JP2008226650A - High pressure discharge lamp device - Google Patents

Abstract

An object of the present invention is to provide a high-pressure discharge lamp device with little flickering and a long life by superimposing current pulses of a magnitude effective against flickering.
A high-pressure discharge lamp device according to the present invention includes a high-pressure discharge lamp having a pair of electrodes at both ends and an arc tube filled with mercury inside, and supplies a lamp current to the high-pressure discharge lamp by a lighting device. In the high pressure discharge lamp device that superimposes the same current pulse as the polarity of the lamp current on the lamp current when it is turned on,
Assuming that the maximum value of the current pulse is A, the unipolar lamp current center value is B, the pulse width of the current pulse is C, and the half cycle of the lamp current is T ₀ ,
1.6 ≦ A / B ≦ 2.0 (1)
4.5% ≦ C / T ₀ ≦ 5.8% (2)
It is characterized by satisfying the relationship.
[Selection] Figure 3

Description

  The present invention relates to a high-pressure discharge lamp device used for a projector device or the like.

  A high-pressure discharge lamp (hereinafter also referred to as a lamp) of a high-pressure discharge lamp device used for a projector device or the like changes in electrode shape due to electrode wear of the arc tube, and an arc spot shift occurs. In general, in the case of an alternating current lighting method, a spot shift every cycle is felt as flickering.

As a countermeasure, a method is adopted in which a superimposed pulse is added to the current waveform for each cycle to increase the temperature at the tip of the electrode to optimize the halogen cycle (see, for example, Patent Document 1).
Japanese National Patent Publication No. 10-501919

  However, in the method of Patent Document 1, a constant current pulse is always generated, which may cause considerable damage to the electrode, rather than optimizing the halogen cycle.

  The present invention has been made to solve the above-described problems, and provides a high-pressure discharge lamp device with less flickering and a longer life by superimposing current pulses having an effective magnitude against flickering. For the purpose.

The high-pressure discharge lamp device according to the present invention includes a high-pressure discharge lamp having a pair of electrodes at both ends and an arc tube in which mercury is enclosed, and the lighting device supplies the lamp current to the high-pressure discharge lamp to light it. In the high-pressure discharge lamp device that superimposes the same current pulse as the polarity of the lamp current on the lamp current,
Assuming that the maximum value of the current pulse is A, the unipolar lamp current center value is B, the pulse width of the current pulse is C, and the half cycle of the lamp current is T ₀ ,
1.6 ≦ A / B ≦ 2.0 (1)
4.5% ≦ C / T ₀ ≦ 5.8% (2)
It is characterized by satisfying the relationship.

  The high-pressure discharge lamp apparatus according to the present invention has less flickering and a longer life because the maximum value of the current pulse, the unipolar lamp current center value, and the pulse width of the current pulse satisfy the expressions (1) and (2). Has the effect of becoming.

Embodiment 1 FIG.
FIGS. 1 to 5 are diagrams showing the first embodiment. FIG. 1 is a side view in which a portion of the high-pressure discharge lamp 10 is broken, FIG. 2 is a sectional view of the arc tube 1, and FIG. 4 is a diagram showing an example of the waveform of the lamp current, FIG. 4 is a diagram showing a life test result of the high-pressure discharge lamp 10, and FIG. 5 is an optimum of the maximum value A of the current pulse / the center value B of the unipolar lamp current and the pulse width C. It is a figure which shows an area | region.

  As shown in FIG. 1, in the high-pressure discharge lamp 10, the arc tube 1 is fixed so that the optical axis coincides with the neck portion 5a of the reflector 5 (concave reflector) having an opening 20 for emitting light forward. Has been. On the outer peripheral surface of the reflector 5, terminals 6a and 6b to which lead wires 4b from the electrodes of the arc tube 1 are connected are arranged. The arc tube 1 is provided with a trigger coil 7 for starting the arc tube 1. A pair of electrodes are provided inside the arc tube 1, and the electrode on the opening 20 side of the reflector 5 is a first electrode 3a, and the electrode on the neck 5a side of the reflector 5 is a second electrode 3b.

  As shown in FIG. 2, the arc tube 1 includes a quartz glass bulb 8 and a sealing portion 2 formed to extend on both sides of the bulb 8. Mercury is sealed inside the bulb 8, and a part of the first electrode 3 a and the second electrode 3 b is sealed with the sealing portion 2. A lead wire 4 a and a lead wire 4 b are drawn out from the sealing portion 2.

  FIG. 3 shows the waveform of the lamp current supplied to the high-pressure discharge lamp 10 by the lighting device. Since the lighting device is the same as the conventional lighting device, description thereof is omitted. In FIG. 3, the horizontal axis represents time, and the vertical axis represents lamp current. A current pulse (sometimes simply referred to as a pulse or a superimposed pulse) is superimposed every half cycle of the rectangular wave lamp current. This optimizes the halogen cycle.

