JP2019023081A - Imaging apparatus - Google Patents

Abstract

To provide an imaging apparatus mounted on a room mirror, capable of imaging preferably a front scenery of a vehicle.SOLUTION: A drive recorder 1 is mounted on a room mirror 2 installed on a vehicle, and includes a mirror part 3 and a camera 11. The camera 11 has an imaging direction tilted by 20° from a horizontal direction to a normal direction at a center location of a mirror surface of the mirror part 3. In this case, the imaging direction of the camera 11 coincides approximately with a front direction of the vehicle in a state where the mirror part 3 is adjusted into a usage state.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a technique for photographing a front landscape from a vehicle.

  2. Description of the Related Art Conventionally, there is known a room mirror that is integrally provided with a camera that captures a front landscape of a vehicle. For example, Patent Document 1 discloses a camera built-in room mirror in which a camera is installed in an internal space of a case constituting a room mirror, and the shooting direction of the camera is configured to be constant regardless of the angle adjustment of the room mirror. Yes.

JP 2007-022495 A

  In Patent Document 1, there is a problem that a space for eliminating the interference between the camera and the rearview mirror case is required, and the rearview mirror case becomes large.

  The present invention has been made to solve the above-described problems, and a main object of the present invention is to provide an imaging apparatus that is attached to a rearview mirror and can appropriately photograph a front landscape of a vehicle.

  The invention described in claim is an imaging apparatus that is mounted on a rearview mirror provided in a vehicle and photographs a front landscape of the vehicle, and is in a normal direction in the center position of the mirror portion and the mirror surface of the mirror portion. And a photographing means having a photographing direction inclined by a first angle in a horizontal direction, wherein the photographing direction of the photographing means is the vehicle when the mirror portion is adjusted to a use state. It is characterized by being set to an angle substantially coincident with the front direction.

The front view and back view of a drive recorder are shown. The top view of a drive recorder is shown. The block diagram of a drive recorder is shown. The top view and side view in a vehicle in case a vehicle is a right steering wheel are shown. It is a figure which shows the relationship between a picked-up image and a cut-out image. It is an example of a display. The rear view and top view of a drive recorder in case a vehicle is a left steering wheel are shown. It is a schematic block diagram of the system which concerns on a modification.

  In one preferred embodiment of the present invention, there is provided a photographing device that is attached to a room mirror provided in a vehicle and photographs a front landscape of the vehicle, the mirror unit and a method at a center position of a mirror surface of the mirror unit Photographing means having a photographing direction inclined by a first angle in the horizontal direction with respect to the line direction, wherein the first angle is a photographing direction of the photographing means in a state where the mirror unit is adjusted to a use state. Is set to an angle that substantially matches the front direction of the vehicle.

  The photographing apparatus is mounted on a room mirror provided in a vehicle, and includes a mirror unit and photographing means. The photographing means has a photographing direction inclined by a first angle in the horizontal direction with respect to the normal direction at the center position of the mirror surface of the mirror portion. Here, the first angle is set to an angle at which the photographing direction of the photographing unit substantially coincides with the front direction of the vehicle in a state where the mirror portion is adjusted to the use state. Here, “the angle at which the photographing direction of the photographing means substantially coincides with the front direction of the vehicle” refers to an angle at which the photographing direction of the photographing means is within a 10 ° difference from the front direction of the vehicle, for example. According to this aspect, the photographing apparatus can suitably photograph the front scenery centering on the front direction of the vehicle in a state where the mirror unit is adjusted to the use state by the driver.

  In one aspect of the photographing apparatus, the photographing apparatus includes an acceleration sensor that detects acceleration, and an image control unit that outputs an image obtained by cutting out a part of an image photographed by the photographing unit based on an output of the acceleration sensor. And comprising. According to this aspect, the photographing apparatus can recognize the inclination of the photographing apparatus and the like based on the output of the acceleration sensor, and can appropriately cut out and output the portion showing the front direction of the vehicle.

  In another aspect of the photographing apparatus, the photographing apparatus is configured such that the image control unit is based on an angular difference between the normal direction and the front direction of the vehicle, which is calculated based on an output of the acceleration sensor. The center position of the image output by the image control means is changed. According to this aspect, the photographing device can appropriately cut out and output the portion of the vehicle front direction reflected from the photographed image.

