Magnetically operated matrix display panel and elements therefor

Claim 1

A display panel comprising: a display surface structure; a display switching unit; and a drive unit; in which, letting an arrangement of N vertical lines of arrangement spaced a predetermined distance from adjacent ones of them in a horizontal direction be represented by a 1 , a 2 , . . . a N , respectively, the display surface structure has M display elements D i1 , D i2 , . . . D iM disposed on the vertical line a i (i=1, 2, . . . N) at predetermined intervals in a vertical direction; in which the display element D ij (j=1, 2, . . . M) is formed with a block member with uniform cross section having an outer periphery forming a plurality of display surfaces of different colors to form a plurality of edges parallel to and around an axis extending in the horizontal direction, a magnetic piece of a first type disposed near each of the edges except one of them and a magnetic piece of a second type disposed near the remaining edge, the display element D ij being supported by supporting means in a manner to be rotatable about the axis and to permit a selected one of the display surfaces to lie in a vertical plane; in which the display switching unit has a first erasing head E i , a second erasing head F i and a writing head G i disposed to be movable along each vertical line a i in the vertical direction, the first erasing head E i having magnets numbering one less than the edges of the block member, the second erasing head F i having a magnet, the writing head G i having electromagnets of the same number as the magnets of the first erasing head; and in which the drive unit has means for simultaneously moving down the first erasing heads E 1 to E N , the second erasing heads F 1 to F N and the writing heads G 1 to G N and means for driving the electromagnets of the writing heads G 1 to G N in synchronism with the movement of the writing heads G 1 to G N .