JPH01129130A - 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 6,700+ 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 6,700+ 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 transmissivity in the vicinity of a wavelength 610nm. A light passing 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 valve 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 is applicable to three colors having a correlated color temperature in the range of 6700K±200.
A characteristic evaluator is used to evaluate the degree of deviation of the chromaticity point of a wavelength range fluorescent lamp from the blackbody locus.

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 (Differen
ce of u v Diagram ), and this value is determined by the following equation.

DUV=(-1) to JO3X((u-uo) 2+(v
-vo) 2) 0・'---(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: Reference light source that has the same color temperature as the sample light source V coordinate V・: V coordinate of the sample light source When the value of DUV increases in the positive direction, the light color of the light source becomes greenish, and conversely, when the value of DUV 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, in order to obtain the DUV value of a light source, it is obtained from the spectral distribution of the light source by xy color chromaticity coordinate meter calculation, and the UV value is calculated from the Xy coordinate.
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 whose correlated color temperature of the light source is within the range of 6700K±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 an 8-wavelength fluorescent lamp in the above 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 high 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 an R/G-D converter, and 7 is a display section. FIG. 2 is a characteristic diagram of the R/G-D converter. This figure shows R/
As a result of calculating the G value and DUV value, it became clear that R/
G-DUV, characteristic diagram.

The operation of the characteristic evaluator for the high color temperature three-wavelength fluorescent lamp of this embodiment configured as described above will be described below. When the sample light source is a high color temperature three-wavelength fluorescent lamp having a spectral radiant energy distribution as shown in FIG. 8, the light emitted from the sample light source 1 passes through the lens 2 and enters the light receiving section 3. . Here, the light receiving section 3 has a wavelength of 5
Filter with spectral transmittance near 450 m (half width 5
nm) and a filter (half width 5 nm) having a spectral transmittance near a wavelength of 610 nm.

The light that has passed through the light receiving section 3 is passed through the photoelectric conversion section 4, and electrical signals corresponding to the spectral radiant energy of the sample light source 1 itself at a wavelength of around 545 nm and spectral radiant energy around a wavelength of 810 nm are 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 having a relative spectral energy distribution as shown in FIG. 8, an R/G value of 0.41 is calculated by the divider 5 in FIG.

Next, the value of DUV is determined by the R/G-D converter 6 of FIG. From FIG. 2 showing the characteristics of the R/G-D converter 6, a DUV value of 0.0 can be read for an R/G value of 0.41, and the DUV value is displayed on the display section 7 in FIG. be done. This shows that the light color of this high color temperature three-wavelength fluorescent lamp is the same as the light color of a black body having the same color temperature, and that the chromaticity point is on 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 with a correlated color temperature of 6700K±200,
Spectral radiation energy near nm and wavelength 545 nm
The value of the ratio to the spectral radiant energy in the vicinity reveals the degree of deviation of the chromaticity point of the light source from the blackbody locus, which is extremely useful in practical terms for evaluating the light color and color rendering properties of the light source. It is.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a fluorescent lamp characteristic evaluator in an embodiment of the present invention, Fig. 2 is a characteristic diagram of an R/G-D converter, and Fig. 3 is a block diagram of a fluorescent lamp characteristic evaluator in an embodiment of the present invention. color temperature 3
FIG. 3 is a diagram showing a relative spectral energy distribution of a wavelength range 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 Figure 2

Claims (1)

[Claims] For a three-wavelength fluorescent lamp with a correlated color temperature in the range of 6700K±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 of 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. .