  In another aspect of the imaging apparatus, the imaging apparatus includes a detecting unit that detects a vanishing point in an image captured by the imaging unit, and the imaging unit based on the vanishing point detected by the detecting unit. Image control means for cutting out and outputting a part of the photographed image. Also according to this aspect, the photographing device can appropriately cut out and output the portion of the front direction of the vehicle from the photographed image.

  In another aspect of the photographing apparatus, the photographing apparatus includes a display unit configured in a part of the mirror unit, and the display unit displays an image output by the image control unit. According to this aspect, the photographing apparatus can make the driver preferably visually recognize an image obtained by photographing a front landscape of the vehicle.

  In another aspect of the imaging apparatus, the imaging apparatus includes a nonvolatile memory for storing an image, and the nonvolatile memory is rotated based on a direction of gravity applied to a mirror surface direction of the mirror unit. The output image of the image control means is stored. According to this aspect, it is possible to always store an image of the front scenery viewed from the front in the nonvolatile memory regardless of the manner in which the photographing apparatus is attached to the room mirror.

  In another aspect of the photographing apparatus, the photographing apparatus includes a superimposing unit that superimposes and outputs a text or a figure on an image photographed by the photographing unit, and the superimposing unit is arranged in a mirror direction of the mirror unit. The direction of the text or figure is rotated based on the direction of gravity applied. According to this aspect, the photographing apparatus can appropriately set the direction of text or graphics to be superimposed on the image photographed by the photographing means.

  In another aspect of the photographing apparatus, the photographing unit has a photographing direction inclined with respect to the normal direction by the first angle that is an angle within a range of 10 ° to 30 °. According to this aspect, the photographing apparatus can suitably photograph the front landscape in the front direction of the vehicle in the use state after the angle adjustment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Hereinafter, the “shooting direction” refers to a direction that is the front of the camera and that passes through the center of the field of view (shooting range) of the camera.

[Schematic configuration]
FIG. 1 shows a drive recorder 1 according to the present embodiment. Specifically, FIG. 1A shows a front view in a state where the drive recorder 1 is attached to the room mirror 2 in the vehicle interior (also simply referred to as “attached state”), and FIG. The rear view of the drive recorder 1 in a mounting state is shown. Hereinafter, the longitudinal direction of the drive recorder 1 is “Y-axis direction”, the short direction of the drive recorder 1 is “Z-axis direction”, and the direction perpendicular to the Y-axis and Z-axis is “X-axis direction”. Is determined as shown in the figure.

  The drive recorder 1 shown in FIG. 1 mainly includes a mirror unit 3, a camera (photographing unit) 11, a display (display unit) 10 existing on the back surface of the mirror unit 3, and clamping units 16 </ b> A to 16 </ b> D. And the drive recorder 1 is fixed with respect to the room mirror 2 when the clamping parts 16A-16D clamp the room mirror 2 in the mounting state. When the drive recorder 1 is mounted, the mirror surface of the room mirror 2 and the back surface of the drive recorder 1 overlap.

  FIG. 1 shows the mounted state of the drive recorder 1 when the vehicle is a right steering wheel. When the vehicle is a left steering wheel, the vehicle is rotated 180 ° on the YZ plane from FIG. 1 (B). The drive recorder 1 is mounted on the room mirror 2. The case where the vehicle is a left steering wheel will be described in detail in the section [Handling to the left steering wheel].

  The mirror unit 3 is, for example, a half mirror, and transmits part of the incident light and reflects other light. Thereby, the mirror unit 3 functions as a normal mirror that reflects the rear landscape of the vehicle when the display 10 on the back surface is not emitting light, and allows the light emitted from the display 10 to pass through when the display 10 is in emitting light. The driver is caused to visually recognize the display content on the display 10.

  The display 10 displays an image cut out from an image shot by the camera 11 (also referred to as “captured image Im”) (also referred to as “cutout image Imc”). As will be described later, the cut-out image Imc is an image cut out from the captured image Im so that the front landscape in the front direction of the vehicle becomes the center of the image, and has fewer vertical and horizontal pixels than the captured image Im. In addition, the display 10 superimposes and displays an image (also referred to as “guidance image”) representing characters, figures, and the like for guiding the driver on the cutout image Imc. In FIG. 1A, the display 10 displays a guide image representing the vehicle speed and a square frame guide image highlighting a lit signal light superimposed on the cut-out image Imc.

