JPS62139236A - Beam index methodical flat color picture reproducer - Google Patents

Abstract

PURPOSE:To enable a stable color picture to be reproduced, by disposing respective ends of plural light conducting passages to the outside of the glass receptacle of a flat index tube in such a manner that the ends glare at a fluorescent screen, putting together the other respective ends of the light conducting passages so as to be conducted to the common light receiving surface of a light detector, and taking in light index signals from index fluorescent material stripes. CONSTITUTION:Four light conducting passages 8R1, 8R2, 8L1, 8L2 are provided to the outside of a face plate 1', in such a manner that respective ends of the passages glare at a fluorescent screen 3 via the face plate 1' and respective other ends of the passages face a common light detector 9. The respective ends of the light conducting passages 8R1, 8R2, 8L1, 8L2 outside the face plate 1' are disposed as the incident ends of light index signals 7' from the vicinity of respective corners of the fluorescent surface 3. The light index signals 7' enter from the respective incident ends of the light conducting passages 8R1, 8R2, 8L1, 8L2, and they repeat reflections in the light conducting passages to be transmitted so as to appear at the output ends. The output ends of the four light conducting passages are put together, and the light detector 9 is disposed opposite to the bundled ends.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention is directed to a phosphor screen formed by three primary color phosphor stripes of red, green, and blue and an index phosphor stripe. A beam index that uses a flat beam index tube that projects electron beams from an angle to reduce the thickness when viewed from the phosphor screen, and efficiently collects optical index signals from the entire surface of the phosphor screen. The present invention relates to a flat color image reproducing device.

[Background of the invention]

In a conventional common cathode ray tube, the electron gun and the electron beam deflection device are arranged on an axis substantially perpendicular to the phosphor screen.

Since the depth dimension of such a cathode ray tube becomes long, a color image reproducing apparatus using such a cathode ray tube inevitably becomes large in size. Therefore, cathode ray tubes are known as flat cathode ray tubes, which are made smaller by projecting electron beams at angles other than perpendicular to the phosphor screen, thereby reducing the thickness as seen from the phosphor screen. A small index-type color television receiver using a flat cathode ray tube was developed, and an example of this is the IEEE, ICCE85 (19
1985) "A Color Flat Cathode Ray Tube" commercial by Yamano et al.

Yamano, et al: A C0LOR
F LATCATHODE RAY TUBE:I
EEE.

I CCE85. P182-183. (1985)
).

An outline of a conventional example of such a beam index type flat color image reproducing device will be explained below.
FIG. 3(a) is a plan view thereof, and FIG. 13(b) is a sectional view of the same side. In these figures, 1 is a flat glass container;
1' is a face plate, 3 is a fluorescent screen, 4 is an electron gun, 5
1 is an electron beam, 6 is a deflection yoke, 7 is emitted visible light, 7' is an optical index signal, 9 is a photodetector, 10 is an index signal processing circuit, and 11 is a terminal.

In an ordinary cathode ray tube, the electron beam emitted from the electron gun hits the phosphor screen at right angles, but in flat cathode ray tubes, the electron beams emitted from the electron gun do not hit the phosphor screen at right angles, as shown by the broken line in Figure 13(b). They do not collide, but collide obliquely at an angle θ, and an image is projected in the direction of arrow A, which is perpendicular to the direction of the electron beam.

That is, the electron beam 5 from the electron gun 4 is deflected by the deflection yoke 6.
A raster is formed on the phosphor screen 3 by vertical and horizontal deflection, red (R) and green (G).

Emitted light 7 from the blue (B) three primary color phosphors is emitted to the outside of the face plate 1'.

FIG. 14 is an explanatory diagram of the phosphor screen structure of the flat beam index tube shown in FIG. 13. In the phosphor screen structure shown in the figure, a conductive film 2' made of graphite is formed on the inner surface of a glass container 1, a part of the conductive film 2' is removed, and an index phosphor stripe I is coated on the conductive film. 3 primary color phosphor stripes (R.

G and B), and a protective film 3' was further applied on the phosphor.

The optical index signal 7' from the index phosphor (2) is absorbed by the light condensing plate 13 (FIG. 13(b)) provided on the outside of the glass container 1, propagates inside the light condensing plate 13, and is transmitted through the light condensing plate 13 (FIG. 13(b)). When the light is incident on the photodetector 9, it is converted into an index signal.

The index signal obtained by the photodetector 9 and the video signal supplied to the terminal 11 in this way are processed by the index signal processing circuit 10, and a drive signal that causes the desired color phosphor to emit light with a desired amount of electric beam is generated. This drive signal is supplied to the electron gun 4 to reproduce a color image with the correct hue.

In the conventional example described above, it is necessary to remove a portion of the conductive film 2' in order to guide the optical index signal from the index phosphor (3) to the light condensing plate 13, so there is a problem that the coating process for the phosphor screen becomes complicated. Ta.

To simplify the coating process of the phosphor screen, the three primary color phosphors and the index phosphor are coated in the same layer, and the visible light from the three primary color phosphors and the optical index signal from the index phosphor are emitted in the same direction. A flat beam index tube is considered.

