JPH0370776B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an artificial light source device, and particularly to a solar simulator (simulated sunlight irradiation device). Artificial light source devices, especially solar simulators, reproduce standard natural sunlight at all times in factories and laboratories without being affected by changes in weather or seasons.

Such solar simulators have recently come into widespread use for the development and quality control of solar cells and heat collection equipment for obtaining energy for air conditioning and heating from natural sunlight.

One of the important optical properties required for a solar simulator is that its spectral distribution should be as close as possible to natural sunlight (relative radiant energy distribution), from the ultraviolet region to the visible and infrared regions. One example is that it has the following.

Natural sunlight on the ground generally has a spectral distribution as shown in Figure 1A.
Are known. In FIG. 1, the horizontal axis represents wavelength (unit: nanometers = nm), and the vertical axis represents relative intensity of radiant energy.

By the way, xenon lamps and halogen lamps are generally used as light sources for solar simulators. The continuous emission spectrum distribution of a xenon lamp is shown in FIG. As is clear from the comparison between waveforms A and B in Figure 1, the emission spectrum distribution of a xenon lamp is significantly different from that of natural sunlight on the ground.

Therefore, in order to bring the emission spectral distribution of a xenon lamp closer to the spectral distribution of natural sunlight on the ground, a filter with characteristics as shown in FIG. 1C is required.

An example of a conventional solar simulator equipped with a spectral distribution correction filter necessary for this purpose is shown in FIG. In the same figure, 1a, 1b,
1c is a xenon lamp as a unit light source, 2a, 2b, and 2c are reflecting mirrors (parabolic mirrors, etc.) provided behind the corresponding unit light sources, respectively.
3 is an integral optical system (or Drude optical system).

The light emitted from each unit light source 1a to 1c is reflected by the corresponding reflecting mirror 2a to 2c, and
The light is focused on the integrating optical system 3. Light emitted from the integrating optical system 3 is projected onto the irradiated surface 4. In this way, there is no unevenness in illuminance on the irradiated surface 4.
In addition, light with good parallelism can be obtained.

5 is a spectral distribution correction filter placed in front of the integrating optical system 3. As mentioned above, this correction filter 5 is required to have transmission characteristics as shown in FIG. 1C.

As the spectral distribution correction filter 5, a multilayer vapor deposited thin film type interference filter is widely used. By the way, the transmission characteristics of this filter are from 800nm to 950nm, as is clear from C in Figure 1.
It is necessary to exhibit a steep slope within the range of m.

However, with current filter manufacturing technology,
It is almost impossible to manufacture a filter with transmission characteristics (hereinafter referred to as spectral characteristics) as shown in FIG. 1C with high precision and sufficient reproducibility. For this reason, a correction filter having spectral characteristics within permissible tolerances has the drawback of being extremely expensive.

In addition, if you try to lower the price by increasing the tolerance, the dispersion of the spectral characteristics will increase, and by replacing the correction filter, the spectral characteristics of the solar simulator will exceed the permissible limit. The disadvantage was that it was easy to disperse.

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned drawbacks of the prior art and to provide an artificial light source device that uses a correction filter with a large tolerance and whose spectral characteristics do not exceed the tolerance limit. shall be.

To achieve the above object, in the present invention, the light emission of each of a plurality of unit light sources, including unit light sources whose continuous emission spectral distribution is different from other lamps, such as an incandescent lamp versus a xenon lamp, is substantially controlled. By irradiating the entire upper illuminated surface and equipping at least one of the plurality of light sources with a spectral correction filter on a one-to-one basis, the total amount of light emitted from each unit light source is All of the plurality of unit light sources and filters are selected in relation to each other so that the resulting overall continuous spectral distribution on the irradiated surface becomes desired.

Next, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a schematic configuration diagram showing an embodiment of the present invention. In the figure, the same reference numerals as in FIG. 2 represent the same or equivalent parts.

In the figure, unit light sources 1a to 1c are rare gas high pressure discharge lamps such as xenon lamps, argon lamps, and krypton lamps, or incandescent lamps. The unit light sources 1a to 1c are not all the same lamp, but at least one has a different spectral distribution from the other lamps. In this embodiment, the light sources 1a and 1b were xenon lamps, and the light source 1c was an incandescent lamp. 3a, 3b,
3c is an integrating optical system provided corresponding to the unit light sources 1a, 1b, and 1c, and projects the light emitted from each unit light source onto substantially the same range on the irradiated surface 4.

5a, 5b, 5c are respective unit light sources 1
This is a correction filter attached to the integrating optical system corresponding to a, 1b, and 1c. The respective correction filters 5a to 5c are selected so that the total emission spectrum of the light emitted from the light sources 1a to 1c has a desired distribution on the irradiated surface.

For example, when the desired spectral distribution is that of natural sunlight, the correction filters 5a and 5 corresponding to the light sources 1a and 1b are
b has spectral characteristics for removing components with longer wavelengths than near-infrared components from the light emitting components of the xenon lamp. On the other hand, the correction filter 5c corresponding to the light source 1c has spectral characteristics for removing visible light and ultraviolet components from the light emitting components of the incandescent lamp.

By passing through each of the correction filters 5a to 5c having such spectral characteristics,
The spectral distribution of light on the irradiated surface can be approximated to that of natural sunlight.

In this example, one of the plurality of light sources was used as another light source, that is, an incandescent lamp with an emission spectrum distribution different from that of a xenon lamp, so as described above, a correction filter having simple spectral characteristics was used. Therefore, the irradiated surface can be irradiated with light with almost the same spectral distribution as when using an ideal filter having complicated spectral characteristics as shown in FIG. 1C.

As is not clear from the above description, according to the present invention, a correction filter having simple spectral characteristics and a correction filter that could not be used in the prior art due to deviations from the specifications are used to compensate for natural sunlight. It is possible to obtain irradiation light that approximates light. Therefore, the cost of the correction filter can be significantly reduced, and accordingly, the cost of the solar simulator can be reduced and maintenance can be made easier.

Furthermore, although the above describes an example in which the present invention is applied to an artificial light source device for use in a solar simulator, it can also be applied to other general artificial light source devices, such as a light source device for artificially growing plants. It will be clear that the invention is applicable.

[Brief explanation of drawings]

Fig. 1 is a spectral spectral curve diagram for explaining the characteristics of a correction filter, Fig. 2 is a schematic diagram of a conventional solar simulator, and Fig. 3 is a schematic diagram of an embodiment of the present invention. . 1a-1c... unit light source, 2a-2c... reflecting mirror, 3a-3c... integrating optical system, 4... irradiated surface, 5a-5c... correction filter.

Claims (1)

[Claims] 1. A plurality of unit light sources including at least one unit light source whose continuous emission spectral distribution is different from that of other unit light sources; and light from each unit light source is applied to substantially the entire illuminated surface. In order to project uniformly, an optical system is provided for each of the unit light sources, and a spectrum correction filter is provided for at least one of the plurality of unit light sources in a one-to-one correspondence, The combination of the emission spectrum distribution of each unit light source and the transmission characteristics of the spectrum correction filter is such that all of the plurality of unit light sources and filters are mutually combined so that the overall continuous spectrum of light on the irradiated surface is corrected to a desired distribution. An artificial light source device selected in relation to.