JP2006229341A - Imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device capable of surely notifying a user of occurrence of an abnormality in an imaging unit.
An imaging apparatus 1 according to the present invention includes an imaging unit 2 that captures an imaging target, a recording unit 8 that records a video signal output from the imaging unit as video information, and the video signal based on the video signal. At least one of an abnormality in the video signal and an abnormality in the visual field, a signal abnormality detection unit 4 that detects an abnormality in the video signal, a visual field abnormality detection unit 3 that detects an abnormality in the visual field of the imaging unit based on the video signal, And a notification unit 6 that performs notification corresponding to the detected abnormality.
[Selection] Figure 2

Description

  The present invention relates to an image pickup apparatus that picks up an image pickup target using a CCD (Charge Coupled Devices) or the like, and more particularly to an image pickup apparatus having a function of detecting an abnormality in an image pickup state.

  In order to objectively verify the situation and the cause of a car accident, a method for recording a surrounding image (video information of an imaging target) at the time of the accident using an imaging device attached to the car has already been proposed. . This type of imaging apparatus has a recording unit for recording an image (video information), and is sometimes called a driving recorder.

  An image obtained by imaging of this type of imaging device is not always displayed on the display device, and usually an image for a certain period of time before and after the occurrence of the accident is recorded in the recording unit. The image recorded in this recording unit is used for investigating the cause of the accident. Due to the property that the image is not always displayed on the display device, even if some abnormality occurs in the imaging device, the occurrence of the abnormality cannot be immediately known. This may cause a problem that normal image recording is not performed when necessary.

  In order to solve this problem, Patent Document 1 below proposes to issue a warning when an abnormality occurs in the imaging apparatus or the recording apparatus.

JP-A-4-245886

  An abnormal situation where the image (video information) is not normally recorded in the recording unit is caused by various causes, but the abnormal situation is verified from various directions, and if an abnormality occurs, the driver of the car, etc. It is important to make sure that the occurrence of an abnormality is informed.

  Note that the technique disclosed in Patent Document 1 cannot accurately recognize the occurrence of the abnormal situation.

  SUMMARY An advantage of some aspects of the invention is that it provides an imaging apparatus that can reliably notify the user of the occurrence of an abnormality in the imaging unit.

  In order to achieve the above object, an imaging apparatus according to the present invention includes an imaging unit that images an imaging target, a recording unit that records a video signal output from the imaging unit as video information, and the video signal based on the video signal. Detection of at least one of an abnormality in the video signal and an abnormality in the visual field, a signal abnormality detection unit that detects an abnormality in the video signal, a visual field abnormality detection unit that detects an abnormality in the visual field of the imaging unit based on the video signal And a notification unit that performs notification corresponding to the detected abnormality.

  Accordingly, it is possible to notify the user of a situation in which the imaging target cannot be correctly recorded due to an abnormality in the video signal or an abnormality in the visual field.

  Specifically, for example, the video signal output from the imaging unit includes a luminance signal for a reproduction screen configured by a plurality of pixels, and the visual field abnormality detection unit is based on the luminance signal. An edge component calculation unit that calculates an edge component of luminance for each pixel, and an edge component summation unit that calculates a value corresponding to the sum of the edge components in pixels within a predetermined range of the reproduction screen, The abnormality detection unit determines that the field of view is abnormal when a value corresponding to the sum continues to be equal to or less than a predetermined first threshold for a predetermined first period or more.

  More specifically, for example, the video signal output from the imaging unit includes a luminance signal for a playback screen composed of a plurality of pixels, and the signal abnormality detection unit A luminance level detection unit that calculates a value corresponding to the total luminance in pixels within a predetermined range, and the signal abnormality detection unit continues the value corresponding to the total for a predetermined second period or longer. When the predetermined second threshold value or less is reached, it is determined that the video signal is abnormal.

  More specifically, for example, the video signal output from the imaging unit includes a luminance signal for a playback screen composed of a plurality of pixels, and the signal abnormality detection unit A luminance fluctuation detecting unit that calculates a value corresponding to the sum of the magnitudes of the respective fluctuation components after calculating the magnitude of the fluctuation component of the luminance in the pixels within a predetermined range for each pixel; The unit determines that the video signal is abnormal when a value corresponding to the sum is continuously equal to or less than a predetermined third threshold for a predetermined third period or more.

  Further, specifically, for example, the video signal output from the imaging unit includes a first color difference signal and a second color difference signal for a reproduction screen composed of a plurality of pixels, and the signal abnormality detection The unit calculates, for each pixel, the magnitude of the first difference value corresponding to the difference between the value of the first color difference signal and the predetermined first reference value in the pixels within the predetermined range of the reproduction screen. A color difference variation detecting unit that calculates a value corresponding to the sum of the magnitudes of the one difference value, and the signal abnormality detecting unit continuously determines a value corresponding to the sum for a predetermined fourth period or longer. When the value is equal to or lower than the fourth threshold value, it is determined that the video signal is abnormal.

  Further, specifically, for example, the video signal output from the imaging unit includes a first color difference signal and a second color difference signal for a reproduction screen composed of a plurality of pixels, and the signal abnormality detection The unit calculates, for each pixel, the magnitude of the first difference value corresponding to the difference between the value of the first color difference signal and the predetermined first reference value in the pixels within the predetermined range of the reproduction screen. A value corresponding to the sum of the magnitudes of the one difference value is calculated, and the magnitude of the second difference value corresponding to the difference between the value of the second color difference signal and the predetermined second reference value in the pixels within the predetermined range. Is calculated for each pixel, and then includes a color difference variation detection unit that calculates a value corresponding to the sum of the magnitudes of the second difference values. The signal abnormality detection unit corresponds to the sum of the first difference values. The value continuously falls below a predetermined fourth threshold for a predetermined fourth period or longer, One fifth period over which a value corresponding to the sum of the second difference value is determined in advance, when continuously equal to or less than a predetermined fifth threshold value, the video signal is determined to be abnormal.

  Specifically, for example, the signal abnormality detection unit includes a synchronization abnormality detection unit that detects whether or not a synchronization signal included in the video signal is abnormal, and the signal abnormality detection unit Determines that the video signal is abnormal when it is determined that the synchronization signal is abnormal.

  The “value corresponding to the sum” in the description of the visual field abnormality detection unit and the description of the signal abnormality detection unit is, for example, the sum itself, and, for example, the sum is a pixel within the predetermined range. (A value proportional to the sum), for example, a value obtained by adding some correction value to the sum.

  For example, the imaging device may be attached to a moving body having an engine, and the notification unit may perform the notification when the engine is started.

  Accordingly, the user can surely know the occurrence of the abnormality, and the willingness to perform some maintenance on the imaging apparatus increases. This increases the probability that the imaging device is kept normal, and facilitates investigation of the cause when an accident occurs.

  In addition, for example, after the notification at the time of starting the engine is performed, when the engine is started n times (n is a natural number) without eliminating the abnormality corresponding to the notification, the notification unit May notify the content different from the notification.

  For example, if “notification of contents different from the above notification” is a content that strongly appeals the user to the necessity of maintenance or the like, the willingness to perform maintenance is further increased. This increases the probability that the imaging device is kept normal, and facilitates investigation of the cause when an accident occurs.

  In addition, for example, the notification unit may perform the notification by causing an external display device to display information on a window that can provide repair information of the imaging device.

  Performing the above notification contributes to an increase in willingness to perform some maintenance on the imaging apparatus.

  In addition, for example, when a visual field abnormality is detected, a cleaning unit that performs a cleaning operation for eliminating the visual field abnormality may be further provided.

