JPH0111712Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to a cathode ray tube device for a monochrome display that emits orange to yellow light, and more particularly to a cathode ray tube device for a monochrome display that has a high brightness, low color unevenness, and a long afterglow orange to yellow light emitting phosphor film. In recent years, high-resolution cathode ray tube devices have been desired for use in computer terminal display devices, aircraft control system display devices, etc. that display detailed characters and graphics. The phosphor film of such a high-resolution cathode ray tube device for display needs to be composed of a phosphor with long afterglow property. This is because if the phosphor film of the cathode ray tube device is composed of a phosphor with short afterglow property, flickering occurs on the screen due to the slow scanning speed of the phosphor film. In general, the phosphor that makes up the phosphor film of such a high-resolution display cathode ray tube device has an afterglow time (herein, the time required for the luminance to drop to 10% of the excitation level after excitation is stopped). It is necessary that the short afterglow phosphor (hereinafter referred to as "10% afterglow time") is several tens to hundreds of times longer than the short afterglow phosphor that constitutes the phosphor film of an ordinary cathode ray tube device. Furthermore, as the use of this type of cathode ray tube device as a display has become more widespread, it has become easier to use.
In order to reduce eye fatigue and increase usage efficiency, there is a growing movement to apply ergonomics in this field as well. In view of the above points, cathode ray tube devices for displays are required to have a large number of performances as shown below. (1) No flicker (the fluorescent film has an afterglow time that matches the frame frequency of the cathode ray tube device), (2) Bright (high brightness of the fluorescent surface), (3) Easy to see ( (4) High-resolution display possible (the beam diameter of the cathode ray tube device is sufficiently fine); (5) Contains no pollutants. (Especially in Japan, it is difficult to put it into practical use if it contains pollutants.) (6) Less deterioration (no brightness deterioration of the fluorescent surface or color shift due to this). In particular, cathode ray tube devices for monochrome displays (hereinafter referred to as cathode ray tube devices) that emit orange to yellow light and have high resolution are widely used in these applications because they cause less visual fatigue even when viewed for long periods of time. The inventors of the present invention have studied the above-mentioned cathode ray tube device that emits orange to yellow light in order to satisfy the above-mentioned demands from the aspect of ergonomics. Noting that many of these performances are based on the characteristics of the phosphors used in cathode ray tube devices, we investigated long-lasting orange to yellow-emitting phosphors. As such phosphors, those shown in the "Conventional" column of Table 1 below are known. However, nothing is known that satisfies all of the above-mentioned performances. In general, the most preferred of these (particularly in Japan in terms of cadmium pollution) are the green-emitting manganese-activated zinc silicate phosphor (P39 phosphor) and the red-emitting manganese-activated zinc phosphate phosphor (P27). Mixed fluorescers (fluorescers) are often used. However, this mixed phosphor is
Point A (P39 phosphor) and point B (P27 phosphor) on the chromaticity diagram
Since it is a mixture of phosphors of two colors whose emission colors are significantly different from each other, color unevenness is easily visible when the resolution is set to high. In addition, the afterglow characteristics of each phosphor are curve a (P27 phosphor) and curve b in Figure 2.
