Have you ever seen a car position lamp reflected on the back camera?
Or maybe the position ramp of the oncoming car or the following car appears in the image of the drive recorder?
Oh, it’s OK with a signal.
I regularly project the image of the back camera on the display while driving Tesla.
Then I notice that the position lamp is flashing.
It is lit instead of blinking when seen with the naked eyes.
I feel that there are many flashing position lamps in the Lexus car. It was Mercedes that I saw today.
Some vehicles have position lamps that do not flash, do they?
Somehow I knew the mechanism of the LED, so I had predicted what it would be like, but if I looked it out my prediction was wrong.
It seems to be caused by the difference in lighting method.
There are two lighting methods for LED, which are the dynamic lighting (also called pulsed lighting or dihity lighting) and the static lighting.
Each has advantages and disadvantages, I think that it is decided by the idea of the person in charge in making a car.
The advantages and disadvantages of each are as follows.
|
Name |
Lighting method |
Advantage |
Disadvantage |
Notes |
|
Dynamic lighting |
Flicker at a constant frequency at high speed |
Flicker at a constant frequency at high speed Lifetime is long because the operation time of LED is shorter than that of static method. |
The circuit becomes complicated |
It looks like it is flashing when you look through the drive recorder |
|
Static lighting |
Always keep the current flowing and keep on lighting |
Since it is not flashing, flicker does not occur, there is no stress caused by it. Easy circuit |
Power consumption increases |
Since the LED is far more power-saving than the conventional mini light bulb, it is better to unify it here. Personally I think. |
So why is it blinking when I see it on the display although it is lit with the naked eyes, it is caused by the performance of the camera.
To be more specific, the frame rate of the camera.
The principle of the camera is releasing the shutter at high speed and linking the pictures and making it a video.
This “high speed” is point.
When there is a difference between the blinking speed of the LED and the interval of releasing the shutter of the camera, or the timing deviates, the lighting appears to blink through the monitor.
It is easy to understand by drawing.
When the frame rate of the camera is smaller than the blinking of the LED, it blinks on the display as shown below.
If you want to eliminate the blinking of this LED, there is a way to make the position lamp static. But it is difficult in reality.
As one you can do, improve the performance of the camera.
However, the blinking interval of the LED = the frame rate of the camera does not solve it.
Accurately it will be settled if luck is good.
As also shown in the figure, as shown in the figure below, even if the timing is shifted even at the same frame rate as the LED blinking, it disappears at all when it fails.
So the best is to replace it with a camera with a high frame rate.
If this is the case, as many photos are taken and connected as shown below, the LEDs appearing on the monitor do not seem to be blinking.
However, increasing the performance of the camera will increase the cost.
It seems that the frame rate is slightly shifted as a countermeasure against the LED signal machine of the drive recorder.
A drive recorder with camera performance of 27.5 fps (Frames Per Second) or 29 fps is sold as a countermeasure against LED traffic signal.
Please refer when you buy the drive recorder.
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