Apparatus for adjusting the size of a sewing machine pattern

An apparatus for adjusting the size of a sewing machine pattern, said apparatus comprising:

• a stitch forming arrangement including a vertically movable needle and a needle-thread capturing means which cooperates with said needle;
• a central processing unit (CPU);
• rotational phase detecting means, connected to the CPU, for generating a timing signal in synchronism with a vertical motion of said needle;
• cloth moving means for moving an embroidery frame with cloth stretched thereon in an X-axis direction and in a Y-axis direction perpendicular thereto in response to the timing signal;
• stitch data storage means, connected to the CPU, for storing stitch data corresponding to each of a plurality of embroidery patterns;
• pattern selecting means, connected to the CPU, for selecting a desired one of said plurality of patterns stored in said stitch data storage means;
• display means for displaying the pattern selected;
• magnification selecting means, connected to the CPU and capable of being manually operated, for adjusting the size of the pattern;
• magnification displaying means, connected to the CPU, for displaying an adjustment value selected by said magnification selecting means;
• number-of-stitches determining means, connected to the CPU, for classifying the number of stitches into one of a plurality of stages in correspondence with the adjustment value selected;
• key code discriminating means, connected to the CPU, for determining whether the stitch data is valid or invalid on the basis of a relevant one of key codes respectively associated with a plurality of items of stitch data for forming the pattern in correspondence with the number of stitches determined;
• and
• size adjusting means, connected to the CPU, for adjusting the size of the pattern in correspondence with the adjustment value selected,
• wherein size adjustment is made with respect to stitch data which are consecutively read and determined to be valid.