JPH047940B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for inspecting the optical axis of a headlamp, and is particularly suitable for inspecting whether the center position of the optical axis of an automobile headlamp is within a standard value range. The present invention relates to a headlamp optical axis inspection method and apparatus.

[Conventional technology]

2. Description of the Related Art Conventionally, when inspecting the optical axis of a headlamp in an automobile inspection factory, a headlamp tester 10 as shown in FIG. 5 has been used. This tester 10 has four light receiving elements 14a, 14b, 14c, and 14d around a lens 12. When testing using this tester 10, the tester 10 is moved to a position where the irradiated light from the headlamp 16 is received and the amount of light received by each light receiving element is constant, and the optical image by the irradiated light from the headlamp 16 is transferred to the lens 12. The image was projected onto a screen through a cable, and inspection was carried out using the highest illuminance point on the screen as the optical axis.

However, when a halogen headlamp is used as the headlamp 16, there are _two maximum illuminance points as shown in FIG _. Connected straight line L
This caused the problem that it could not be unambiguously determined.

Therefore, the applicant of the present application determined the height position of the headlamp by detecting the direct light of the headlamp, as described in Japanese Patent Application Laid-Open No. 179639/1982, and conducted a main optical axis inspection from this headlamp height position. Find a window that shows the passing range, display this window as an image on a display device, and then find the center of gravity of an isoluminant closed curved surface with a certain illuminance or more from the light distribution pattern of the headlamp on a screen installed in front of the vehicle. The present invention has proposed an apparatus in which an image is displayed on the display device and the position of the headlamp is adjusted so that the center of gravity of the isoluminant closed surface is within the window.

[Problem that the invention seeks to solve]

However, the method previously filed by the applicant requires two television cameras, etc. to determine the optical axis position of the headlamp. There was a demand for something that could test the

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide an optical axis inspection of a headlamp that can accurately measure the optical axis inspection of a headlamp with a simple operation and a simple configuration. An object of the present invention is to provide a method and a device thereof.

[Means for solving problems]

To achieve the above object, the present invention, as shown in FIG. ),
The captured image is displayed on the CRT screen (step 102), and the acceptable range of the optical axis of the headlamp is displayed on the CRT screen (step 1).
04), find the center of gravity position of the isoluminant closed surface in the light distribution pattern (step 106), and display this center of gravity position on the CRT screen as the optical axis (step 10).
8) The optical axis of the headlamp is inspected by displaying the position of the center of gravity.Furthermore, the present invention provides a screen for projecting a light image produced by the light irradiated by the headlamp, and a light distribution pattern based on the light image on the screen. A television camera that selects a light distribution pattern with equal illuminance to take an image, a memory unit that converts the composite video signal output from the television camera into image data and stores it, and a CRT that receives the composite video signal. a display section that displays images on the screen;
A standard value setting section that outputs the standard value indicating the acceptable range of the optical axis of the headlamp as image data, and the image data of the memory section are imported, and based on this image data, the center of gravity position of the isoluminant closed surface is calculated. A device comprising a center-of-gravity calculation unit that outputs values as image data, and a composite video signal generation unit that converts each of the image data into a video signal, and further converts this signal into a composite video signal and outputs it. It is.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 2 shows the configuration of a preferred embodiment of the invention. In FIG. 2, a translucent screen 32 is movably installed on the vehicle inspection line to project an optical image produced by the light emitted from the headlamp 30. An inspection table 36 is installed on the opposite side of the vehicle 34 with the screen 32 as a border, and a television camera mounting stand 3 is mounted on this inspection table 36.
8 is fixed so as to be movable in the horizontal direction. A support stand 40 is attached to the television camera mount 38 so as to be movable up and down, and an industrial television camera 42 is fixed to this support stand 40. Further, a control device 44 is fixed on the inspection table 36, and a CRT 48 and an operation section 50 for outputting various settings and command values by operating operation buttons are arranged on the front panel 46 of the control device 44. There is.

The television camera 42 is configured to image the light distribution pattern 52 on the screen 32 and output a composite video signal resulting from this image to the control device 44 . When capturing an image of this light distribution pattern, by adjusting the lens aperture 54, the light distribution pattern 5
It is possible to select a light distribution pattern with equal illuminance from among the two to capture an image.

The control device 44, as shown in FIG.
CPU 60, A/D converter 6 that constitutes the memory section
2, a frame memory 64, a center of gravity calculation circuit 68 as a center of gravity position calculation section, a standard data memory 70, a video RAM 72 constituting a composite video signal generation section,
switch 74, output data controller 76,
I/O port 78, CRT48 that constitutes the display section
and a CRT controller 80, and are connected to an output data controller 76, a frame memory 64, a center of gravity calculation circuit 68, etc. via a bus line 82.

Composite video signal S ₁ output from the television camera 42
is the CRT controller 80 via the switch 74.
and is also supplied to the A/D converter 62. Therefore, the image captured by the television camera 42 is displayed on the screen of the CRT 48, and the video signal of the composite video signal _S1 is converted into a digital signal by the A/D converter 62, and the image data is stored in the frame memory 64. is stored as . The image data stored in the frame memory 64 is
It is output to the center of gravity calculation circuit 68 according to a command from the CPU 60. When the image data is supplied to the center of gravity calculation circuit 68, the center of gravity calculation circuit 68 calculates the position of the center of gravity of the isoluminant closed surface (hot zone) based on the image data.

