JP4083279B2 - Image processing headlight tester - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a headlight tester for measuring a central luminous intensity and an irradiation light distribution pattern of a vehicle headlight, and in particular, an image analysis of an irradiation light distribution pattern by an image forming CCD camera fixed to a main body frame and an image processing unit. In particular, the present invention relates to an image processing headlight tester that is capable of obtaining an appropriate quality determination.
[0002]
[Prior art]
  The headlight tester for detecting the center luminous intensity of the vehicle headlight and the deviation of the optical axis of the passing beam with respect to the traveling beam traverses on a rail 50 installed perpendicular to the course center where the test vehicle is introduced as shown in FIG. A trolley 51 placed freely, a main body frame 56 in which an upright leg 52 of the trolley 51 can be raised and lowered via a vertical lifting mechanism 53, and a main body frame 56 via a left and right rotation mechanism 55 and a vertical rotation mechanism 54. The light receiving unit 60 is mounted on the top.
  The light receiving unit 60 performs a required test so that the Fresnel lens 11 provided in front of the light receiving unit faces the headlight 10 of the vehicle under test with a distance of, for example, 1 m. It is composed.
[0003]
  As shown in FIG. 9, the light receiving unit 60 condenses the irradiation light from the headlight 10 and forms the central optical axis of the light receiving unit lens group, and a part of the condensed irradiation light obliquely upward. A headlight that is composed of a half mirror 62 to be reflected, a light distribution projection screen 63 that receives projection of the reflected condensed irradiation light, a front-facing lens 64a, an optical mirror 64b, and a scope glass 64c provided behind the half mirror 62. A counter finder 64 and a vehicle front finder 65 provided above the light receiving unit 60 are configured.
[0004]
  When using the light receiving unit 60 having the above configuration,
  There are headlight focusing using the headlight directing viewfinder 64 and direct operation with the vehicle using the vehicle directing viewfinder.
  For focusing the headlight, after the light receiving unit 60 faces the vehicle, the image of the headlight 10 is converted into the scope glass 64c of the headlight facing finder 64 by traversing the carriage 51 and operating the up-and-down lifting mechanism 53. It is an operation that can be tied to the center of Further, the vehicle facing operation is performed by swinging a vehicle facing finder 65 that can be turned up and down in the vertical mounting section passing through the central optical axis of the light receiving unit 60, and through the finder. This is a visual operation in which the vertical plane drawn by the gaze of the measurer coincides with or is parallel to the vertical plane passing through the vehicle axis.
[0005]
  Alternatively, apart from the above configuration, a laser oscillator 66 having a point-like irradiation pattern may be provided above the vehicle facing finder 65 so as to be able to swing up and down in the vertical mounting section including the central optical axis of the Fresnel lens 11. Thus, by visually observing the pointed locus of the laser oscillator, the light receiving unit 60 is directly opposed to the vehicle via the left / right rotation mechanism 55.
[0006]
  Alternatively, instead of the vehicle-facing finder 65 or the laser oscillator 66 provided on the finder 65, a point-shaped irradiation pattern is provided on the central optical axis of the Fresnel lens 11 that condenses the irradiation light of the headlight 10. A laser oscillator 70 is provided so that the Fresnel lens 11 of the light receiving unit 60 faces the headlight 10.
  In the case of the laser oscillator 70 having the dot-like irradiation pattern, when the light receiving unit 60 is vertically swung by the vertical rotation mechanism 54, the light beam emitted from the laser oscillator is received by the light receiving unit 60 (strictly, a Fresnel lens). 11) Since the vertical mounting section that passes the central optical axis is formed, it is visually checked whether the vertical mounting section matches the vehicle axis vertical plane including the axis of the vehicle. The movement mechanism 55 makes them coincide or parallel.
[0007]
  Next, the carriage 51 is traversed and the main body frame is moved up and down to irradiate the beam center projection of the headlight with the irradiation beam light of the laser oscillator 70, and the optical axis of the irradiation light of the headlight is set to the Fresnel lens 11. Match with the central optical axis.