  As shown in FIG. 3, the maximum value of the current pulse is A, the unipolar lamp current center value is B, and the pulse width of the current pulse is C. The pulse width C is the width at the base of the current pulse.

Five 120W high-pressure discharge lamps 10 were extracted and subjected to a life test. The maximum value of the current pulse is A, the unipolar lamp current center value is B, and the pulse width C is a parameter. A / B = 1.8 and the pulse width C were 220 μsec (1 line), 250 μsec (1 line), 280 μsec (2 lines), and 320 μsec (1 line). The lighting frequency is 90 Hz. Therefore, the half cycle of the lamp current is 5.556 msec. The ratio of each pulse width C to the lamp cycle half cycle T ₀ (5.556 msec) is 4.0% for 220 μsec, 4.5% for 250 μsec, 5.0% for 280 μsec, and 5.8% for 320 μsec. .

In the life test, each lamp was lit for a predetermined time, and flickering was observed for several tens of minutes after lighting. The result is shown in FIG. The flicker is expressed by the following equation, where MAX is the maximum value of illuminance (instantaneous value) and MIN is the minimum value.
Flicker = (MAX−MIN) / (MAX + MIN) / 2 (3)

In FIG. 4, the reference value (3%) is an allowable level of flicker. The measurement was performed by observing the flickering of each lamp for a predetermined time at an arbitrary time during the life test. The ratio C / T ₀ (%) of the lamp current with the pulse width C to the half cycle T ₀ is used as a parameter.

In the lamp with C / T ₀ of 4.0%, the flicker greatly exceeds the reference value. Each lamp with C / T ₀ of 4.5 to 5.8% was below the reference value. Thus, it can be seen that flickering may be achieved by setting C / T ₀ to 4.5% or more.

FIG. 5 shows the optimum region for the flickering of the current pulse based on the result of the life test described above. The horizontal axis of FIG. 5 is the maximum current pulse value A / one-polarity lamp current center value B, and the vertical axis is the ratio C / T ₀ of the lamp current with the pulse width C to the half cycle T ₀ . As shown in FIG. 5, the optimum region without flicker is that the maximum value A of current pulse / one-polar lamp current center value B is 1.6 to 2.0, and C / T ₀ is 4.5 to 5.8. %. When C / T ₀ exceeds 5.8%, electrode wear occurs, so the upper limit of C / T ₀ is set to 5.8%.

As described above, according to the present embodiment, the current pulse is superimposed every half cycle of the rectangular wave lamp current, the maximum value of the current pulse is A, the unipolar lamp current center value is B, and the current pulse If the pulse width is C and the half cycle of the lamp current is T ₀ ,
1.6 ≦ A / B ≦ 2.0 (1)
4.5% ≦ C / T ₀ ≦ 5.8% (2)
By satisfying this relationship, the high-pressure discharge lamp 10 with less flickering and a long life can be obtained.

  The life test was performed at a lighting frequency of 90 Hz, but it was confirmed by other life tests that flickering would be reduced if the above equations (1) and (2) were satisfied even at other lighting frequencies. did.

FIG. 4 is a diagram showing the first embodiment, and is a side view in which a part of the high-pressure discharge lamp 10 is broken. FIG. 3 shows the first embodiment and is a cross-sectional view of the arc tube 1. FIG. 3 shows the first embodiment, and shows an example of a waveform of a lamp current supplied to the high-pressure discharge lamp 10. FIG. 5 shows the first embodiment, and shows the life test result of the high-pressure discharge lamp 10. FIG. 5 is a diagram illustrating the first embodiment, and is a diagram illustrating an optimum region of a current pulse maximum value A / unipolar lamp current center value B and a pulse width C;

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Light-emitting tube, 2 Sealing part, 3a 1st electrode, 3b 2nd electrode, 4a lead wire, 4b lead wire, 5 reflector, 5a neck part, 6a terminal, 6b terminal, 7 trigger coil, 8 valve, 10 High pressure discharge lamp, 20 openings.

Claims (1)

A high-pressure discharge lamp having an arc tube in which a pair of electrodes are arranged at both ends and mercury is enclosed therein, and when the lamp current is supplied to the high-pressure discharge lamp by a lighting device to be lit, the polarity of the lamp current In a high-pressure discharge lamp device that superimposes the same current pulse on the lamp current,
When the maximum value of the current pulse is A, the unipolar lamp current center value is B, the pulse width of the current pulse is C, and the half period of the lamp current is T ₀ ,
1.6 ≦ A / B ≦ 2.0 (1)
4.5% ≦ C / T ₀ ≦ 5.8% (2)
A high pressure discharge lamp device characterized by satisfying the following relationship: