JP4650469B2 - Imaging apparatus and lens abnormality diagnosis system - Google Patents

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 malfunction or failure may occur.
In the infrared detector according to Patent Document 1, self-diagnosis of component parts, particularly self-diagnosis of lens abnormality cannot be performed while imaging.

  The present invention has been made in view of such circumstances, and self-diagnosis of a decrease in transmittance due to the presence or absence of lens abnormality, for example, lens dirt, cracks, scratches, coating peeling, etc., while imaging is performed. An object of the present invention is to provide a lens abnormality diagnosis system that can be used, and an imaging device that constitutes the lens abnormality diagnosis system.

An imaging apparatus according to a first aspect of the present invention is an imaging apparatus comprising a lens and an imaging element that captures an image obtained by condensing with the lens, and an incident angle with respect to the optical axis of the lens is equal to or greater than a half field angle . In addition, an irradiation unit that irradiates the lens with light whose angle with respect to the optical axis of the light beam incident on the lens is equal to or greater than a half angle of view , and receives and receives the light irradiated from the irradiation unit and transmitted through the lens The light-receiving part which outputs the value according to the intensity | strength of light, and the stop which interrupts | blocks this external light so that external light other than the light from the said irradiation part may not enter into the said light-receiving part are provided.
In the imaging device according to a second aspect of the present invention, the irradiating unit includes a light source and a collimator lens that collimates the light emitted from the light source, and a virtual straight line connecting the principal point of the lens and the light receiving unit; The collimator lens is arranged so as to be substantially parallel to the optical axis of the collimator lens.
In the imaging device according to a third aspect, the irradiating unit includes a light source, a collimator lens that collimates the light emitted from the light source, and a reflecting mirror that reflects the collimated light from the collimator lens and enters the lens. The reflecting mirror is arranged such that an imaginary straight line connecting the principal point of the lens and the light receiving unit and an optical axis of parallel light are substantially parallel to each other.
In the imaging device according to a fourth aspect of the invention, the irradiating unit includes a light source capable of irradiating parallel light, and the light source includes an imaginary straight line connecting the principal point of the lens and the light receiving unit, and an optical axis of the parallel light. Are arranged so as to be substantially parallel to each other.
According to a fifth aspect of the present invention, the irradiating unit includes a light source capable of irradiating parallel light, and a reflecting mirror that reflects the parallel light emitted from the light source and makes it incident on the lens. Is arranged such that a virtual straight line connecting the principal point of the lens and the light receiving portion and the optical axis of the parallel light are substantially parallel to each other.

In the first to fifth aspects of the invention, the light emitted from the irradiation unit and transmitted through the lens is collected on the light receiving unit without being collected 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 greater than a half angle of view, the light is not incident on the image sensor and is condensed outside the image sensor. The diaphragm blocks the external light so that external light other than the light from the irradiating unit does not pass through the lens and enter the light receiving unit, so that the external light is not collected on the light receiving unit.
Accordingly, the light receiving unit receives only the light emitted from the irradiation unit and transmitted through the lens, and outputs a value corresponding to the intensity of the received light. Since this value corresponds to the transmittance of the lens, the presence or absence of lens abnormality can be diagnosed by referring to this value.
In addition, since the light from the irradiating unit irradiated on the lens is not condensed on the image sensor, the value necessary for diagnosing the lens abnormality can be obtained while imaging.
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.

When a reflecting mirror is provided, light from the light source is reflected by the reflecting mirror and enters the lens.
Therefore, compared to 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 unit is high, and the imaging apparatus can be downsized.

Further, when the collimator lens is provided, the parallel light generated by the collimator is irradiated onto the lens and is condensed on the light receiving unit. The parallel light is more accurately collected on the light receiving unit than the non-parallel light.
Therefore, it is possible to minimize the light from the irradiating part that is focused on the image sensor.

The imaging apparatus according to a sixth aspect is characterized in that the irradiation unit irradiates light to a predetermined range including the entire surface of the lens or a central portion of the lens.

In the sixth invention, when the light from the irradiating unit is irradiated on the entire surface of the lens, the light transmitted through the entire surface of the lens is condensed on the light receiving unit.
Therefore, the light receiving unit can output a value 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 light receiving unit.
Therefore, the light receiving unit can output a value indicating the presence or absence of abnormality in the predetermined range of the lens.

An image pickup apparatus according to a seventh aspect of the invention is characterized in that it comprises a diagnostic means for diagnosing the presence or absence of an abnormality of the lens based on a value output from the light receiving unit.

In the seventh invention, the diagnostic means self-diagnose the presence / absence of an abnormality related to the transmittance of the lens based on the value output by the light receiving unit.

