A grid with graduation-markings of equal width relative to each other and succeeding in nonequidistant spacings, wherein the graduation-markings define center lines which follow each other in distances corresponding with a cycle of n graduation markings. The cycle has a period length of units and wherein each full numbered multiple of a unit occurs as spacing between two graduation markings exactly k times.
An angle finder (10) and level (40) are disclosed. The level (10) and angle (40) have digital displays (17) which provide a visual, numerical representation of the angular alignment of a reference surface in relation to a gravitational vector. Angle finder (10) and level (40) are controlled by a microprocessor (19). A disc enclosure (18) contains a rotatably mounted disc (23) on which is mounted a weight (26). Weight (26) keeps disc (23) in a relatively constant position relative to the gravitational vector. Also mounted in the disc enclosure (18) are photodetectors (27), (28) and (29). Disc (23) contains markings (30) which, in the disclosure of this application, each represent two degrees of arc. The three photodetectors (27), (28) and (29) sense the movement of markings (30) and by logical computation microprocessor (19) determines the angular alignment of the reference surface. In another embodiment of the invention, a disc enclosure ( 18') includes u-throat detectors (60), (61) and (62) which count the passage of markings (55) on a transparent disc (50) in the manner described above.
This system includes a composite memory (5) in which are memorized the data for images to be displayed for each frame. A video display processor (12) controls the screen (8). A central processing unit (1) effects the composition of the image with the memory and an address processor (10), the extraction of the point data to be displayed being effected by a time base circuit (BT) synchronized with the sweeping of the screen, and by a control device (15) for dynamic access which distributes the access times among different units utilizing the memory. The memory (5) includes a first control memory for the memorization of a data word for a line or group of lines making up the image, each word having an address value for addressing a second control memory which contains, at each of these addresses, at least one display attribute data word characterizing the contents of the line(s) corresponding to the value of the respective address of the first control memory. A zone memory is provided for storing, in addressable zones, the text or graphics information for those lines which have intelligible information. For each of the lines having such information, a data word following the display attribute data word contains the initial address in the zone memory of the corresponding zone which contains the intelligible information to be displayed on the line.
In a position indicating device, especially for an industrial sewing machine, with a slotted wheel (3) and a first track (6) of slots (4) having, e.g., 512 slots (4), to permit a null-point synchronization over a relatively small range of rotational angles, and the establishment of definite angular positions, a second track (8) with slots (7) of various widths is provided. The first track (6) of slots (4) is associated with two light barrier arrangements comprising emitters (11a, 11b), receivers (12a, 12b), and masks (13a, 13b) while the second track (8) is associated with one light barrier arrangement. Evaluating systems are connected to the receivers (12) so that, on the basis of the number of slots (4) of the first track (6), the size of the slots (7) passing in each case and corresponding approximately to a multiple of the slot width may be determined through evaluating systems (14, 28) connected to the output, and in this manner to define the rotary angle position.