[0008]
  An optical axis sensor substrate 72 that can be rotated and superimposed on the light distribution projection screen 63 of the light receiving unit 60 that has been directly facing by the facing means is provided and reflected by the half mirror 62 on the substrate. Reflection irradiationlight'sIt is intended to receive irradiation.
[0009]
  As shown in FIG. 10, the optical axis sensor base 72 is provided with sensor groups 73a, 73b, 73c and 73d at symmetrical positions in the vertical and horizontal directions with respect to the center thereof. The reference axes of the optical axis sensor substrate 72 and the light distribution projection screen 63 are aligned. The irradiation light distribution pattern projected onto the aligned screen 63 can be visually observed to determine whether the passing pattern is good or bad.
[0010]
[Problems to be solved by the invention]
  The conventional headlight tester facing method described above is a complicated and inaccurate operation between the headlight imaging position visually confirmed by the headlight facing finder and the vehicle visually observed through the vehicle facing finder. Necessitates correct confrontation. Further, since the directly-inclined means by the laser oscillators 66 and 70 is based on the remote indirect means by visual observation, which has been developed recently (described in Japanese Patent Application No. 5-53869 and Japanese Patent Application No. 7-55028), accurate correct It is in a situation where it is not possible to expect pair operations. Also, the quality determination made by visually detecting the deviation of the optical axis of the irradiation light distribution pattern on the light distribution projection screen set by the inaccurate facing operation is complicated and inaccurate. It was.
[0011]
  The present invention has been made in view of the above-mentioned problems of the conventional headlight tester, and is intended to automate the facing operation by introducing a facing light intensity sensor substrate, and by introducing a CCD camera for image formation and image processing. The purpose is to provide a headlight tester that automates visual inspection when detecting a light distribution pattern.
[0012]
  Therefore, the invention described in claim 1 of the present invention is
  A carriage provided on the front surface of a course center for vehicle introduction at a predetermined interval and provided on a rail laid at right angles to the course center so as to be able to traverse left and right, and a main body provided on an upright leg of the carriage via a vertical elevating mechanism In a headlight tester composed of a frame, a light receiving unit provided on the frame via a left-right rotation mechanism and a vertical rotation mechanism,
  The light receiving unit includes a Fresnel lens that collects the irradiation light from the headlight, a half mirror for obtaining an irradiation light distribution pattern of the condensed irradiation light, a light distribution projection screen, and a condensed irradiation light transmitted through the half mirror. A light-receiving unit provided with a facing means for directly facing the light-receiving unit to the optical axis;
  An object of the present invention is to provide an image processing headlight tester provided with a CCD camera for forming an image of the irradiation light distribution pattern and an image processing unit for image analysis. The purpose of the present invention is to provide an image processing headlight tester that specifies the fixed position of the CCD camera and the configuration of image analysis.
  It is another object of the present invention to provide an image processing headlight tester that specifies the configuration of the facing means.
[0013]
(Delete)
[0014]
(Delete)
[0015]
(Delete)
[0016]
[Means for Solving the Problems]
  The invention described in claim 1
  A carriage provided on a rail laid at right angles to a course center for vehicle introduction and provided so as to freely traverse left and right, a main body frame provided on an upright leg of the carriage via a vertical elevating mechanism, a left-right rotation mechanism on the main body frame, and And a light receiving portion provided via a vertical rotation mechanism,
  The light receiving unit condenses the irradiation light from the headlight and forms a central optical axis of the light receiving unit lens group, a half mirror that reflects a part of the condensed irradiation light, and the reflected irradiation light of the half mirror A headlight tester configured to include a light distribution projection screen that receives the right-angle irradiation and a means for directly facing the light receiving unit to the optical axis of the condensed irradiation light that has passed through the half mirror,
  The facing means is composed of a facing condensing lens provided on the back of the half mirror and a facing light intensity sensor substrate, and a photoelectric element group is placed on the facing light intensity sensor substrate at symmetrical positions at equal distances in the vertical and horizontal directions. In addition, a central light intensity sensor is provided at the center, and the left and right rotation mechanism and the vertical rotation mechanism are adjusted so that the output of the photoelectric element group is equal while maintaining the output of the center light intensity sensor at the maximum. Configured to be able to face each other,
  A CCD camera for image formation which is fixed to a main body frame and can only be moved left and right or up and down by the carriage and the lifting mechanism to image an irradiation light distribution pattern on a light distribution projection screen of the light receiving unit; An image processing unit for image analysis that calculates a barycentric coordinate value of a traveling beam, a bending point coordinate value of a cut line of a passing beam, and a hot zone X and Y tangent coordinate value of a passing beam,
  horizontal directionTo the traveling beamSaidWhen the light-receiving part is directly facing, on the center optical axis of the light distribution projection screen,CCD for image formationCamera optical axisThe CCD camera so thatFixed to the body frameShi, To the passing beamAboveIt is characterized in that the downward angle of the optical axis of the low beam can be detected from the deviation of the irradiation light distribution pattern of the light distribution projection screen imaged by the CCD camera when the light receiving part is directly opposed. is there.
