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5 Vision Functions SIP LACE 80S-20/F4/F5 Us er Manual 5.5 Teach Fiducial 05/99 Issue from Software Version SR.405.xx 5 - 56 Line en gineer Fig. 5.5.16 Teach fiducial menu, Teach search area video image Use the arrow key …

SIPLACE 80S-20/F4/F5 User Manual 5 Vision Functions

05/99 Issue from Software Version SR.405.xx 5.5 Teach Fiducial

Line engineer 5 - 55

solder-stop lacquer will exhibit poor reflection characteristics. However you should not select too small a

field as this may impair the uniqueness of the fiducial among other things.

Press

Esc

to quit this option.

NOTE

However, if you wish to use a fiducial despite the fact that it has a low uniqueness value, you should

ensure that the fiducial has a good quality value (see ’Test Option’, Page 5 - 67.)

If the quality is bad as well, it would be better to select another fiducial (see ’Criteria for Creating Fiducials’

in Section 5.2.5 from Page 5 - 19.

Changing existing fiducials

During each teaching process the centering offsets are set to zero. If this is not done, optical centering with

the fiducial structure field boundaries will not be correct, the measurement results would be distorted.

5.5.4.3

Search Area

Option

The search area is a freely selectable field within the field of view of the camera.

NOTE

– Always select a size for the search area which will still also take into account tolerances in board

positioning.

– Make sure that there are no other structures within the search area as otherwise fiducial re-identification

could unnecessarily be made more difficult.

– Repeat the tests with different search area sizes. It may also be appropriate to optimize

the uniqueness value.

When you select the

Search area

option

– the menu closes,

– the teaching process is launched,

– the video image is shown with fiducial and search area, and

– header and footer with commentary, measurement results, key assignments and command sequences are

displayed.

5 Vision Functions SIPLACE 80S-20/F4/F5 User Manual

5.5 Teach Fiducial 05/99 Issue from Software Version SR.405.xx

5 - 56 Line engineer

Fig. 5.5.16

Teach fiducial

menu,

Teach search area

video image

Use the arrow keys to change the camera position. You can specify the step width by entering a number in

the range 1 - 6.

Use the

and

keys to move the fiducial structure boundaries and teach them at the same time. With the

space bar you can toggle between horizontal and vertical directions. With the

Tab

key you can toggle the

field step width between 1 pixel and 10 pixels.

Press

Return

to launch the teaching process.

The uniqueness value appears as the measurement results. This may vary between 0 (= unsatisfactory) and

100 (= very good) differentiation capability.

Practice shows that a uniqueness value of at least 60 must be achieved for fiducials and ink dots.

Repeat the teaching process a number of times with changed field sizes. In this way you can optimize the

uniqueness value.

Press Esc to quit this option.

NOTE

However, if you wish to use a fiducial despite the fact that it has a low uniqueness value, you should

ensure that the fiducial has a good quality value (see ’Test Option’, Page 5 - 67.)

If the quality is bad as well, it would be better to select another fiducial (see ’Criteria for Creating Fiducials’

in Section 5.2.5 from Page 5 - 19.

Fiducial No. = 8 Uniqueness = 70

Blank: hor./vert.

Tab : step width

Change search area

1..6 : x/y step

: y axis +

: y axis -

x/y step width = ...Direction = ...Field step = ...

Ret: teach

- : smaller

+ : larger

: x axis +

: x axis -

SIPLACE 80S-20/F4/F5 User Manual 5 Vision Functions

05/99 Issue from Software Version SR.405.xx 5.5 Teach Fiducial

Line engineer 5 - 57

5.5.5

Contrast Sensitivity

The

Contrast sensitivity

menu provides options for optimizing the contrast between the fiducial and its sur-

roundings.

NOTE

All of the options in this menu are only accessible if you have loaded a fiducial beforehand. If you have done

so, this will be indicated by the text on the button being black (rather than grayed out).

The fiducial number and fiducial name are displayed in the

Fiducial

display field.

If you have not loaded a fiducial you will only be able to selected the

Program transform 5

option.

Fig. 5.5.17

Contrast sensitivity

menu, options

Each pixel of the video camera contains one unit of 8-bit gray-scale information. The significance of the values

is as follows:

0 = black and

255 = white