  Further, for example, when at least one of the video signal abnormality and the visual field abnormality is detected, the recording unit records information corresponding to the detected abnormality in association with the video information. Good.

  According to the above, when the video information recorded in the recording unit is used to investigate the cause of the accident, the information corresponding to the abnormality can be referred to together with the video information. The video information when there is some abnormality is relatively low in reliability as evidence. That is, by configuring as described above, the reliability of recorded video information can be evaluated.

  As described above, according to the imaging apparatus of the present invention, it is possible to reliably notify the user of the occurrence of an abnormality in the imaging unit.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 is a diagram illustrating a state in which an imaging device 1 according to an embodiment of the present invention is attached to a vehicle 60.

  The vehicle 60 is provided with a room mirror 61 in front of the driver's seat, and the imaging device 1 can image (capture) an imaging object (landscape) in front of the vehicle 60 (traveling direction). It can be attached to the backside of the machine. The mounting location of the imaging device 1 in the vehicle 60 is not limited to the room mirror 61. For example, you may attach to the roof of a vehicle 60, a side mirror (not shown), etc. Further, if necessary, the imaging device 1 may be attached to any location of the vehicle 60 so that the imaging target (landscape) behind the vehicle 60 (opposite to the traveling direction) can be imaged. The imaging device 1 may be attached to any location of the vehicle 60 so that an imaging target (landscape) in other directions inside and outside can be imaged.

  The vehicle 60 includes a windshield 63 disposed between the imaging device 1 and the imaging target, an engine 66 for moving the vehicle 60 forward and backward, an ignition switch 65 for starting the engine 66, An acceleration sensor 62 that detects the acceleration of the vehicle 60, a display device 64 such as a liquid crystal display used in a car navigation system, and water droplets attached to the imaging target side of the windshield 63 (outside the vehicle 60). And a wiper 67.

  FIG. 2 is a block diagram illustrating the configuration of the imaging device 1 of FIG. An imaging apparatus 1 in FIG. 1 includes an imaging unit 2, a visual field abnormality detection unit 3 that detects visual field abnormality of the imaging unit 2, and a signal abnormality detection unit 4 that detects abnormality of a video signal output from the imaging unit 2. The abnormal state of the imaging unit 2 is determined based on the detection result of the visual field abnormality detection unit 3 and the detection result of the signal abnormality detection unit 4, and the determination result is notified to the notification unit 6, the signal processing unit 7, the determination history recording unit 9, and When there is an abnormality in the abnormal state determination unit 5 transmitted to the comparison unit 10, the notification unit 6 that notifies the user when there is an abnormality, and appropriate processing for the video signal output from the imaging unit 2 A signal processing unit 7 that outputs video information to the recording unit 8 and outputs the video information to the recording unit 8 in association with the video information when the imaging unit 2 has an abnormality. In response to the output of the processing unit 7, the video signal from the imaging unit 2 is converted into video information. A recording unit 8 that records the determination result, a determination history recording unit 9 that records a determination result by the abnormal state determination unit 5 as a determination history, and a comparison unit 10 that compares the determination history and the determination result of the current abnormal state determination unit 5 And a cleaning unit 11.

  FIG. 3 is a diagram illustrating a configuration of the imaging unit 2. The lens 21 forms an image corresponding to an imaging target on three CCD (Charge Coupled Devices) 23, 24, and 25. A lens protection cover (not shown) for protecting the lens 21 may be disposed on the imaging target side of the lens 21. The dichroic prism 22 splits the light beam incident through the lens 21 into three primary colors of red (R), green (G), and blue (B). The CCD 23 receives the red spectral component and converts it into an electrical signal. The CCD 24 receives the green spectral component and converts it into an electrical signal. The CCD 25 receives the blue spectral component and converts it into an electrical signal.

  The image processing circuit 26 generates an NTSC (National Television Standards Committee) video signal based on the electrical signal converted by the CCD 23, the electrical signal converted by the CCD 24, and the electrical signal converted by the CCD 25. To do. This video signal is supplied as a video signal from the imaging unit 2 to the signal processing unit 7, the signal abnormality detection unit 3, and the visual field abnormality detection unit 4. For the sake of concrete explanation, it is assumed that the video signal generated by the image processing circuit 26 conforms to the NTSC system, but the video signal may be generated according to another system. In addition, although a three-plate type configuration is illustrated as the imaging unit 2, it is needless to say that a single-plate type imaging unit (not shown) using a color filter may be adopted as the imaging unit 2. The image processing circuit 26 also controls the operation of the CCDs 23, 24 and 25.

The video signal generated and output by the image processing circuit 26 includes a luminance signal Y, a color difference signal RY, a color difference signal BY, and a synchronization signal (horizontal synchronization signal and vertical synchronization signal). . A value indicating the intensity of the red spectral component received by the CCD 23, a value indicating the intensity of the green spectral component received by the CCD 24, and a value indicating the intensity of the blue spectral component received by the CCD 25 are respectively represented by E _R , E _G and Let E _B be a value indicating the intensity of the luminance signal Y, a value indicating the intensity of the color difference signal RY, and a value indicating the intensity of the color difference signal _BY , respectively, E _Y , E _RY and E _BY . A value indicating the intensity of the color difference signal G-Y is defined as E _GY . Then, for example, the following expression (1) consisting of four equations is established.
E _Y = 0.3E _R + 0.59E _G + 0.11E _B
E _RY = 0.7E _R -0.59E _G -0.11E _B
E _GY = −0.3E _R + 0.41E _G −0.11E _B
E _BY = −0.3E _R + 0.41E _G + 0.89E _B (1)

  The signal processing unit 7 (FIG. 2) performs processing such as image quality correction and image compression on the video signal from the imaging unit 2. The video information obtained by the image quality correction or the like (the video signal represented by data) is given to the recording unit 8, and the video information is recorded by the recording unit 8. The recording unit 8 is a recording medium such as a memory card or a video tape, for example.

  As described above, the vehicle 60 is provided with the acceleration sensor 62, and when the detected acceleration exceeds a predetermined threshold, a recording command signal is transmitted from the acceleration sensor 62 to the imaging device 1 as an accident or the like. Is done. The imaging device 1 causes the recording unit 8 to record a video signal (video information) for a certain period of time before and after the time when the recording command signal is received as a reference. The video signal (video information) recorded in the recording unit 8 is left as evidence indicating the situation before and after the accident. In order to enable the recording of the video information for a certain period of time, a buffer memory including a semiconductor memory such as a DRAM (Dynamic Random Access Memory) is provided between the signal processing unit 7 and the recording unit 8. (Not shown). The buffer memory temporarily stores a video signal (video information) given from the signal processing unit 7. A part of the temporarily stored video signal (video information) is recorded in the recording unit 8 in response to the recording command signal. Further, the video signal (video information) other than the above-mentioned fixed time may be recorded in the recording unit 8. The recording operation of the video signal (video information) of the recording unit 8 in the following description is a recording operation at an arbitrary timing.

(Visibility abnormality detection unit)
FIG. 4 shows a reproduction screen (reproduction image) when the video signal output from the imaging unit 2 is displayed as an image on a display device such as the display device 64. The reproduction screen of FIG. 4 is composed of a plurality of pixels (for example, 640 × 480 pixels) arranged two-dimensionally. However, the four dotted lines in FIG. 4 are provided to explain the operation of the visual field abnormality detection unit 3 and do not appear on the actual reproduction screen.

