80S-2080F480F4-680F5 User’s Manual - 第240页
SIPLACE 80S-20/F4/F4-6/F5 User’s Manual 5 Vision Functi ons Edition 03/98 from S oftware Version S R.404.xx 5.2 PCB Vision System Line engi neer 5 - 19 5.2 PCB Vision System The PCB v ision syste m regis ters the pr ecis…
5 Vision Functions SIPLACE 80S-20/F4/F4-6/F5 User’s Manual
5.1 Overview of the Vision Systems in the SIPLACE 80S-20/F4/F4-6/F5 Machines Edition 03/98 from Software Version SR.404.xx
5 - 18 Line engineer
SIPLACE 80S-20/F4/F4-6/F5 User’s Manual 5 Vision Functions
Edition 03/98 from Software Version SR.404.xx 5.2 PCB Vision System
Line engineer 5 - 19
5.2 PCB Vision System
The PCB vision system registers the precise position of the board by surveying fiducials and then determines
the offset along the x and y axes, the skew with respect to the direction in which the boards are transported,
and also the shear of the board. The PCB vision system also registers and evaluates reject fiducials (ink
dots).
5.2.1 System Description
The PCB vision system for PCB position recognition consists of
l the optical system for PCB position recognition
Each gantry has its own PCB position recognition system (see Fig. 5.1.2, Page 5 - 5).
PLEASE NOTE:
PCB position detection is only carried out with gantry 1.
l the vision evaluation unit
Each machine accommodates in the control unit an evaluation unit for PCB and component position recog-
nition (see Fig. 5.1.4, Fig. 5.1.7 and Fig. 5.1.10).
The optical PCB position recognition system consists of a CCD camera (a SONY XC75) with integrated imag-
ing and illuminating optics. The field of view of the board module is 5.7 mm x 5.7 mm. A search area can be
programmed by size and position within the dimensions of the field of view. The imaging lens is a special
measuring lens which compensates for virtually all measuring errors resulting from warping of the board. The
lighting is only switched on while fiducials are being registered.
The vision evaluation unit (MVS) is a single-board system which conforms with the VME standard. The hard-
ware consists of:
l the MVS motherboard with vision processor and interface connections
The rear side of the board accommodates
– the plug-in connections for the VME bus and
– the high-speed communications unit (HS
3
L).
Machine PCB camera MVS evaluation unit
80S-20 (2 gantries) 2 1
80F
4
(1 gantry)
11
80F
4
-6 (1 gantry)
11
80F
5
(1 gantry)
11
Tab. 5.2.1
5 Vision Functions SIPLACE 80S-20/F4/F4-6/F5 User’s Manual
5.2 PCB Vision System Edition 03/98 from Software Version SR.404.xx
5 - 20 Line engineer
On the front side of the board are the connection sockets for
– the screen
– up to 4 camera inputs
– two serial interfaces (RS232 or RS422)
and the indicator LEDs for
– the CPU
– the vision processor
– the camera input
– the screen display.
The RESET and CANCEL switches are located beneath the indicator LEDs.
l the MVS camera interface (piggyback board) for up to four CCD cameras.
5.2.2 Technical Data
Camera model: SONY XC75
Number of pixels: Camera 768 (H) x 494 (V), Image 640 (H) x 484 (V)
Field of view: 5.7 mm x 5.7 mm
Illumination method: Incident light method (activated during measurement)
Image processing: Correlation principle, gray scale system
Processor cycle time: < 200 msec
Screen: RGB monitor (VGA mode) 640 x 484 pixels in the station computer
Fiducials: Library memory for up to 255 fiducial definitions
5.2.3 Description of Functions
Before placement the location, skew and shear of the board is determined by the PCB vision system using the
position of the fiducials. Deviations from the setpoint values are then included in the calculation of the place-
ment positions of the components as corrections.
A board must have at least 2 fiducials if the system is to be able to detect deviations in the board position and
the skew of the board. The presence of 3 fiducials will furnish additional information concerning compression
or stretching of the board or of the board layout.
5.2.4 Sequence of Functions
Before a fiducial can be used for board recognition it must first be ’taught’ to the machine. In other words, the
fiducial structure parameters must have been saved in the PCB vision system for that pattern.
The fiducial structure can be taught using the PCB vision camera mounted on the gantry and the vision
program. The vision evaluation unit determines the significant fiducial structure parameters using digital
image processing methods.
Measurement takes place in two stages:
– 2-D pattern search (2-dimensional process) in the coarse grid and provisional determination of the