[0017]
  With the above configuration, the light receiving unit collects the Fresnel lens that collects the irradiation light from the headlight, the half mirror that reflects a part of the condensed irradiation light, the light distribution projection screen that receives the right angle irradiation of the reflected irradiation light, and the half mirror Since it is configured to include a facing means provided at the rear of the
  Irradiation light from the headlight is condensed by a Fresnel lens, and a part of the condensed irradiation light is incident at right angles on a light distribution projection screen disposed in another part by a half mirror, and the other condensed irradiation light is the half mirror. , And then enters the direct-facing means provided at the rear part behind it.
[0018]
  First, the facing means is made to face the optical axis of the traveling beam from the headlight.
  In the directly facing light receiving unit, a part of the condensed irradiation light is incident on the light distribution projection screen disposed below, for example, through the half mirror, and an irradiation light distribution pattern can be formed.
  Further, for the “passing” beam, the light receiving unit is rotated so as to face the optical axis of the “passing” beam, and the irradiation light distribution pattern of the beam is rotated on the light distribution projection screen. To form.
  That is, the irradiation light distribution pattern of the “passing” beam formed on the light distribution projection screen as described above is formed so as to be shifted from the irradiation light distribution pattern of the traveling beam by the rotation angle. The shift is imaged by the image forming CCD camera fixed to the main body frame by the horizontal movement of the carriage with respect to the rotation and the vertical movement mechanism by the vertical movement mechanism, and is analyzed by the image processing unit. Then, the quality of the headlight is determined.
[0019]
  In addition, the confrontation means isAnd a converging condensing lens that forms a circular light beam by condensing irradiation light transmitted through a half mirror, and a confronting photometric sensor substrate provided on an appropriate optical axis other than the focal point of the lens. Is.
[0020]
  With the above-described configuration, the condensing irradiation light incident on the above-mentioned facing means is first further condensed by the front-facing condensing lens to form a clear circular light beam, and the facing light intensity sensor substrate disposed in the rear-stage portion Is irradiated.
  The directly facing light intensity sensor substrate is provided on, for example, an appropriate rear optical axis other than the focal point of the directly condensing lens, and thus receives the circular light beam irradiation.
[0021]
  In addition, if the light receiving unit is swung up and down and left and right through the up and down and left and right traversal and the up and down rotation mechanism and the left and right rotation mechanism, the light receiving unit is reliably and easily aligned with the optical axis of the irradiation light of the headlight You can make them face up.
[0022]
  That is, the facing means of the present invention is not a direct operation for the headlight itself, but the optical axis of the Fresnel lens coincides with the optical axis of the irradiation light emitted from the headlight, and the optical axis of the irradiation light itself It is intended to face itself.
[0023]
  The invention of claim 1horizontal directionTo the traveling beamAboveWhen the light-receiving part is directly facing, on the center optical axis of the light distribution projection screen,CCD for image formationCamera optical axisThe CCD camera so thatFixed to the body frameShi, To the passing beamSaidIt is characterized in that the downward angle of the optical axis of the low beam can be detected from the deviation of the irradiation light distribution pattern of the light distribution projection screen imaged by the CCD camera when the light receiving part is directly opposed. is there.