  The visual field abnormality detection unit 3 detects a visual field abnormality of the imaging unit 2 based on the luminance signal Y included in the video signal. The operation of the visual field abnormality detection unit 3 will be described with reference to the reproduction screen of FIG. The visual anomaly detection unit 3 divides the reproduction screen of FIG. 4 into nine areas A1, A2, A3, A4, A5, A6, A7, A8, and A9, and calculates the sum of the edge components for each area. . FIG. 5 shows the configuration of the visual field abnormality detection unit 3. The visual anomaly detection unit 3 includes an edge component calculation unit 31 that calculates a luminance edge component for each pixel based on the luminance signal Y included in the video signal, and an edge component that calculates the sum of the edge components for each divided region. And a summing unit 32.

  The operation of the visual field abnormality detection unit 3 will be described by paying attention to a region A5 at a certain timing. At this timing, it is assumed that the field of view of the imaging unit 2 is normal (hereinafter, this timing is referred to as “when the field of view is normal”). FIG. 6A shows the luminance of each pixel in the area A5 when the field of view is normal. FIG. 6B illustrates the edge component of each pixel in the region A5 when the field of view is normal. FIG. 6C shows the binarized edge component of each pixel in the area A5 when the field of view is normal.

The area A5 includes pixels D1, D2, D3, D4, D5, D6, D7, D8, and D9. The edge components of the pixels D1, D2, D3, D4, D5, D6, D7, D8, and D9 are respectively represented as G _D1 , G _D2 , G _D3 , G _D4 , G _D5 , G _D6 , G _D7 , G _D8, and G _D9. And Actually, the area A5 and each of the other areas are configured to have two-dimensionally arranged pixels of (several 10 to several 100) × (several 10 to several 100).

  For simplification of description, it is assumed that the luminance of each pixel D1 to D9 represented by the luminance signal Y is digitized by 0 to 15 of 4 bits. It is assumed that the larger the numerical value of luminance, the higher the luminance. Actual luminance is digitized by 8 bits, 10 bits, or the like. With the pixel D5 as a reference, the pixel D2 side is defined as the left side, the pixel D8 side as the right side, the pixel D4 side as the upper side, and the pixel D6 side as the lower side.

  As shown in FIG. 6A, the luminance values of the pixels D1, D2, D3, D4, D5, D6, D7, D8, and D9 are 1, 1, 2, 10, 8, 8, 1, 0, and 0, respectively. Suppose there was. That is, it is assumed that there is a line with relatively high luminance on the line connecting the pixels D4, D5, and D6.

In this case, the edge component calculation unit 31 converts the edge component G _D4 of the pixel D4 into an equation: G _D4 = (− 1) × (luminance of the pixel D1) + 2 × (luminance of the pixel D4) + (− 1) × (The luminance of the pixel D7). For this reason, G _D4 = (− 1) × 1 + 2 × 10 + (− 1) × 1 = 18. Similarly, the edge component calculation unit 31 converts the edge component G _D5 of the pixel D5 into an equation: G _D5 = (− 1) × (luminance of the pixel D2) + 2 × (luminance of the pixel D5) + (− 1) × (Brightness of the pixel D8). Therefore, G _D5 = (− 1) × 1 + 2 × 8 + (− 1) × 0 = 15. Similarly, the edge component calculation unit 31 converts the edge component G _D6 of the pixel D6 into an equation: G _D6 = (− 1) × (luminance of the pixel D3) + 2 × (luminance of the pixel D6) + (− 1) × (The luminance of the pixel D9). Therefore, G _D6 = (− 1) × 2 + 2 × 8 + (− 1) × 0 = 14.

Thus, the edge component calculation unit 31 sets E _Y as the luminance of the calculation target pixel for which the edge component is to be calculated, E _YL as the luminance of the pixel adjacent to the left side of the calculation target pixel, and is adjacent to the right side of the calculation target pixel. When the luminance of the pixel is E _YR , the edge component G _Do of the calculation target pixel is calculated according to the following equation (2).
G _Do = (− 1) × E _YL + 2 × E _Yo + (− 1) × E _YR (2)

When calculating the edge components of the pixels D1, D2, and D3, the luminance of the rightmost pixel of the region A2 adjacent to the left side of the region A5 is used. When calculating the edge components of the pixels D7, D8, and D9, the luminance of the pixel at the left end of the region A8 adjacent to the right side of the region A5 is used. Other edge components G _D1 , G _D2 , G _D3 , G _D7 , G _D8, and G _D9 are also calculated according to the above equation (2). However, for simplification of explanation, it is assumed that they are all 3.

  The edge component calculation unit 31 binarizes each calculated edge component with a predetermined threshold value. Now, this threshold is set to 8, for example. Edge components of 8 or more are set to “1”, and edge components of 7 or less are set to “0”. As a result, the binarized edge components of the pixels D1, D2, D3, D4, D5, D6, D7, D8, and D9 are 0, 0, 0, 1, respectively, as shown in FIG. 1, 1, 0, 0, 0.

  The edge component summing unit 32 calculates the sum of the binarized edge components (hereinafter referred to as “sum S1”). In the above example, the sum S1 of the binarized edge components in the region A5 is 0 + 0 + 0 + 1 + 1 + 1 + 0 + 0 + 0 = 3. The visual field abnormality detection unit 3 compares this sum S1 with a predetermined visual field threshold value (first threshold value). This visibility threshold is 2, for example. In this case, since the sum S1 is larger than the visibility threshold (3> 2 is established), the vision abnormality detection unit 3 determines that there is no abnormality in the field of view corresponding to the area A5 of the imaging unit 2. The relatively large sum S1 of edge components is because it can be determined that the imaging unit 2 accurately captures the contour of the imaging target. Then, the visual anomaly detection unit 3 resets the visual anomaly flag associated with the region A5 (if already reset, the state is maintained).

  The visual field abnormality detection unit 3 also calculates the sum of binarized edge components for each of the regions A1 to A4 and A6 to A9 other than the region A5, and compares the sum with the visual field threshold value. . When the sum of the binarized edge components is larger than the visual field threshold, it is determined that there is no abnormality in the visual field corresponding to the region of interest, and the visual field abnormality flag associated with the region of interest is reset.

  The visibility threshold values may be different from each other between the regions A1 to A9, or may coincide with each other. Moreover, one part may correspond and the remainder may differ. The state of the visual field abnormality flag is stored in, for example, the internal memory of the visual field abnormality detection unit 3 or the internal memory of the abnormal state determination unit 5.

  Next, when there is a lens protective cover (not shown) for protecting the lens 21 on the surface of the lens 21, foreign matter such as mud and dust adheres to the surface of the lens protective cover, and the foreign matter is a region. Consider the case of appearing on A5 (hereinafter referred to as “when visibility is abnormal”). Even when the surface of the lens 21 or the surface of the lens protective cover is damaged, the situation is the same as in the case of the above-described abnormal vision. FIG. 7A shows the luminance of each pixel in the region A5 when the visual field is abnormal. FIG. 7B shows an edge component of each pixel in the region A5 when the visibility is abnormal. FIG. 7C shows a binarized version of the edge component of each pixel in the area A5 when the visibility is abnormal.

  The imaging unit 2 sets an imaging target located at a distance of several tens of centimeters (or several meters) to several hundreds of meters on the traveling direction side of the vehicle 60 on the imaging surface of the CCDs 23, 24, and 25 with reference to the lens 21 or the CCD 23. Therefore, when a foreign object adheres to the surface of the lens 21 or the like, the imaging unit 2 cannot capture the outline of the foreign object. That is, the foreign object cannot be focused, and the outline and unevenness of the foreign object are blurred in the video signal (not determined as an edge).