(P39 phosphor), and since the afterglow curves are significantly different, in the mixed phosphor, a color shift occurs in the afterglow compared to the emitted light color, which is not preferable. Furthermore, the brightness is insufficient, and the ergonomic requirements mentioned above cannot be satisfied at all. The inventors of the present invention have obtained an improved cathode ray tube device that does not have the drawbacks of the most currently used cathode ray tube device whose phosphor film is a mixture of P39 and P27 phosphors. As a result of our research, we have found that a cathode ray tube device in which a phosphor film is constructed using a new mixed phosphor and is combined with an electron gun or the like that scans a specific cathode ray can satisfy all of the above requirements. This led to the discovery of this idea. The cathode ray tube device of the present invention has a long afterglow red-orange emitting europium-activated indium borate phosphor and a long afterglow green emitting manganese activated zinc silicate phosphor on the face plate facing the electron gun that emits cathode rays. The present invention is characterized in that an orange to yellow emitting phosphor film is formed, the main component of which is a mixed phosphor in which phosphors are mixed in a weight ratio of 1/5 to 99/1. The phosphor film of the cathode ray tube device of the present invention may be formed only from the above-mentioned mixed phosphor that emits orange or yellow light with a long afterglow property, or the emitted light color and afterglow time may be adjusted. It may also be formed from a mixture of small amounts of other phosphors to achieve this. Furthermore, the afterglow time values mentioned in this specification are all values when the current density of the stimulating electron beam emitted from the electron gun is 0.4 μA/cm ² , and the values of afterglow time described in this specification are values when the current density of the stimulating electron beam emitted from the electron gun is 0.4 μA/cm 2 . Since the beam diameter of cathode rays cannot be directly measured, beam diameter is defined as the _diameter of the luminous intensity distribution of the luminescent spot emitted in the just-focus area when the cathode ray beam is irradiated onto the fluorescent surface. , corresponds to the spot diameter (defined at 10% of the peak brightness). The present invention will be explained in detail below. The cathode ray tube part of the cathode ray tube device of the present invention is almost the same as a monochromatic cathode ray tube such as a conventional cathode ray tube for black and white television, except for the electron gun (including the driving performance of the electron gun) and the fluorescent film structure. It is. That is,
In the cathode ray tube device of the present invention, as shown in FIG. 1, an electron gun 3 is provided in a neck portion 2 of a funnel 1, and a fluorescent film 5 is formed on the entire surface of a face plate 4 facing the electron gun 3. Cathode ray tube (generally, an aluminum vapor-deposited film 6 is provided on the back side of the fluorescent film 5 to prevent charge-up during excitation).
and a device for driving the cathode ray tube. Here, the phosphor film 5 is made of a mixed phosphor that emits orange or yellow light with a specific long afterglow, and the electron gun 3 can emit cathode rays with a specific beam diameter and a specific frame frequency. The phosphor film 5 used in the device of the present invention is composed of a long afterglow orange to yellow emitting mixed phosphor, and this mixed phosphor consists of a long afterglow red orange emitting europium-activated indium borate phosphor and Obtained by mixing with a green afterglow-emitting manganese-activated zinc silicate phosphor. The europium-activated indium borate phosphor is a phosphor that has not been put to practical use in the past because its emission color is reddish-orange, which is not commonly used. As a light body, the composition formula is (In _1-x M〓 _x ) BO ₃ :Eu _y Ln _z (However, M〓 is Sc, Y, Gd, Lu, La, Al, In,
At least one of Bi and Ga, Ln is Tb,
At least one of Pr, Sm and Dy, and
x, y and z are 0≦x≦0.3, 0.002≦y, respectively
A europium-activated indium borate phosphor (hereinafter simply referred to as a borate phosphor), which satisfies the following conditions: ≦0.2, 0≦z≦0.001, is preferred from the viewpoint of brightness and afterglow characteristics. On the other hand, the long-afterglow green-emitting manganese-activated zinc silicate-based phosphor is a phosphor that has been widely used as a green-emitting component phosphor in conventional cathode ray tubes for displays, as described above, and is particularly suitable for the present invention. The _{compositional formula} of _{the phosphor} used in
A manganese-activated zinc silicate-based phosphor (hereinafter abbreviated as silicate phosphor), which satisfies the condition (≦b≦0.01), is preferable from the viewpoint of brightness, afterglow characteristics, and the like. The silicate phosphor may contain a trace amount of arsenic. The arsenic content at this time is limited to 0.0002 mol or less based on the phosphor matrix from the viewpoint of afterglow characteristics and pollution (however, if strict pollution-free is desired, it is recommended to exclude arsenic) ). Furthermore, in the silicate phosphor, part of the Zn is replaced by Mg,
Ba may be substituted, and a portion of Si may be substituted with Ge. The afterglow characteristics of the borate phosphor and silicate phosphor are as shown in curves d and c in Figure 2, and the afterglow characteristics of the conventional P27 phosphor (curve a) and P39 phosphor (curve Although the afterglow time is shorter than in b), the afterglow completely disappears in about 60 milliseconds, so the image is sharp without unnecessary afterglow tails. Moreover, all of these phosphors have similar afterglow characteristics, and no color shift in the afterglow is visually observed. It also has the characteristic that no color shift occurs in the afterglow characteristics no matter what mixing ratio is selected. Third
In the CIE chromaticity coordinates shown in the figure, a mixed phosphor of a borate phosphor (point C) and a silicate phosphor (point A) is a mixture of emitted light colors on a straight line connecting points C and A. It can be freely selected depending on the ratio. However, in view of color unevenness due to unevenness of the mixing ratio and color reproduction, in the present invention, the mixing ratio K = borate phosphor weight/silicate phosphor weight is set in the range of 1/5 to 99/1. A range of 1/4 to 19/1 is particularly preferred. As is clear from Figure 3, the mixed phosphor of the present invention has better color purity than the conventional mixed phosphor (P27 phosphor and P39 phosphor) no matter which mixing ratio is selected. Also, since points A and C are close, there is little color unevenness.
