Abstract:
The present invention relates to a bidirectional semiconductor switch (M1, M2) with extremely low control power consumption and a bootstrap circuit which allows reliable start of operation of the switch and the hosting device after unlimited duration of mains interruptions. Intelligent control options are provided by operating from a small energy storage and no extra means are required to recover from a depleted energy storage condition. The absence of audible noise and mechanical wear also enables more frequent recharging cycles and allows smaller and thus cheaper energy storage components.
Abstract:
An LED lamp(1) is provided, having at least one LED unit (4) arranged in a housing(2),a first (5, 5', 5'', 5''') and a second (6) lamp cap being arranged spaced from each other on opposing ends of the housing(2),said lamp caps (5, 5', 5'', 5''', 6) each comprising at least one contact element for connecting said LED unit (4) with a lamp fixture. To enhance the safety of the LED lamp (1) during removal of the lamp (1) from the fixture, said first lamp cap (5, 5', 5'', 5''') comprises contact breaking means(40, 40', 40''), configured to electrically disconnect said contact elements of said first(5, 5', 5'', 5''')and second (6) lamp caps from each other when said LED lamp (1) is removed from said lamp fixture.
Abstract:
Driver circuits (1) for driving load circuits (2) comprising first and second light circuits (21-22, 71-72) are in first / second modes for input voltages having first / second voltage amplitudes, the second voltage amplitudes being larger than the first voltage amplitudes. The first light circuits (21, 71) are on in the first and second modes. The second light circuits (22, 72) are off in the first modes and are on in the second modes. A control circuit (31-34, 41, 42, 81-84, 101, 121-130) controls amplitudes of currents flowing through at least the first light circuit (21, 71) in dependence of the modes to extend control. These currents may get smaller current amplitudes in higher modes. Light outputs of the first light circuit (21, 71) may get smaller in higher modes. A total light output of all light circuits (21- 22, 71-72) may remain substantially constant during all modes.
Abstract:
Bleeder circuits (1) for combinations of phase cutting dimmers (2) and light emitting diode circuits (3) comprise active circuitry (4) to increase a number of options. The active circuitry (4) may comprise a current limiting circuit (5) for limiting a current flowing through the bleeder circuit (1). The active circuitry (4) may comprise a voltage detecting circuit (6) for activating or deactivating,in response to a detection result,the current limiting circuit (5) and may comprise control circuitry such as a micro processor circuit (7) for controlling the current limiting circuit (5) and may comprise a control circuit (9) for using information derived from a current flowing through the light emitting diode circuit (3) for controlling the current limiting circuit (5) and for controlling at least a part of the light emitting diode circuit (3) that comprises anti- parallel light emitting diodes (31-32) or serial and/or parallel light emitting diodes (33- 36).
Abstract:
A disconnecting circuit (SW1, RS, COM, CO) for a power converter (1) supplies power to a load device (LO; 2). The disconnecting circuit (SW1, RS, COM, CO) comprises a switch (SW1) arranged in series with the power converter (1) to disconnect a supply of power to the load device (LO, 2). A sense circuit (RS) supplies a sensed value indicating an operation mode of the load device (LO, 2). A controller (CO, COM) receives the sensed value to control the switch (SW1) to disconnect the supply of the power from the load device (LO, 2) when the sensed value drops below a reference level indicating a standby mode of the load device (LO, 2).
Abstract:
An ignition unit (3) for igniting a discharge lamp (1), especially a high intensity discharge (HID) lamp or an ultra high intensity discharge (UHP) lamp, and a switch unit, which especially can be manually operated by a user, for switching on a discharge lamp is disclosed. Furthermore, a circuit arrangement for operating such a discharge lamp (1) comprising a lamp driver (21) and an ignition unit (3), and a discharge lamp unit comprising a discharge lamp (1) or lamp burner, preferably a reflector and such a circuit arrangement is described, which advantageously can be used due to a small volume and a small weight for example in ultra bright torches like Ujoy® torches or Ujoy® lamps or Ujoy® projection systems.
Abstract:
The invention describes an image projection method, which method comprises the steps of displaying a micro-image in a liquid crystal display element (1, 1'), which liquid crystal display element (1, 1') comprises rows (R1, R2,..., Rj,..., Rm) of pixels (P1, P2,..., Pi,..., Pn) arranged in a two-dimensional array for displaying the micro-image, generating laser light (BR, BG, BB, LR, LG, LB) by means of a laser light source (2RGB, 2R, 2G, 2B), scanning the laser light (BR, BG, BB, LR, LG, LB) to traverse the micro-image on the liquid crystal display element (1, 1') in a line- wise manner to generate an image and projecting the image onto a screen (3). The invention further describes a projection system (10, 10', 10") comprising a liquid crystal display element (1, 1'), which liquid crystal display element (1, 1') comprises rows (R1, R2,..., Rj,..., Rm) of pixels (P1, P2,..., Pi,..., Pn) arranged in a two-dimensional array for displaying a micro-image, a laser light source (2RGB, 2R, 2G, 2B) for generating laser light (BR, BG, BB, LR, LG, LB), a scanning unit (4RGB, 4R, 4G, 4B) for scanning the laser light (BR, BG, BB, LR, LG, LB) to traverse the micro -image on the liquid crystal display element (1, 1') in a line- wise manner to generate an image and a projection optic unit (8) for projecting the image onto a screen (3).
Abstract:
The present invention relates to a method of operating a projection system comprising several solid state light sources (2, 3, 4) of different colour 13, 14, 15) and at least one spatial light modulator (1) having an array of switchable elements. Said array is illuminated by at least one of said light sources (2, 3, 4) for several illumination periods and is addressed such that the light is timely and spatially modulated to project images onto a screen. In the present method said light sources (2, 3, 4) are controlled to emit light modulated in amplitude (15) and/or time (18) during said illumination periods of said array. With the present method an increased greyscale resolution of the projection system can be achieved.
Abstract:
This invention describes a method for driving a gas discharge lamp (1), whereby an alternating voltage (U) is applied to the gas discharge lamp (1), the alternating voltage (U) having a first polarity during a first time interval (tfl, tsl) and a second polarity opposite to the first polarity during a second time interval (tf2, ts2). In this method, the first time interval (tfl) and the second time interval (tf2) are repeated alternately during a first operation mode. During a second operation mode, the electrical power (P) being provided to the gas discharge lamp (1) is smaller compared to the first operation mode, and the first time interval (tsl) and the second time interval (ts2) are repeated alternately, whereby in this second operation mode the duration of the first time interval (tsl) is at least a multiple of the duration of the second time interval (ts2). Furthermore, the invention describes an appropriate driving unit (4) for driving a gas discharge lamp (1), and an image rendering system, particularly a projector system, comprising a gas discharge lamp (1) and such a driving unit (4).
Abstract:
Ignition of a gas discharge lamp 10, which has a gas containing main space and two inner electrodes, of a lighting unit 4 of a lighting system is achieved by the use of a high frequency resonance circuit. The resonance circuit is connected to the inner electrodes and to a supply device 2, which supplies an alternating supply voltage. An outer electrode 22 is arranged near one the inner electrodes and to a node of the resonance circuit. Upon supplying the supply voltage a high voltage alternating burst will be generated at the outer electrode. This will result into a discharge of the gas in the main space. In turn, this will induce a discharge of the remaining gas. Then the frequency of the supply voltage will increase and a small reactive current only will remain to flow through the resonance circuit.