  For this reason, the difference in luminance between adjacent pixels is reduced as a whole. For example, as shown in FIG. 7A, the luminances of the pixels D1, D2, D3, D4, D5, D6, D7, D8, and D9 when the visual field is abnormal are respectively 3, 4, 3, 4, 4, 5, 5, 4 and 5.

In this case, the edge component G _D4 of the pixel D4 calculated by the edge component calculation unit 31 is G _D4 = (− 1) × 3 + 2 × 4 + (− 1) × 5 = 0 according to the above equation (2). . The edge component G _D5 of the pixel D5 is G _D5 = (− 1) × 4 + 2 × 4 + (− 1) × 4 = 0. The edge component G _D6 of the pixel D6 is G _D6 = (− 1) × 3 + 2 × 5 + (− 1) × 5 = 2. According to the above equation (2), other edge components G _D1 , G _D2 , G _D3 , G _D7 , G _D8, and G _D9 at the time of visual anomaly are also calculated. Suppose there was.

  The edge component calculation unit 31 binarizes each calculated edge component with a predetermined threshold value. This threshold value is set to “8” as in the case of normal visibility. Edge components of 8 or more are set to “1”, and edge components of 7 or less are set to “0”. As a result, the binarized edge components of the pixels D1, D2, D3, D4, D5, D6, D7, D8, and D9 are all 0 as shown in FIG.

  The edge component summing unit 32 calculates the sum S1 of the binarized edge components. When the visibility is abnormal, the sum S1 of the binarized edge components in the region A5 is 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 = 0. The visual field abnormality detection unit 3 compares the sum S1 with the visual field threshold value (first threshold value). This visibility threshold is 2, for example. In this case, since the sum S1 of the binarized edge components is less than or equal to the visibility threshold (or less than the visibility threshold), the visibility abnormality detection unit 3 uses the visibility abnormality flag associated with the region A5. (If already set, keep its state).

  The video signal from the imaging unit 2 is sent to the visual field abnormality detection unit 3, for example, 30 times per second, and the visual field abnormality detection unit 3 repeats the sum S1 in the region A5 for each video signal or at a predetermined interval. And the above-mentioned visibility threshold. When the visibility abnormality flag associated with the region A5 remains set for a predetermined first period (for example, several tens of seconds to several minutes) or more, that is, binarization corresponding to the region A5. When the total sum S1 of the edge components that have been continuously kept below the visibility threshold for the first period or longer (or less than the visibility threshold), the visibility abnormality detection unit 3 has the visibility of the imaging unit 2 Judge as abnormal. More specifically, it is determined that the field of view corresponding to the region A5 is abnormal. If the imaging unit 2 does not accurately capture the contour of the imaging target, the sum of the edge components is relatively small. If the state continues for a certain time or more, it can be determined that there is a high possibility that the field of view of the imaging unit 2 is blocked by foreign matter or the like.

  The visual field abnormality detection unit 3 also calculates the sum of binarized edge components for each of the regions A1 to A4 and A6 to A9 other than the region A5, and compares the sum with the visual field threshold value. . If the sum of the binarized edge components is less than or equal to the visibility threshold value in the focused area, the visibility abnormality flag associated with the focused area is set. When the visual field abnormality flag associated with the region of interest remains set for the first period or longer, the visual field abnormality detection unit 3 determines that the visual field of the imaging unit 2 is abnormal. More specifically, it is determined that the field of view corresponding to the focused area is abnormal.

  When it is determined that the field of view of the imaging unit 2 is abnormal, the visual field abnormality detection unit 3 uses information indicating that the field of view of the imaging unit 2 is abnormal (hereinafter referred to as “visual field abnormality information”) as an abnormal state determination unit 5. To communicate. At this time, it may be transmitted to the abnormal state determination unit 5 including which region the visual field corresponding to is abnormal. On the other hand, when it is determined that the field of view of the imaging unit 2 is not abnormal (that is, normal), the visual field abnormality detecting unit 3 displays information indicating that the field of view of the imaging unit 2 is normal (hereinafter, the normal field of view information). Is transmitted to the abnormal state determination unit 5.

  The abnormal state determination unit 5 that has received the visual field abnormality information causes the notification unit 6 to perform notification corresponding to the occurrence of abnormality in the visual field of the imaging unit 2. Further, the visual field abnormality information is transmitted to the signal processing unit 7 via the abnormal state determination unit 5, and the signal processing unit 7 adds the visual field abnormality information to the video information corresponding to the video signal. The recording unit 8 records video information and visual field abnormality information associated with visual field abnormality in association with each other. By referring to the visual field abnormality information together with the video information, the reliability of the video information in the recording unit 8 can be evaluated. It can be said that the video information recorded at the time of visual anomaly has relatively low reliability as evidence.

  In addition, although the example which divides | segments a reproduction | regeneration screen into nine area | regions A1-A9 was shown, the number of the area | regions to divide | segment may be arbitrary. In some cases, there is no need to divide the playback screen. In this case, the sum of the edge components is calculated for the entire playback screen, and the sum is compared with the visibility threshold.

  Further, the value obtained by dividing the sum S1 of the binarized edge components by the number of pixels included in the region A5, that is, the average value of the binarized edge components of each pixel in the region A5 is defined as the visibility threshold value. You may compare. In this case, the average value when the visual field is normal in FIG. 6C is “3/9”, and the average value when the visual field is abnormal in FIG. 7C is “0/9”. Thus, the visibility threshold may be set to “2/9” or the like that can be distinguished from each other.

  In addition, it is not always necessary to binarize the calculated edge components, and the edge components before binarization may be summed, and the summed value may be compared with the visibility threshold. The sum of the edge components when the field of view is normal as shown in FIG. 6B is “3 + 3 + 3 + 18 + 15 + 14 + 3 + 3 + 3 = 65”, and the sum of the edge components when the field of view is abnormal as shown in FIG. Therefore, the field-of-view threshold value may be set to “27” or the like that can be distinguished from each other in correspondence with this.

  Further, the value obtained by dividing the sum of the edge components before binarization by the number of pixels included in the region A5, that is, the average value of the edge components (edge components before binarization) of each pixel in the region A5, You may compare with a visibility threshold value. In this case, the average value when the visual field is normal in FIG. 6C is “65/9”, and the average value when the visual field is abnormal in FIG. 7C is “14/9”. Thus, the visibility threshold may be set to “3” or the like that can be distinguished from each other.

  Further, as a method for calculating the edge component of each pixel, the method as shown in Expression (2) has been exemplified. However, the present invention is not limited to such an edge component calculation method, and various known edge component calculation methods. Is applicable. When calculating an edge component for a certain pixel, instead of evaluating the correlation with the luminance of pixels adjacent in the left-right direction, the correlation with the luminance of pixels in the vertical direction or diagonal direction may be evaluated. Further, the edge component may be calculated by combining these.

(Signal error detector)
Next, the operation of the signal abnormality detection unit 4 will be described. FIG. 8 is a block diagram illustrating a configuration of the signal abnormality detection unit 4. The signal abnormality detection unit 4 determines whether the video signal is abnormal based on the luminance signal Y, and determines whether the video signal is abnormal based on the luminance signal Y. A luminance variation detector 42, a color difference variation detector 43 that determines whether the video signal is abnormal based on the color difference signal RY and / or the color difference signal BY, and a synchronization signal included in the video signal And a synchronization abnormality detection unit 44 that determines whether or not the video signal is abnormal based on this.

