JPH01129125A - Evaluator of characteristic of fluorescent lamp - Google Patents

Abstract

PURPOSE:To evaluate the optical color and the color rendering properties of a light source, by comparing a spectral radiation energy in the vicinity of a wavelength 610nm with one in the vicinity of a wavelength 545nm and by clearing up the deviation of the chromaticity point of the light source whose correlation color temperature is within a range of 3,000+ or -200K, from a blackbody track. CONSTITUTION:A light source 1 is a three-wavelength band emission type fluorescent lamp whose correlation color temperature is within a range of 3,000+ or -200K. A photosensing element 3 is constituted by a filter having a spectral transmittivity in the vicinity of a wavelength 545nm and a filter having the spectral transmittivity in the vicinity of a wavelength 610nm. A light transmitted through the photosensing element 3 is converted into an electric signal by a photoelectric conversion element 4. From an output signal of the conversion element 4 a value of R/G is calculated by a divider 5. A value of DUV (degree of deviation of a chromaticity point from a blackbody track) is determined by an R/G-D converter 6 and displayed in a display unit 7. Thereby the optical color and the color rendering properties of the light source 1 are evaluated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to characteristics for evaluating the degree of deviation of the chromaticity point from the blackbody locus of a three-wavelength fluorescent lamp having a correlated color temperature in the range of aooo±200. Use the evaluator.

The degree of deviation of the chromaticity point of a conventional fluorescent lamp from the blackbody locus is generally expressed by the distance between the chromaticity point of the lamp and the blackbody locus on the CIE 1960 UC5 chromaticity diagram. Generally, DU V (Differe
nce of u v Diagram),
This value is determined by the following formula.

D U V = (-1)KX103x((u-uo)
2+ (v-we) 2) ” 5...(1) However,
uo: U coordinate of the reference light source that has the same color temperature as the sample light source U: U coordinate of the sample light source vo: V coordinate of the reference light source that has the same color temperature as the sample light source V: V coordinate of the sample light source If the value of DUV is positive As the DUV value increases in the negative direction, the light color of the light source becomes greenish, and conversely, as the DUV value increases in the negative direction,
It is recognized that the light color of the light source tends to be reddish.

It also means that as the absolute value of DUV increases, the chromaticity point of the light source moves away from the chromaticity point of the reference light source.

Therefore, from the DUV value of a light source, the light color and color rendering properties of that light source can be determined to a certain extent, which is a very useful value.

Conventionally, to find the DUV value of a light source, the xy chromaticity coordinates are calculated from the spectral distribution of the light source, and the uv
It was converted into coordinates and calculated using equation (1).

Problems to be Solved by the Invention As described above, in order to obtain DUV, which is a very useful value for evaluating the light color and color rendering properties of a light source, conventionally the xy chromaticity coordinates have been calculated from the spectral distribution of the light source. This required complicated calculations, such as converting the xy coordinate values into uv coordinates, and then calculating the equation (1).

The present invention has been made in view of the above, and an object of the present invention is to provide a device for determining the DUV value of a three-wavelength fluorescent lamp with a correlated color temperature of a light source in the range of aooo±200 with a simple configuration. It is said that

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a light-emitting fluorescent lamp with a wavelength of 610
Spectral radiation energy near nm and wavelength 545 nm
Clarifying the relationship between the value of the ratio of spectral radiant energy in the vicinity (hereinafter referred to as R/G) and the value of DUV,
This device uses a converter having this characteristic (hereinafter referred to as an R/G-D converter) to determine the DUV value.

According to the above-described configuration, the present invention calculates the DUV value from the ratio of the spectral radiant energy in the vicinity of a wavelength of 610 nm and the spectral radiant energy in the vicinity of a wavelength of 545 nm for a three-wavelength fluorescent lamp having the above-mentioned correlated color temperature range. You can ask for it.

Embodiment FIG. 1 is a block diagram showing an embodiment of a characteristic evaluator for determining the DUV value of a low color temperature three-wavelength emitting fluorescent lamp of the present invention.

In FIG. 1, 1 is a sample light source, 2 is a lens, 3 is a light receiving section, 4 is a photoelectric conversion section, 5 is a divider, 6 is a converter/G-D converter, and 7 is a display section. FIG. 2 is a characteristic diagram of the R/G-D converter. This figure shows the R/G-DUV values revealed as a result of calculating R/G values and DUV values using several three-wavelength fluorescent lamps in the above 1IFJ color viewing temperature range as sample light sources. It is a characteristic diagram.

The operation of the characteristic evaluator for the low color temperature three-wavelength fluorescent lamp of this embodiment constructed as described above will be described below. When the sample light source is a low color temperature three-wavelength fluorescent lamp with a spectral radiant energy distribution as shown in FIG. . Here, the light receiving section 3 has a wavelength of 5
A filter with spectral transmittance near 45 nm (half width 5
nm) and a filter (half-value width of 5 nm) having a spectral transmittance near a wavelength of 610 nm. The light that has passed through the light receiving section 3 is converted into a photoelectric converter 4 at wavelength 5 of the sample light source 1 itself.
Spectral radiant energy and wavelength around 45 nm 61
An electrical signal corresponding to spectral radiation energy near 0 nm is obtained. The R/G value of the output signal from the photoelectric conversion unit 4 is calculated by a divider 5. In the case of a sample light source with a relative spectral energy distribution as shown in Figure 3, R/G
The value of 0.89 is calculated by the divider 5 in the fs1 diagram #! The value of DUV is determined by the R/G-D converter 6 shown in FIG. From FIG. 2 showing the characteristics of the R/G-D converter 6, a DUV value of 10.0 can be read for an R/G value of 0.89, and the DUV value is displayed on the display section 7 in FIG. be done. As a result, it can be seen that the light color of this low color temperature three-wavelength fluorescent lamp is somewhat greenish, and the chromaticity point is somewhat distant from the black body locus.

Effects of the Invention As described above, according to the present invention, with a simple circuit configuration, in the spectral distribution of a three-wavelength fluorescent lamp having a correlated color temperature of 3000±200, a wavelength of 610 nm can be obtained.
From the value of the ratio of the spectral radiant energy in the vicinity of m and the spectral radiant energy in the vicinity of a wavelength of 545 nm, the degree of deviation of the chromaticity point of the light source from the original locus becomes clear, and the light color and color rendering properties of the light source can be evaluated. It is extremely useful in practical terms.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a fluorescent lamp in an embodiment of the present invention, Fig. 2 is a characteristic diagram of an R/G-D converter, and Fig. 3 is a low color temperature 3 wavelength sample light source used in the embodiment. FIG. 3 is a diagram showing the relative spectral energy distribution of an area-emitting fluorescent lamp. 1... Sample light source, 2... Lens, 3... Light receiving section,
4... Photoelectric conversion unit, 5... Divider, 6... R/G
- D converter, 7...Name of display agent Patent attorney Toshio Nakao 1 person/---WipeR brother source 2-1-lens 1 3- Light receiving gear 1 Figure 2 Figure 3 Kumicho (71M)

Claims (1)

[Claims] For a three-wavelength fluorescent lamp with a correlated color temperature in the range of 3000±200K, there is a light receiving section that has a filter that transmits light around a wavelength of 610 nm and a filter that transmits light around a wavelength around 545 nm, and spectroscopy at these wavelengths. A fluorescent lamp characteristic evaluator consisting of a divider that calculates the ratio of radiant energy and a converter that calculates the deviation of the chromaticity point of the sample light source from the blackbody locus from the value of the ratio of spectral radiant energy at these wavelengths. .