JPH02135277A - Fluorescent lamp - Google Patents

Abstract

PURPOSE:To obtain a fluorescent lamp suitable for lighting of show case of food, etc., suppressing chromatic divergence caused by deterioration of blue by adding a fluorescent substance component such as bluish green europium activated strontium borophosphate to each component of red, green and blue fluorescent substances. CONSTITUTION:The aimed fluorescent lamp equipped with a fluorescent substance layer obtained by further blending each component of red, green and blue fluorescent substances with a fluorescent substance component such as bluish green europium activated strontium borophosphate or a fluorescent substance component showing an approximately blue color.

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a fluorescent lamp consisting of three narrow wavelengths (red, green, and blue), and is particularly suitable for illuminating showcases for selling food. 9 (b) Conventional technology In showcases where foods such as meat, fish, vegetables, fruits, etc. are displayed and sold chilled, lighting is used on the tops and shelves of the showcases to create a display effect. has been done. A fluorescent lamp is generally used as this light source. These fluorescent lamps come in various colors, generally daylight (D) and daylight white (
N), white (W), and warm white (W W ), but daylight color is not used because it is pale and makes the color of the meat look bad. The warm white color has become dark and is also not used.

The showcase lamps currently in use are daylight white N.
There are many color temperature ranges of white and W.

On the other hand, there is a color rendering index Ra that indicates how similar the appearance of an object is when viewed under sunlight due to the light emitted from a fluorescent lamp.When considered from the perspective of this color rendering index Ra, a showcase lamp uses one with a high rating of Ra92-95. In addition, special lamps that emphasize the red color are also used for meat only, in response to the desire to emphasize the red color of meat, but when the red color is produced, the luminous flux of the lamp decreases, making the lamp dark. There is.

Incidentally, in recent years, narrow wavelength lamps of three wavelengths (blue, green, and red) have been widely used, mainly for home use, in place of the conventional wide wavelength lamps.

And, this kind of three-wavelength lamp was developed in 1983 and +679.
6. ．． As shown in the publications of No. 16798, improvements in phosphor materials have made it possible to obtain fluorescent lamps with high color rendering and excellent luminous efficiency. It has become.

(c) Problems to be solved by the invention However, although this lamp is effective for general households as it has increased opening and brightness, when used, it causes problems such as blue, green, and red, which will be explained later. The disadvantage is that the blue deteriorates rapidly, and as the blue deteriorates, the overall color becomes yellowish. When this yellow color appears, food, especially meat, has the disadvantage that the color of the meat turns yellow and looks very bad.

The present invention has been developed by focusing on the above points, and utilizes the superiority of luminance and brightness of a three-wavelength narrow-band lamp, and furthermore, it is a fluorescent lamp designed to minimize color shift due to blue deterioration. The purpose is to provide lamps.

(d) Means for Solving the Problems The fluorescent lamp according to the present invention includes a blue-green fluorescent material such as europium-activated strontium borophosphate in each of the red, red, and blue phosphor components to suppress deterioration of the blue color. The phosphor layer is formed by adding a body component and a phosphor component that emits light in the vicinity of blue.

In addition, a fluorescent lamp equipped with this phosphor layer has a color of 9 degrees 50
The light is turned on at a value exceeding 00°K to reduce the appearance of color shift.7Furthermore, among the three wavelength phosphor components, the blue phosphor deteriorates significantly at the beginning, and then becomes stable. Therefore, the ultraviolet 'f, 9= , °K[')j
By using a VR color phosphor that has been stabilized and degraded, it is possible to prevent the meter from deteriorating over the course of one hour.

(E) Effect: Pursuit of phosphor components that are blue-green or similar to the five colors.
Since II can compensate for the deterioration of the blue color, yellowing of the fluorescent lamp color can be suppressed. Therefore, even after long-term use as a product showcase, the color of the products in good condition is maintained, and the display effect is excellent.

When the light is turned on at a color temperature exceeding 5000°K, the yellowing caused by the decrease in the luminous flux of the 17 colors can be made visually difficult to notice. Furthermore, the red, green, and i! Among the phosphor components of t and blue-green, the blue phosphor has been stably degraded by UV irradiation, etc., so that there is almost no effect of blue degradation, and color shift over time can be avoided. This will suppress the

(f) Example Hereinafter, one embodiment of the present invention will be described based on the drawings.