  First, the operation of the luminance level detection unit 41 will be described. The luminance level detection unit 41 focuses on the luminance of pixels within a predetermined range (hereinafter referred to as “evaluation pixels”) included in the reproduction screen as shown in FIG. Video signals are sequentially sent from the imaging unit 2 to the luminance level detection unit 41. The luminance level detection unit 41 calculates the sum of the luminances of the evaluation pixels represented in the luminance signal Y (hereinafter referred to as “total S2”) for each video signal or at regular intervals.

  When the sum S2 is continuously below the luminance level threshold (second threshold) for a predetermined second period (for example, several tens of seconds to several minutes) (or less than the luminance level threshold). The visual field abnormality detection unit 3 determines that the video signal from the imaging unit 2 is abnormal. More specifically, it is determined that the luminance signal Y is abnormal.

  The luminance level threshold is set to a value close to the black level of the playback screen. For example, if the luminance is digitized by 0 to 15 of 4 bits, the larger numerical value corresponds to the larger luminance, and the predetermined range including the evaluation pixel is the region A5, the luminance level threshold value Is “9”. When the luminance is in a state as shown in FIG. 6A, the sum S2 is 1 + 1 + 2 + 10 + 8 + 8 + 1 + 0 + 0 = 31. Since 31> 9, it is determined that the video signal in this state is normal. On the other hand, if the state in which the sum S2 is 4 or 5 continues for the second period or longer, it is determined that the video signal is abnormal. This is because if the state in which the sum S2 is close to the black level continues for a certain time or more, the video signal is likely to be abnormal (in other words, the imaging unit 2 is likely to be faulty).

  Further, a value obtained by dividing the total sum S2 by the number of evaluation pixels, that is, an average value of luminance may be compared with a luminance level threshold value. In this case, the brightness level threshold is set smaller than the above example (for example, “1”).

  Further, when the total sum S2 continuously exceeds a predetermined threshold for a predetermined period (for example, several tens of seconds to several minutes), it is determined that the video signal from the imaging unit 2 is abnormal. It may be. More specifically, it may be determined that the luminance signal Y is abnormal. In this case, the threshold value is set to a value close to the white level of the reproduction screen.

  Next, the operation of the luminance fluctuation detection unit 42 will be described. The luminance fluctuation detection unit 42 focuses on the luminance fluctuation component of the evaluation pixel. Video signals are successively sent from the imaging unit 2 to the luminance fluctuation detection unit 42. The luminance fluctuation detection unit 42 calculates the magnitude (absolute value) of the luminance fluctuation component of the evaluation pixel represented in the luminance signal Y for each evaluation pixel, and then sums the magnitude of the fluctuation component in each evaluation pixel. (Hereinafter referred to as “total S3”). The calculation of the sum S3 is performed for each video signal or at regular intervals.

  For example, consider a case where the pixels D1, D2, D4, and D5 in FIG. 6 are evaluation pixels. The luminances of the pixels D1, D2, D4 and D5 in the previous screen (previous frame) are 1, 1, 10 and 8, respectively, as shown in FIG. 9A, and the pixels D1, Assume that the luminances of D2, D4, and D5 are 4, 2, 6, and 8, respectively, as shown in FIG. In this case, the magnitudes of the fluctuation components (difference values) of the pixels D1, D2, D4, and D5 are | 4-1-1 == 3, | 2-1 | = 1, respectively, as shown in FIG. | 6-10 | = 4 and | 8-8 | = 0. Then, the sum S3 between the previous screen (previous frame) and the current screen (current frame) is 3 + 1 + 4 + 0 = 8. In this way, the sum S3 between the previous screen (previous frame) and the current screen (current frame), which are consecutive frames, is calculated one after another.

  When the sum S3 is continuously lower than the luminance fluctuation threshold (third threshold) for a predetermined third period (for example, several tens of seconds to several minutes) (or lower than the luminance fluctuation threshold). The visual field abnormality detection unit 3 determines that the video signal from the imaging unit 2 is abnormal. More specifically, it is determined that the luminance signal Y is abnormal. If the state in which the total sum S3 is equal to or lower than the luminance variation threshold, that is, the state in which the luminance does not change so much continues for a certain time or more, the video signal is likely to be abnormal (in other words, the imaging unit 2 This is because there is a high possibility of failure.

  The luminance variation threshold is set to a value that can discriminate between abnormal and normal video signals. For example, if the luminance is digitized by 0 to 15 of 4 bits, and the larger numerical value corresponds to the larger luminance, the luminance variation threshold value is “2”.

  Further, a value obtained by dividing the total sum S3 by the number of evaluation pixels, that is, an average value of the luminance variation components may be compared with the luminance variation threshold. In this case, the luminance variation threshold is set smaller than the above example (for example, “2/9”).

  Next, the operation of the color difference variation detection unit 43 will be described. As described above, the video signal from the imaging unit 2 includes the color difference signal RY and the color difference signal BY. A display device such as the display device 64 displays a reproduction screen as shown in FIG. 4 based on the luminance signal Y, the color difference signal RY, the color difference signal BY, and the synchronization signal. The color difference variation detection unit 43 focuses on the value of the color difference signal in the evaluation pixel.

Here, the value of the color difference signal means the value of intensity E _RY (hereinafter simply referred to as “color difference signal value E _RY ”) and the value of intensity E _BY (hereinafter simply referred to as “color difference”) expressed by the above formula (1). Signal value E _BY "). The color difference signal value E _RY and the color difference signal value E _BY will be described as being expressed by 8 bits and can take values of 0 to 255, respectively. In this case, a state where both the color difference signal value E _RY and the color difference signal value E _BY coincide with 128 (or a value close to 128) corresponds to a state where there is no color component in the region including the evaluation pixel. Incidentally, the color difference signal value E _RY and the color difference signal value E _BY has deformation and to allow can take a value of -127～128, deformation to be represented by 10 bits is of course possible.

Video signal is sequentially sent from the imaging unit 2 to the color difference variation detection unit 43. The color difference variation detection unit 43 calculates the magnitude of the difference value between the color difference signal value E _RY in the evaluation pixel and a predetermined first reference value (hereinafter referred to as “first difference value”) for each evaluation pixel, The sum of the magnitudes of the first difference values at each evaluation pixel (hereinafter referred to as “sum S4”) is calculated. Similarly, the color difference variation detection unit 43 calculates the magnitude of a difference value (hereinafter referred to as “second difference value”) between the color difference signal value E _BY and a predetermined second reference value in the evaluation pixel for each evaluation pixel. After that, the total sum of the second difference values in each evaluation pixel (hereinafter referred to as “sum S5”) is calculated. The sums S4 and S5 are calculated for each video signal or at regular intervals.

  Here, both the first reference value and the second difference value are set to 128. However, the first reference value may be set to a value different from 128, and the second reference value may be set to a value different from 128. The first reference value and the second reference value may be different values.

For example, consider a case where the pixels D1, D2, D4, and D5 in FIG. 6 are evaluation pixels. Pixel D1 in a certain frame, D2, D4 and chrominance signal values of D5 E _RY is, as shown in FIG. 10 (a), when each is 215,108,160 and 83, the pixel D1, D2, D4 and D5 As shown in FIG. 10B, the magnitudes of the first difference values are | 215−128 | = 87, | 108−128 | = 20, | 160−128 | = 32, and | 83−128 |, respectively. = 45. Then, the total sum S4 becomes 87 + 20 + 32 + 45 = 184. Similarly, the sum S5 is also calculated.