A lens abnormality diagnosis system according to an eighth aspect of the present invention is based on the imaging device according to any one of the first to sixth aspects, an acquisition unit that acquires a value output by the light receiving unit, and a value acquired by the acquisition unit. And a diagnostic device having diagnostic means for diagnosing the presence or absence of abnormality of the lens.

In the eighth invention, the acquisition unit of the diagnostic device acquires the value output by the light receiving unit of the imaging device, and the diagnostic unit self-diagnose whether there is an abnormality in the lens based on the value acquired by the acquisition unit. To do.

In a lens abnormality diagnosis system according to a ninth aspect of the present invention, the diagnostic device includes a storage unit that stores a threshold value, and the diagnosis unit compares the value acquired by the acquisition unit with the threshold value stored in the storage unit. By doing so, the presence or absence of abnormality of the lens is diagnosed.

In the ninth invention, the storage means of the diagnostic apparatus stores a threshold value for diagnosing the presence or absence of lens abnormality, and the diagnosis means stores the value acquired by the acquisition means and the storage means. By comparing with the threshold value, it is diagnosed whether there is an abnormality in the lens, particularly an abnormality related to the transmittance of the lens.

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, the irradiation unit that irradiates the lens with light having an incident angle equal to or greater than the half field angle, the light receiving unit that receives the light irradiated from the irradiation unit and transmitted through the lens, and the outside light does not enter the light receiving unit. Thus, by providing the diaphragm that blocks the external light, it is possible to self-diagnose whether there is an abnormality in the lens while performing imaging.

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 an embodiment 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 a thermopile, pyroelectric element, and bolometer. A substantially rectangular infrared imaging element 13a is provided. The distance between the principal point O of the infrared lens group 11 and the infrared imaging unit 13 in the direction of the optical axis L is such that the optical axis L of the infrared lens group 11 passes through the center of the infrared imaging element 13a and the focal point is infinite. The infrared lens group 11 is arranged so as to be substantially equal to the focal length f of the infrared lens group 11. Since the depth of field becomes deeper as the focus is adjusted farther, the subject in the distance range from 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 image data per second, and outputs the image data to the signal processing unit 17.

  The signal processing unit 17 AD converts the luminance signal into digital image data, performs various correction processes on the AD converted image data, and outputs the image data to an external device via the input / output unit 18. .

  FIG. 2 is an optical path diagram of the infrared imaging device 1. At the periphery of the infrared imaging element 13a, a light receiving unit 14 is provided for self-diagnosis of the abnormality of the infrared lens group 11, for example, the presence or absence of dirt, cracks, scratches, etc. of the infrared lens group 11. Specifically, an outer side of one long side of the infrared imaging element 13a, a substantially central portion in the longitudinal direction, and a virtual straight line connecting the principal point O of the infrared lens group 11 and the light receiving unit 14, and the optical axis L of the infrared lens group 11 It is arranged so that the angle formed by and becomes about 12 °. The light receiving unit 14 includes, for example, a thermopile, a pyroelectric infrared sensor, etc., photoelectrically converts the received infrared light, and outputs a light intensity voltage value indicating the intensity of the received infrared light via the input / output unit 18 to an external device. Output to.

On the front side of the infrared lens group 11, diagonally outward in the radial direction, in particular on the side opposite to the light receiving portion 14, the infrared ray whose incident angle θ with respect to the optical axis L of the infrared lens group 11 is greater than or equal to the half field angle α in the vertical direction, specifically An irradiating section 15 for diagnosing a lens that makes an infrared ray having an incident angle θ of about 12 ° incident on the infrared lens group 11 is disposed. The irradiation unit 15 is arranged so as to be located outside the field of view of the infrared lens group 11.
The irradiation unit 15 includes a light source 15a that emits infrared rays having a predetermined intensity, and a collimator lens 15b. The light source 15a has a filament that generates heat when energized, for example, and is disposed at the focal point of the collimator lens 15b. The collimator lens 15b is a lens that converts infrared rays emitted from the light source 15a into parallel light. The collimator lens 15b receives the principal point O of the infrared lens group 11 and the light reception so that the incident angle with respect to the optical axis L of the infrared lens group 11 is about 12 °. The virtual straight line connecting the portions 14 and the optical axis of the collimator lens 15b are arranged so as to be substantially parallel. In FIG. 1, for convenience of drawing and explanation, the incident angle θ is shown larger than the actual angle.

