JP4893446B2 - Light measuring method and lighting apparatus for discharge lamp - Google Patents

Description

  The present invention relates to an optical measurement method for a discharge lamp and a lighting fixture to which the optical measurement method is applied.

  Conventionally, as a method for measuring the cumulative lighting time and deterioration of a discharge lamp, a method of measuring from the light output value of the discharge lamp is known. As a light measurement method for measuring the light output of the discharge lamp, a method of directly measuring the light output of the discharge lamp using a light output sensor or a method of using reflected light is used. In these optical measurement methods, it can be used to some extent in a fluorescent lamp with a relatively small amount of light and a relatively low temperature of the discharge lamp, but in a high-intensity discharge lamp with a large amount of light emission and a high temperature of the discharge lamp. It is difficult to use these methods.

  Moreover, in a high-intensity discharge lamp, there is an optical measurement method for detecting while avoiding a high temperature by attaching a sensor to a reflection plate and detecting the light quantity of the entire discharge lamp (for example, see Patent Document 1).

However, in the light measurement method as shown in Patent Document 1, it is possible to measure the light quantity of the entire discharge lamp. Therefore, it is difficult to measure the cumulative lighting time and deterioration of a discharge lamp from the amount of light only by measuring the amount of light at the initial time or during use.
JP 2004-213955 A

  The present invention has been made to solve the above-described conventional problems, and an optical measurement method capable of easily measuring the cumulative lighting time and the degree of deterioration of a discharge lamp, and the optical measurement method are applied. It aims at providing a lighting fixture.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided an optical measuring method for a discharge lamp in which electrodes are arranged at an upper part and a lower part in a discharge tube, and a straight line connecting these electrodes is substantially vertical. , Two measurement points of light output are installed, one of which is for the upper part or the lower part of the electrode, and the other one is for the substantially central part of the two electrodes. is there.

  According to a second aspect of the present invention, in the light measurement method for a discharge lamp according to the first aspect, a ratio of both measurement values at the measurement points of the two light outputs is calculated, and the calculation result is calculated as a lighting time of the discharge lamp or This is converted into deterioration.

  A third aspect of the present invention is the discharge lamp optical measurement method according to the first or second aspect, wherein the discharge lamp is a high-intensity discharge lamp.

  According to a fourth aspect of the present invention, there is provided a lighting apparatus using a discharge lamp in which electrodes are disposed at an upper part and a lower part in a discharge tube, and a straight line connecting the two electrodes is substantially vertical. The measurement is carried out by the photodetection sensor, one of which is for the upper or lower part of the electrode and the other one is for the substantially central part of the electrodes. By calculating a value, it is provided with a calculation means for converting into the lighting time or deterioration of the discharge lamp.

  A fifth aspect of the present invention is the lighting fixture according to the fourth aspect of the present invention, further comprising a reflecting plate that is disposed to face the discharge lamp and provided with a plurality of openings, The measurement is made through the opening.

  According to the first aspect of the present invention, since the degree of deterioration of the light output due to the cumulative lighting time differs for each part of the discharge lamp, by measuring the light output at two measurement points, The degree of deterioration can be determined.

  According to the invention of claim 2, it is possible to easily determine the cumulative lighting time or the degree of deterioration of the discharge lamp from the ratio of the measured values.

  According to the invention of claim 3, by applying to a high-intensity discharge lamp, it is possible to perform measurement with a high-output discharge lamp, which could not be determined conventionally.

  According to the invention of claim 4, it is possible to determine the cumulative lighting time or the degree of deterioration of the discharge lamp in the actually installed lighting fixture.

  According to the invention of claim 5, the optical output measurement at a plurality of measurement points can be easily performed.

  An optical measurement method according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 shows a configuration of a lighting fixture to which an optical measurement method is applied. The luminaire 1 includes a discharge lamp 2 having a discharge tube 3 and a base 4, a reflection plate 5 that covers the discharge tube 3 and reflects light from the discharge tube 3 to an irradiation area, and a socket 6 that supplies power to the base 4. And a light detection sensor 7 for detecting the light output of the discharge tube 3. The lighting fixture 1 controls the lighting circuit 81 and the display unit 82 based on the detection circuit from the lighting circuit 81 for lighting the discharge lamp 2, the display unit 82 for displaying the lighting status of the discharge lamp 2, and the light detection sensor 7. And a power supply circuit 84 that supplies power to the lighting circuit 81 and the like. The discharge lamp 2 is a high-intensity discharge lamp, for example. The discharge lamp 2 is installed such that a straight line connecting the upper electrode 32a and the lower electrode 32b is substantially vertical.

  The discharge lamp 2 includes an arc tube 31 that emits light. The arc tube 31 is filled with an argon gas containing a luminescent substance such as mercury or sodium, and discharges between the upper electrode 32a installed at the upper part and the lower electrode 32b installed at the lower part to emit light. To do. Nitrogen gas is sealed between the arc tube 31 and the discharge tube 3, and oxidation of the metal portion inside the discharge tube 3 is prevented by the nitrogen gas. The reflecting plate 5 covering the discharge tube 3 is made of, for example, metal or resin, and the inner surface is processed so that light is reflected, and has openings 51 (having a diameter of, for example, several mm) at two locations. A light detection sensor 7 for measuring the light output of the arc tube 31 is installed in each of the openings 51. Thereby, the lighting fixture 1 measures the light output at the two measurement points of the arc tube 31 by the light detection sensor 7.

  That is, one opening 51 which is one of the measurement points is provided at a position corresponding to the upper edge portion 33 of the upper electrode 32a. The light output from the edge portion 33 is indicated by L1. The other opening 51, which is another one of the measurement points, is provided at a position corresponding to the central portion 34 between the two electrodes. The light output from the central portion 34 is indicated by L2. A portion that discharges inside the arc tube 31 is referred to as a plasma portion 35. The photodetection sensor 7 includes a photodetection element such as a photodiode and an amplifier that amplifies a signal detected by the photodetection element. The light detection sensor 7 detects the light outputs L1 and L2 at two measurement points of the upper edge portion 33 of the upper electrode 32a and the central portion 34 through the two openings 51, and sends the detection signals to the control portion 83. Output. The control unit 83 calculates a detection signal from the light detection sensor 7, converts the calculation result into the cumulative lighting time and the degree of deterioration of the discharge lamp 2, and displays the result on, for example, a liquid crystal or an LED included in the display unit 82.

  Next, a description will be given of a method in which the control unit 83 calculates the measured value of the light output of the arc tube 31 and converts it into the cumulative lighting time and the degree of deterioration of the discharge lamp. FIG. 2 shows the relationship between the index of light output ratio at the edge portion 33 and the central portion 34 and the cumulative lighting time. The vertical axis in the figure represents an index when the light output ratio at the time of discharge tube replacement is 1 in the light output ratio obtained by dividing the light output value at the central portion 34 by the light output value at the edge portion 33 (hereinafter referred to as light output). The horizontal axis indicates the cumulative lighting time. The light output ratio index increases from 1 when the discharge tube is replaced at the beginning of lighting, but thereafter monotonously decreases, and the light output ratio index decreases as the cumulative lighting time increases. Therefore, based on the relationship between the cumulative lighting time and the light output ratio index, the light output measurement values at the edge portion 33 and the central portion 34 can be converted into the cumulative lighting time and the degree of deterioration.

  The relationship between the cumulative lighting time and the light output ratio index is considered as follows. When the arc tube 31 continues to be lit, a luminescent material such as metal enclosed in the arc tube 31 becomes a blackened material and adheres to the inner surface of the arc tube 31. The blackened material does not adhere so much to the inner surface in the vicinity of the plasma portion 35, and adheres more to the inner surface of the edge portion 33. The adhering blackened material absorbs infrared rays to generate heat, and the generated heat is conducted to the entire arc tube 31 and the temperature of the edge portion 33 also rises. When the temperature of the edge portion 33 rises, the edge portion 33 emits light by the black body radiation of alumina that is the material of the arc tube 31. And since the light output L1 from the edge part 33 is based on black body radiation, the cumulative lighting time of the discharge lamp 2 becomes long, blackening increases, and it increases as temperature rises. On the other hand, in the central portion 34, even if blackened material adheres to the inner surface of the arc tube 3, it becomes optically thick and only absorbs light. Therefore, the light output L 2 from the central portion 34 is from the plasma portion 35. Most of this is due to the light emission. Accordingly, the light output L2 from the central portion 34 decreases as the cumulative lighting time of the discharge lamp 2 becomes longer and the discharge lamp 2 deteriorates. The light output ratio index decreases as the cumulative lighting time becomes longer.

