The color sensor has high reliability in detecting similar colors and hues. It realizes the color detection by measuring the reflection ratio of the three primary colors which constitute the object color. Because of the high precision of this color detection method, the sensor can accurately distinguish extremely similar colors, or even different tones of the same color.
Generally, sensors have red, green and blue light sources. Three kinds of light are emitted by the same lens and reflected by the target object. The amount of light reflected or absorbed depends on the color of the object.
The sensor has two measurement modes. One is to analyze the proportion of red, green and blue light. No matter how the detection distance changes, it can only cause the change of light intensity, and the proportion of three colors of light will not change. Therefore, it can be detected even when the target has mechanical vibration.
The second mode is to use the reflected light intensity of red, green and blue to achieve the purpose of detection. Using this mode, the detection of tiny color discrimination can be realized, but the sensor will be affected by the mechanical position of the target. No matter which mode is applied, most sensors have guidance function, which makes it very easy to set. Most of these sensors have some form of built-in charts and thresholds that can be used to determine operational characteristics.
Working principle of color sensor
The basic working principle of the color sensor is to control the single chip microcomputer to send instructions to the sensor, read the information received by the sensor, and then after calculation, send the results to the LED lamp or pulse width modulation output. Fig. 1 is a light path diagram of the system. It can be seen from the figure that the light emitted from the high brightness LED and other light sources propagates to the convex lens 2 through the convex lens 1 in a straight line. Among them, the light also passes through a half lens and focuses on the object at the convex lens 2 to generate an image. The above is the process of light propagation in a straight line. When the light irradiates the object, the reflected light will be generated from the object and will be focused to the half lens through the convex lens 2. Since the half lens is used, the light can not be penetrated in a straight line and can only be reflected to the convex lens 3. At this time, the light from the convex lens 3 is the signal sent to the color sensor.
When the sensor receives the light signal, the output frequency will change accordingly. Control the single-chip microcomputer to collect the frequency, and make appropriate judgment and calculation, then the single-chip microcomputer can output.
Due to the characteristics of the sensor itself, 64 photodiodes are integrated on a single chip. These photodiodes are divided into four types, namely red, green, blue and white filters. In this way, as long as you choose in the software design, you can easily realize the detection of various colors. For high-speed printing and related industries, this is very simple and convenient And it is practical, and it is very convenient for the expansion and improvement of the product, just need to adjust in the software.
Function of color sensor
1. Color recognition function
2. Color recognition function independent of working distance
3. It can also provide reliable detection for vibrating objects
4. White LED
5. Dynamic and remote control teaching function
6. Trigger input
7.3 color channel, level 5 threshold
8. Reflectors can be used
Application of color sensor
With the development of modern industrial production to the direction of high speed and automation, the color recognition work which has been dominated by human eyes for a long time in the production process will be more and more replaced by the corresponding color sensors. For example:
The use of color to classify documents in library can greatly improve the work of shelving management and statistics.
In the packaging industry, product packaging uses different colors or decorations to express its different properties or uses.
Editor in charge: CC