[0024]
  The above configuration, that is, the light distribution projection screen (with respect to the reflected irradiation light from the half mirror) positioned in the light receiving unit at the time when the central optical axis of the light receiving unit is horizontal and the beam direction is horizontally opposed to the traveling beam. The center of the irradiation light distribution pattern by the traveling beam is formed on the optical axis of the CCD camera, so that the optical axis of the CCD camera is fixed to the central optical axis of the central optical axis. .
[0025]
  However, the light receiving part is rotated by the swing angle of the “passing” beam with respect to the “passing” beam, and the formed irradiation light distribution pattern is projected onto the light distribution projection screen rotated with the rotation. However, since the CCD camera for image formation is fixed to the main body frame that is not allowed to rotate only by moving left and right up and down by the horizontal movement of the carriage and the vertical lifting mechanism with respect to the rotation,
  The image captured by the image forming CCD camera shows that the irradiation light distribution pattern of the “passing” beam is shifted by the deflection angle with respect to that of the traveling beam.
  In addition, not only the deflection angle but also the light intensity of each part can be compared by image analysis.
[0026]
  Further, the image analysis according to claim 1 is configured to calculate a barycentric coordinate value of the traveling beam, a bending point coordinate value of the cut line of the passing beam, and a hot zone X and Y tangent coordinate value of the passing beam. It is characterized by that.
[0027]
  With the above configuration, the quality of the light distribution characteristics of the headlight can be automatically determined.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, the form of the Example of this invention is demonstrated with the example of illustration. However, the dimensions, shapes, relative positions, etc. of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Absent.
  FIG. 1 is a cutaway side view of a main part showing a schematic configuration of an image processing headlight tester of the present invention, and FIG. 2 is a cross-sectional view showing a schematic configuration of a light receiving unit in FIG. 3A is a longitudinal sectional view of the facing means of FIG. 2, and FIG. 3B is a front view of the facing light intensity sensor substrate of FIG. FIG. 4 is a block diagram showing a schematic configuration of an image processing system of the image processing headlight tester. FIG. 5 shows an image forming position in which the main body frame is fixed and the relative positions of the light receiving unit internal devices when the light receiving unit of FIG. 2 is vertically swung by the vertical rotation mechanism 54 shown in FIG. It is a figure which shows the condition of the positional relationship of a CCD camera. 6A is the center-of-gravity coordinate data of “traveling beam”, FIG. 6B is the bending point coordinate data of the cut line of “passing beam”, and FIG. 6C is the X and Y tangent coordinate data of the hot zone of “passing beam”. Indicates. FIGS. 7A and 7B are diagrams illustrating cut lines for Z light distribution. FIGS. 8A to 8D are explanatory diagrams for obtaining the bending point of the cut line of the Z light distribution.
[0029]
  As shown in FIG. 1, an image processing headlight tester according to the present invention includes a carriage 51 provided on a rail 50 arranged at right angles to a vehicle introduction course center (not shown) so as to freely traverse left and right, and the carriage. A body frame 56 that is vertically moved up and down by an up-and-down lift mechanism 53 on an upright leg 52 that is erected on the left and right, and is mounted on the frame via a left-right rotation mechanism 55 and an up-and-down rotation mechanism 54 so as to be able to rotate left and right and up and down. And the image processing CCD camera fixed to the main body frame and an image processing unit 30 (not shown).
[0030]
  The light receiving unit 20 is configured to be spaced from the headlight 10 by, for example, approximately 1 m.
[0031]
  As shown in FIG. 2, the light receiving unit 20 collects the light emitted from the condensing Fresnel lens 11 having the horizontal central optical axis X and the headlight 10 by the Fresnel lens 11, and a part of the condensed irradiated light 10a. A half mirror 12 that reflects light vertically downward, a light distribution projection screen 13 that is horizontally provided at a lower position so as to receive a right angle irradiation of reflected irradiation light, and a facing means 16 provided on the back of the half mirror 12. More.
