In many industries dot-peening of 2D codes has become standard. The X-Y axis of an electromechanical process is controlled to vary the size, shape and spacing of the mark to be produced.
Treatment and/or machining to prepare the surface of the part is sometimes needed to improve the readability of the code.
Most lighting integrated with cameras are usually unsuitable for reading 2D dot-peened codes. Co-axial, directed lighting, when used on metallic surfaces will reflect a shiny image onto the camera’s lens. Anyone who has seen a movie directed by J. J. Abrams will be familiar with lens flare and how it makes the image useless for machine vision purposes.
Red or Blue LEDs: By cutting out the more intense green light it allows for reducing glare in the image, while retaining contrast for the image capture.
Low Angle lighting: By mounting the lighting at a low angle, you minimise the reflection (or “shine”) back onto the lens whilst maintaining light on the object to catch the ridges made by the dot-peened code. You can achieve this best with a LED ring light.
LED Ring light: Depending on the shape of the code on the surface of the part, you can use this style of light to create the low angle needed; alternatively, for another code shape, you can use a LED bar light.
LED Bar light: Arranged in a square or parallel configuration this will highlight most dot-peened code shapes.
By exploiting the above configuration you can be sure of delivering a clear, matt image to your camera.