  Then, the total sum S4 continues to be equal to or less than the color difference variation threshold α (fourth threshold) for a predetermined fourth period (for example, several tens of seconds to several minutes) (or less than the color difference variation threshold α). And the sum S5 is continuously lower than the color difference variation threshold β (fifth threshold) for a predetermined fifth period (for example, several tens of seconds to several minutes) (or less than the color difference variation threshold β). The visual field abnormality detection unit 3 determines that the video signal from the imaging unit 2 is abnormal. More specifically, it is determined that the color difference signals (color difference signal RY and color difference signal BY) are abnormal. A state in which the total sum S4 is equal to or smaller than the color difference variation threshold value α and the total sum S5 is equal to or smaller than the color difference variation threshold value β, that is, a state where there is no color component (or almost no color component) in the region included in the evaluation pixel continues for a certain time or more. This is because there is a high possibility that the video signal is abnormal (in other words, there is a high possibility that the imaging unit 2 is out of order).

  The color difference variation threshold value α and the color difference variation threshold value β are set to values that can determine whether the video signal is abnormal or normal. For example, the color difference variation threshold α and the color difference variation threshold β are set within a range of 1 to 20. The color difference variation threshold α and the color difference variation threshold β may be the same or different from each other.

Further, a value obtained by dividing the total sum S4 by the number of evaluation pixels, that is, an average value of the color difference signal value E _RY may be compared with the color difference variation threshold value α. In this case, the color difference variation threshold value α is set smaller than the above example (for example, 1 to 5). Similarly, a value obtained by dividing the total sum S5 by the number of evaluation pixels, that is, an average value of the color difference signal value E _BY may be compared with the color difference variation threshold β. In this case, the color difference variation threshold β is set smaller than the above example (for example, 1 to 5).

  Regardless of the sum S5, the sum S4 is continuously lower than the color difference variation threshold value α (fourth threshold value) for a predetermined fourth period (for example, several tens of seconds to several minutes) or longer (or It may be determined that the video signal is abnormal when the condition that it is less than the color difference fluctuation threshold α is satisfied. On the contrary, regardless of the sum S4, the sum S5 is continuously equal to or less than the color difference variation threshold β (fifth threshold) for a predetermined fifth period (for example, several tens of seconds to several minutes) ( Alternatively, it may be determined that the video signal is abnormal when the condition that it is less than the color difference variation threshold β is satisfied. However, as described above, it is desirable to evaluate both values of the sums S4 and S5 from the viewpoint of reliably preventing erroneous detection of an abnormality in the video signal.

  The region including the evaluation pixel focused on by the luminance level detection unit 41, the region including the evaluation pixel focused on by the luminance variation detection unit 42, and the region including the evaluation pixel focused on by the color difference variation detection unit 43 all coincide. However, they may be different from each other. Further, the evaluation pixel focused on by the luminance variation detection unit 42 and the evaluation pixel focused on by the color difference variation detection unit 43 may be a single pixel. When the evaluation pixel is a single pixel, the sum S3 matches the magnitude of the luminance fluctuation component in the evaluation pixel, the sum S4 matches the magnitude of the first difference value in the evaluation pixel, and the sum S5 is the second in the evaluation pixel. It matches the size of the difference value.

  Next, the operation of the synchronization abnormality detection unit 44 will be described. The synchronization abnormality detection unit 44 detects whether or not there is an abnormality in the synchronization signal (horizontal synchronization signal and / or vertical synchronization signal) included in the video signal from the imaging unit 2. When it is determined that the synchronization signal is abnormal, the visual field abnormality detection unit 3 determines that the video signal from the imaging unit 2 is abnormal. More specifically, it is determined that the synchronization signal (horizontal synchronization signal and / or vertical synchronization signal) is abnormal.

  Since the number of pixels and the frame rate of the CCDs 23, 24, and 25 constituting the imaging unit 2 are determined in advance, the waveforms that the horizontal synchronization signal and the vertical synchronization signal should be originally (that is, the horizontal synchronization signal and the vertical synchronization signal are normal). The waveform in a certain case (hereinafter referred to as “reference waveform”) is naturally determined. The synchronization abnormality detection unit 44 determines whether or not the synchronization signal is abnormal by comparing the phase of the reference waveform with the phase of the video signal from the imaging unit 2. For example, it is determined that the synchronization signal is abnormal when a certain phase shift is detected.

  Further, instead of such a method, it is possible to count how many horizontal synchronizing signals (or vertical synchronizing signals) exist within a predetermined period and compare the counted number with a predetermined reference value. Good. When the horizontal synchronization signal (or vertical synchronization signal) is normal, the number of horizontal synchronization signals (or vertical synchronization signals) that will exist within the predetermined period is set as the reference value. If the arrangement state of the pixels in the CCD 23, 24 and 25 in the row and column directions and the frame rate are determined, the reference value is naturally determined. For example, when the number of horizontal synchronization signals (or vertical synchronization signals) within a predetermined period deviates from the reference value by a certain value or more, it is determined that the synchronization signal is abnormal.

(Operation when signal is abnormal)
“Information indicating that an abnormality has occurred in the video signal (luminance signal Y) (hereinafter referred to as luminance level abnormality information)” detected by the luminance level detection unit 41, “Video” detected by the luminance fluctuation detection unit 42 Information indicating that an abnormality has occurred in the signal (luminance signal Y) (hereinafter referred to as luminance variation abnormality information) ”and“ video signal (color difference signal) detected by the color difference variation detector 43 has occurred. Information (hereinafter referred to as color difference abnormality information) ”and“ information indicating that an abnormality has occurred in the video signal (synchronization signal) detected by the synchronization abnormality detection unit 44 (hereinafter referred to as synchronization abnormality information). ) ”Is transmitted to the abnormal state determination unit 5. The information obtained by integrating the luminance level abnormality information, luminance variation abnormality information, color difference abnormality information, and synchronization abnormality information is hereinafter referred to as “signal abnormality information”. Also. The timing at which the signal abnormality detection unit 4 determines that “an abnormality has occurred in the video signal” is hereinafter referred to as “when the signal is abnormal”.

  Upon receiving the signal abnormality information, the abnormal state determination unit 5 causes the notification unit 6 to perform notification corresponding to the occurrence of an abnormality in the video signal or notification for notifying the occurrence of a failure in the imaging unit 2. . At this time, the content of the notification may be varied according to the received abnormality information.

  The luminance level abnormality information, luminance fluctuation abnormality information, color difference abnormality information, and synchronization abnormality information sent from the signal abnormality detection unit 3 are transmitted to the signal processing unit 7 via the abnormal state determination unit 5. The signal processing unit 7 adds the transmitted luminance level abnormality information, luminance fluctuation abnormality information, color difference abnormality information, and synchronization abnormality information to the video information corresponding to the video signal. At this time, information indicating abnormality of the video signal may be simply added without distinguishing the luminance level abnormality information, luminance fluctuation abnormality information, color difference abnormality information, and synchronization abnormality information. Since the signal abnormality information is added to the video information when the signal is abnormal, the recording unit 8 records the video information and the signal abnormality information in association with each other. By referring to the signal abnormality information together with the video information, the reliability of the video information in the recording unit 8 can be evaluated.

(Notification part)
The notification unit 6 provides notification corresponding to the occurrence of an abnormality in the field of view of the imaging unit 2 and notification corresponding to the occurrence of an abnormality in the video signal (hereinafter referred to as “abnormal notification”). Is performed by light emission by a light emitting element such as an LED (Light Emitting Diode) or output of sound.