When the light receiving unit 14 and the irradiating unit 15 are arranged in this way, the infrared light irradiated from the irradiating unit 15 and transmitted through the infrared lens group 11 is condensed on the light receiving unit 14 and does not enter the infrared imaging element 13a.
FIG. 3 is an explanatory diagram conceptually showing a condensing region by the infrared lens group 11. As shown in FIG. 3, the horizontal arrow passing through the center of the infrared image sensor 13a indicates the horizontal direction of the infrared image sensor 13a, and the vertical arrow passing through the center indicates the vertical direction. Three concentric circles indicate condensing areas where infrared rays radiated from a subject within a predetermined field of view are collected by the infrared lens group 11. The outermost concentric circle a1 is centered on the principal point O of the infrared lens group 11, and the infrared rays in the field of view A having a half cone angle of 15 ° with respect to the optical axis L of the infrared lens group 11 are incident on the image plane. The condensed light collection area is shown. Similarly, concentric circles a2 and a3 on the inner side indicate a range in which infrared rays within a field of view having a conical shape with a semiconical angle of 10 ° and 5 ° are condensed on the image plane in order from the outer side.

  As shown in FIGS. 2 and 3, the infrared rays radiated from the visual field A are condensed on the condensing region indicated by the concentric circle a1, but the imaging surface of the infrared imaging element 13a occupies a part of the condensing region. Therefore, a part of the infrared ray incident on the infrared lens group 11 is condensed outside the infrared imaging element 13a. For example, infrared rays having an incident angle with respect to the optical axis L of the infrared lens group 11 equal to or greater than a half angle of view are condensed outside the infrared imaging element 13a. As shown in FIGS. 2 and 3, since the half angle of view α in the vertical direction of the infrared imaging device 1 is about 9 °, the incident angle of the infrared lens group 11 with respect to the optical axis L in the vertical direction is the vertical half image. An infrared ray having an angle of 9 ° or more, for example, an infrared ray having an incident angle of about 12 ° irradiated from the irradiation unit 15 is not collected on the infrared imaging element 13a but is collected on the light receiving unit.

A field stop 16 is disposed on the front side of the infrared lens group 11.
FIG. 4 is a schematic front view showing the field stop 16 and the light collection state on the image plane. FIG. 4A is a schematic diagram of the field stop 16. The field stop 16 covers an annular portion 16b having an inner diameter substantially equal to the effective aperture of the infrared lens group 11 and the front side of the irradiating unit 15, and external light B other than infrared rays from the light source 15a does not enter the light receiving unit 14. Thus, a semicircular light shielding portion 16a for narrowing the field of view is provided.

  FIG. 4B is a schematic diagram showing a condensing state on the image plane when the field of view is narrowed by the field stop 16. A hatched portion C indicates a region where the external light B is blocked by the light blocking portion 16 a of the field stop 16. A white portion D indicates a region where infrared rays from the irradiation unit 15 are collected and substantially coincides with the position of the light receiving unit 14. A portion E indicates a region that is incident on the infrared lens group 11 from the outside and is focused on the infrared imaging unit 13 and its periphery, and the infrared imaging element 13a is included in this portion.

  FIG. 5 is a schematic diagram illustrating a configuration of an obstacle detection system including the infrared imaging device 1. An obstacle detection system (lens abnormality diagnosis system) according to an 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. And an image processing device (diagnostic device) 3 having an object detection function and a lens abnormality diagnosis function for diagnosing the presence or absence of abnormality of the infrared lens group 11.

  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. 6 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 / output unit 34, a video output unit 35, a communication interface unit 36, and a storage unit 37.

  The input / output unit 34 is connected to the input / output unit 18 of the infrared imaging device 1 via the cable 7, and inputs the image data and the light intensity voltage value output from the infrared imaging device 1. The image data input to the input / output unit 34 is sequentially stored in the image memory 32 in units of one frame. The input / output unit 34 outputs a light source control signal under the control of the control unit 31. The light source control signal output from the image processing device 3 is input to the light source 15a via the input / output unit 18 of the infrared imaging device 1, and the light source 15a is turned on or off according to the light source control signal.

  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 image data to the display device 4 and causes the display device 4 to display an 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 is likely to come into contact or collide is detected in the obstacle detection process, the alarm device 5 outputs that effect by voice, 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 a message to that effect by voice, warning sound or the like, and the display device 4 displays “lens abnormality”. Etc. are displayed.

  The image memory 32 is an SRAM, flash memory, SDRAM, or the like, and temporarily stores image data input from the infrared imaging device 1 via the input / output 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 light intensity voltage value output from the light receiving unit 14 when the light is transmitted through the normal infrared lens group 11 before use and free of dirt, scratches, etc. and condensed on the light receiving unit 14 is measured. The obtained light intensity voltage value is multiplied by a predetermined ratio, for example, 0.8, and a value obtained by the multiplication is set as a threshold value.

