Abstract: The general field of the invention is that of display devices including a liquid-crystal matrix screen composed of elementary pixels, said screen including at least a first electrode used as voltage reference and called the “backplane,” a second electrode in the form of a matrix electronic network delivering the drive voltages for controlling the pixels and control electronics for said electrodes, said screen being used in the so-called “normally black” mode, that is to say that in the absence of applied voltages, the optical transmission of the pixels is substantially zero. In the device according to the invention, the “backplane” drive voltage is a variable periodic voltage, the amplitude of variation of this voltage being sufficient so that in the absence of voltage on the second electrode, the optical transmission of the pixels is sufficient to be detected by an observer.

Abstract: An integrated method of detecting an image defect in an LCD screen consists in verifying the consumption of current on a power supply bus of the image display means (row driver 20, column driver 30, counter electrode CE), during capacitive charges or discharges of the selection lines Li and/or columns ColRj. The method comprises the integration of a current measurement chain comprising a measurement resistor Rm on the power supply bus and measurement 41 and comparison 42 circuits providing outside the screen a detection signal Sd which is processed by an external circuit for safety management.

Abstract: A shift register driven by two complementary clock signals is integrated on an active-matrix substrate of a flat screen for controlling selection of rows of image points of the flat screen is disclosed. The shift register includes a control transistor driven by one of the clock signals, and connected between this clock signal and an output node connected to a corresponding row. The shift register also includes a capacitor connected between an internal node connected to the gate of the control transistor. The output node is discharged each time the flat screen starts.

Abstract: An integrated method of detecting an image defect in an LCD screen consists in verifying the consumption of current on a power supply bus of the image display means (row driver 20, column driver 30,counter electrode CE), during capacitive charges or discharges of the selection lines Li and/or columns ColRj. The method comprises the integration of a current measurement chain comprising a measurement resistor Rm on the power supply bus and measurement 41 and comparison 42 circuits providing outside the screen a detection signal Sd which is processed by an external circuit for safety management.

Abstract: In a shift register driven by two complementary clock signals for controlling the selection of the rows R(n) of image points of a flat screen, a control transistor T3 is driven by one of the clock signals, and connected between this clock signal and the output node Sn connected to the corresponding row. A capacitor connected between an internal node Pn, connected to the gate of the control transistor T3 and the output node Sn is discharged at least each time the screen starts, by discharge means T5 provided in each stage.

Abstract: The general field of the invention is that of display devices comprising a liquid-crystal matrix screen composed of elementary pixels, said screen comprising at least a first electrode used as voltage reference and called the “backplane”, a second electrode in the form of a matrix electronic network delivering the drive voltages for controlling the pixels and control electronics for said electrodes, said screen being used in the so-called “normally black” mode, that is to say that in the absence of applied voltages, the optical transmission of the pixels is substantially zero. In the device according to the invention, the “backplane” drive voltage is a variable periodic voltage, the amplitude of variation of this voltage being sufficient so that in the absence of voltage on the second electrode, the optical transmission of the pixels is sufficient to be detected by an observer.

Abstract: The technical field of the invention is that of secure display devices. The latter comprise at least one matrix screen, electronics for controlling the screen, a fault-detection circuit and electronic means for managing the display device, the screen consisting of pixels placed in lines and in columns, the lines of pixels being controlled by an electronic “drivers” card comprising electronic means arranged so as to generate a first electronic signal representative of the correct or incorrect operation of the said electronic “drivers” card, the fault-detection circuit arranged so as to generate, from the first signal, a second signal processed by the electronic means for managing the display device.

Abstract: An electronic device for multiplexing several loads to the terminals of a source of alternating electrical energy. The source(4) of alternating electrical energy is coupled by electromagnetic flux to the loads by using primary excitation windings 71, 81 and 91 connect to the terminals of the source (4) of alternating electrical energy and secondary windings respectively corresponding to the number of loads. The secondary windings are at least partially coupled to the primary winding and are each connected to the terminals of a load. The coupling is inhibited by auxiliary winding 73 which are each totally coupled with the secondary winding 72. The inhibition function is controlled in order to inhibit all the magnetic couplings except for one and this particular one changes as a function of the respective load to be coupled to the source 4 of alternating electrical energy.

Abstract: The radiator and the sensor each comprise three pairs of Helmholtz coils which are disposed along three orthogonal axes respectively. The coils are wound in pairs of grooves which have different depths and are recessed in a cubic support. The radiator and sensor are particularly useful for helmet-type viewfinders.

Abstract: The circuit disclosed can be used to process synchronous video signals, especially those coming from two standard CCD sensors. It comprises two channels connected at the output to the two inputs, respectively, of an adder circuit which gives the mixed video signal. The first channel comprises a subtractor circuit which receives the two video signals, a high-frequency filter circuit to eliminate the low-frequency spectrum ranging between 0 and a determined limit frequency, an amplifier circuit to balance the gain of the two channels and a fast change-over/sampler circuit connected to the first input of the adder during half of each dot cycle, while the second input of the adder continually receives one of the video signals. The mixed signal thus comprises an unchanged low-frequency component which eliminates faults in the sensors related to non-homogeneity.