  Simultaneously with the above light emission or the like, or in place of the above light emission or the like, the display device 64 provided in the vehicle 60 displays an abnormality in the visual field of the imaging unit 2 or an abnormal video signal. You may make it perform the display which shows having generate | occur | produced. These displays are also a kind of “abnormality notification”. The display device 64 can be regarded as an external device (an external device of the imaging device 1) controlled by a control signal from the notification unit 6. The control signal is transmitted from the notification unit 6 to the display device 64 by wire or wirelessly. The display device 64 may be considered to be provided in the notification unit 6. In this case, the imaging device 1 includes the display device 64. Further, although different from the situation of FIG. 1, the display device 64 itself may be incorporated in the imaging device 1.

  The notification unit 6 performs the above-described abnormality notification when the engine 66 (see FIG. 1) is started. More specifically, when the ignition switch 65 is turned on, the engine 66 is switched from the non-operating state to the operating state, or a predetermined time (for example, several milliseconds to several seconds) elapses from that point. Then, abnormality notification is started. This makes it possible for the driver of the vehicle 60 and the like to surely know the occurrence of a visual field abnormality and to increase the willingness to perform some maintenance on the imaging device 1. Further, when the engine 66 is started, even if the display device 64 is used for abnormality notification, the operation of the navigation system is not hindered.

  This abnormality notification can be canceled by the user's operation. In addition, the abnormality notification may be performed by the notification unit 6 even when the engine 66 is not started. For example, when the abnormal state determination unit 5 receives visual field abnormality information or signal abnormality information, the notification unit 6 may immediately notify the abnormality.

  The visual field abnormality information and the signal abnormality information received by the abnormal state determination unit 5 are recorded in the determination history recording unit 9 as a history. Now, it is assumed that the engine 66 is stopped after a visual field abnormality or a signal abnormality is detected and a first abnormality notification (hereinafter referred to as “first abnormality notification”) is performed when the engine 66 is started. When the engine 66 is started next time, the comparison unit 10 records the contents of the determination history recording unit 9, the current visual field state, and the video signal state (that is, whether there is visual field abnormality information and signal abnormality information at the present time). Compare Then, when the abnormality content indicated by the first abnormality notification has not been resolved, the comparison unit 10 cooperates with the abnormal state determination unit 5 and performs abnormality notification (hereinafter, “ Second abnormality notification ”).

  For example, in the first abnormality notification, when the abnormality in the visual field is detected again by the operation of the visual field abnormality detection unit 3 after the next engine 66 start in spite of the notification regarding the abnormality in the visual field, The second abnormality notification having a content different from that of the abnormality notification is performed. The second abnormality notification is a content that strongly appeals the necessity of maintenance or the like to the driver of the vehicle 60 or a content that further increases the willingness to perform the maintenance. For example, information (contact information and / or location; hereinafter referred to as “window information”) related to a window (so-called service center or the like) that can provide repair information (information necessary for performing repair or the like) of the imaging apparatus 1 is notified. Include in the content. By cooperating with the display device 64, the window information can be displayed. The window information is recorded in advance in, for example, the recording unit 8 or another recording unit (not shown). Further, when there are a plurality of the above-mentioned windows, it is preferable that the window information regarding all the windows can be notified. However, the notification of the window information may be included not only in the second abnormality notification but also in the first abnormality notification.

  Further, the display device 64 (or the imaging device 1) receives position information (information for knowing the current value of the vehicle 60, the display device 64, or the imaging device 1) transmitted from a GPS (Global Positioning System) satellite. A receiving unit (not shown), a map acquisition unit (not shown) that can acquire map information related to the map around the vehicle 60, the display device 64, or the imaging device 1 from a DVD (Digital Versatile Disk) or the like, and the received position A current location measuring unit (not shown) that measures the current location of the vehicle 60, the display device 64, or the imaging device 1 based on the information, and based on the received location information, the acquired map information, and the measured current location. When the vehicle 60, the display device 64, or the surrounding map of the imaging device 1 and the current location can be displayed, the information on the nearest window is provided to the driver of the vehicle 60 using these functions. By Rukoto may perform an abnormality notification (first abnormality notification and / or the second abnormality notification). At this time, a display (so-called navigation) for guiding the vehicle 60 to the nearest window may be performed. Based on the position information, the map information, and the current location, the nearest window is determined from a plurality of windows.

  Although the example in which the second abnormality notification is performed when the abnormality content indicated by the first abnormality notification is not resolved when the engine 66 is started next after the first abnormality notification is performed, the engine has been described above. The second abnormality notification may be performed for the first time when the abnormality content indicated by the first abnormality notification is not resolved even if the start of 66 is repeated a plurality of times. That is, after the first abnormality notification is performed, the abnormality corresponding to the first abnormality notification is not resolved, and the engine 66 is started n times (n is an arbitrary natural number). You may make it perform a 2nd abnormality alert | report for the first time. Once the second abnormality notification is performed, the abnormality notification that is performed is the second abnormality notification until the abnormality corresponding to the second abnormality notification is resolved.

(Washing part)
Next, the operation of the cleaning unit 11 (see FIG. 2) will be described. When the visual field abnormality detection unit 3 determines that the visual field of the imaging unit 2 is abnormal, the visual field abnormality detection unit 3 (or the abnormal state determination unit 5) outputs a cleaning command signal to the cleaning unit 11. Receiving this, the cleaning unit 11 performs a cleaning operation for eliminating the visual field abnormality.

  The cleaning unit 11 is, for example, a wiper (not shown) for wiping off foreign matters such as mud and dust adhering to the surface of the lens 21 (FIG. 3) on the imaging target side. For example, it is a gas delivery device (blower; not shown) which sends out (injects) gas in order to peel off adhesion of the foreign matter. Further, when a lens protection cover (not shown) for protecting the lens 21 is disposed on the imaging target side of the lens 21, the wiper has a function of wiping off foreign matters adhering to the imaging target side surface of the lens protection cover. The gas delivery device plays a role of peeling off foreign matter adhering to the surface of the lens protection cover on the imaging target side. In addition, you may make it provide both said wiper and gas delivery device. Further, when performing the above-described operation of the wiper, it is preferable to use a cleaning liquid together.

  Further, as shown in FIG. 1, the imaging device 1 is attached to the inside of a vehicle 60 provided with a wiper 67 on a windshield 63, and is positioned in the traveling direction of the vehicle 60 via the windshield 63 in a region that the wiper 67 crosses. In the case of imaging an imaging target to be performed, the cleaning operation may be performed by operating the wiper 67. Specifically, for example, the vehicle 60 is provided with a control unit (not shown) that controls the operation of the wiper 67, and when it is determined that the field of view of the imaging unit 2 is abnormal, the cleaning unit 11 performs the wiper drive. A signal is sent to the control unit by wire or wirelessly. Then, the control unit that has received the wiper drive signal operates the wiper 67 for a predetermined time. As a result, the foreign matter that obstructs the imaging of the imaging target is removed from the windshield 63.

  Depending on the installation status of the imaging apparatus 1 or the like, the outline of the foreign matter attached to the windshield 63 is blurred during imaging. That is, the cause of determining that the field of view of the imaging unit 2 is abnormal may be a foreign matter attached to the windshield 63. Therefore, the visual field abnormality may be resolved by operating the wiper 67 as described above.

