JPH04113788A - Projection type television receiver, crt and color plastic lens used therefor - Google Patents

Abstract

PURPOSE:To prevent the deterioration in the prightness and contrast by employing a colored plastic lens with dye uniformly distributed therein for a lens being part of a projection lens unit and forming a multi-layer interference film to an inner face of a CRT face plate. CONSTITUTION:For example, in the case of a green projection unit, most of the component 11 of a green spectrum is reflected by a multilayer interference film 23, a chromaticity point 12 changes to a point 13 and the brightness is increased by nearly 40%. Then most of the component 10 is absorbed by the colored plastic lens 3a and the brightness is reduced by nearly 20%. Then only the spectrum component 9 is projected on a screen and color aberration is largely improved and the chromaticity point approaches the chromaticity point 14 of the standard television system. Furthermore, the reduction in the brightness due to the lens 3a is compensated by using the multi-layer interference film 23. Moreover, the similar effect to above in the case of red and blue object units is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a projection television apparatus comprising three CRTs and a projection lens unit.

(Prior Art) In recent years, there has been an increasing demand for high image quality and near-natural color reproduction for projection television devices, but one of the negative factors is that red, green, and blue CRT
Examples include unnecessary components contained in the Q light spectrum components.

Conventionally, methods for removing unnecessary components included in the CR7 emission spectrum include a method of forming a multilayer interference film on some lenses of the projection lens unit, and a method of using a colored plastic lens for a part of the projection lens unit. ,CR
There is a method of forming a multilayer interference film on the inner surface of the T face plate. Regarding the above three methods, Figures 2 to 1
This will be explained with reference to Figure 2.

FIG. 8 is a sectional view of a main part of a projection television apparatus in which a multilayer interference film is formed on some lenses of a projection lens unit.

In the figure, a CR with a CRT phosphor 1 formed on its inner surface.
On the front side of the T-face plate 2, there are provided a first degree, a second degree, and a second degree. Third. A projection lens unit consisting of 4th and 5th five lenses 3° 4, 5, 6 and 7 is arranged, and the 3rd
A multilayer interference layer M8 is formed on one side of the lens 50. The multilayer interference film 8 is formed by vacuum deposition of a high refractive index film such as Tie, ZrO, and S10. , MgF, etc., are alternately laminated with a film thickness that is an integral multiple of 174 of the reference wavelength, and exhibits high transmittance for light of a specific wavelength and Shows high reflectance for light.

FIG. 9 is a transmission characteristic diagram of the multilayer interference film 8 used in the green CRT, in which a transmission characteristic curve A shows the transmittance intensity of the multilayer interference film 8, and a spectrum line B shows the emission spectrum of the green CRT. For the projection lens unit provided with the multilayer interference film 8 as described above, the light emitted from the green CRT having emission spectrum components 9, 10 and +1 shown in curve B passes through the first and second lenses 3 and 4. Most of the unnecessary components 11 are reflected by the multilayer interference film 8, and only spectral components 9 and 10 are transmitted. and,
The light passes through the third, fourth, and fifth lenses 5, 6, and 7, and is enlarged and projected onto the screen. Since the spectral component 11, which is one of the causes of chromatic aberration, is hardly projected, chromatic aberration is reduced.

If this is expressed in the CIE chromaticity diagram shown in Figure 5, green CR
The chromaticity point 12 of T is projected as the chromaticity point 13 and can be brought close to the chromaticity point 14 of a standard television.

FIG. 10 is a transmission characteristic diagram of the multilayer interference film 8 used in the red CRT, where the transmission characteristic curve C shows the transmittance intensity of the multilayer interference film 8, and the spectrum line shows the emission spectrum of the red CRT. The red light emitted from the red CRT and having spectral components 15, 16 and 17 is reflected by the multilayer interference film 8 having the transmittance characteristics as shown in the figure, with the unnecessary component 16 being reflected by the same operation as above. , the chromatic aberration of the image enlarged and projected onto the screen is reduced. If this is expressed in the CIE chromaticity diagram shown in Figure 6, red CRT
The chromaticity point 18 of is projected as the chromaticity point 19, which can be brought close to the chromaticity point 20 of a standard television. (Japanese Unexamined Patent Publication No. 1-254087) FIG. 11 is an enlarged cross-sectional view of the main part of a projection television device using a colored plastic lens as a part of the projection lens unit. The difference from the example is that instead of the multilayer interference film 8 formed on the third lens 5, the second lens 3 has high transmittance for light in a specific wavelength range, and has high transmittance for light in other wavelength ranges. The key point is that a colored plastic lens 3a in which a dye having high absorption rate is uniformly distributed is used. Since the rest is the same as the first conventional example described above, the same components are given the same reference numerals and their explanations will be omitted.