Furthermore, what is noteworthy about the mixed phosphor of the present invention is that its luminance is 1.5 to 2 times higher than that of the conventional mixed phosphor, which has an emission color closest to that of the mixed phosphor. Furthermore, both of the two types of phosphors constituting this mixed phosphor show little deterioration in brightness even after long-term aging, and therefore almost no color shift occurs in the mixed phosphor. Table 1 shows the evaluation of the characteristics of the mixed phosphor of the present invention as described above, together with the evaluation of the characteristics of the conventional phosphor.

【table】

[Table] In the device of this invention, the above mixed phosphor
ZnS:CuAl, ZnS:CuAlGa, ZnS:AuAl,
ZnS:AuAlGa, ZnS:CuAuAl, ZnS:CuCl,
Ln ₂ O ₂ S: Eu or Tb (Ln is at least one of La, Y, Gd and Lu; the same applies hereinafter), Ln ₂ O ₃ : Eu,
The characteristics can also be improved by mixing LnVO ₄ :Eu, Ln ₂ O ₃ :EuDy, P27, P13, P25, etc. Furthermore,
Mixed phosphor contains Y ₂ SiO ₅ :Ce, Y ₃ Al ₅ O ₁₂ : Ce, Y ₃
(AlGa) ₅ O ₁₂ :Ce, YAlO ₃ :Ce, ZnO:Zn, etc. can be mixed to improve the sensitivity to a light pen. In cathode ray tube devices for displays, it is necessary to irradiate cathode rays with a small beam diameter onto a fluorescent surface in order to improve resolution. In this case, it is necessary to apply cathode rays to each spot for a certain period of time in order to impart sufficient excitation energy to each spot. Therefore, in order to obtain high resolution and sufficient brightness, the frame frequency must be lowered. For this reason, the phosphor is required to have a certain afterglow characteristic, and it is desirable that the phosphor has sufficient brightness without causing color shift or the like. The device of the present invention can obtain better image quality than conventional devices during cathode ray irradiation.In other words, the device of the present invention not only has the above-mentioned phosphor film, but also has a phosphorescent film as described above. As a cathode ray, the beam diameter at the fluorescent surface is 0.05 to 0.4
It is recommended that a specific cathode ray with a frame frequency of 25-50 Hz in mm be used. In addition, in the device of the present invention, particularly good effects can be obtained when the frame frequency is 30 to 50 Hz. That is, according to the cathode ray tube device of the present invention, due to the combination of the specified scanning cathode ray and the specified fluorescent film, flicker is reduced compared to the conventional device, as shown in the column “Invention” in Table 1. It is possible to obtain a screen that is 1.5 to 2 times brighter than the conventional one and an image that emits orange to yellow light that is easy to see, resulting in a high-resolution display that is pollution-free and has little deterioration. As described above, the cathode ray tube device of the present invention uses a good fluorescent surface and specific cathode ray scanning to obtain images that are high in brightness and exhibit orange to yellow light emission that fully satisfies ergonomic conditions, and is suitable for industrial use. Its utility value is extremely high. Next, the present invention will be explained by way of examples. Example 1 Borate phosphor (InBO ₃ :Eu) surface treated with at least one surface treatment agent of silicates, phosphates, zinc hydroxide or aluminates (average particle size 7μ)