[0032]
  As shown in FIG. 3A, the facing means 16 is a facing condensing lens 14 provided on the back of the half mirror 12 on the central optical axis (optical axis of incident irradiation light) X of the Fresnel lens 11. And the direct-facing light intensity sensor substrate 15. In other words, the condensed irradiation light 10a transmitted straight through the half mirror 12 is further condensed by the confronting condensing lens 14 to form a clear circular ridge-shaped irradiation light 10b on an appropriate optical axis other than the focal point of the subsequent portion. The light is incident on the directly facing photometric sensor substrate 15.
  As shown in FIG. 3 (B), photoelectric element groups 13a, 13b, 13c, and 13d are provided on the front-facing light intensity sensor substrate 15 at symmetrical positions that are equidistant in the vertical and horizontal directions. A CdS element 19 for central luminous intensity is provided for converting the intensity of light into an electric resistance value. Needless to say, a photodiode (for example, a silicon photodiode) that converts light intensity into a current value can be used instead of the CdS element for central luminous intensity.
[0033]
  At the time of facing, while maintaining the output of the central light intensity sensor CdS element 19 at the maximum, the output by the circular beam-shaped irradiation light 10b of the photoelectric element groups 13a, 13b, 13c, 13d becomes an equal value. The Fresnel lens 11 of the light receiving unit 20 is adjusted by the left and right turning mechanism 55, the up and down turning mechanism 54, the up and down raising and lowering mechanism 53, and the left and right traversing mechanism provided in the carriage 51. The optical axis of the irradiation light coincides with the central optical axis X of the Fresnel lens so as to face the optical axis.
  That is, the above-mentioned facing is not a facing operation with respect to the headlight 10 itself, but the center optical axis of the Fresnel lens 11 is made to coincide with the optical axis of the light emitted from the headlight 10 so as to face the optical axis of the irradiated light itself. It is a thing.
[0034]
  By the way, as shown in FIG. 2, the image forming CCD camera 17 has a horizontal light distribution projection screen 13 which is positioned when the light receiving unit 20 is directly opposed to a traveling beam having a beam direction in the horizontal direction. 1 is fixed to the main body frame 56 of FIG. 1 so as to have the optical axis of the camera on the central optical axis Y (vertical direction).
  The CCD camera 17 is fixed at a position that does not hinder the irradiation of the condensed irradiation light 10a as shown in FIG.
  That is, the movement of the CCD camera with respect to the shake angle of the light receiving unit 20 is only horizontal movement of the carriage and vertical movement or horizontal movement by the vertical lifting mechanism 53.
[0035]
  For example, as shown in FIG. 5, when the light receiving unit 20 is rotated to the optical axis X2 downward by an angle α with respect to the horizontal optical axis X1, the Fresnel lens 11, the half mirror 12, the directly condensing lens 14, Both the luminous intensity sensor substrate 15 and the light distribution projection screen 13 rotate by an angle α. However, the CCD camera 17 does not rotate only by descending on the vertical line Y as shown by the dotted line.
  That is, the irradiation light distribution pattern formed on the light distribution projection screen 13 causes a shift corresponding to the deflection angle α as a result of the rotation, but the CCD camera 17 that moves vertically captures the shift accurately. Become.
[0036]
  As shown in FIG. 4, the image processing unit 30 has an image forming CCD camera 17 fixed to the main body frame in the image input unit 31, and a host computer 35, an image output unit 34, and a display unit 36 on the output side. The image processing unit 30 incorporates an AD converter, a memory, a DA converter, an image processor 32, and a control microprocessor 33.
[0037]
  The image processor 32 is configured to perform preprocessing for performing spatial filter processing of an image and the like, and operations such as density gradation conversion, filtering, and feature extraction. That is, preprocessing for thinning such as area for binarization of the target image, numbering, shrinkage, expansion, etc. is performed, and then a filter for extracting the center of gravity and edge is set by setting a threshold value, and binary It has a function to extract the contour of the ghost image.
