Patent ID: 9027478
Filing Date: 2015-05-12
Classification: B41F,B41P,G03B,H05K

Abstract:
1. A screen printing device which makes a screen mask provided with a pattern hole to abut against a board so as to print a paste, comprising: a board positioning part which holds a board transported from an upstream and positions the board to a predetermined position by moving the board relatively in a horizontal direction and in a vertical direction; a screen printing part which prints the paste on the board through the pattern hole by sliding a squeegee on the screen mask to which the paste is supplied; an imaging part which has an upper imaging optical axis and a lower imaging optical axis whose imaging directions are an upwards direction and a downwards direction, respectively, and whose planar positions are offset by a predetermined distance, the imaging part performing a mark imaging operation imaging a mask recognition mark formed on the screen mask through the upper imaging optical axis, and imaging a board recognition mark formed on the board through the lower imaging optical axis; and an imaging part moving mechanism which horizontally moves the imaging part relative to the board and the screen mask; wherein the imaging part comprises a single camera disposed with a posture of horizontally facing towards an incidence optical axis through which an imaging light is incident; a third half mirror having a semi-reflective surface disposed to obliquely face downwards and towards the camera, and horizontally reflecting an imaging light, which is incident through the lower imaging optical axis, to be incident on the camera through the incidence optical axis, a mirror which has a full reflective surface that is disposed to obliquely face downwards and towards the camera, which is disposed at a position further than the third half mirror from the camera, and which horizontally reflects an imaging light which is incident through the upper imaging optical axis to pass through the third half mirror and then be incident on the camera through the incidence optical axis, and an upper illuminating part and a lower illuminating part which individually illuminate respective imaging objects at the time of imaging through the upper imaging optical axis and at the time of imaging through the lower imaging optical axis, and the upper illuminating part includes a first vertical illumination board and a first half mirror obliquely opposed to the first vertical illumination board, the lower illuminating part includes a second vertical illumination board and a second half mirror obliquely opposed to the second vertical illumination board, by operating the first vertical illumination board, the imaging object is irradiated with an illumination light, which is reflected upwards by the first half mirror, from the coaxial direction of the upper imaging optical axis, and by operating the second vertical illumination board, the imaging object is irradiated with an illumination light, which is reflected downwards by the second half mirror, from the coaxial direction of the lower imaging optical axis, wherein the imaging part further comprises an illumination control part which switches to operate the upper illuminating part and the lower illuminating part according to the imaging objects.