摘要:
The invention describes a method of heating a preform (1) characterized by a radius (R), a material thickness (t), and a material absorption spectrum, which method comprises the steps of selecting, depending on a desired temperature profile, a desired effective absorption coefficient for the preform (1) on the basis of the preform radius (R) and material thickness (t); generating a laser radiation beam (L) comprising radiation with a wavelength spectrum compiled on the basis of absorption coefficients of the absorption spectrum to satisfy the effective absorption coefficient and directing the laser radiation beam (L) at the preform (1) to heat the preform (1). The invention further describes a driving arrangement (7) for controlling a laser radiation generating unit (9) of a preform heating system (10), a preform heating system (10), and a computer program.
摘要:
The invention describes a method of heating a preform (1) characterized by a radius (R), a material thickness (t), and a material absorption spectrum, which method comprises the steps of selecting, depending on a desired temperature profile, a desired effective absorption coefficient for the preform (1) on the basis of the preform radius (R) and material thickness (t); generating a laser radiation beam (L) comprising radiation with a wavelength spectrum compiled on the basis of absorption coefficients of the absorption spectrum to satisfy the effective absorption coefficient and directing the laser radiation beam (L) at the preform (1) to heat the preform (1). The invention further describes a driving arrangement (7) for controlling a laser radiation generating unit (9) of a preform heating system (10), a preform heating system (10), and a computer program.
摘要:
In this method an arc-length control value, indicating the current length of a discharge arc of the gas-discharge lamp (1), is monitored and the lamp (1) is driven in a first operation mode (OMP) with a first current wave-shape when the arc-length control value indicates that the arc-length is higher than a switching threshold, which first current wave-shape is selected to result in a tip (31) growing on an electrode (30) of the lamp (1), and the lamp (1) is driven in a second operation mode (OMn) with a second current wave-shape when the arc-length control value indicates that the arc-length is lower than a switching threshold, which second current wave-shape is selected such that the tip (31) on the electrode (30) is at least partly melted back. In this method an operating frequency of the lamp is switched from a first frequency value (fi) to a second frequency value (f2), which second frequency • (f 2) value is higher than the first frequency value (fi)′, if a first time criterion pertaining to a duration of driving of the lamp (1) in the second operation mode (OMn) is fulfilled and the operating frequency is switched from the second frequency value (f2) to the first frequency value (fi), if a second time criterion pertaining to a duration of driving of the lamp (1) in the first operation mode (OMP) is fulfilled.
摘要:
In this method an arc-length control value, indicating the current length of a discharge arc of the gas-discharge lamp (1), is monitored and the lamp (1) is driven in a first operation mode (OMP) with a first current wave-shape when the arc-length control value indicates that the arc-length is higher than a switching threshold, which first current wave-shape is selected to result in a tip (31) growing on an electrode (30) of the lamp (1), and the lamp (1) is driven in a second operation mode (OMn) with a second current wave-shape when the arc-length control value indicates that the arc-length is lower than a switching threshold, which second current wave-shape is selected such that the tip (31) on the electrode (30) is at least partly melted back. In this method an operating frequency of the lamp is switched from a first frequency value (fi) to a second frequency value (f2), which second frequency • (f 2) value is higher than the first frequency value (fi)′, if a first time criterion pertaining to a duration of driving of the lamp (1) in the second operation mode (OMn) is fulfilled and the operating frequency is switched from the second frequency value (f2) to the first frequency value (fi), if a second time criterion pertaining to a duration of driving of the lamp (1) in the first operation mode (OMP) is fulfilled.
摘要:
A method and a circuit arrangement are described for operating a discharge lamp is described, especially a high-intensity discharge lamp or lamps (HID) or UHP [ultra high performance]-lamp, which is/are distinguished by a first and a second operating phase with a higher first or a lower second frequency of the lamp AC, wherein the operating phases are activated alternatingly at defined intervals and for defined periods of time, in order to achieve a stable arc discharge and only a low burnout or rise in burning voltage of the lamp during its life by configuring certain forms of electrode tips. Furthermore, are described an illumination unit with a discharge lamp and such a circuit arrangement as well as a projection system with a projection display and such an illumination unit.
摘要:
A method and a circuit arrangement operate a discharge lamp, such as a high-intensity discharge lamp (HID) or ultra high performance lamps (UHP). The discharge lamp has first and second operating phases with a higher first or a lower second frequency of the lamp's alternating current (AC). The operating phases are activated alternatively at defined intervals and for defined periods of time, in order to achieve a stable arc discharge and only a low burnout or rise in burning voltage of the lamp during its life by configuring certain forms of electrode tips.
摘要:
The invention describes a method of driving a gas-discharge lamp (1), wherein the lamp (1) is driven at any one time using one of a number of driving schemes, and wherein the lamp (1) is driven at a nominal operating power (Pnom) or at a reduced operating power (Pdim). When the lamp is being driven at the nominal operating power (Pnom), a driving scheme switch-over occurs according to a relationship between a first target voltage (VT1) and the operating voltage of the lamp (1), and, when the lamp is being driven at the reduced operating power (Pdim), a driving scheme switch-over occurs according to a relationship between a second target voltage (VT2) and the operating voltage of the lamp (1), which second target voltage (VT2) is determined on the basis of the reduced operating power (Pdim). The invention further describes a driving unit (10) for driving a gas-discharge lamp (1) according to this method.
摘要:
The invention relates to a lighting unit comprising at least a high-pressure gas discharge lamp, which comprises at least a lamp bulb (1) with a discharge space (21) in which two electrodes (41, 42) are arranged and in which a gas mixture with ingredients capable of condensation is present, wherein a risk of condensation deposit between and/or on the two electrodes (41, 42) exists, and which comprises an ignition device and a unit for local heating (5) of the lamp bulb (1), characterized in that the lighting unit comprises at least one unit for local cooling (6) of the lamp bulb (1).
摘要:
The invention describes a method of shutting down a high pressure discharge lamp (1) in which a pair of electrodes (2) are disposed in an arc tube (3). This method comprises the steps of reducing the lamp power (PA) to a reduced operation level that enables the maintenance of an arc discharge between the electrodes (2) in a transition state from a lighting state to an extinguished state; driving the lamp (1) at the reduced operation level such that that the lamp (1) cools down; monitoring the lamp voltage (U) during this lamp power reduction process and during driving of the lamp (1) at the reduced operation level with regard to a defined discharge process stability criteria and increasing the lamp power (PA) if the discharge process stability criterion is not satisfied; completely shutting down the lamp power (PA) after sufficient duration to allow the lamp (1) to cool down to a state in which the gas pressure is such that the lamp (1) could be reignited shortly after being extinguished. Moreover the invention describes an appropriate driving unit (7) for driving a high pressure discharge lamp (1) and an image rendering system (40), particularly a projector system, comprising such a driving unit (4).
摘要:
The invention describes a heating system (13) for heating a body (1) of a preform having a material thickness bounded by a first surface (2) and a second surface (4). The heating system (13) comprises at least a light source arrangement (12) which is arranged to emit a number of directed light beams (17) and a coupling arrangement (15, 21) realized to deliberately couple light from the light source arrangement (12) in a specific direction into the body (1) during at least a certain minimum period such that the light is essentially guided along a longer path (19) between the first (2) and second surface (4). Furthermore, the invention concerns a method of heating a body (1) of a preform.