  Next, a method for converting the measured value of the light output into the cumulative lighting time or the degree of deterioration of the discharge lamp will be described. When the discharge tube 3 is replaced and lighting is started, the control unit 83 detects the light outputs L1 and L2 of the upper edge portion 33 and the central portion 34 of the upper electrode 32a by the light detection sensor 7, and the light output ratio. And the light output ratio at the start of lighting is set to 1, which is a reference. Thereafter, the light output L1 and L2 are detected by the light detection sensor 7 as needed according to the cumulative lighting time, the light output ratio is calculated, and the index when the light output ratio at the start of lighting is 1 is calculated. Then, the control unit 83 converts the light output ratio index into the accumulated lighting time from the relationship between the predetermined cumulative lighting time and the light output ratio index, and displays it on the display unit 82. Further, when the light output ratio index becomes smaller than a predetermined deterioration standard, the control unit 83 sets the discharge lamp 2 to the dimming state or displays the deterioration on the display unit 82. The reference value for degradation of the light output ratio index is a value such as 0.8, for example, and differs depending on the type of light source used. Thus, by calculating the light output values at the two measurement points of the discharge tube 3, the cumulative lighting time and the degree of deterioration of the discharge lamp 2 can be easily determined.

  Next, a modification of the optical measurement method according to the present embodiment will be described with reference to FIG. FIG. 3 shows a configuration of a lighting fixture according to this modification. In the present modification, unlike the embodiment, one of the openings 51 is provided at a position corresponding to the central portion 34, and the other opening 51 corresponds to the lower edge portion 33 of the lower electrode 32b. In the position. The light output from the edge portion 33 is indicated by L3. The light detection sensor 7 detects light outputs L2 and L3 at two measurement points of the central portion 34 and the lower edge portion 33 of the lower electrode 32b through the two openings 51. The control unit 83 calculates a detection signal from the light detection sensor 7, converts the light output into the cumulative lighting time and the degree of deterioration of the discharge lamp 2, and displays the light output on the display unit 82. The optical measurement method in this modification can obtain the same effects as those of the embodiment.

  In addition, this invention is not restricted to the structure of the said various embodiment, A various deformation | transformation is possible in the range which does not change the meaning of invention. For example, the discharge lamp may be a normal discharge lamp that is not a high-intensity discharge lamp. Alternatively, the light output may be guided from one of the two openings 51 to one light detection sensor by, for example, an optical fiber, and the light output at two places may be measured by time division. Further, even when the discharge lamp 2 is installed so that the straight line connecting the upper electrode 32a and the lower electrode 32b does not become substantially vertical, the measurement may be performed by adjusting the measurement point of the light output. The light output may be calculated based on the difference between the two light outputs.

The block diagram of the lighting fixture which concerns on embodiment of this invention. The related figure of the cumulative lighting time of the discharge lamp which concerns on embodiment of this invention, and a light output ratio index | exponent. The block diagram of the modification of the lighting fixture which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lighting fixture 2 Discharge lamp 3 Discharge tube 32a Upper electrode (electrode)
32b Lower electrode (electrode)
33 Edge (upper part of electrode) (lower part of electrode)
34 Center part 5 Reflecting plate 51 Opening part 7 Light detection sensors L1, L2, L3 Light output

Claims (5)

In the light measurement method of the discharge lamp, electrodes are arranged at the upper and lower parts in the discharge tube, and the straight line connecting these two electrodes is set to be substantially vertical.
Two light output measurement points are installed, one of which is for either the upper part or the lower part of the electrode, and the other is for the substantially central part of the two electrodes. An optical measurement method for a discharge lamp characterized by   2. The optical measurement method for a discharge lamp according to claim 1, wherein a ratio between the two measurement values at the two light output measurement points is calculated, and the calculation result is converted into a lighting time or deterioration of the discharge lamp. .   The said discharge lamp is a high-intensity discharge lamp, The optical measurement method of the discharge lamp of Claim 1 or Claim 2 characterized by the above-mentioned. In the lighting fixture using the discharge lamp, the electrodes are arranged at the upper and lower portions in the discharge tube, and the straight line connecting these two electrodes is set to be substantially vertical.
Two light detection sensors are installed, one of which is for either the upper part or the lower part of the electrode, and the other one is for the substantially central part of the two electrodes.
An illuminating apparatus comprising a calculating means for calculating a measurement value measured by the photodetection sensor to convert it into a lighting time or deterioration of the discharge lamp. A reflector that is disposed opposite the discharge lamp and provided with a plurality of openings;
The lighting apparatus according to claim 4, wherein the light detection sensor measures through the opening.

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