Generally, the luminous flux of a phosphor decreases over time.

The graph shown in Figure 1 shows the deterioration curves of the conventionally used three-wavelength (red, green, blue) phosphor and the blue-green phosphor added as the fourth phosphor of the present invention. show. As can be understood from the figure, the three wavelengths of red, green, and blue all deteriorate over time, but the deterioration of blue is particularly rapid at around 600 to 1000 hours during the cutting stage. After that, the rate of deterioration slows down over time, but ultimately the degree of deterioration is the greatest.

The causes of this blue deterioration are: (1) The glass of the fluorescent lamp deteriorates, making it difficult for blue light with a short wavelength to pass through. (2) Insufficient exhaust inside the lamp causes the oxygen inside to ionize, accelerating the deterioration. ) Deterioration due to ultraviolet rays, etc. is considered.

These problems have been partly prevented by applying a resin coating over the fluorescent paint, but there is no solution to the difference in deterioration of the powder itself. Therefore, considering that the deterioration of the blue color cannot be prevented because there is no substitute for it from a material standpoint and there is currently no way to prevent the deterioration of the blue color, we will reduce the effect of the deterioration of the blue color and do not change the color of the lamp light. A method is needed.

Therefore, by adding a powder that is closest to blue and degrades more slowly than blue, such as a blue-green phosphor powder, to the conventional three-wavelength (red, green, blue) phosphor powder, the conventional three-wavelength, The gist of the present invention is to reduce the effects of deterioration compared to blue, green, and red.

Specific examples will be described below.

First, among the three wavelengths, yttrium oxide phosphor activated with trivalent europium, which is a rare earth phosphor, is used as the red phosphor, and lanthanum phosphate activated with xerium and terbium is used as the green phosphor. A barium magnesium aluminate phosphor activated with europium is used as the blue phosphor. As the first phosphor for these three wavelengths, a strontium borophosphate phosphor activated with europium, which exhibits blue-green color, is used.

The proportions of each of the above phosphors are shown in the table below.

A phosphor made of such a combination is applied to the inner surface of the glass tube of a fluorescent lamp, dried and fired, then both ends of the glass tube are sealed, the inside of the tube is evacuated and mercury and gas are filled, and then the exhaust tube is removed. A fluorescent lamp was completed by sealing the lamp.

Next, this fluorescent lamp and a conventional three-wavelength fluorescent lamp were lit at the rated lamp power, and the relationship between color change and time elapsed was 1.
71 tl, and the graph shown in Figure 2 was created (1'). The figure is a chromaticity diagram showing how much the overall color has shifted due to the deterioration of blue over time, compared to conventional blue and green.

In the diagram (b) showing the red lamp, compared to the initial stage, 6
80ttlr over 0011r, 120011r
, it can be seen that when it comes to 200011r, it deviates to Daifuku. On the other hand, the blue i'f) of the present invention! , green, and red lamps are as shown in the same gravel diagram (A), and after exceeding 60 llr, 80011r, 120011r, 200011
It can be seen that the color shift is stable, with almost no deviation even when the lamp reaches R, and that the color deviation is suppressed as much as possible compared to conventional lamps.

In addition, in the example, it was decided to add a blue-green color close to blue to the conventional blue, green, and red, and europium-activated borosinate was used as the blue-green phosphor. It is not necessary to be limited to this, and the same effect can be produced even if phosphors of other colors near blue are used. Also, three wavelengths (
The phosphors (red, green, blue) are also not limited to the above components.

Furthermore, i? + In the fluorescent lamp of the present invention, which is composed of blue-green, green, and red phosphor components, if the color temperature is set to a high value exceeding 5000 K, the color shift can be made more difficult to notice visually. This is explained using the chromaticity diagram in Figure 3. In the figure, even if a color shift occurs in the range and direction within each oval, it is not recognized as a color shift by the human eye. .A deviation larger than this ellipse appears to the human eye as a color deviation.

The chromaticity points of the three primary colors, red, blue, and green, are indicated by R, B, and G. A Kelvin curve based on a black body is drawn in the center, and the color temperature (in degrees) is displayed above the Kelvin curve. Observing this Kelvin curve, color temperature, and direction of the ellipse,
You can see that when the blue color disappears, the colors of green and red shift toward yellow. For example, color temperature 6000°~7000°
The direction of the ellipse is the same as that of the ellipse (1) for the +3 circle (1), which is in the range of +3, and the ellipse (II), which is in the lower color temperature range of 3,500'K to 4,000'. The shape is more oriented toward yellow than the oval (II). This indicates that at positions where the color temperature is high, the color becomes longer in the direction of yellow, and the range that is invisible to the naked eye even if it shifts to yellow becomes wider. Therefore, in order to make the color shift difficult to visually distinguish, this phosphor has a color temperature of 5000°K.
Setting the value to a high value exceeding 1 is also an effective means of reducing the deviation of one color.

If we pay attention to the blue deterioration curve in FIG. 1 again, we can see that it deteriorates rapidly in a short period of time (from 60011 to +00011r), and thereafter the degree of deterioration weakens and enters a stable state. Therefore, in the blue phosphor, the parts that deteriorate significantly should be degraded with ultraviolet rays, etc. before use, and then used in other colors (red.

By mixing green + t'r green), it is possible to equalize the speed of deterioration and prevent deviation of one color. It can be said that one method more effective in preventing color shift is to provide a means for using the blue phosphor after deterioration and stabilization of the red, green, and blue-green phosphors.

(G) Effects of the Invention As mentioned above, the phosphor of the fluorescent lamp of the present invention has the following properties:
The traditional Ippunami (111 points in terms of brightness and brilliance)
It was created by adding blue-green fluorescent t (or a phosphor component near blue) such as europium-activated strontium borophosphate to each phosphor component of red + tJr record, so this blue-green component, etc. It can prevent the deterioration of the blue color and easily prevent the conventional drawbacks such as yellowish emission color.In addition, this phosphor made of such a combination of phosphor components can be used at a color temperature exceeding 5000°K. Even if the chromaticity is such that blue becomes yellowish due to deterioration of the chromaticity, it is difficult to visually notice the color shift, which is very effective in preventing color shift.In addition, this phosphor is made of In this process, the blue phosphor component used is one that has been stably degraded in advance by ultraviolet rays, etc., and this is mixed with other phosphor components, so the deterioration rate of blue is different from that of other colors. As a result, unlike in the past, only the deterioration of the blue color stands out and its influence becomes strong, causing color shift to appear.Therefore, with this improved three-wavelength lamp, it is suitable for use in food showcases. When used, the color appearance is good and the display effect of foods can be greatly maintained over a long period of time.

[Brief explanation of the drawing]

Fig. 1 shows the luminous flux j of various phosphors over time (Fig. 73
The figure shows the color temperature Ja: 50 rJ in the fluorescent lamp of the present invention.
A chromaticity diagram ratio of 1130, which shows that it is possible to prevent color shift by setting a value higher than OoK (Fig. 1)

Claims (3)

[Claims] (1) In a narrow wavelength fluorescent lamp consisting of three wavelengths of red, green, and blue, each of the red, green, and blue phosphor components includes a phosphor component such as europium-activated strontium borate that exhibits a blue-green color. Alternatively, a fluorescent lamp is provided with a phosphor layer created by adding a phosphor component exhibiting a color near blue. (2) In a narrow wavelength fluorescent lamp consisting of three wavelengths of red, green, and blue, each of the red, green, and blue phosphor components includes a phosphor component such as europium-activated strontium borate that exhibits a blue-green color; 2. The fluorescent lamp according to claim 1, wherein the fluorescent lamp is provided with a phosphor layer made by adding a phosphor component exhibiting a color near blue and is lit at a color temperature exceeding 5000°K. (3) In a narrow wavelength fluorescent lamp consisting of three wavelengths of red, green, and blue, red and green phosphor components and a blue phosphor component that has been degraded in advance by ultraviolet irradiation, etc., exhibit a bluish-green color. 2. The fluorescent lamp according to claim 1, comprising a phosphor layer prepared by mixing a phosphor component such as europium-activated strontium borophosphate or a phosphor component exhibiting a color near blue.