Method and apparatus for thermal expansion based print head alignment

A method for automated print head alignment, comprising:

• configuring a carriage plate configured to receive at least two print heads;
• providing a biasing mechanism for urging at least one of said at least two print heads in a first direction along an alignment path;
• associating an expansion block with said carriage plate, wherein said expansion block, when heated, expands in a second direction along said alignment path, wherein said first and second directions are collinear, and wherein said expansion block is in mechanical communication with at least one of said at least two print heads to effect movement of said at least one print head in said second direction in response to expansion of said expansion block;
• providing a heater element in thermal contact with said expansion block;
• providing an imaging system for capturing an alignment pattern printed by said at least one print head;
• providing a control system in communication with said heater element and said imaging system, said control system configured to cause said alignment pattern to be printed, to receive and analyze imaging information from said imaging system, and to control operation of said heater element in accordance therewith to heat said expansion block, wherein resulting linear expansion of said expansion block moves said at least one print head in said second direction to effect print head alignment, said control system further configured to effect repeated printing of said alignment pattern, receipt and analysis of said imaging information, and operation of said heater element until a printed alignment pattern indicates that correct print head alignment has been achieved;
• and
• associating a clamping mechanism with said carriage plate for selectably securing said print head against movement to maintain print head alignment without regard to expansion of said expansion block and/or bias exerted by said biasing mechanism.