What Is an Image Dimension Measurement System?
Image dimension measurement systems are machines that measure an object as an image and then convert it to binary values to obtain its dimensions.
By inputting CAD data, the difference between the data and the actual measured value can be compared. It is also possible to create a measurement program based on CAD data to improve work efficiency.
Image dimension measurement systems make it possible to measure the dimensions of various samples. Since the measurement is non-contact, they can also be used to measure the size of circular holes, such as screw holes. They measure with images, and can also measure the size of areas where the shape is distorted, such as peeled surfaces.
Uses of Image Dimension Measurement Systems
Image dimension measurement systems are used to confirm that products are processed according to a given design. As mentioned earlier, this device measures dimensions and can measure a variety of samples.
Examples of dimensional measurements using image dimension measurement systems are as follows:
- Measurement of the maximum outer shape, hole diameter, hole position, and hole pitch of a printed circuit board.
- Measurement of width and length of printed circuit board exterior, resist peeling, silk peeling, etc.
- Measurement of the maximum external shape, hole diameter, hole position, and hole pitch of metal components.
These measurement results can also be saved as data.
Principle of Image Dimension Measurement Systems
Image dimension measurement systems take an image and process it to obtain dimensions. The key points are the number of pixels and the size of each pixel, with the “size of one pixel” being particularly important. For example, if the height x width size of one pixel is 1 mm and 300 pixels are lined up horizontally in one image, the size of one field of view is “1 mm x 300 pixels” or 300 mm. As the size of this single pixel changes, the size of the entire image also changes.
If the number of pixels in one image and the size of one pixel are known, dimensions can also be calculated. When recognizing the shape and determining the dimensions of a product from its image, a process called “binarization” is the key point. The image is represented by two values, 1 if the color exceeds a certain density in the image and 0 if it does not.
A black-and-white boundary is then displayed on the image. By recognizing these boundaries, the device can determine the dimensions from the image. In image processing, the strength of the light source also affects the binarization of the boundary. Therefore, it is necessary to change the intensity of the light source depending on the sample.