摘要:
A method for generating display correction waveforms (Fm) for a CRT display comprises the steps of selecting one of a plurality of trace portions (Dpar) for forming part of a correction waveform (Vpar), the trace portions having different average values. Completing each of the correction waveform by combining each selected trace portion (Dpar) with a respective retrace portion (Dcomp) such that all completed correction waveforms (Vpar) have a predetermined average value.
摘要:
An apparatus for convergence correction in a TV receiver with a CRT display comprises a display screen (101) with photo sensors (S1-S8) positioned adjacent to screen edges. A cathode ray tube (GCRT) generates a raster for illuminating the display screen (101) and the photo sensors (S1-S8). A signal generator (310/500) generates a video signal (AV) having a first part (M) for convergence alignment and a second part (APL1) having sufficient video signal amplitude to cause an average level of beam current (IG) loading corresponding to an average level that can occur during broadcast video reception. The video signal (AV) being coupled to the cathode ray tube for illuminating the display screen (101) and sensors (S1-S8). The video signal (AV) facilitating convergence alignment with the average level of beam current (IG) loading to ensure that convergence alignment is maintained during broadcast video reception.
摘要:
A method for generating display correction waveforms (Fm) for a CRT display comprises the steps of selecting one of a plurality of trace portions (Dpar) for forming part of a correction waveform (Vpar), the trace portions having different average values. Completing each of the correction waveform by combining each selected trace portion (Dpar) with a respective retrace portion (Dcomp) such that all completed correction waveforms (Vpar) have a predetermined average value.
摘要:
A projection display comprises a display device (CRT) forming an image (M) for projection onto a display screen (700). A photo sensor (S) is adjacent to the display screen (700) and generates a first signal (Isen) responsive to a level of the projected image (M) illumination incident on the photo sensor (S). A detector (275) is coupled to receive the first signal (Isen) and generates an output signal (202) indicative of detecting the first signal (Isen). A source (Q2/D) of a predetermined detection threshold value (Iref) is coupled to the detector (275) for determining a threshold at which the detection of the first signal (Isen) occurs. Wherein the first signal (Isen) exceeds the predetermined detection threshold value (Iref), the detector (275) detects and generates the output signal (202) indicative of signal detection, and generates a second signal (Vlit) for coupling to the source (Q2/D) to change the predetermined detection threshold value (Iref).
摘要:
A method for determining raster positioning in a video projection display apparatus comprises the steps of detecting illumination by a first edge (LE) of a measurement image (M) moving in a first direction. Detecting illumination by a second edge (TE) of the measurement image (M) moving in a second direction, and calculating movement values related to the first (LE) and second (TE) edge illuminations of the detecting steps.
摘要:
A method of operating a photo sensor (S) in a projection display device comprises the steps of, illuminating the sensor (S) with a projected image (M). Detecting a signal (Isen) from the sensor (S) responsive to the illumination by the projected image (M). Changing a threshold value (Iref) of the detector until the signal (Isen) detection ceases. Storing a value representative of the threshold value (Iref) which terminated detection of the signal (Isen) from the sensor.
摘要:
A projection display apparatus comprises a display device (CRT) forming an image (M) for projection to illuminate a display screen (700). A current source (250) generates a current (Iref). A current sink (S) is adjacent to the display screen (700) and is coupled to the current source (250) for receiving the current (Iref). A detector (275) is coupled to the current source (250) and the current sink (S) for receiving the current (Iref) and detecting a presence of the received current (Iref). Wherein a first condition, absent illumination by the projected image (M) on the current sink (S), the current (Iref) from the source (250) divides and is coupled to the detector (250) in accordance with a first ratio, the detector (275) assuming a first state indicative of the absence of illumination, and in a second condition in accordance with an intensity of illumination by the projected image (M) on the current sink (S), the current (Iref) from the current source (250) is received by the current sink (S) in accordance with a second ratio and the detector (275), absent the received current (Iref), assumes a second state indicative of illumination on the current sink (S).
摘要:
A projection television display apparatus comprises a display device (CRT) with an image (M) formed for projection and a display screen (700) for receiving the projected image (M). A plurality of photo sensors (S1-S8) are located adjacent to edges of the display screen (700) and each generates an output signal (Isen) responsive to an intensity of illumination by the projected image (M). A detector (275) with controllable detection threshold (Iref) is coupled to the photo sensors (S1-S8) for generating a signal (202) having a first state when the output signal (Isen) generated by each of the plurality photo sensors (S1-S8) is greater than the detection threshold (Iref), and a second state when the output signal (Isen) generated by each of said plurality photo sensors (S1-S8) is less than the detection threshold (Iref). A controller (301/900) is coupled to the display device (CRT) and to the detector (275) for setting the detection threshold (Iref) for the output signal (Isen) generated by each one of the plurality of photo sensors (S1-S8). In response to the signal (202) having the first state, the controller (301/900) moves the image (M) on the display device (CRT) to sequentially illuminate another one of the plurality of photo sensors (S1-S8).
摘要:
An apparatus for convergence correction in a TV receiver with a CRT display comprises a display screen (101) with photo sensors (S1-S8) positioned adjacent to screen edges. A cathode ray tube (GCRT) generates a raster for illuminating the display screen (101) and the photo sensors (S1-S8). A signal generator (310/500) generates a video signal (AV) having a first part (M) for convergence alignment and a second part (APL1) having sufficient video signal amplitude to cause an average level of beam current (IG) loading corresponding to an average level that can occur during broadcast video reception. The video signal (AV) being coupled to the cathode ray tube for illuminating the display screen (101) and sensors (S1-S8). The video signal (AV) facilitating convergence alignment with the average level of beam current (IG) loading to ensure that convergence alignment is maintained during broadcast video reception.