[0038]
  Further, on the output side, a host computer 35 that instructs the image processing processor 32 to specify the type of processing and parameters and performs storage management of analysis transfer data for the processing result, and an image output that outputs the image processing result as image information. The unit 34 and the display unit 36 are provided.
[0039]
  Since it is the above configuration, in use, first, the Fresnel lens 11 of the light receiving unit 20 is directly opposed to the traveling beam of the headlight 10, but at the time of facing,
  As shown in FIG. 3, the CdS element 19 and the photoelectric element groups 13a, 13b, 13c, and 13d, which are sensors for the central light intensity provided on the directly-facing light intensity sensor substrate 15 forming the facing means 16, are directly focused. In response to the circular light beam 10b collected by the lens 14 and formed into a sharp and clear circular light beam, the output of the photoelectric element group is made uniform while maintaining the output of the CdS element 19 at the maximum. The center optical axis X of the Fresnel lens 11 of the light receiving unit 20 is adjusted by the left and right turning mechanism 55, the up and down turning mechanism 54, the up and down raising and lowering mechanism 53, and the left and right traversing mechanism provided in the carriage 51. It is made to correspond to the optical axis of the traveling beam of the light 10.
[0040]
  Next, the image distribution CCD camera 17 inputs the captured light distribution pattern of the traveling beam of the headlight 10 to the image input unit 31, and the image processing unit 30 instructs the control microprocessor 33 to Necessary image processing is calculated by the image processor 32, and image data for the irradiation light distribution pattern of the traveling beam of the headlight 10 is obtained in the image output unit 34.
[0041]
  As described above, as shown in FIG. 5, the traveling light beam distribution pattern is such that the optical axis of the headlight 10 irradiation (light traveling beam) faces the light receiving unit 20 and the central optical axis is the reference horizontal axis X1. The center of gravity coordinate data is obtained by image processing from the image obtained by the image forming CCD camera 17 shown by the solid line. That is, the light distribution pattern shown in FIG.
[0042]
  Next, the headlight 10 is switched to the “passing” beam, and the center light of the light receiving unit 20 that faces the traveling beam, for example, as shown in FIG. 5 in order to face the optical axis of the irradiation light of the “passing” beam. It is rotated from the axis X1 to the central optical axis X2 with the deflection angle α to obtain image data of the irradiation light distribution pattern of the “passing” beam, transferred to the host computer 35, and displayed on the display unit 36 for visual observation. To.
[0043]
  Next, the inflection point of the cut line shown in FIG. 6B of the switched “passing” beam (when the optical axis of the irradiation light is changed to the optical axis X2 having an angle α downward from the reference optical axis X1), and FIG. The hot zone shown in (C) is obtained as follows.
  In this case, in order to make the light receiving unit 20 face the “passing” beam, by rotating the light receiving unit 20 to the state shown by the two-dot chain line in FIG. The light distribution projection screen 13 and its central vertical optical axis rotate together with the Fresnel lens 11, the half mirror 12, and the facing means 16 by a swing angle α. Therefore, the irradiation light distribution pattern projected on the light distribution projection screen rotated by the deflection angle α is compared with the irradiation light distribution pattern of the traveling beam projected on the light distribution projection screen when facing the traveling beam. Causes a horizontal shift.
[0044]
  On the other hand, the CCD camera 17 is only allowed to move in the vertical direction by the up-and-down lifting mechanism 53 and to the left and right by the left-and-right traversing mechanism provided on the carriage, with respect to the rotation of the shake angle α of the light receiving unit 20. Since it is fixed to 56, it moves down on the Y axis as shown by the two-dot chain line in FIG. (In this case, only vertical movement)
  That is, the horizontal deviation of the irradiation light distribution pattern due to the “passing” beam can be imaged by the CCD camera that descends on the Y axis. Thus, the image forming CCD camera 17 detects the shift angle β (α = β).
