Abstract: A field emission device (10) includes a video memory device (12) that receives video data in parallel for each of three colors red, green, and blue. The video memory device (12) provides the video data in color sequential manner to a controller (14). The controller (14) provides appropriate control and data signals in response to the video data to drive a field emission device display (22). The video memory device has a first storage area (30) for a first color (red), a second storage area (32) for a second color (green), and a third storage area for a third color (blue). The second storage area (32) has capacity to store all of the second color of a frame, the first storage area (30) is two-thirds the size of the second storage area (32), and the third storage area (34) is one-third larger than the second storage area (32). The different sizes of the respective storage areas allows for 100% use of memory space without waste.

Abstract: In a television receiver in which image frequency signals for desired signals are removed when television broadcasting signals are frequency-converted through a local oscillator and mixers, the local oscillator generates biaxial orthogonal signals to be frequency-converted by respective mixers, an output signal of one mixer being phase-shifted to be added to an output signal of the other mixer so as to thereby offset only the image frequency signals. The local oscillator and a phase shifter operate so as to follow the frequency change of the intermediate frequency signal so as to thereby stabilize the suppression of the image frequency signal.

Abstract: To filter a signal delivered in interleaved form, there is provision for the introduction, in series, of a filter on half frames having a bandpass transfer function on the horizontal plane and a high-pass transfer function on the vertical plane. It is shown that this filter then carries out a general bandpass transfer function on the total image signal. Steps are taken to make the center frequency of this filter correspond to a desired resolution of the image. It is shown then that by acting in this way it is possible to heighten the contours of the structures. The invention can be applied particularly to medical radiography.

Abstract: A broadcast receiver (22) for receiving television broadcast signals carrying encoded data e.g. teletext information, includes a tuner (30), a demodulator (32) and a data extractor (36) for decoding the data. The receiver is coupled to a computer through a bus (38) and an interface controller (40). The tuner (30), the demodulator (32) and the data extractor (36) are each individually controllable by the interface controller (40) in response to instructions from the computer to vary any of the tuning, the demodulation parameters, or the data extraction parameters. A data processor (54) processes the extracted data, and can also control the tuner (30), the demodulator (32) and the data extractor (36).

Abstract: A TV receiver has a tuner and a controller for controlling a tuning operation of the tuner. The controller includes a calculation unit for effecting a calculation of preferred stations using as parameters tuned channels and the times for which the channels are selected. A tuning frequency arrangement storing unit determines the channels that are frequently watched by a user on the basis of the calculation and stores indications of the channels. The channel indications thus stored are read out in ranked order to perform a tuning operation in response to successive actuation of a preferred-station key.

Abstract: A gamma correction circuit in which digitized video intensity values are divided into high and low intensity ranges. Every fourth high value is gamma corrected in a lookup table and written to a frame buffer. All of the low intensity values are written to the buffer without gamma correction. The data in the buffer is mapped by a second lookup table before being converted to an analog signal. The second table maps the low intensity values to gamma corrected values and does not change the value of the high intensity values. When data is read from the frame buffer for further processing before display on a CRT, the lower intensity values need not be inverse gamma corrected. The high intensity values are inverse gamma corrected via a lookup table before such further processing.

Abstract: A channel selecting apparatus for television receiving apparatus and the like which memorizes channel data (about whether signals are present or not in respective channels) in a memory circuit connected to an operating circuit preparing channel selecting data. The received frequency is tuned with the broadcast signal input into an antenna terminal and is then confirmed and analyzed. This is used to determine whether the broadcast signal input into the antenna terminal is a TV signal or CATV signal and whether the CATV signal is of an STD, HRC or IRC system and the receiving mode is automatically determined.