  The camera 11 is disposed on the back surface portion of the drive recorder 1 that does not overlap the rearview mirror 2 when the drive recorder 1 is mounted. Further, the shooting direction of the camera 11 (that is, the direction of the camera 11) is inclined by 20 ° laterally with respect to the normal (also referred to as normal “Ln”) at the center position of the mirror surface of the mirror unit 3. Yes. Here, the above-mentioned “20 °” is a standard left-right inclination angle when a driver of a general physique sets the inclination of the rearview mirror 2, and is the “first angle” in the present invention. It is an example. Thereby, in the state which the driver | operator adjusted the angle of the drive recorder 1, the imaging | photography direction of the camera 11 substantially corresponds with the front direction (front direction) of a vehicle. This will be described with reference to FIG.

  FIG. 2 shows a top view of the drive recorder 1. In the example of FIG. 2, the drive recorder 1 is tilted counterclockwise by 20 ° so that the mirror 3 of the drive recorder 1 is directed toward the driver.

  Here, as shown in FIG. 2, the shooting direction of the camera 11 indicated by the arrow 41 is inclined clockwise (clockwise) by 20 ° on the horizontal plane (that is, the XY plane) with respect to the normal line Ln. Further, the normal Ln is inclined counterclockwise (counterclockwise) by 20 ° on the horizontal plane with respect to the front direction of the vehicle by adjusting the angle of the mirror 3 of the driver. As a result, in the example of FIG. 2, the shooting direction of the camera 11 indicated by the arrow 41 matches the front direction of the vehicle.

  Thereafter, the installation state of the drive recorder 1 shown in FIG. 2, that is, the normal line Ln is inclined counterclockwise in the XY plane by 20 ° with respect to the front direction of the vehicle, and the drive recorder 1 is perpendicular to the horizontal plane. This state is also called “reference state”.

  FIG. 3 is a functional block diagram of the drive recorder 1. As shown in FIG. 3, the drive recorder 1 includes a display 10, a camera 11, an acceleration sensor 12, a nonvolatile memory 13, and a control unit 14.

  The acceleration sensor 12 detects acceleration in the three-axis directions of the X axis, the Y axis, and the Z axis, and supplies the detection signal to the control unit 16. The nonvolatile memory 13 is a storage medium such as an SD card, for example, and stores a captured image Im generated by the camera 11 or a cutout image Imc displayed on the display 10 based on the control of the control unit 14.

  The control unit 14 includes a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores a control program executed by the CPU, data, and the like, and a RAM (Random) in which various data are sequentially read and written as a work memory when the CPU operates. Access Memory) and the like, and performs overall control of the drive recorder 1.

  For example, the control unit 14 overwrites the captured image Im or the cutout image Imc for a predetermined time in the temporary memory, and when the acceleration sensor 12 detects an acceleration equal to or greater than a predetermined value, the captured image Im or the cutout stored in the temporary memory is detected. The image Imc is written into the nonvolatile memory 13. Further, the control unit 14 performs various recognition processes such as detection of a preceding vehicle, detection of a lane, detection of a lighting color of a traffic light, and the like based on the recognition result based on the captured image Im. The image is superimposed on the cutout image Imc and displayed on the display 10. The control unit 14 is an example of “image control means” and “superimposition means” in the present invention.

[Generation Method of Cutout Image Imc]
Next, a method for generating the cutout image Imc will be described. Schematically, the control unit 14 determines the center position of the cut-out image Imc on the photographed image Im based on the difference in inclination between the normal Ln in the horizontal direction and the vertical direction when compared with the reference state illustrated in FIG. Move. Thereby, the control unit 14 suitably generates the cut-out image Imc centered on the front direction of the vehicle even when the angle of the mounted drive recorder 1 is adjusted according to the physique of the driver, etc. 10 is displayed.