  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. 7 is a flowchart showing a processing procedure of the control unit 31 related to the self-diagnosis of the infrared lens group 11.

  The control unit 31 applies a light source control signal to the light source 15a via the input / output unit 34, thereby turning on the light source 15a (step S11) and acquiring the light intensity voltage value from the light receiving unit 14 (step S12). And the control part 31 turns off the light source 15a by giving a light source control signal to the light source 15a via the input-output part 34 (step S13).

  Next, the control unit 31 reads the threshold value from the storage unit 37 (step S14), and determines whether or not the light intensity voltage value acquired in step S12 is less than the threshold value (step S15). 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 light intensity voltage value is less than the threshold value (step S15: YES), the control unit 31 issues a warning that the infrared lens group 11 is abnormal (step S16), and ends the process. When it determines with a light intensity voltage value being more than a threshold value (step S15: 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 infrared light irradiated from the irradiation unit 15 is not condensed on the infrared imaging element 13a, and the infrared light irradiated from the irradiation unit 15 is only transmitted to the light receiving unit 14. Condensate. Further, since the infrared imaging device 1 includes the field stop 16, the infrared rays emitted from the subject are not collected on the light receiving unit 14, but are collected on the infrared imaging element 13a. Then, the light receiving unit 14 outputs a light intensity voltage value corresponding to the intensity of the infrared light irradiated from the irradiation unit 15 and transmitted through the infrared lens group 11.
Therefore, it is possible to obtain a light intensity voltage value for self-diagnosis of the presence or absence of abnormality of the infrared lens group 11 while performing imaging.

  Further, the image processing device 3 can diagnose the presence or absence of an abnormality in the infrared lens group 11 based on the light intensity voltage value output from the light receiving unit 14. Since the light intensity voltage value corresponds to the transmittance of the infrared lens group 11, whether the transmittance of the infrared lens group 11 is normal is diagnosed by comparing the light intensity voltage value with a threshold value. be able to.

  Furthermore, since the irradiation unit 15 includes a collimator lens 15b and converts the infrared rays from the light source 15a into parallel light and enters the infrared lens group 11, the irradiation unit 15 more accurately emits light from the light source 15a than when the collimator lens 15b is not provided. Can be condensed on the light receiving unit 14. Therefore, the adverse effect of the infrared rays from the irradiation unit 15 on the imaging process can be minimized.

  FIG. 8 is a schematic diagram showing the infrared imaging device 101 according to the first modification. The infrared imaging apparatus 101 according to the first modification is configured such that the irradiation unit 115 irradiates the entire front side of the infrared lens group 11 with infrared rays for lens diagnosis.

  The irradiation unit 115 includes a light source 15a, a collimator lens 115b, and a planar reflecting mirror 115c. The collimator lens 115 b has a diameter substantially equal to that of the infrared lens group 11 and is fixed so as to face the same direction as the infrared lens group 11. The infrared light flux from the collimator lens 115 b is parallel light having a diameter substantially equal to the diameter of the infrared lens group 11.

  The plane reflecting mirror 115c reflects the infrared rays from the collimator lens 115b and is fixed in such a posture that the reflected infrared rays are 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, the infrared rays for lens diagnosis are incident on the entire surface of the infrared lens group 11, and the infrared rays transmitted through the infrared lens group 11 are condensed on the light receiving unit 14. The presence or absence of dirt, cracks, scratches, etc. on the entire surface of the infrared lens group 11 can be diagnosed.

  Moreover, since the irradiation part 115 is provided with the plane reflective mirror 115c, the freedom degree of arrangement | positioning of the light source 15a and the collimator lens 115b which comprise the irradiation part 115 improves, and the infrared imaging device 101 can be reduced in size.

  FIG. 9 is a schematic diagram showing an infrared imaging device 201 according to the second modification. The infrared imaging apparatus 201 according to the second modification is configured such that the irradiation unit 215 causes the infrared rays for lens diagnosis to enter a predetermined range including the central portion of the infrared lens group 11 and the periphery of the central portion.

  The irradiation unit 215 includes a light source 15a and a collimator lens 215b. The collimator lens 215b is arranged so that the optical axis of the collimator lens 215b and the virtual straight line passing through the principal point O of the light receiving unit 14 and the infrared lens group 11 substantially coincide. In FIG. 9, for convenience of drawing and explanation, the incident angle θ is shown larger than the actual angle.

