Abstract: The focus position of each projection apparatus is changed depending on the configuration state of a projection system comprising a plurality of projection apparatuses.

Abstract: A display apparatus according to this invention performs control so as to reduce the difference between image data input to a display unit and an image which is displayed on a display surface and acquired by an acquisition unit, based on the image data and the image.

Abstract: When a communication connection with a device is disconnected during execution of a display based on data transmitted from the connected device, it can be controlled to continue or end the display according to a class of the device. A display apparatus 1 includes a USB connector 102 used to connect an external device so as to be able to communicate with that device. The display apparatus 1 also includes a CPU 107 which controls to make a display based on data received from the external device with which a communication connection is established via the USB connector 102. The CPU 107 acquires class information indicating a class of the external device, the communication connection of which is established.

Abstract: A liquid crystal display device dividing a single frame of an image signal into m fields and driving the signal at m times speed, including (a) a circuit comparing a concerned frame's image signal with that of an immediately preceding frame for each pixel in the first field, and performing correction so the gradation becomes higher or lower than the concerned frame's image signal with an increase or decrease in the gradation, respectively, (b) a circuit generating an inversion pattern for cyclically inverting polarity of a drive voltage applied to a liquid crystal in m/2 fields including the first field, and (c) a circuit making the drive voltage applied to the liquid crystal in m/2 fields including the first field and the drive voltage applied to the liquid crystal in remaining m/2 fields opposite in polarity to each other on the basis of the pattern.

Abstract: At least one exemplary embodiment is directed to a video display apparatus that can use a controller to calculate a correction value and determine the sampling clock to improve the accuracy of a correction clock, where the correction clock can be used for error reduction, so that degradation of the contrast can be reduced.