  Hereinafter, a case where the vehicle is a right steering wheel will be described. For example, the control unit 14 determines whether the drive recorder 1 is mounted on the right-hand drive vehicle or the left-hand drive vehicle based on the acceleration in the Z-axis direction (ie, gravitational acceleration) output from the acceleration sensor 12.

  FIG. 4A shows a top view of the inside of the vehicle when the vehicle is a right steering wheel. FIG. 4B shows a side view of the vehicle when the vehicle is a right steering wheel.

  In this case, first, based on the output of the acceleration sensor 12, the control unit 14 tilts the normal line Ln with respect to the front direction of the vehicle on the horizontal plane (also referred to as “horizontal tilt angle θh”, see FIG. 4A). ) And the elevation angle of the normal Ln with respect to the horizontal plane (also referred to as “vertical tilt angle θv”, see FIG. 4B). In this case, preferably, the control unit 14 calculates a statistical value for a predetermined period such as a moving average with respect to the output values of the X, Y, and Z axes of the acceleration sensor 12, and based on the calculated statistical value. The horizontal tilt angle θh and the vertical tilt angle θv may be calculated.

  Next, the control unit 14 determines the center position of the cut-out image Imc on the captured image Im according to the difference between the detected horizontal tilt angle θh and the horizontal tilt angle θh in the reference state (that is, 20 °). Shift horizontally from the center position. Further, the control unit 14 determines the center position of the cut-out image Imc on the captured image Im according to the difference between the detected vertical tilt angle θv and the vertical tilt angle θv in the reference state (that is, 0 °). Shift vertically from the center position. This will be described with reference to FIG.

  FIG. 5 is a diagram illustrating the positional relationship between the captured image Im and the cut-out image Imc. In FIG. 5, the position “Pimc” indicates the center position of the cut-out image Imc, and the position “Pim” indicates the center position of the captured image Im. In addition, the horizontal and vertical widths of the cut-out image Imc are set shorter than the captured image Im in consideration of the angles that the horizontal inclination angle θh and the vertical inclination angle θv can take.

  In the example of FIG. 5, the control unit 14 determines that the horizontal tilt angle θh detected by the acceleration sensor 12 is larger by a predetermined angle than the horizontal tilt angle θh (that is, 20 °) in the reference state, and according to the predetermined angle. The center position Pimc is shifted from the center position Pim to the right by the distance “Lh”. In this case, for example, the control unit 14 stores in advance a map or an expression indicating an appropriate setting value of the distance Lh for each candidate value of the predetermined angle described above, and refers to the map or the like to determine the distance Lh. Set. On the other hand, when the detected horizontal inclination angle θh is smaller than the horizontal inclination angle θh in the reference state, the control unit 14 sets the center position Pimc to the left of the center position Pim according to the angle difference between these horizontal inclination angles θh. Shift to

  Similarly, in the example of FIG. 5, the control unit 14 determines that the vertical inclination angle θv detected by the acceleration sensor 12 is larger than the vertical inclination angle θv (that is, 0 °) in the reference state by a predetermined angle. The center position Pimc is shifted from the center position Pim by a distance “Lv” corresponding to the angle. In this case, for example, the control unit 14 stores in advance a map or an expression indicating the set value of the appropriate distance Lv for each of the above-mentioned candidate values of the predetermined angle, and refers to the map or the like to determine the distance Lv. Set. When the detected vertical inclination angle θv is smaller than the vertical inclination angle θv in the reference state, the control unit 14 raises the center position Pimc above the center position Pim according to the angle difference between these vertical inclination angles θv. Shift to

  In the example of FIG. 5, as a result of moving the center position Pimc based on the horizontal tilt angle θh and the vertical tilt angle θv, the center position of the cut-out image Imc matches the shooting direction of the camera 11 with the front direction of the vehicle. The center position of the photographed image Im photographed in the case of being present. That is, the control unit 14 determines the cutout range of the cutout image Imc so that the vanishing point on the extension line in the front direction of the vehicle becomes the center position of the cutout image Imc.