91g of silicate phosphor (Zn ₂ SiO ₄ :Mn,Sb) (average particle size 7μ) was added with a solvent, etc., and the slurry of the mixed phosphor obtained by thorough mixing was applied using the well-known sedimentation coating method. A fluorescent film was formed on the inner surface of the face plate, and then a cathode ray tube was manufactured through various steps such as filming and metal backing, and a scanning circuit for an electron gun was added to form a cathode ray tube device. Various characteristics of the fluorescent surface of this cathode ray tube device were measured by varying the beam diameter and frame frequency of the cathode rays emitted from the electron gun on the fluorescent surface, and as a result, good images were obtained. The chromaticity point of this image is (x, y) =
(0.556, 0.432) (point D in Figure 3) good orange emission (note that the emission spectrum at this time is
) shown in the figure. In addition, the luminance of the tube surface is twice as bright as that of a conventional cathode ray tube device, which has a chromaticity point closest to point D (the phosphor film is a mixture of P39 and P27 phosphors). . Furthermore, the afterglow time of the fluorescent surface is
It took 25 milliseconds. Furthermore, as a result of long-term aging of this cathode ray tube device, there was little deterioration in the brightness of the fluorescent surface and almost no color shift. Example 2 Borate phosphor (InBO ₃ :Eu) (average particle size 7.5μ)
80g and silicate phosphor (Zn ₂ SiO ₄ :Mn,As,Sb:
However, As is 1×10 ^-4 gatom/mole) (average particle size
A cathode ray tube device was manufactured in the same manner as in Example 1 except that 20 g of 7.5μ) was used. This cathode ray tube device showed good images. The chromaticity point of this image is (x,
y) = (0.503, 0.475) (point E in Figure 3) showed good yellow-orange luminescence. Furthermore, compared to the conventional cathode ray tube device having a chromaticity point closest to point E, the luminance of the tube surface was twice as bright. The afterglow time of the fluorescent surface was 25 milliseconds. Furthermore, as a result of long-term aging of this cathode ray tube device, there was little deterioration in the brightness of the fluorescent surface and there was almost no color shift. Example 3 70 g of borate phosphor [(In _0.9 Sc _0.1 )BO ₃ :Eu] (average particle size 8μ) and silicate phosphor (Zn ₂ SiO ₄ :Mn)
A cathode ray tube device was manufactured in the same manner as in Example 1 except that 30 g (average particle size: 8 μ) was used. This cathode ray tube device showed good images. The chromaticity point of this image is (x, y) = (0.457, 0.511) (point F in Figure 3), which showed good orange-yellow luminescence. In addition, compared to the conventional cathode ray tube device having a chromaticity point closest to point F, the luminance of the tube surface was 1.5 times brighter. The afterglow time of the fluorescent surface was 30 milliseconds. Furthermore, as a result of long-term aging of this cathode ray tube, there was little deterioration in the brightness of the fluorescent surface, and there was almost no color shift.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of the device of the present invention;
The figure is a graph of relative luminescence intensity, and Figure 3 is a graph of CIE
This is a chromaticity diagram, and FIG. 4 is a graph of relative luminance.

Claims (1)

[Scope of utility model registration request] On the face plate facing the electron gun that emits cathode rays, a long-afterglow red-orange-emitting europium-activated indium borate-based phosphor and a long-afterglow green-emitting manganese-activated zinc silicate-based phosphor are placed in weight ratios. A cathode ray tube device for a monochrome display, characterized in that an orange to yellow emitting phosphor film is formed mainly of a mixed phosphor mixed in a ratio of 1/5 to 99/1.