Abstract: There is provided an information display device in which speed of detecting input coordinates on a display screen is increased. A coordinate detection circuit 7 detects indication coordinates at a tip end of an electronic pen 6 based on an induction voltage induced at a detection electrode of the electronic pen 6 in scanning a row electrode G and a column electrode S. A coordinate output circuit 17 obtains indication coordinates at the tip end of the electronic pen 6 based on a movement amount detection signal from a movement amount detecting section 20 of the electronic pen 6. A coordinate signal generating circuit 18 outputs an x-coordinate signal and a y-coordinate signal by combining the indication coordinates detected by the coordinate detection circuit 7 and the indication coordinates obtained by the coordinate output circuit 17.

Abstract: The active matrix type display apparatus of this invention includes a display medium made of an electro-optical material; a pair of substrates opposing each other with the display medium interposed therebetween; a plurality of pixel electrodes formed in a matrix on one of the substrates; a plurality of row electrodes; a plurality of column electrodes; switching devices each of which is disposed so as to correspond to each of the pixel electrodes, connects the corresponding pixel electrode to the column electrode corresponding to the pixel electrode, and is connected to the row electrode corresponding to the pixel electrode through a control terminal thereof; a row electrode driving circuit for applying a voltage to each of the row electrodes so that the corresponding switching device become conductive only in a row electrode scanning term during a horizontal scanning term assigned to each of the row electrodes; a column electrode driving circuit for alternately applying two kinds of voltages to each of the co

Abstract: The column electrode driving circuit is suitable for driving a display apparatus which has a delta arrangement display unit. The video signals for two rows in the display unit are sampled simultaneously by two sample-hold circuits with sampling timings which differ mutually by one-half of the sampling period. The outputs of the two sample-hold circuits are alternatingly supplied to column electrodes of the display unit.

Abstract: A driving method of the invention is suitable for an active matrix type liquid crystal display apparatus having row and column electrodes. The driving method includes the steps of applying a gate-one pulse for writing data for one line to the column electrodes to each of the row electrodes. The gate-on pulse has a pulse waveform which includes at least one concave portion during a horizontal period.

Abstract: A switching circuit selects a display control circuit in an image display period, and selects a detection control circuit in an x-coordinate detection period. A row electrode drive circuit outputs row electrode scanning pulses in the image display period to sequentially scan row electrodes. A column electrode drive circuit outputs column electrode scanning pulses in the x-coordinate detection period to sequentially scan column electrodes. A coordinate detection circuit detects coordinates at a tip end of a detection pen based on an induction voltage induced at a tip electrode of the detection pen due to the scanning pulses. Accordingly, by detecting a y-coordinate at the tip end of the electronic pen in the image display period and detecting the x-coordinate in the x-coordinate detection period, a display-integrated type tablet device can achieve an increase in area of its display screen, high productivity, cost reduction, and high coordinate detection accuracy.

Abstract: A liquid crystal display panel is so constructed that a plurality of pixels are arranged in a matrix form having the number of lines twice that of horizontal scanning lines for one field of interlaced scanning video signals obtained by scanning an original image every other line, the arrangement of the pixels being shifted horizontally by one-half of a pixel between adjacent upper and lower lines. A row driving circuit applies, to the pixels in the upper line of the two adjacent upper and lower lines, data voltages obtained by sampling a video signal representing one horizontal scanning line by a clock signal of the timing that matches the number of pixels in the upper line and the arrangement of the pixels, and applies, to the pixels in the lower line, data voltages obtained by sampling the above video signal representing one horizontal scanning line by a clock signal of the timing shifted by 1/2 cycle from the above clock signal.

Abstract: In an active matrix substrate including an array of thin film transistors arranged in a matrix, source buses and gate buses formed on an insulating substrate, a contact pad is formed on the source buses and the gate buses so that a metal portion of these buses is exposed, in order to provide an access for probing to monitor the waveform of signals.

Abstract: When a specific signal (such as copy guard signal) is added between horizontal synchronizing signals in a composite synchronizing signal, and the addition period of the specific signal is defined in a specific period on the basis of the vertical synchronizing signal, the composite synchronizing signal is masked to remove the specific signal, thereby obtaining a masked composite synchronizing signal. Afterwards, from the masked composite synchronizing signal, the horizontal synchronizing signal and vertical synchronizing signal are obtained. In the case of composite synchronizing signal containing noise, without masking, the horizontal synchronizing signal and vertical synchronizing signal are directly obtained from the composite synchronizing signal. Therefore, when noise is not present, the horizontal synchronizing signal and vertical synchronizing signal may be obtained without disturbing the video image.

Abstract: An improved row electrode driving circuit can drive a matrix type display apparatus without necessitating digital signals transmitted between partial row electrode driving circuits. Each of the partial row electrode driving circuits is allocated with a number. In each of the partial row electrode driving circuits, shift register shifts a pulse signal to sequentially output it from a plurality of outputs. At each time when a predetermined number of clock pulses have been counted, a count signal is produced. When the shift direction is set to the upper direction, a signal indicating the allocated number is produced. When the shift direction is set to the lower direction, a signal indicating a number which is obtained by subtracting the allocated number from a specified number is produced. When this number and the clock pulse count number satisfy a predetermined relationship, the pulse signal is output.

Abstract: An improved column electrode driving circuit can drive a matrix type display apparatus without necessitating that digital signals be transmitted between partial column electrode driving circuits. Each of the partial column electrode driving circuits is allocated with a number. In each of the partial column electrode driving circuits, a shift register shifts a sample signal to sequentially output it from a plurality of outputs. At each time when a predetermined number of clock pulses have been counted, a count signal is produced. When the shift direction is set to the right direction, a signal indicating the allocated number is produced. When the shift direction is set to the left direction, a signal indicating a number, which is obtained by subtracting the allocated number from a specified number, is produced. When this number and the clock pulse count number satisfy a predetermined relationship, the sample signal is output.

Abstract: A phase looped oscillating circuit includes a signal comparing device which can compare a plurality of different input signals with each other and emit a signal based on this comparison. The signal comparing device emits a control signal to a level converting device, a signal converting device is operatively connected to the level converting device. A signal from the converting device is received by an oscillating device and an oscillating signal is fed back to the signal comparing device via a divider. To compensate for fluctuation of an invertor in the signal converting device, the signal comparing device provides a fixed level signal stabilized at a 50% duty cycle. This stabilization also stabilizes electrical noises that may be present.

Abstract: The invention relates to a drive apparatus for a liquid crystal display device. The voltage, to be applied to longitudinally and latitudinally arranged liquid crystal cells of the liquid crystal display device, is altered in polarity from field to field and from frame to frame, whereby the occurrence of flicker is prevented. The field discriminating device counts the numbers of lines in first and second fields by synchronizing a vertical synchronizing signal at a leading point of a field time. Thereafter the difference in the number of lines between the first and second fields is detected, the field times being thereby discriminated. When a video signal is erroneous, the field discriminating device provides a field discriminating signal, the level of which is changed alternately from field time to field time.

Abstract: The invention relates to a drive apparatus for a liquid crystal display device. The voltage, to be applied to longitudinally and latitudinally arranged liquid crystal cells of the liquid crystal display device, is altered in polarity from field to field and from frame to frame, whereby the occurrence of flicker is prevented. The field discriminating device counts the numbers of lines in first and second fields by synchronizing a vertical synchronizing signal at a leading point of a field time. Thereafter the difference in the number of lines between the first and second fields is detected, the field times being thereby discriminated. When a video signal is erroneous, the field discriminating device provides a field discriminating signal, the level of which is changed alternately from field time to field time.