[0045]
  The extraction of the inflection point of the cut line has two cases: a process (a) in the case of external setting when the binarization threshold is set to a predetermined value in advance and a process (b) by the area division type discriminant analysis means. Yes, an example of the extraction method is shown below.
  a, external setting;
  1) Apply a sobel to the target grayscale image, set the threshold,
  2) Thinning,
  3) Hough transform to obtain the required approximate straight line,
  b, area division type discriminant analysis means;
  1) Multiply the subject grayscale image with a Sobel to perform background correction and density correction.
  2) Perform expansion contraction or smoothing,
  3) Create a histogram,
  4) Excluding low gradation values (0 to 15 gradation values)
  5) Excluding gradation values with a frequency of 500 pixels or more on the low gradation value side,
  6) A threshold is set by discriminant analysis.
  7) Thinning,
  8) A Hough transform is performed to obtain a required approximate straight line. Thus, “coordinate data of the refraction point of the passing beam” shown in FIG. 6B is obtained, and “passing” shown in FIG. The tangent coordinates of the hot zone of the beam can also be obtained, and the quality of the headlight can be determined or adjusted.
[0046]
  It should be noted that the luminous intensity of the center coordinate of the hot zone needs to be set to a predetermined dimming value or less with respect to the selected horizontal luminous intensity and vertical luminous intensity determined by law.
[0047]
  Further, as shown in FIGS. 7A and 7B, which are modified examples of the cut line of the low beam (when the optical axis of the irradiation light is changed to the optical axis X2 that is lower than the reference optical axis X1 by the angle α). Explains the case of obtaining the coordinate value of the bending point (elbow point) P of the Z light distribution cut line (both are shown for the left side lane, but the right side lane shows a symmetrical shape) To do.
  First, the same operation as that for obtaining the bending point and hot zone of the cut line of the passing beam described above is performed to obtain the same state. Now, assuming the moving point m moving from the left to the right on the cut line of the Z light distribution shown in FIG. 7A, the horizontal above the Z light distribution as shown in FIG. 8A. There is a moving point m on the line, and this moving point m is m in the figure as shown in FIG.₀, M₁, M₂As shown in FIG. 8 (b), when moving to the inflection point Q, the moving point m becomes the moving point m. Turn right from the current straight line. Thereafter, as shown in FIG. 8C, the moving point m crosses the V axis and turns to the left. When the left curve at this time is reached and the tightest point in the curve is obtained, this is set as the bending point P.
[0048]
  Now, as shown in FIG. 8 (d), the upper left corner of the figure is the origin of coordinates (0, 0), and from the left side of the cut line L, three points m are sequentially spaced.₀(X₀, Y₀), M₁(X₁, Y₁), M₂(X₂, Y₂) Is extracted, and the “difference difference” of the three points is calculated based on the Y coordinate. And the formula is
k = (Y₂-Y₁)-(Y₁-Y₀)
It is represented by
[0049]
  The point where the value of k indicates “maximum absolute value on the minus side” (X) when the examination to the right end of the cut line L is completed.₁, Y₁) As an elbow point, that is, a bending point P. That is, there is only (5), which is one of the counterclockwise points among the points indicated by (1) to (7) in FIG.
  (1) (Right curve): +
        (2) (Horizontal): 0
        (3) (Right curve) +
        (4) (Line): 0
        (5) (Left curve):-
        (6) (Horizontal): 0
        (7) (Right curve): +
  In this way, it is possible to easily obtain the correct bending point P coordinate value of the cut line of the Z light distribution, which has been difficult to obtain conventionally.
[0050]
【The invention's effect】
  With the above configuration, the complicated operation and inaccurate determination found in the conventional headlight tester can be eliminated, and automation and high efficiency of automatic alignment and visual inspection can be achieved. Furthermore, it is possible to easily obtain the correct bending point P coordinate value of the cut line of the Z light distribution, which has been difficult to obtain conventionally.
[Brief description of the drawings]
FIG. 1 is a cutaway side view of an essential part showing a schematic configuration of an image processing headlight tester of the present invention.