  The infrared imaging device 201 according to the second modification is configured to irradiate infrared rays for lens diagnosis on the central portion of the infrared lens group 11 that is important for the optical performance of the infrared imaging device 201. The presence or absence of abnormality of the infrared lens group 11 can be effectively diagnosed, and the irradiation unit 215 can be configured to be smaller than the case where the entire surface of the infrared lens group 11 is irradiated with infrared rays. The apparatus 201 can be reduced in size.

  In this embodiment, as an example, an infrared imaging device that images a subject with infrared rays is illustrated. However, the present invention is applied to an imaging device that captures a subject with visible light and light of other wavelengths. May be.

  Moreover, although the infrared imaging device provided with the collimator lens has been described, a collimator mirror may be provided instead of the collimator lens. By providing the collimator mirror, the degree of freedom in arrangement can be improved and the infrared imaging device can be downsized.

  Furthermore, although the collimator lens is provided in the present embodiment, the collimator lens is unnecessary when a light source capable of irradiating parallel light is provided. 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 example in which the light receiving unit is arranged on the long side of the infrared imaging device has been described, it may be arranged on the short side of the infrared imaging device. What is necessary is just to select suitably the arrangement | positioning according to the arrangement environment of an infrared imaging device.

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

  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 of this invention. It is an optical path diagram of an infrared imaging device. It is explanatory drawing which shows notionally the condensing area | region by an infrared lens group. It is a typical front view which shows the condensing state in a field stop and an image surface. 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 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 a 1st modification. It is a schematic diagram which shows the infrared imaging device which concerns on a 2nd modification.

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 Light-receiving part 15,115,215 Irradiation part 15a Light source 15b, 115b, 215b Collimator lens 16 Field stop 16a Light-shielding part 31 Control part (acquisition means, diagnostic means)
37 storage unit 115c plane reflecting mirror L optical axis

Claims (10)

In an imaging apparatus including a lens and an imaging element that captures an image obtained by condensing with the lens,
An irradiation unit that irradiates the lens with light having an incident angle with respect to the optical axis of the lens equal to or greater than a half angle of view , and an angle of light flux incident on the lens with respect to the optical axis ;
A light receiving unit that receives light emitted from the irradiation unit and transmitted through the lens, and outputs a value corresponding to the intensity of the received light;
An imaging device comprising: a diaphragm that blocks external light other than light from the irradiation unit so as not to enter the light receiving unit.   The irradiation unit is
  A light source;
  A collimator lens for collimating the light emitted from the light source;
  With
  The virtual straight line connecting the principal point of the lens and the light receiving unit and the optical axis of the collimator lens are arranged to be substantially parallel.
  The imaging apparatus according to claim 1.   The irradiation unit is
  A light source;
  A collimator lens for collimating the light emitted from the light source;
  A reflecting mirror that reflects parallel light from the collimator lens and enters the lens;
  With
  The reflector is
  The virtual straight line connecting the principal point of the lens and the light receiving unit and the optical axis of the parallel light are arranged so as to be substantially parallel.
  The imaging apparatus according to claim 1.   The irradiation unit is
  It has a light source that can emit parallel light,
  The light source is
  The virtual straight line connecting the principal point of the lens and the light receiving unit and the optical axis of the parallel light are arranged so as to be substantially parallel.
  The imaging apparatus according to claim 1.   The irradiation unit is
  A light source capable of emitting parallel light;
  A reflecting mirror that reflects parallel light emitted from the light source and enters the lens;
  With
  The reflector is
  The virtual straight line connecting the principal point of the lens and the light receiving unit and the optical axis of the parallel light are arranged so as to be substantially parallel.
  The imaging apparatus according to claim 1. The irradiation unit is
The imaging apparatus according to any one of claims 1 to 5 , wherein light is applied to a predetermined range including an entire surface of the lens or a central portion of the lens. Based on the values the light receiving portion is output, the image pickup apparatus according to any one of claims 1 to 6, characterized in that it comprises a diagnostic means for diagnosing the presence or absence of abnormality of the lens. An imaging device according to any one of claims 1 to 6 ,
A lens abnormality comprising: an acquisition unit that acquires a value output by the light receiving unit; and a diagnostic device that has a diagnosis unit that diagnoses the presence or absence of an abnormality of the lens based on the value acquired by the acquisition unit. Diagnostic system. The diagnostic device comprises:
Storage means for storing the threshold value;
The diagnostic means includes
The lens abnormality according to claim 8 , wherein the lens abnormality is diagnosed by comparing the value acquired by the acquisition unit and the threshold value stored in the storage unit. Diagnostic system. The diagnostic device comprises:
The lens abnormality diagnosis system according to claim 8 or 9 , further comprising means for issuing a warning when the lens is diagnosed as having an abnormality.

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