2, 3, and 4 are transmission characteristic diagrams of colored plastic lenses 3a used for green, red, and blue CRTs, respectively, and transmission characteristic curves E, F, and G respectively indicate the transmittance of the colored plastic lenses 3a. The spectral lines B, D and H show the emission spectrum of the CRT, respectively. In the case of the colored plastic lens 3a, the effect of reducing chromatic aberration and improving the chromaticity point can be obtained by the same operation as the multilayer interference film 8. If this is expressed in a CIE chromaticity diagram, in the case of a green CRT, as shown in Figure 5,
The chromaticity point 12 of is projected as the chromaticity point 21 and approaches the chromaticity point 14 of a standard television, and in the case of a red CRT, the chromaticity point 12 is
As shown in the figure, the chromaticity point 2o of a standard television can be obtained from the chromaticity point 18 of a red CRT.

However, in the case of a blue CRT, almost no effect is observed, and as shown in FIG. 7, no change is obtained at the chromaticity point of the blue CRT, which remains at 22.

FIG. 12 is an enlarged sectional view of main parts of a projection television apparatus showing a third conventional example. The difference between this conventional example and the first conventional example shown in FIG. That is, a multilayer interference film 23 is formed between the inner surface of the CRT face plate 2 and the CRT phosphor 1. Since the rest is the same as the first conventional example, the same components are given the same reference numerals and their explanations will be omitted. Furthermore, the multilayer interference film 23 is formed using the same material as the multilayer interference film 8 and by the same manufacturing method.

Figures 2, 3 and 4 show transmission characteristic curves ■, J of the multilayer interference film 23 of green, red and blue CRTs, respectively.
and K are shown superimposed. The effect obtained by the multilayer interference film 23 provided on the inner surface of the CRT face plate 2 is that chromatic aberration is reduced and the chromaticity point is improved, the same as when it is formed on the projection lens unit. Regarding the chromaticity point,
In the case of green CRT, chromaticity point 12 to chromaticity point 1 in Figure 5
3. In the case of a red CRT, the chromaticity point 18 in FIG. 6 changes to the chromaticity point I9, and in the case of a blue CRT, the chromaticity point 22 in FIG.
The chromaticity point 24 can be obtained from green and red CR
For T, the color purity approaches the chromaticity points 14 and 20 of standard television, and for blue CRT, there is an effect of further improving the color purity beyond the chromaticity point 25 of standard television.

In addition, the brightness of the red and green CRTs is increased by approximately 40% due to the change in light dispersion characteristics caused by the multilayer interference film 23.

(Problem to be Solved by the Invention) However, when the multilayer interference film 8 is formed on the third lens 5 of the projection lens unit, although there is an effect of improving both chromatic aberration and chromaticity point, it is not perfect, and the screen The projected image had problems such as a decrease in brightness (approximately 20 to 40%), a decrease in contrast (approximately 20 to 40%), and unevenness in color and brightness between the center and the periphery.

In addition, when replacing with the colored plastic lens 3a, there is an improvement effect on both chromatic aberration and chromaticity point, but it is not perfect.
In addition, the image projected on the screen is the multilayer interference film 8
Compared to the above case, the reduction in contrast and the unevenness of color and brightness occurring between the center and the periphery can be solved, but there is a problem in that the brightness decreases ((about 20 to 40%)).

Further, when the multilayer interference film 23 is formed on the inner surface of the CRT face plate 2, there is a problem in that although there is an effect of improving both chromatic aberration and chromaticity point, it is not perfect.

The present invention solves the above problems and provides a projection television device whose chromaticity point is closer to the color reproduction range of a standard television, with less deterioration in brightness and contrast.

(Means for Solving the Problems) In order to solve the above problems, the present invention has a part of the lens of the projection lens unit that transmits light in a specific wavelength range and has a high sensitivity to light in other wavelength ranges. Uses colored plastic lenses with uniformly distributed dyes that have an absorbing rate, and
A multilayer interference film is formed on the inner surface of the CRT face plate, which has a high reflectance for light outside a specific wavelength range.

(Function) The multilayer interference film provided on the inner surface of the CRT face plate 2 and the colored plastic lens provided in a part of the projection lens unit filter only the necessary light out of the light emitted from the CRT phosphor l. It transmits light and reflects or absorbs unnecessary light, making it possible to bring the chromaticity point closer to that of standard television.

(Example) An example of the present invention will be described with reference to FIGS. 1 to 7. FIG. 1 is an enlarged sectional view of essential parts showing a projection lens unit and a CRT face plate of a projection television apparatus according to the present invention.

In the figure, the projection television apparatus according to the present invention is different from the conventional examples shown in FIGS. 8, 11, and 12 in that a multilayer interference film 23 is formed on the inner surface of the CRT face plate 2. , a colored plastic lens 3a is used for the first lens of the projection lens unit, and each lens has the same transmission characteristics as the conventional example. Since the rest is the same as the conventional example, the same components are given the same reference numerals and their explanations will be omitted.

Next, the operation of the projection unit configured as described above will be explained.

First, in the case of a green projection unit, as shown in FIG.
In the green emission spectrum having components 0 and 11, most of the component 11 is reflected by the multilayer interference film 23 having the transmission characteristic curve ■, and the chromaticity point changes from chromaticity point 12 to chromaticity point 13 shown in FIG. Brightness increases by about 40%. Next, a colored plastic lens 3 exhibiting a transmission characteristic curve E shown in FIG.
Most of component 10 is absorbed by a, and the chromaticity point is the fifth
The chromaticity point shown in the figure changes from 13 to 26, and the brightness is about 2.
0% decrease. and second to fifth lenses 4, 5.6
As a result, only the spectral component 9 shown in Fig. 2 is projected onto the screen, and the chromatic aberration is greatly improved, and the chromaticity point is also the same as the standard shown in Fig. 5. It approaches the chromaticity point 14 of the television, and can obtain chromaticity points that cannot be obtained individually. Furthermore, the increase in brightness obtained by the multilayer interference film 23 provided on the inner surface of the CRT face plate 2 can compensate for the decrease in brightness due to the use of the colored plastic lens 3a, so there is no decrease in brightness as a projection unit. .

Also, in the case of the red projection unit, the same effect as above can be obtained, and the spectral components 15°16 and 1 shown in FIG.
7, most of the component 17 is reflected by the multilayer interference film 23 having the transmission characteristic curve J shown in FIG. 3, and most of the component 16 is reflected by the colored plastic lens 3a having the transmission characteristic curve F. As a result of the absorption, a significant reduction in chromatic aberration and a standard television chromaticity point of 20 as shown in FIG. 6 can be achieved without reduction in brightness.

Furthermore, in the case of the blue projection unit, the same operation
It is possible to significantly reduce chromatic aberration and obtain a chromaticity point 24 with good color purity exceeding the chromaticity point 25 of the standard television shown in FIG.

(Effects of the Invention) As explained above, according to the present invention, there is no chromatic aberration.
A high-brightness projection television device with a wide color reproduction range can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of the main parts of the projection lens unit and CRT face plate of the projection television apparatus according to the present invention, and FIG. 2 is a green phosphor emission spectrum diagram and the multilayer interference film and colored plastic used in the present invention. The transmittance characteristic diagram of the lens, Figure 3 is the red phosphor emission spectrum diagram and the transmittance characteristic diagram of the multilayer interference film and colored plastic lens used in this invention, and Figure 4 is the blue phosphor emission spectrum diagram and the transmittance characteristic diagram used in this invention. Transmittance characteristic diagrams of the multilayer interference film used; Figures 5, 6, and 7 are enlarged views of the CIE chromaticity diagram around green, around red, and around blue, and Figure 8 is an enlarged view of the first conventional example. FIGS. 9 and 10 are enlarged cross-sectional views of the main parts of a projection television device, and FIGS. 9 and 10 show the emission spectra of the green and red CRTs used therein, as well as transmission characteristics of the multilayer interference film. FIGS. FIG. 2 is an enlarged cross-sectional view of a main part of a projection television apparatus showing second and third conventional examples. DESCRIPTION OF SYMBOLS 1... CRT phosphor, 2... CRT face plate, 3... Third lens, 3a... Colored plastic lens, 4... Second lens, 5...
・Recommended 3 lenses, 6...4th lens, 7...5th lens, 8,23...multilayer interference film, 9.10
．． 11...spectral components of green CRT, 12...
・Chromaticity point of green CRT, 13...Chromaticity point of green projection light transmitted through multilayer interference film, 14.20.25...
Chromaticity point of standard television, 15.16.17...Spectral components of red CRT, 18...Chromaticity point of red CRT, 19...Chromaticity point of red projection light transmitted through multilayer interference film , 20... Chromaticity point of projection light transmitted through a colored plastic lens and standard television, 21... Chromaticity point of green projection light transmitted through a colored plastic lens, 22... Blue CRT and blue plastic lens The chromaticity point of the colored projection light transmitted through, 24.
...Chromaticity point of blue projected light that has passed through the multilayer interference film and colored plastic lens, 26...Chromaticity point of green projected light that has passed through the multilayer interference film and colored plastic lens, A, C. I, J, K... Transmission characteristic curve of multilayer interference film, B...
Emission spectrum of green CRT, D...Emission spectrum of red CRT, E. F, G...transmission characteristic curve of colored plastic lens,
H: Emission spectrum of blue CRT. Patent applicant□ Matsushita Electric Industrial Co., Ltd.

