Inspection of containers employing a single area array sensor and alternately strobed light sources

Apparatus for inspecting a container that comprises:

• a first light source for generating light energy of a first character, including means for directing said light energy from said first source onto a predetermined portion of a container under inspection,
• a second light source for generating light energy of a second character different from said first character, including means for directing said light energy from said second source into the same predetermined portion of the container under inspection,
• an area array light sensor disposed to receive a two-dimensional image of the said portion of the container illuminated by said first and second light sources,
• means for sequentially and alternately energizing said first and second light sources, and downloading from said sensor alternate first and second two-dimensional images of the container portion as illuminated by said first and second light sources respectively, and
• means for comparing said first and second two-dimensional images to identify commercial variations that affect optical characteristics of the container,
• wherein said sensor includes means for scanning two-dimensional images thereon in sequential frames, and wherein said first and second images are obtained by scanning sequential frames from said sensor during which said first and second light sources are respectively alternately illuminated.

A method of inspecting a container for variations that affect commercial acceptability of the container, comprising the steps of:

• (a) alternately directing first and second light energies of different character into a portion of the container,
• (b) obtaining first and second two-dimensional images of the portion of the container illuminated in said step (a) during illumination by said first and second light energies respectively, and
• (c) detecting commercial variations at the container that affect optical properties of the container by comparison of said first and second images to each other, wherein said step (b) comprises The steps of:
• (b1) directing said first and second light energies alternately into a single area array sensor to develop two-dimensional images of the illuminated portion of the container at said sensor and (b2) scanning said two-dimensional images from said sensor, and
• wherein said step (b2) is carried by:
• (b2a) controlling said sensor in sequential scan frames of equal time duration (b2b) directing said first and second light energies into the container during sequential first and second scan frames at said sensor, and (b2c) scanning said sensor during said first and second scan frames to obtain said two-dimensional images.

A method of inspecting a sealing surface of a container for variations that affect commercial acceptability of the container, comprising the steps of;

• (a) alternately directing first and second light energies of different character into the sealing surface of the container,
• (b) obtaining first and second two-dimensional images of the sealing surface of the container illuminated in said step (a) during illumination by said first and second light energies respectively, and
• (c) detecting commercial variations at the container sealing surface that affect optical properties of the container sealing surface by comparison of said first and second images to each other,
• wherein said step (b) comprises the steps of:
• (b1) directing said first and second light energies alternately into a single area array sensor to develop two-dimensional images of the illuminated sealing surface of the container at said sensor, and (b2) scanning said two-dimensional images from said sensor, and
• wherein said first light source is such as to obtain at said sensor a two-dimensional image of light energy reflected from the sealing surface against a dark background, and said second light source is such as to obtain at said sensor a two-dimensional image of light energy reflected from high points at said sealing surface against a dark background.