Driving equipment for multi-gradation level reproduction
AssigneeNippon Telegraph & Telephone Public Corporation
InventorTakashi Saito
Life of this patent
Estimating the term…
Abstract
An input picture signal is converted, for each picture element, into a K-bit, first time-serial signal having "ls" corresponding in number to the gradation level of the picture element, and the first time-serial signal are written in a random access memory, sequentially updating its column addresses upon every writing of K bits in its column direction. The random access memory is read out, updating its row addresses upon every reading out of M bits in the row direction. A second time-serial signal thus read out from the random access memory is subjected to a serial-parallel conversion by steps of M bits and parallel outputs of the M bits are supplied to recording elements respectively corresponding thereto.
Claims10
A driving equipment for multi-gradation level reproduction, comprising:
- pulse number modulated signal generating means for converting an input picture signal including gradation level information into a serial digital signal, having K (an integer 2 or more) bits P.sub.i,1, P.sub.i,2, . . . , P.sub.i,K (i being the number of a picture element) per picture element, corresponding to the gradation level of the picture element to obtain a first time-serial signal P.sub.1,1, P.sub.1,2, P.sub.1,3, . . . , P.sub.1,K, P.sub.2,1, P.sub.2,2, P.sub.2,3, . . . , P.sub.2,K, . . . , P.sub.M,1, P.sub.M,2, P.sub.M,3, . . . , P.sub.M,K ;
- sequence converting means for converting the first time-serial signal into a second time-serial signal which, letting each bit of the first time-serial signal be represented by P.sub.i,j (j=1, 2, . . . K), has bits P.sub.1,1, P.sub.2,1, P.sub.3,1, . . . , P.sub.M,1, P.sub.1,2, P.sub.2,2, P.sub.3,2, . . . , P.sub.M,2, . . . , P.sub.1,K, P.sub.2,K, P.sub.3,K, . . . , P.sub.M,K so that the number j may continue for M bits while changing in a sequential order;
- serial-parallel converting means for serial-parallel converting the second time-serial signals by steps of M bits into parallel signals of M bits;
- and
- dirving means for applying the parallel signals of M bits simultaneously to M reproduction elements.
Dependencies are inferred from the claim text.