  FIG. 6 is a display example of the display 10 on which the cutout image Imc shown in FIG. 5 is displayed. As shown in FIG. 6, the control unit 14 displays the cutout image Imc generated based on the vertical tilt angle θv and the horizontal tilt angle θh on the display 10 and displays guide images 80 and 81 for guiding the driver. It is displayed. In FIG. 6, the control unit 14 cuts out a guide image 80 that surrounds a lighting signal lamp that is recognized based on the captured image Im, and a guide image 81 that represents the vehicle speed acquired based on the output of a distance sensor or the like (not shown). Is superimposed.

  As shown in FIG. 6, the control unit 14 has the same direction of the driver's line of sight even when the drive recorder 1 is appropriately angle-adjusted from the reference state shown in FIG. 2 according to the physique of the driver. A cut-out image Imc whose direction is the shooting direction can be generated and displayed on the display 10. Further, since the camera 3 is tilted in advance so that the shooting direction of the camera 3 substantially coincides with the front direction of the vehicle in the state where the mirror unit 3 is adjusted to the use state, the pixels of the shot image Im and the cutout image Imc The number can be made closer. That is, an image showing the front direction of the vehicle can be displayed without extremely degrading the resolution of the cutout image Imc displayed on the display 10.

[Response to the left handle]
Next, a case where the vehicle is a left steering wheel will be described. FIG. 7A shows a rear view of the drive recorder 1 when the vehicle has a left handle, and FIG. 7B shows a top view of the drive recorder 1 when the vehicle has a left handle.

  As shown in FIG. 7A, when the vehicle is a left handle, the drive recorder 1 is rotated 180 ° on the YZ plane from the state shown in FIG. 1B when the vehicle is a right handle. It is attached to the room mirror 2. In this case, the drive recorder 1 is mounted on the rearview mirror 2 with the sandwiching portions 16A and 16B sandwiching the lower end position of the room mirror 2 and the sandwiching portions 16C and 16D sandwiching the upper end position of the rearview mirror 2.

  In this case, as shown in FIG. 7B, the shooting direction of the camera 11 indicated by the arrow 41 is inclined counterclockwise (counterclockwise) by 20 ° on the XY plane with respect to the normal line Ln. In FIG. 7B, the normal Ln is inclined clockwise (clockwise) by 20 ° on the XY plane with respect to the front direction of the vehicle. Therefore, in the state shown in FIG. 7B, the shooting direction of the camera 11 indicated by the arrow 41 substantially matches the front direction of the vehicle.

  Then, the control unit 14 regards the state shown in FIG. 7B as the reference state, and determines the center position of the cut-out image Imc in the captured image Im as in the description of FIGS. 4 and 5. Specifically, the control unit 14 determines the horizontal tilt angle θh (that is, 20 °) and the vertical tilt angle θv (that is, 0 °) in the reference state, and the horizontal tilt angle θh and the vertical tilt angle θv that are detected by the acceleration sensor 12. The center position of the cut-out image Imc on the captured image Im is determined based on each angle difference.

  After determining the range of the cutout image Imc, the control unit 14 displays the cutout image Imc on the display 10 without being inverted upside down. Here, since the display 10 and the camera 11 are both turned upside down as in the case of the right-hand drive vehicle, the control unit 14 causes the driver to visually recognize the cut-out image Imc in the correct orientation.

  In addition, the control unit 14 displays the guide image to be superimposed on the cutout image Imc on the display 10 so as to overlap the cutout image Imc in a state rotated by 180 °. In this case, the control unit 14 is not limited to the guidance image generated in association with the image recognition result (for example, the guidance image 80 in FIG. 6), but includes guidance indicating various information such as an operation menu, the current time, and the traveling speed of the vehicle. An image (for example, the guide image 81 in FIG. 6) is also displayed by being rotated by 180 ° and superimposed on the cut-out image Imc. As a result, the control unit 14 causes the driver to visually recognize the guidance image by superimposing it on the cutout image Imc in an appropriate direction.

  In addition, when the captured image Im or the cutout image Imc is recorded in the nonvolatile memory 13, the control unit 14 rotates the shot image Im or the cutout image Imc recorded in the nonvolatile memory 13 by 180 ° and then stores it in the nonvolatile memory 13. Record. In this manner, when the non-volatile memory 13 is taken out from the drive recorder 1 and the captured image Im or the cut-out image Imc recorded in the non-volatile memory 13 by a PC or the like is reproduced, the captured image Im or the cut-out image Imc is displayed. It can suppress suitably displaying in the state reversed up and down.

