JPS5941525B2 - Method and device for measuring light distribution pattern of vehicle lamps - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for measuring a light distribution pattern of a vehicle lamp;
The present invention relates to an apparatus for carrying out this method, and more particularly to a method and apparatus for measuring a light distribution pattern of a sealed beam lamp (SB lamp) for use in a vehicle, for example, which has a light distribution pattern with clear contrast between bright and dark areas.

BACKGROUND OF THE INVENTION As vehicles such as automobiles advance and become faster, various performance requirements for vehicle lamps are also becoming faster.

In particular, headlights are required to have the ability to illuminate relatively far distances in order to ensure safe driving, and at the same time, to avoid causing glare to drivers of oncoming vehicles. For this reason, laws and regulations stipulate vehicle lamps in which the light distribution pattern of the lamp is effective only in a specific direction. For example, in automobile headlights, the light distribution pattern is required to clearly separate bright and dark areas in the vertical direction. By the way, in order to measure the light distribution pattern of a vehicle lamp whose light distribution pattern has been improved in this way, conventionally, the light from the lamp to be measured is irradiated onto a screen on which a prescribed light distribution pattern is marked, and the light distribution pattern is measured by a human being. A method is adopted in which it is determined by visual perception whether the light distribution pattern of the lamp to be measured has a prescribed light distribution pattern.

However, in such a method, there is a problem that the discrimination accuracy varies depending on the measurer, and the inspection accuracy decreases.

In addition, this method requires human visual manipulation to determine pass/fail using human vision, which requires an extremely large amount of labor and time when measuring and inspecting a large number of lamps. The disadvantage is that you have to spend a lot of money. In view of the above points, the present invention has been made to solve such problems and eliminate such drawbacks, and its purpose is to rely on the operator's visual observation to determine the quality of the light distribution pattern using a simple configuration. It can be done automatically without any trouble, improving work efficiency, and it can be used to accurately check whether the light distribution pattern of the light emitted from the lamp to be measured is the specified one.
Moreover, it is an object of the present invention to provide a method and apparatus for measuring a light distribution pattern of a vehicle lamp, which can be automatically and quickly determined.

In order to achieve such an object, the method for measuring a light distribution pattern of a vehicle lamp according to the present invention includes a method in which predetermined upper and lower limit reference values are determined, and the light distribution pattern to be measured is sandwiched between bright and dark boundaries. A pair of sensors facing each other are arranged in a row? Light is irradiated from the lamp to be measured onto the screen, and the light is captured directly on the screen by the sensor, and the amount of light detected by this sensor is compared with a predetermined reference value set in advance, and the deviation is calculated. The light distribution pattern measuring device for a vehicle lamp of the present invention measures the light distribution pattern of the lamp to be measured by measuring the irradiation light from the lamp to be measured. A group of sensors are arranged in parallel rows and capture light directly on the screen. , a scanning means that time-divisionally scans the detection outputs from this sensor group and sequentially extracts them; and a scanning means that compares the illuminance information obtained by this scanning means with a predetermined reference value and uses the comparison output as a light distribution pattern. The apparatus further includes arithmetic means for outputting a determination signal.

Embodiments of the present invention will be described in detail below based on the drawings.

First, before describing embodiments of the present invention, in order to facilitate understanding of the present invention, a light distribution standard currently in force will be briefly described as an example thereof.

FIG. 1 is a diagram showing an example of a light distribution pattern standard for explaining the present invention. When projecting the light distribution from an SB lamp onto a screen 7.62 meters away, for example, the high luminous intensity zone (hot zone) H of the low beam
The upper division of Z is, for example, ±3.81c of the horizontal line H! n
Also, the left-hand side separation must be between the straight-front vertical line V and the right side thereof, for example, 10.16 cm.
To illustrate this, the diagonally shaded area shown in FIG. 1 is the divided standard range. Now, the present invention is implemented as follows.

FIG. 2 is a configuration diagram for explaining an example of the basic configuration of the method and device for measuring the light distribution pattern of a vehicle lamp according to the present invention, and a shows the arrangement relationship of each device;
b shows the block configuration. First, the second
In Figure a, SC is a screen portion on which the light distribution from the lamp L to be measured is projected, and a pair of sensors are arranged in a row facing each other on this screen portion SC. CPU
is an arithmetic unit that performs arithmetic processing on the information taken out from this screen unit SC. Next, in Figure 2b, REC
is a light receiving section arranged in the screen section SC shown in FIG.
The SW is a switch section with a built-in switch such as a judgment start switch, and the CPU is a calculation section that is controlled by the output of the switch section SW.
It has functions such as memory. SEL-SW is a judgment criterion selection switch section. DP is a display section that displays the determination results from the calculation unit CPU, and this display section DP is provided with a number display, a point display section, etc. so that the details of the determination results of the light distribution pattern can be checked. POW is a power supply unit that supplies required power supply voltage to each device. In the apparatus configured in this way, the screen part SC shown in FIG. By measuring the amount of light with a sensor, inputting the measured information to the calculation unit CPU, and comparing it with a reference value in the memory, it is possible to determine whether the edges of the pattern are within the standard.

Furthermore, by determining the brightness/darkness ratio of the light distribution pattern, it is possible to determine whether the pattern is blurred. Here, an upper limit reference value is determined for one of the pair of sensors, and a lower limit reference value is determined for the other. Next, an example of a concrete implementation method of the present invention will be explained with reference to FIG.

In FIG. 3, the same reference numerals as in FIG. 2 indicate corresponding parts, and S represents a photodiode S. ,s,,s2...
...An optical sensor made of Sn, this optical sensor S has a pair of sensors facing each other, and a photodiode S. ,sl,
s2...Sn are arranged in rows on the screen. The optical sensor S is a pair of sensors arranged in a continuous line on the screen SC shown in FIG. A sensor group (band) is configured to capture light directly on the screen SC. LA is an optical amplifier that amplifies the output of the optical sensor S, and is a photodiode S. ,S,
......Optical amplifiers LA, , respectively corresponding to Sn
LA2... Consists of LAn. S
CN is a scanner that sequentially extracts the outputs of the optical amplifiers LA1 to LAn by time division, and this scanner SCN is configured to be controlled by a channel selection signal CS from the arithmetic unit CPU. It is. TR is Sukiyana 1 SCN
PA is a temperature correction circuit that takes the extracted output of the optical sensor as input and compensates for characteristic changes due to temperature changes of the optical sensor, and PA is a power amplifier circuit for reducing the voltage in the transmission line. and the scanner SCN constitute the light receiving section REC shown in FIG. 2b. Here, the power amplifier circuit PA for correcting the voltage drop caused by the transmission line is provided as necessary, and is not necessarily required. AD is an analog-to-digital converter that converts the analog quantity from the power amplifier circuit PA into a digital quantity, and SW is a switch section consisting of a start switch S-SW, a reset switch R-SW, and a print switch P/SW. Therefore, it is configured to control the calculation section CPU, and this switch section SW corresponds to the switch section SW shown in FIG. 2b.

CPU-DIS is a status display unit that displays the status of the calculation unit CPU, MEM is a storage unit that stores programs and reference value data, and DS is controlled by a switch selection signal SS from the calculation unit CPU, and a photodiode S. -S2O
This digital switch DS is a digital switch that selects reference value data respectively corresponding to the reference value selection switch SEL-SW shown in FIG. 2b.
Then, the calculation unit CPU compares the illuminance information detected by the optical sensor S with the reference value β selected by the digital switch DS, and outputs the comparison output as a light distribution pattern determination signal P. It has functions. Next, the operation of the embodiment shown in FIG. 3 will be explained.

First, by operating the start switch S/SW of the switch SW, a command signal CMD for lighting the lamp under test L is output from the calculation unit CPU to the lamp control circuit LC. A light distribution pattern of the light is projected on a screen SC shown in FIG. 2a.
Then, for example, 20 photodiodes Sl, S2, etc. of the optical sensor S arranged on the screen SC.
A minute current proportional to the illuminance of the light is output from S2O. The output current of this optical sensor S is amplified by an optical amplifier LA,
The 20 points of light reception data that is the output is processed by the calculation unit C.
The scanner SCN, which is controlled by the channel selection signal CS from the PU, performs time-division scanning and sequentially extracts the data. The output of the optical amplifier LA taken out in this manner is sequentially input to the temperature correction circuit TR, where changes in the detection characteristics of the optical sensor S with respect to temperature changes are corrected. After being amplified to a required level by the PA, it is transmitted to the arithmetic unit CPU. If you die on the calculation side,
The start signal ST from the arithmetic unit CPU is sent to the analog-to-digital converter AD, and the power amplifier PA. l. V)
The analog quantity is converted into a digital quantity corresponding to the light quantity, and is sent to the calculation unit CP via an input register (not shown) together with the A/DEND signal that indicates the end of the IX//D conversion.
The data are sequentially input to U.