To find this center of gravity position, calculate the position vector sum Σ(X _i · Y _i ) and area S of the hot zone, and use this to calculate the center of gravity position G (X, Y).
Y)=Σ(X _i , Y _i )/S. The calculated center of gravity position G (X, Y) is output as image data to the video RAM 72 via the output data controller 76.
is stored in

Furthermore, in order to set the standard value indicating the acceptable range of the optical axis of the headlamp 30, when the operation button that constitutes the standard value setting section is operated, the standard value data corresponding to this operation is transmitted via the I/O port 78. It is stored in the standard value data memory 70. This standard value data is stored in the video RAM 72 as image data according to a command from the output data controller 76. Note that the image data stored in the frame memory 64 is also stored in the video RAM 72 according to a command from the output data controller 76.

Various image data stored in the video RAM 72 is converted into a video signal and combined with a horizontal synchronization signal and a vertical synchronization signal. Then, the composite video signal _S2 is sent to the CRT controller 8 via the switch 74.
Output to 0. The CRT controller 80 has a video amplifier, a synchronizing signal separation circuit, a vertical deflection circuit, a horizontal deflection circuit, etc., and can display an image according to a composite video signal on the screen of the CRT 48.

In the above configuration, the switch 74 is operated to output the output signal of the television camera 42 directly to the CRT controller 80, the screen 32 is moved to a position out of the imaging range of the television camera 42, and the head lamp 30 is turned off. The image taken by the television camera 42 is displayed on the screen of the CRT 48. In this state, TV camera 4
The television camera 42 is moved so that the origin P of No. 2 overlaps the center Q of the headlamp 30.

Next, the switch 74 is operated to the opposite side, the screen 32 is set between the television camera 42 and the headlamp 30, the headlamp 30 is turned on, and the light distribution pattern 52 of the light irradiated by the headlamp 30 is projected on the screen 32. When this light distribution pattern 52 is imaged with the television camera 42,
Video signals obtained by imaging are sequentially stored in the frame memory 64 as image data. These image data are sequentially stored in the video ram 72, and the video output from the video ram 72 is displayed on the screen of the CRT 48. Here, when the examiner adjusts the lens aperture 54 while looking at the binarized image displayed on the screen of the CRT 48, an arbitrary isoluminant closed surface (hot zone) Z ₁ can be created as shown in FIG.
It can be displayed on the CRT48 screen.

At this time, image data within the hot zone Z ₁ is sequentially transferred from the frame memory 64 to the centroid calculation circuit 6.
8, and the gravity center calculation circuit 68 calculates the gravity center position of the hot zone _Z1 . This calculated value is then stored as image data in the video RAM 72, converted to a composite video signal, and then transferred to the CRT 48.
An image is displayed as an optical axis 84 on the screen.

In addition, the head lamp 30 can be turned on by operating the operation button.
When a standard value indicating the acceptable range of the optical axis is set, this standard value data is stored in the standard value data memory 70 via the I/O port 78, and then stored in the video RAM 72 as image data according to a command from the output data controller 76. has been done. Therefore, when the optical axis 84 is displayed, the image data in the standard range is converted into a composite video signal and displayed on the screen of the CRT 48 as an image showing the approximately rectangular standard range 86. Therefore, the inspector can determine whether the optical axis inspection of the headlamp 30 has passed or not based on whether the optical axis 84 is displayed within the standard range 86.

As described above, in this embodiment, the center of gravity within the hot zone _Z1 of the light distribution pattern is set to the optical axis 84.
Since the measurement was made as
The optical axis of 0 can be accurately measured.

Furthermore, according to this embodiment, the optical axis of the headlamp 30 can be inspected with a single television camera, so the optical axis of the headlamp 30 can be inspected with an inexpensive configuration and simple operation.

〔Effect of the invention〕

As explained above, according to the present invention, the optical axis of the headlamp is inspected by measuring the optical axis of the headlamp based on the composite video signal captured by a single television camera, so that the optical axis of the headlamp can be inspected with a simple configuration. An excellent effect can be obtained in that the optical axis of the headlamp can be accurately inspected by a simple operation.

[Brief explanation of drawings]

FIG. 1 is a flowchart for explaining the present invention, FIG. 2 is an overall configuration diagram of a device to which the present invention is applied, and FIG. 3 is a specific configuration diagram of the device according to the present invention.
FIG. 4 is a diagram showing an example of image display by the device according to the present invention, FIG. 5 is a perspective view of a conventional headlamp tester, and FIG. 6 is a diagram showing an example of image display by the conventional device. 30...head lamp, 32...screen,
42... Television camera, 44... Control device, 48
...CRT, 50...Operation unit, 60...CPU, 6
4... Frame memory, 68... Center of gravity calculation circuit,
72...Video RAM, 80...CRT controller.

Claims (1)

[Claims] 1. Select a light distribution pattern with equal illuminance from among the light distribution patterns on the screen by the irradiation light of the headlamp, display the captured image on the CRT screen, and determine the acceptable range of the optical axis of the headlamp. Display on the CRT screen, find the center of gravity of the isoluminant closed surface in the light distribution pattern, and use this center of gravity as the optical axis.
A method for inspecting the optical axis of a headlamp, characterized in that the optical axis of the headlamp is inspected by displaying the position of the center of gravity on a CRT screen. 2. A screen that projects a light image from the light irradiated by the headlamp, a television camera that selects and captures an equiluminous light distribution pattern from the light image on the screen, and a composite video signal output from the television camera. A memory section that converts the video signal into image data and stores it, a display section that receives the composite video signal and displays the image on the CRT screen, and outputs the standard value indicating the acceptable range of the optical axis of the headlamp as image data. a standard value setting unit, a barycenter position calculation unit that takes in image data from the memory unit, calculates the barycenter position of the isoluminant closed surface based on this image data, and outputs this calculated value as image data; What is claimed is: 1. An optical axis inspection device for a headlamp, comprising: a composite video signal generating section that converts the signal into a video signal and further converts this signal into a composite video signal and outputs the composite video signal.