Sharp Kabushiki Kaisha Corporation

Masahiro Yoshimura

Yasuo Torimaru

Tutomu Nakamura

An image display device having unit image elements each arranged in a matrix formation and adapted to display a character signal synthesized with or superposed on an image signal further comprises means for matching the dot timing of the character signal and the scanning timing determined by the number of image elements of the image display device so that characters can be clearly displayed against a background image.

Image display device

A dot matrix image display system displays a desired portion of an image in increased magnification on a dot matrix image display panel. A shift circuit functions to automatically shift the position of the enlarged portion in a predetermined direction on the dot matrix image display panel. The shift circuit determines not only the portion to be displayed with increased magnification but also a speed at which the enlarged display is shifted.

Dot matrix panel display control

A selection circuit is connected between a display composed of unit picture elements arranged in a dot matrix and a vertical scanning circuit, the selection circuit effects the selection of odd or even lines in the display. The advantages offered by such an arrangement are elimination of the necessity of interlaced scanning in the scanning circuit itself, cutting the number of steps in half in the scanning circuit during interlaced scanning, increase in the margin in operating speed and elimination of limitations on circuit configuration, device construction and materials used.

Image display panel drive

An electronic viewfinder comprises a plurality of picture elements which form a matrix image display device. A drive circuit is connected to the display device to cause the electronic viewfinder to selectively display a portion of the image, corresponding to the video signal being received by the drive circuit, at an increased magnification. The drive circuit includes frequency divider circuits for providing shift clock pulse signals at frequencies corresponding to the available rates of magnification of the image portion. The drive circuit further includes delay circuits for delaying synchronizing signals to select the portion of the image which is to be displayed. The electronic viewfinder having this drive circuit, is capable of providing increased resolution for a portion of an image by enlarging the image, while allowing the electronic viewfinder to be formed by a relatively small number of picture elements, so that the electronic viewfinder may be miniaturized and manufactured at a reduced cost.

Electronic viewfinder

A display circuit for a matrix display includes a plurality of picture elements comprising display elements driven by drive circuits. A data regenerative circuit determines whether an external video signal is to be displayed or whether the image being displayed by the picture elements is to be held. When the image currently stored in the picture elements is to be held, the data regenerative circuit reads the stored image data from a selected picture element, regenerates the level of the data signal and causes this data to be rewritten into the selected picture element.

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Nara, Japan

Masahiro Yoshimura