The calculation unit CPU calculates the illuminance based on the digital amount corresponding to the amount of light inputted from the analog-to-digital converter AD, and calculates the illuminance according to the standard controlled by the switch selection signal SS output in synchronization with the channel selection signal CS. It is compared with a reference value β inputted from the data selection digital switch DS via the input register. Then, if the illuminance is permissible with respect to the reference value, photodiode S is used. A light distribution pattern that fits the installation point is judged to be good,
This is temporarily stored in the storage unit MEM. That is, photodiode S. If the illuminance information at the installation point is acceptable with respect to the reference illuminance at that installation point, the light distribution pattern at that installation point is determined to be good, and this is temporarily stored. . Then, based on the measured light intensity by the photodiode S, which is input in the same way, the illuminance information at the installation point of the photodiode S1 is calculated, and the illuminance information is compared with the reference illuminance at the installation point of the photodiode S1. If the light distribution pattern is acceptable, the light distribution pattern at the installation point of the photodiode S1 is determined to be good, and is temporarily stored in the storage unit MEM. From then on, photodiode S2...Sn
When the illuminance for each installation point of the photodiodes S2...Sn is calculated and all the calculated illuminance information allows the reference illuminance for each installation point of the photodiodes S2...Sn, the calculation unit CP
U determines that the light distribution pattern of the lamp L to be measured is a specified one, and outputs a discrimination signal P via an output register (not shown).
is sent to the display section DP. Thereby, the display section DP displays that the light distribution pattern of the lamp L to be measured is a specified one. Therefore, according to this embodiment, the light distribution pattern of the lamp L to be measured can be measured accurately, automatically, and quickly. In this way, by measuring the amount of light with multiple sensors installed on the standard line of the light distribution pattern and comparing the measurement information with the reference value in memory, it is possible to check whether the edges of the light distribution pattern are within the standard. It can be determined whether the light distribution pattern is "blurred" or not by taking the bright/dark ratio of the measured light quantity.

The present invention has been described above using an example in which a light sensor arranged on a screen constitutes a sensor band consisting of a pair of sensors arranged at a constant interval as illuminance detection means. is not limited to this, and the pair of sensors constituting the sensor band can be provided at positions sandwiching the bright/dark boundary of the light distribution pattern to be measured, and
It is also possible to arrange the sensor strips in a configuration in which they form approximately a right angle.

Further, a photodiode of such a sensor can be provided at the bottom of a tube buried above the screen. As is clear from the above description, according to the present invention, without using complicated means, the sensor directly captures light on a screen soil arranged in a row, and determines the amount of light irradiated on the screen and the preset value. By using a simple circuit configuration that measures the deviation from a predetermined reference value (light amount), there is no need to rely on manual visual operation as in the past, thereby solving all the inconveniences and inconveniences based on this. Not only is it possible to determine whether the light distribution pattern of the light emitted from the lamp under test conforms to the specified specifications, it can be determined accurately, automatically, and quickly, so it is extremely effective in practical use. It's large.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a light distribution pattern standard for explaining the present invention, and FIG. 2 is a diagram for explaining an example of the basic configuration of the light distribution pattern measuring method for a vehicle lamp according to the present invention and its device. FIG. 3 is a block diagram for explaining an example of a specific implementation method of the present invention. S...Sensor, SC...Screen,
L...Light to be measured, SCN...Scanner CPU...Calculation unit, MEM...
Storage section, DP...display section.

Claims (1)

[Scope of Claims] 1. A screen in which predetermined upper and lower limit reference values are determined and a pair of sensors facing each other at positions sandwiching the bright/dark boundary of the light distribution pattern to be measured are arranged in a row is covered with a screen. By emitting light from a measuring lamp and capturing the light directly on the screen with the sensor, comparing the amount of light detected by this sensor with a predetermined standard set in advance, and measuring the deviation. A method for measuring a light distribution pattern of a vehicle lamp, characterized in that the light distribution pattern of the lamp to be measured is measured. 2. It consists of a screen that receives the irradiated light from the lamp to be measured, and a pair of sensors that are arranged in a row on this screen and are provided oppositely at positions sandwiching the bright/dark boundary of the light distribution pattern to be measured. A sensor group that directly captures light on the screen, a scanning device that time-divisionally scans and sequentially extracts the detection output from the sensor group, and illuminance information obtained by the scanning device and a predetermined reference value. 1. A light distribution pattern measuring device for a vehicle lamp, comprising: arithmetic means for comparing and outputting the comparison output as a light distribution pattern determination signal. 3. The light distribution pattern measuring device for a vehicle lamp according to claim 2, wherein a sensor group consisting of a pair of sensors is installed in a shape forming a substantially right angle. 4 The photodiodes of the sensors that make up the sensor group are
A light distribution pattern measuring device for a vehicle lamp according to claim 2 or 3, wherein the device is provided in a cylindrical bottom part buried on a screen.