To provide heald frame movement which is improved so as to always maintain an equal or nearly equal yarn length irrespective of cam angles.

The present invention relates to heald frame movement using a modified cam mechanism in a weaving machine. The modified cam mechanism includes at least two protrusions for lifting heald frames such that a shed formed between a plurality of warp yarns for the passage of a weft carrier provided on the weaving machine remains in the lower to middle region of the shed during beating up operation. During the beating up operation at a predetermined angle of the modified cam, a load is equally applied to each warp yarn, and an oscillating backrest is synchronized to reduce differences in warp yarn length as the heald frames move irrespective of the type of a woven fabric. Further, the improved heald frame movement in the weaving machine can provide weaving ability using yarns with nearly zero elasticity at very high speeds without creating extreme tension.