Thomson Licensing

Deutsche Thomson-brandt Gmbh

Thomson Licensing S.a.

Steffen Lehr

Heinrich Schemmann

Sabine Roth

Petrus Gijsbertus Maria Centen

Rudolf Koblitz

Patrick Vogel

Jeroen Rotte

Volker Neiss

Ruud Van Ree

R&uuml;diger Brunheim

Friedrich Heizmann

Christian Büchler

Nicolaas Johannes Damstra

Franz Dieterle

Michael Grimm

Friedheim Zucker

Christian Buechler

Jose I Rodriguez-Duran

Dietmar Bräuer

Jeoren Rotte

Karl-Heinz Schaaf

Neil Mallory

Image sensor, which comprises a plurality of pixels arranged as a pixel array with rows and columns and at least one read-out arrangement for reading out the pixels row by row. The columns are grouped into blocks with a certain number N of columns. Each read-out arrangement comprises N column read out circuits and an addressing circuit for with at least two groups of addressing lines for addressing the blocks. The blocks are selectively addressed by the groups of addressing lines in a way that a read-out sequence of blocks addressed by the groups is continuous across all blocks.

Image sensor and method for reading out pixels of the image sensor

A circuit for resetting and reading out a pixel cell of a CMOS image sensor is proposed. The circuit allows for reading out the pixel cell at least two times during a main integration interval, thereby generating at least two pixel signals. The circuit further comprises means for combining the at least two pixel signals to an output signal. The means for combining are operable to combine the at least two pixel signals weighted in dependence on a saturation level of the pixel cell. A method for controlling the circuit for reading out the image sensor is also proposed.

Circuit and method for reading out and resetting pixels of an image sensor

An image sensor circuit comprises a pixel cell array having a plurality of pixel cells arranged along a plurality of column lines, a plurality of readout circuits connected to said column lines, each of which comprises an analog-to-digital converter and a multiplexer for selectively applying an output signal of one of said column lines to said analog-to-digital converter. Between two of said column lines which are connected to a first one of said readout circuits located at a first side of said pixel cell array, there is a column line which is connected to a second one of said readout circuits located at a second side of said pixel cell array opposite to said first side.

Image sensor circuit

An image sensor circuit comprises at least one pixel cell for providing an output signal which is variable according to illumination of said pixel cell between a maximum and a minimum level, an analogue-to-digital converter for converting output signals from said pixel cell into digital data, and an offset signal source for providing an offset signal having a level between said maximum and minimum levels. The analogue-to-digital converter is fully differential and is connected to said pixel cell and to said offset signal source.

Image sensor circuit having differential signal path, differential analog-to-digital converter and differential signal offsetting means

The invention relates to a method for initializing a control of a supply voltage of a light source, such as a laser diode, the light source being arranged in a first circuit configuration having an associated first reference voltage level or the light source being arranged in an alternative second circuit configuration having an associated alternative second reference voltage level, the method comprising the steps of gradually changing the supply voltage into the direction of the first reference voltage, measuring a light emission of the light source while gradually changing the supply voltage, if no light emission is measured: starting the control of the supply voltage of the light source after the first reference voltage has been reached and if a light emission is measured gradually changing the supply voltage into the direction of the second reference voltage and starting the control of the supply voltage of the light source after the second reference voltage has been reached.

Method and electronic circuit for controlling of a supply voltage of a laser diode

The present invention relates to an apparatus for reading from and/or writing to optical recording media, which has a tracking device, a four-quadrant detector, two summation points and a phase comparator for tracking in accordance with the differential phase detection method, and also various delay elements that can be set by a control device. The object of the present invention is to propose an apparatus of this type which exhibits the best possible compensation of the error in the track error signal and thus in the tracking signal, the said error being caused on account of the lens movement. To that end, the invention provides for analogue delay elements to be arranged upstream and digital delay elements to be arranged downstream of the summation points. The present invention is suitable for apparatuses for reading from and/or writing to optical recording media, such as CD, CDI, CD-ROM, DVD, CDR and others.

Apparatus for scanning optical recording media using DPD tracking method with analog and digital delay elements

In order to compensate for so-called clipping effects, it is proposed, in an apparatus for reading from and/or writing to an optical recording medium in which the light power of a laser diode () is to be set to a plurality of light power levels,to perform a calibration to a specific light power level (LP) before the actual regulation of the light power. On account of the calibration, the instantaneous gradient of the characteristic curve which describes the dependence of the laser light power on the laser diode current can be inferred in order, on the basis of this information, to take account f a change&#x2014;caused, for example, by ageing r clipping effects&#x2014;in the characteristic curve gradient in the course of the subsequent regulation of the light power of the scanning beam generated by the laser diode ().