2 is a cross-sectional view illustrating a schematic configuration of a light receiving unit in FIG. 1;
3A is a longitudinal sectional view of the facing means of FIG.
  (B) is a front view of the directly facing photometric sensor substrate of (A).
FIG. 4 is a block diagram showing a schematic configuration of an image processing system of the image processing headlight tester of the present invention.
5 shows the relationship between the position of the internal device of the light receiving unit and the position change of the CCD camera for image formation when the reference optical axis of the light receiving unit of FIG. FIG.
6A and 6B are diagrams showing an irradiation light distribution pattern obtained by image processing with respect to an irradiation light distribution of a headlight, in which FIG. 6A shows barycentric coordinate data of a “traveling beam”, and FIG. FIG. 6C shows inflection point coordinate data of the cut line of the “passing beam” for the right traveling, and (C) shows X and Y tangent coordinate data of the hot zone for the “passing beam” for the left traveling and the right traveling.
FIGS. 7A and 7B are diagrams illustrating Z light distribution cut lines. FIGS.
FIGS. 8A to 8D are explanatory diagrams illustrating movement of a moving point on a Z light distribution cut line when a bending point of the Z light distribution cut line is obtained.
FIG. 9 is a side view showing a schematic configuration of a conventional headlight tester.
10 is a plan view showing a schematic configuration of the optical axis sensor substrate of FIG. 9. FIG.
[Explanation of symbols]
  10 Headlight
  11 Fresnel lens
  12 Half mirror
  13 Light distribution projection screen
  14 Direct condensing lens
  15 Face-to-face photometric sensor board
  16 Direct means
  17 CCD camera
  19 Center brightness sensor (CdS element for center brightness)
  20 Light receiver
  30 Image processing unit
  31 Image input section
  32 Image processor
  34 Image output unit
  35 Host computer
  P Bending point (elbow point)

Claims (2)

A carriage provided on a rail laid at right angles to a vehicle introduction course center so as to be laterally movable, a main body frame provided on an upright leg of the carriage via a vertical elevating mechanism, a left-right rotation mechanism on the main body frame, and And a light receiving portion provided via a vertical rotation mechanism,
The light receiving unit condenses the irradiation light from the headlight and forms a central optical axis of the light receiving unit lens group, a half mirror that reflects a part of the condensed irradiation light, and the reflected irradiation light of the half mirror A headlight tester configured to include a light distribution projection screen that receives the right-angle irradiation and a means for directly facing the light receiving unit to the optical axis of the condensed irradiation light that has passed through the half mirror,
The facing means is composed of a facing condensing lens provided on the back of the half mirror and a facing light intensity sensor substrate, and a photoelectric element group is placed on the facing light intensity sensor substrate at symmetrical positions at equal distances in the vertical and horizontal directions. In addition, a central light intensity sensor is provided at the center, and the left and right rotation mechanism and the vertical rotation mechanism are adjusted so that the output of the photoelectric element group is equal while maintaining the output of the center light intensity sensor at the maximum. Configured to be able to face each other,
A CCD camera for image formation which is fixed to a main body frame and can only be moved left and right or up and down by the carriage and the lifting mechanism to image an irradiation light distribution pattern on a light distribution projection screen of the light receiving unit; An image processing unit for image analysis that calculates a barycentric coordinate value of a traveling beam, a bending point coordinate value of a cut line of a passing beam, and a hot zone X and Y tangent coordinate value of a passing beam,
When directly facing the light receiving portion to the main beam in the horizontal direction, on the central optical axis of the light distribution projection screen, the CCD camera so that the optical axis of the CCD camera the image forming is positioned and fixed to the body frame , the fact that detectably constituting a downward angle of the optical axis of the low beam from the deviation of the irradiation light distribution pattern of the light distribution projection screen that is captured by the CCD camera when brought into confronting the light receiving portion to the low beam A featured image processing headlight tester. 2. The image processing head according to claim 1, wherein the calculation of the bending point coordinate value of the cut line of the passing beam includes the case of obtaining the coordinate value of the bending point (elbow point) of the cut line of the Z light distribution. Light tester.

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