Lighting Consulting

Lighting Consulting

It is said that the key to success in image processing is lighting technology.
Our technical experts, who have a wealth of experience in image processing, select lighting which suits the inspection conditions of the object for inspection.

Depending on the object you wish to detect,

  1. How the lighting is directed
  2. The color of the lighting (frequency), and
  3. he shape of the lighting

are decided.

Lighting Consulting

These images of the same object taken from the same direction are very different just because different lighting was used!

How lighting is directed

Representative lighting methods are as follows:

♦Reflected illumination (Dark field illumination)
In this, the simplest method of directing light, light is directed from diagonally above the object of inspection, and an image of the reflections from the surface is taken by a camera. Flat portions appear black, and uneven portions appear white.
Reflected illumination (Dark field illumination)
♦Coaxial epi-illumination (Bright field illumination)
This is a method of directing light in which the optical axis of light directed at the object and the optical axis of the camera which takes an image are matched using a half mirror. Because specular reflected light rebounds, an ideal image can be created even from the image of the object on the mirror surface. In particular, the method in which the half mirror is disposed after the lens (currently the mainstream method) is called pseudo coaxial epi-illumination.
♦Coaxial epi-illumination (Bright field illumination)
♦Transillumination
In this lighting method, light is directed from the rear of the object, and an image is taken of the transmitted light and shade of the object. This method is used when the client would like the external form of the object to be stable when detection is taking place, for example.
Transillumination

Lighting shape

Ring

Ring

LEDs are disposed in a ring shape. Depending on the angle of the LEDs, this lighting shape is further classified into low angle lighting and so on. It is the lighting shape most commonly used in LED lighting.

Bar

Bar

LEDs are disposed in a straight line. The number of LED rows varies. There are also lighting shapes in which bar lighting shapes are disposed in four directions.

Square

Square

LEDs are disposed in lines in a quadrilateral casing. The resulting lighting is indirect rather than direct.

Flat

Flat

LEDs are disposed on a flat surface. Commonly used as backlight.

Coaxial epi-illumination

Coaxial epi-illumination

A shape created to enable the method of directing light termed “coaxial epi-illumination”, rather than a shape classification.
LEDs are disposed to the side, and the optical axis of their light is matched with the optical axis of the camera using a half mirror.