Method and arrangement for regulating the light power of a scanning beam in an apparatus for reading from or for writing to optical recording media

An apparatus for scanning optical recording media, having a detection unit with a photodetector and a reference voltage associated therewith, an evaluation unit having an input, and a connection disposed between the detection unit and the input of the evaluation unit. In such scanning apparatuses, voltage coupling is usually provided between the detection unit and the input of the evaluation unit. Such a coupling arrangement has the disadvantage that the two units must operate in approximately the same voltage range. In the scanning apparatus according to the present invention it is not necessary for the detection unit and the evaluation unit to operate in substantially the same voltage range. According to the present invention, the evaluation unit has a controller, that holds the input of the connection at the value of a reference voltage of the detection unit.

Apparatus for scanning optical recording media

Apparatus for reproduction or recording data or information with a photodetector and digital error signal and evaluation signal processing

The invention relates to a method and a circuit arrangement for a laser control loop with automatic adaptation to the monitoring signal polarity. Use is made of a single-phase method which consists in that a signal produced by the monitor during the starting phase of the laser control loop is compared with a reference value, and in accordance with the result of the comparison the signal produced by the monitor is fed directly or inverted to the comparator for controlling the light power of the laser during the starting phase of the laser control loop. A signal is produced which initially feeds the comparator for controlling the light power the inverted monitoring signal, or directly feeds the monitoring signal, in a fashion always independent of the monitoring signal polarity, but dependent on the polarity of a reference value, and feeds it in a non-inverted fashion in the case of a monitoring signal running up to the reference value. The laser control loop circuit according to the invention ensures that the monitoring signal is fed with a fixed polarity to the first comparator before the reference value for controlling the light power is reached. This is achieved by virtue of the fact that the monitoring signal is fed to a comparator which compares the monitoring signal with a reference value which is smaller than the reference value for controlling the light power. In the case of a monitoring signal not running up to the first reference value, the comparator for controlling the light power still continues to be fed the inverted monitoring signal. The laser control loop is provided, for example, for controlling the light power of a laser in optical scanning systems for recording or reproducing information independently of the monitoring signal polarity and/or the polarity of the monitor diode of the laser.

Laser control loop with automatic adaptation to the monitoring signal polarity

A photodiode detection circuit is used to automatically identify a type of photodiode circuit connected to it. The photodiode circuit comprises at least a photodiode. Once the type of photodiode circuit has been identified by applying a current to it and evaluating a voltage occuring at an input of the detection circuit the photodetection circuit adapts itself to it, e.g. a reverse biasing voltage is/isn't applied to the photodiode of the photodiode circuit. The result is a photodiode detection circuit which uses a forward or a reversed biased photodiode. The photodiode detection circuit is now in a state to measure light falling on the photodiode. The detection circuit may be part of a light intensity monitoring and controlling circuit which allows to regulate the intensity of a laser beam in an optical disk reading/recording device.

Automatically adapting forward or reversed biased photodiode detection circuit

An integrated control circuit forms a driver stage of an output transistor of a switch mode power supply. During a start-up interval of a run mode operation, the control circuit does not consume supply current and does not produce a switching control signal for switching the transistor. During an initialization interval that follows the start-up interval, a reference voltage source that is included in the control circuit is turned on and internal conditions in the control circuit are defined. The switching control signal is generated following the initialization interval.

Start-up circuit for a switch mode power supply

A frequency compensated circuit includes a frequency compensation component and a negative feedback loop for feeding an output signal to the circuit input terminal. The circuit input terminal also receives a compensation signal from the frequency compensation component. A controlled system provides an output signal to the input terminal. A controlled current is supplied to the controlled system to increase the output voltage and the compensation signal from the compensation component can be substantially lower than it is in the prior art type of systems.

Frequency response-compensated circuit

A method of controlling the switching transistor in the switch mode power supply of a television receiver includes the steps of selectively operating the transistor in a stand-by state, a start-up state and an ON-state. During the stand-by state the switching transistor is rendered conductive by applying bursts of pulses at a frequency above, and unsynchronized with, the line frequency of the television receiver. The pulses are separated by changing intervals. During the start-up state the frequency of said bursts of the pulses is continuously reduced and pulses and the duration of the on time of the transistor is determined using a regulation voltage. During the ON-state, line synchronizing pulses are applied and the switching transistor is regulated to the line frequency.

Switch mode power supply for a television receiver and method of

A scanning circuit which utilizes blanking pulses between flyback pulses in a display device includes a line blanking circuit which prevents the generation of spurious blanking pulses by ringing in the blanking pulses. The line blanking circuit includes a capacitor for storing a reference voltage. A comparator is responsive to the reference voltage and to the flyback pulses and provides the blanking pulses when the flyback pulses exceed the reference voltage. The comparator is prevented from resetting for a preselected time period after the falling edge of the blanking pulse and spurious blanking pulses can not be generated during the preselected time period.

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Villingen-Schwenningen, Germany

Steffen Lehr