Claims (11)

[Claims] (1) Three cathode ray tubes (hereinafter referred to as CR
In a projection television device consisting of a projection lens unit (abbreviated as T) and a projection lens unit, a projection unit consisting of at least one combination of a projection lens unit and a CRT is provided with a part of the projection lens unit consisting of a plurality of lenses having a specific wavelength A colored plastic lens is used that uniformly distributes a dye that transmits light in the specified wavelength range, but has a high absorption rate for light in other wavelength ranges. A projection television device characterized by forming a coating having high reflectance. (2) A coating having a high reflectance for light having a wavelength of approximately 670 nm or more is formed on the inner surface of the face plate of the red CRT in the red projection unit of the above projection units, and the projection lens unit is Approximately 60
2. The projection television apparatus according to claim 1, further comprising a colored plastic lens in which a dye having a high absorption power for light having a wavelength of 0 nm or less is uniformly distributed. (3) A coating having a high reflectance for light having a wavelength of approximately 590 nm or more is formed on the inner surface of the face plate of the green CRT in the green unit of the above projection units, and a projection lens unit is further provided with: Approximately 520
2. The projection television apparatus according to claim 1, further comprising a colored plastic lens in which a dye having a high absorption power for light having a wavelength of nm or less is uniformly distributed. (4) In the blue unit of the above projection units, a coating having a high reflectance for light having a wavelength of about 530 nm or more is formed on the inner surface of the face plate of the blue CRT, and a part of the projection lens unit is also coated. 2. The projection television apparatus according to claim 1, further comprising a colored plastic lens in which a dye having a high absorption power for light having a wavelength of about 420 nm or less is uniformly distributed in the part. (5) A projection television apparatus comprising the red, green, and blue projection units according to claim (2), (3), or (4) above. (6) A projection television apparatus comprising three CRTs each having a primary color light emitting surface and a projection lens unit including the red and green projection units according to claim (2) or (3) above. (7) In a projection television device consisting of three CRTs having three primary color light-emitting surfaces and a projection lens unit, a coating with high reflectivity for light having a wavelength of approximately 530 nm or more is formed on the inner surface of the face plate of the blue CRT. A projection television apparatus characterized in that it is combined with the red and green projection units according to claim (2) or (3). (8) In a projection television device consisting of three CRTs having three primary color light-emitting surfaces and a projection lens unit, a green color is formed on the inner surface of the CRT faceplate with a coating having a high reflectance for light having a wavelength of approximately 590 nm or more. A CRT, a blue CRT in which a coating having a high reflectance for light having a wavelength of about 530 nm or more is formed on the inner surface of the CRT face plate;
2) A projection television device comprising the red projection unit described above. (9) Remove unnecessary components on the long wavelength side of the CRT emission spectrum,
2. The projection television apparatus according to claim 1, wherein the unnecessary components on the short wavelength side are removed by a coating formed on the inner surface of the CRT face plate, and the unnecessary components on the short wavelength side are removed by a dye contained in the colored plastic lens. (10) A colored plastic lens used in a projection lens unit, which is combined with a three-primary CRT having a coating with frequency selection characteristics formed on the inner surface of the CRT face plate, and which has frequency selection characteristics different from the frequency characteristics of the coating described above. (11) C in which a coating with frequency selection characteristics different from the above frequency characteristics is formed on the inner surface of the face plate in combination with a colored plastic lens having frequency selection characteristics used as a part of the projection lens unit.
RT.