signal indicating whether or not the vehicle is stopped, and a vehicle stop determination that determines whether or not the vehicle is stopped based on the vehicle speed sensor signal received by the receiving unit. And when the vehicle stop determination means determines that the vehicle is stopped, it may be configured to determine whether or not there is an abnormality in the lens based on a captured image obtained by the imaging device. With this configuration, it is possible to more accurately determine whether there is a lens abnormality.

  Next, the control unit 17 provides the reflecting mirror driving signal to the reflecting mirror driving unit 216b, thereby closing the planar reflecting mirror 216 (step S58) and finishing the process.

FIG. 9 is a flowchart showing a processing procedure of the control unit 31 on the image processing apparatus 3 side according to the self-diagnosis of the infrared lens group 11 in the second embodiment.
The control unit 31 of the image processing device 3 acquires captured image data output from the infrared imaging device 201 when the light source 14a is turned on and off (step S71). Next, based on the acquired captured image data, the control unit 31 calculates a difference in gradation value of each captured image data for each pixel (step S72).

  FIG. 10 is a schematic diagram illustrating a captured image acquired from the infrared imaging device 201 and a captured image after difference calculation. 10A shows a captured image when the light source 14a is turned off, FIG. 10B shows a captured image when the light source 14a is turned on, and FIG. 10C shows each pixel constituting the captured image when the light source 14a is turned on. This is a captured image obtained by subtracting the gradation value of each pixel constituting the captured image when the light source 14a is turned off from the gradation value. As shown in FIG. 10C, the image of the subject is removed by subtracting the gradation value of the captured image when the light source 14a is turned off from the gradation value of the captured image when the light source 14a is turned on, and the irradiation unit 14 Only an image can be obtained.

  When the process of step S72 is completed, the control unit 31 calculates the maximum difference value having the maximum value among the calculated differences (step S73). Next, the control unit 31 reads the threshold value (step S74), and determines whether or not the maximum difference value calculated in step S73 is less than the threshold value (step S75). That is, it is determined whether or not the transmittance of the infrared lens group 11 is in the normal range.

  If it is determined that the maximum difference value is less than the threshold value (step S75: YES), the control unit 31 issues a warning that the infrared lens group 11 has an abnormality (step S76), and ends the process. When it determines with the maximum difference value being more than a threshold value (step S75: NO), the control part 31 complete | finishes a process noting that there is no abnormality in the infrared lens group 11. FIG.

  In the infrared imaging device 201 and the obstacle detection system according to Embodiment 2, the abnormality of the infrared lens group 11 can be diagnosed even when the shutter 215 is arranged between the infrared lenses.

  In the second embodiment, the infrared ray irradiated from the irradiation unit 14 is configured to be incident at a predetermined incident angle θ, but the infrared lens group 11 is rotated while the plane reflecting mirror 216 is rotated. It may be configured to irradiate infrared rays to different locations of the lens and perform self-diagnosis of the abnormality of the infrared lens group 11. In this case, the area of the surface portion of the infrared lens group 11 where abnormality can be diagnosed can be increased without increasing the size of the irradiation unit 14.

  Other configurations, operations, and effects of the infrared imaging device 201 and the obstacle detection system according to Embodiment 2 are the same as the configurations, operations, and effects of the infrared imaging device and the obstacle detection system according to Embodiment 1. Corresponding portions are denoted by the same reference numerals, and detailed description thereof is omitted.

  It should be understood that the embodiment disclosed this time is illustrative in all respects and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic diagram which shows the infrared imaging device which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the structure of the obstruction detection system provided with the infrared imaging device. It is a block diagram which shows the structure of an image processing apparatus. It is a flowchart which shows the process sequence of the control part by the side of the infrared imaging device which concerns on the self-diagnosis of an infrared lens group. It is a flowchart which shows the process sequence of the control part by the side of the image processing apparatus which concerns on the self-diagnosis of an infrared lens group. It is a schematic diagram which shows the infrared imaging device which concerns on the modification of this invention. It is a schematic diagram which shows the infrared imaging device which concerns on Embodiment 2 of this invention. 6 is a flowchart illustrating a processing procedure of a control unit on the infrared imaging apparatus side according to self-diagnosis of an infrared lens group in the second embodiment. 6 is a flowchart illustrating a processing procedure of a control unit on the image processing apparatus side relating to self-diagnosis of an infrared lens group in the second embodiment. It is a schematic diagram which shows the captured image acquired from the infrared imaging device, and the captured image after difference calculation.

Explanation of symbols

1 Infrared imaging device 3 Image processing device (diagnostic device)
DESCRIPTION OF SYMBOLS 11 Infrared lens group 13a Infrared image sensor 14,114 Irradiation part 14a Light source 14b, 114bb Collimator lens 15 Shutter 16,116,216 Planar reflector 31 Control part (acquisition means, diagnostic means, difference calculation means)
37 Memory part L Optical axis

Claims (10)

An imaging apparatus comprising a lens and an image sensor that captures an image obtained by condensing with the lens and outputs a captured image having a gradation value corresponding to the intensity of the collected light,
An imaging apparatus comprising: irradiation means for irradiating the lens with light having an incident angle with respect to the optical axis of the lens that is equal to or smaller than a half angle of view. Comprising a shutter that can be opened and closed and blocks outside light other than the light from the irradiation means;
The irradiation means includes
The imaging apparatus according to claim 1, wherein light is emitted when the shutter is closed. The irradiation means includes
A light source;
The imaging apparatus according to claim 1, further comprising: a reflecting mirror that reflects light from the light source and causes the light to enter the lens. The irradiation means includes
The imaging apparatus according to claim 1, further comprising a collimator, wherein the lens is irradiated with parallel light from the collimator. The irradiation means includes
The imaging apparatus according to any one of claims 1 to 4, wherein light is applied to a predetermined range including an entire surface of the lens or a central portion of the lens. The diagnostic means for diagnosing the presence or absence of an abnormality of the lens based on a gradation value of a pixel constituting a captured image obtained by imaging by the imaging element. The imaging apparatus as described in any one. An imaging device according to any one of claims 1 to 5,
Acquisition means for acquiring a captured image obtained by imaging by the imaging element; and diagnostic means for diagnosing the presence or absence of abnormality of the lens based on a gradation value of a pixel constituting the captured image acquired by the acquisition means. A lens abnormality diagnosis system comprising: a diagnostic device having: The diagnostic device comprises:
Storage means for storing the threshold value;
The diagnostic means includes
The present invention is characterized in that the presence or absence of abnormality of the lens is diagnosed by comparing the gradation value of the pixels constituting the captured image acquired by the acquisition unit and the threshold value stored in the storage unit. The lens abnormality diagnosis system according to claim 7. The diagnostic means includes
A gradation value of each of a plurality of pixels constituting a captured image obtained by imaging by the imaging device when the irradiation unit emits light, and the imaging device when the irradiation unit does not emit light Is provided with difference calculation means for calculating a difference between gradation values of each of a plurality of pixels constituting a captured image obtained by imaging, and diagnosing the presence or absence of abnormality of the lens based on the difference calculated by the difference calculation means The lens abnormality diagnosis system according to claim 7 or 8, wherein the lens abnormality diagnosis system is configured as described above. The diagnostic device comprises:
The lens abnormality diagnosis system according to any one of claims 7 to 9, further comprising means for issuing a warning when the lens is diagnosed as having an abnormality.

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