(Modification)
When it is determined that the field of view of the imaging unit 2 is abnormal or when the video signal is determined to be abnormal, the recording unit 8 uses information corresponding to the abnormality (such as the above-described visual field abnormality information) as video information. As described above, recording is performed in association with each other. Alternatively, the recording operation by the recording unit 8 may be stopped when it is determined that the field of view of the imaging unit 2 is abnormal or when the video signal is determined to be abnormal.

  In the description of the embodiment according to the present invention, the imaging apparatus 1 as illustrated in FIG. 2 is illustrated, but in the present invention, the determination history recording unit 9 and the comparison unit 10 are not necessarily required. Similarly, in the present invention, the cleaning unit 11 is not always necessary.

  In addition, the imaging apparatus according to the present invention can be mounted on various moving bodies in addition to vehicles such as automobiles and motorcycles (so-called motorcycles and electric bicycles). In addition, the imaging apparatus according to the present invention can be attached to other than a moving body. For example, it may be attached to a traffic light or a sign.

  Moreover, although the embodiment in which the imaging device 1 and the acceleration sensor 62 are separate bodies has been illustrated (see FIG. 1), the acceleration sensor 62 may be built in the imaging device 1.

  With the imaging apparatus according to the present invention, it is possible to reliably notify the user of the occurrence of an abnormality in the imaging unit.

It is a figure which shows a mode that the imaging device which concerns on embodiment of this invention is attached to the vehicle. It is a block diagram showing the structure of the imaging device of FIG. It is a figure which shows the structure of the imaging part of FIG. It is a figure which shows an example of the reproduction | regeneration screen at the time of displaying the video signal output from the imaging part of FIG. 2 as an image. It is a figure which shows the structure of the visual field abnormality detection part of FIG. It is a figure for demonstrating operation | movement of the visual field abnormality detection part of FIG. It is a figure for demonstrating operation | movement of the visual field abnormality detection part of FIG. It is a figure which shows the structure of the signal abnormality detection part of FIG. It is a figure for demonstrating operation | movement of the brightness | luminance fluctuation | variation detection part of FIG. It is a figure for demonstrating operation | movement of the color difference variation detection part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Imaging device 2 Imaging part 3 Visual field abnormality detection part 4 Signal abnormality detection part 5 Abnormal state determination part 6 Notification part 7 Signal processing part 8 Recording part 9 Judgment history recording part 10 Comparison part 11 Washing part 21 Lens 22 Dichroic prism 23, 24 , 25 CCD
DESCRIPTION OF SYMBOLS 26 Image processing circuit 31 Edge component calculation part 32 Edge component summation part 41 Brightness level detection part 42 Brightness fluctuation detection part 43 Color difference fluctuation detection part 44 Synchronization abnormality detection part 60 Vehicle 61 Room mirror 62 Acceleration sensor 63 Windshield 64 Display apparatus 65 Ignition Switch 66 Engine 67 Wiper D1-D9 Pixel

Claims (12)

An imaging unit for imaging an imaging target;
A recording unit for recording a video signal output from the imaging unit as video information;
A signal abnormality detector for detecting an abnormality of the video signal based on the video signal;
A visual field abnormality detection unit that detects a visual field abnormality of the imaging unit based on the video signal;
An imaging device comprising: a notification unit that performs notification corresponding to the detected abnormality when at least one of the abnormality of the video signal and the abnormality of the visual field is detected. The video signal output from the imaging unit includes a luminance signal for a playback screen composed of a plurality of pixels,
The visual field abnormality detection unit calculates an edge component of luminance for each pixel based on the luminance signal;
An edge component summing unit that calculates a value corresponding to a sum of edge components in pixels within a predetermined range of the reproduction screen, and
The visual field abnormality detection unit determines that the visual field is abnormal when a value corresponding to the sum is continuously equal to or lower than a predetermined first threshold for a predetermined first period or longer. Item 2. The imaging device according to Item 1. The video signal output from the imaging unit includes a luminance signal for a playback screen composed of a plurality of pixels,
The signal abnormality detection unit includes a luminance level detection unit that calculates a value corresponding to the total luminance in pixels within a predetermined range of the reproduction screen;
The signal abnormality detection unit determines that the video signal is abnormal when a value corresponding to the sum is continuously equal to or lower than a predetermined second threshold for a predetermined second period or longer. The imaging device according to claim 1 or 2. The video signal output from the imaging unit includes a luminance signal for a playback screen composed of a plurality of pixels,
The signal abnormality detection unit calculates the magnitude of a luminance fluctuation component in a pixel within a predetermined range of the reproduction screen for each pixel and then calculates a value corresponding to the total sum of the magnitudes of the fluctuation components Equipped with a detector,
The signal abnormality detection unit determines that the video signal is abnormal when a value corresponding to the sum is continuously equal to or less than a predetermined third threshold for a predetermined third period or more. The imaging device according to claim 1 or 2. The video signal output from the imaging unit includes a first color difference signal and a second color difference signal for a playback screen configured by a plurality of pixels,
The signal abnormality detection unit calculates, for each pixel, a magnitude of a first difference value corresponding to a difference between a value of a first color difference signal and a predetermined first reference value in a pixel within a predetermined range of the reproduction screen. And a color difference variation detector that calculates a value corresponding to the sum of the magnitudes of the first difference values.
The signal abnormality detection unit determines that the video signal is abnormal when a value corresponding to the sum is continuously equal to or lower than a predetermined fourth threshold for a predetermined fourth period or longer. The imaging device according to claim 1 or 2. The video signal output from the imaging unit includes a first color difference signal and a second color difference signal for a playback screen configured by a plurality of pixels,
The signal abnormality detection unit calculates, for each pixel, a magnitude of a first difference value corresponding to a difference between a value of a first color difference signal and a predetermined first reference value in a pixel within a predetermined range of the reproduction screen. Thereafter, a value corresponding to the sum of the magnitudes of the first difference values is calculated, and a second difference corresponding to the difference between the value of the second color difference signal and the predetermined second reference value in the pixels within the predetermined range. A color difference variation detector that calculates a value corresponding to the sum of the magnitudes of the second difference values after calculating the magnitude of the value for each pixel;
The signal abnormality detection unit has a value corresponding to the total sum of the first difference values continuously longer than a predetermined fourth threshold for a predetermined fourth period or more, and a value corresponding to the total sum of the second difference values. 3. The imaging apparatus according to claim 1, wherein the video signal is determined to be abnormal when the video signal continuously falls below a predetermined fifth threshold for a predetermined fifth period or longer. 4. The signal abnormality detection unit includes a synchronization abnormality detection unit that detects whether or not the synchronization signal included in the video signal is abnormal,
The imaging apparatus according to claim 1, wherein the signal abnormality detection unit determines that the video signal is abnormal when the synchronization signal is determined to be abnormal. The imaging device is attached to a moving body having an engine,
The imaging device according to claim 1, wherein the notification unit performs the notification when the engine is started. After the notification at the time of starting the engine, when the engine is started n times (n is a natural number) without the abnormality corresponding to the notification being resolved,
The imaging apparatus according to claim 8, wherein the notification unit performs notification of contents different from the notification. The said notification part performs the said notification by displaying the information regarding the window which can provide the repair information of the said imaging device on an external display apparatus, The said notification is characterized by the above-mentioned. The imaging device described. The imaging apparatus according to claim 1, further comprising a cleaning unit that performs a cleaning operation for eliminating the abnormality in the visual field when the visual field abnormality is detected. . 2. The recording unit according to claim 1, wherein when at least one of an abnormality in the video signal and an abnormality in the visual field is detected, information corresponding to the detected abnormality is recorded in association with the video information. The imaging device according to claim 7.

Images