  As described above, the drive recorder 1 according to the present embodiment is mounted on the room mirror 2 provided in the vehicle, and includes the mirror unit 3 and the camera 11. The camera 11 has a shooting direction inclined by 20 ° in the horizontal direction with respect to the normal direction at the center position of the mirror surface of the mirror unit 3. In this case, in the state where the mirror unit 3 is adjusted to the use state, the shooting direction of the camera 3 substantially matches the front direction of the vehicle. Therefore, the drive recorder 1 can preferably photograph a forward landscape centered on the front direction of the vehicle when the vehicle is traveling.

[Modification]
Hereinafter, modified examples suitable for the above-described embodiments will be described. The following modifications may be applied in any combination to the above-described embodiments.

(Modification 1)
In FIG. 2 and the like, the camera 11 is tilted in the longitudinal direction of the drive recorder 1 by 20 ° with respect to the normal line Ln. However, the installation angle of the camera 11 to which the present invention is applicable is not limited to this. Instead of this, the camera 11 may be tilted in the longitudinal direction of the drive recorder 1 with respect to the normal Ln within a range of 10 ° to 30 ° which is an adjustment range of the driver's room mirror 2 of a general driver. That's fine.

(Modification 2)
In the description of the section “Cutout Image Generation Method”, the control unit 14 determines the center position of the cutout image Imc in the captured image Im based on the detected horizontal inclination angle θh and vertical inclination angle θv. Instead of this, the control unit 14 may detect the vanishing point from the captured image Im by a known method, and determine the range of the cut-out image Imc so that the detected vanishing point is the center.

  In this case, the control unit 14 preferably calculates the position of the vanishing point in the photographed image Im photographed when traveling on a flat and straight road by a statistical method, and fixes it as the center position of the cut-out image Imc. . For example, the control unit 14 calculates vanishing points on the captured image Im for a plurality of captured images Im for which the output of the acceleration sensor 12 at the time of capturing the captured image Im is within a predetermined range, and calculates the calculated disappearance. The average position of the points is determined as the center position of the cutout image Imc. In this way, the control unit 14 cuts out the captured image Im even when the vanishing point in the captured image Im frequently moves when traveling on a road with rough roads or undulations. It is possible to suitably suppress frequent changes in the relative position of the image Imc. In the present modification, the control unit 14 is an example of the “detection unit” in the present invention.

(Modification 3)
The drive recorder 1 can be mounted on the room mirror 2 and has only a photographing function by the camera 11 and may not have a display function by the display 10 or an image recording function by the nonvolatile memory 13.

  FIG. 8 shows an overview of a system according to a modification. In the example of FIG. 8, the drive recorder 1 is connected to the server device 6 via a network. The drive recorder 1 transmits the captured image Im or the cut-out image Imc to the server device 6 when the acceleration sensor 12 detects an acceleration equal to or higher than a predetermined value.

(Modification 4)
The drive recorder 1 may determine which of the captured image Im or the cutout image Imc is to be stored in the nonvolatile memory 13 based on a user input to an input unit (not shown). Then, when the cut-out image Imc is stored in the nonvolatile memory 13 based on the user input, the drive recorder 1 can suitably record a video that accurately captures the front direction of the vehicle. On the other hand, when the captured image Im is stored in the nonvolatile memory 13 based on the user input, the drive recorder 1 can suitably record a video having a wide range of field angles.

DESCRIPTION OF SYMBOLS 1 Drive recorder 2 Room mirror 3 Mirror part 6 Server apparatus 10 Display 11 Camera 12 Acceleration sensor 13 Non-volatile memory 14 Control part

Claims (1)

An imaging device that is mounted on a rearview mirror provided in a vehicle and shoots a front landscape of the vehicle,
Mirror part,
Photographing means having a photographing direction inclined by a first angle in a horizontal direction with respect to a normal direction at a center position of a mirror surface of the mirror portion;
With
The photographing apparatus according to claim 1, wherein the first angle is set such that a photographing direction of the photographing unit substantially coincides with a front direction of the vehicle in a state in which the mirror unit is adjusted to a use state.