Optical lighting system for linear ccd scanning

Abstract

The invention discloses an optical illumination system for linear CCD scanning. The optical illumination system at least comprises a first linear light source, a second linear light source, a third linear light source, a spectroscope, a second Fresnel lens, a third Fresnel lens, a second retroreflector and a third retroreflector. The first linear light source, the second linear light source and the third linear light source are arranged above a detected object and on the front side face and the rear side face of the detected object respectively, and are all horizontally arranged, the right upper surface, the front side face and the rear side face of the detected object are irradiated at the same time, and shadowless lighting is achieved. The first linear light source, the second linear light source and the third linear light source are all formed by matching low-power halogen lamps with optical fibers. The optical illumination system is high in uniformity, large in incident angle and capable of achieving stereoscopic illumination of the front face and the side faces on the detected object, the reflected light of a scanned object directly enters a CCD to be imaged, no optical filter is needed, the resolution range is wide, the limiting requirement for scanned materials is low, the light path structure is simple, energy consumption is low, the energy rate is high, and the service life is long.

Description

Technical field [0001] The invention relates to an optical illumination system for linear CCD scanning, which is applied to a circuit board automatic optical detection equipment, and is specifically used to provide omnidirectional three-dimensional illumination of a detected object during linear CCD scanning, and belongs to the field of electronic manufacturing. Background technique [0002] Most of the existing linear CCD scanning optical illumination systems used for circuit board automatic optical inspection equipment are complex in structure, and the manufacturing and use costs are high. There are two main types currently on the market: [0003] 1. Use LED light belts to achieve linear concentrating. Because of its high requirements for lighting uniformity, the LEDs on each light belt must be strictly screened, and once one of the LEDs fails after use, It is necessary to replace the entire LED light strip, which leads to high manufacturing and use costs; [0004] 2. Use high-po...

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Problems solved by technology

[0003] 1. Use LED light strips to achieve linear spotlight. Because it has high requirements on the uniformity of illumination, the LEDs on each light strip must be strictly screened, and once one of the LEDs fails after use, The entire LED light strip needs to be replaced, which leads to high manufacturing cost and high use cost;

[0004] 2. Use a high-power halogen lamp as the light source to form the required lighting through a complex optical path. The manufacturing cost is high, and the lighting intensity is not enough. It is necessary to increase the power of the halogen lamp (generally 250W) or the number (generally 5) To achieve the necessary brightness, this will inevitably lead to high energy consumption and low energy efficiency of optical detection equipment

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