A side sectional view of such a conventional index tube is shown in FIG.

As seen in the figure, in this case, it is necessary to install the photodetector 9 near the deflection yoke 6 in order to efficiently collect the optical index signal 7'.

When using a solid-state photoelectric conversion element such as a PIN photodiode element as a photodetector, a preamplifier 14 is required to convert the photocurrent into voltage. Since they must be placed in close proximity, there is a problem that the color image reproduction operation becomes unstable due to adverse effects such as the jump of horizontal deflection pulses.

In addition, when using a photodiode with a smaller light-receiving area than a photomultiplier tube, the intensity of the index signal from the part farther from the photoreceptor surface of the photodiode will be lower, and the S/N ratio of the index signal will be lowered. stability deteriorates.

To solve this problem, it is possible to collect the optical index signal using a condensing lens, but this makes it difficult to condense the light over the entire surface of the phosphor screen, and the relative position of the condensing lens and the photodiode's light-receiving surface If the value changes, there may be a portion where almost no optical index signal can be obtained, and there is a problem that the lens and photodiode cannot be used practically because the mounting positional variations must be extremely small.

Furthermore, since a space is required to install the photodiode 5 preamplifier near the deflection yoke, there is a problem that the thickness of the flat color television receiver increases.

In particular, in a system that uses two or more types of index phosphors with different emission wavelengths to obtain two or more types of index optical signals and uses these to improve hue errors, a collection of structures shown in FIG. In the method using the light plate 13,
It is impossible to reliably illuminate the plurality of types of index signals over the entire screen.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a beam index type flat color image reproducing apparatus that can solve all of the problems in the prior art as described above.

[Summary of the invention]

In the present invention, on the outside of the glass container of the flat index tube,
Arrange one end of each of the multiple light guides so that they are facing the fluorescent screen,
The other ends of the light guide paths are guided together to the light receiving surface of a common photodetector, and the optical index signal from the index phosphor stripe is taken in through the light guide path and the photodetector, so that the entire surface of the phosphor screen is This makes it possible to obtain a stable optical index signal over a long period of time, thereby reproducing a stable color image.

(Embodiments of the invention) The present invention will now be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing one embodiment of the present invention, FIG. 2 is a sectional view of the same side, and FIG. 3 is an explanatory diagram of a phosphor screen structure in the same embodiment.

In these figures, 1 is a flat glass container, 1' is a face plate, 2 is a metal bank film, 3 is a phosphor screen or phosphor stripe, 4 is an electron gun, 5 is an electron beam, 6 is a deflection yoke, and 7 is a Visible light, 7' is optical index signal,
811+ 8 R2+ 8 LI+ 8L* are light guide paths, 9 is a photodetector, 10 is an index signal processing circuit, and 11 is a terminal.

Please refer to FIGS. 1 to 3. On the inner surface of the glass container 1 of the deflection beam index tube, there is a metal bank film 2 made by vapor-depositing aluminum, etc., and on top of it are red (R),
A three primary color luminescent stripe 3 that emits green (G) and blue (B) light and an invisible index phosphor stripe I that has an emission peak in the ultraviolet region, for example, are arranged in a specific arrangement relationship with the three primary color phosphor stripes. The optical index light 7' is applied to the outside of the face plate 1' by applying the same layer.

In FIG. 1, four light guide paths 8. ,．． 8. ! , 8L, , 8° such that one end of each faces the fluorescent screen 3 through the face plate 1'.
Moreover, each other end is provided so as to face a common photodetector 9.

For the light guide path, for example, optical fibers made of glass or plastic, or fiber optics in which optical fibers are tightly bundled may be used.

The light guide paths 8□, 8□+ 8t+, 8tz are located outside the face plate 1', and one end of each of them is arranged as an incident end of the optical index signal 7' from near each corner of the fluorescent screen 3. That's why. An electron beam 5 emitted from the electron gun 4 is deflected by a deflection yoke 6 and enters the phosphor screen 3. Three primary color phosphor stripes (R, G, B
) and the optical index signal 7' emitted from the index phosphor stripe (2) pass through the face plate 1' and are emitted to the outside.

The optical index signal 7' is the light guide path 8RI+8+ez
+81.1+ The light enters from each input end of the 8LZ, propagates while being reflected repeatedly within the light guide path, and appears at the output end.

The output ends of the four light guide paths are bundled, and a photodetector 9 is placed opposite the bundled ends. In front of the light receiving section of the photodetector 9, an optical filter (for example, when an index phosphor that emits ultraviolet light is used) passes only ultraviolet light and attenuates visible light so as to receive only the optical index signal. (not shown) may be arranged to receive only the ultraviolet optical index signal.

Each of the incident ends of the four light guides is arranged so as to stare into the vicinity of each corner of the phosphor screen 3, so when the light is collected by the photodetector 9 alone without using the light guide, the light received by the photodetector is In contrast, in the present invention, even in areas far from the light receiving area of the photodetector, the intensity of the optical index signal decreases from areas far from the photodetector, which is almost equivalent to collecting light near each corner of the phosphor screen. Therefore, the variation in the intensity change of the optical index signal can be reduced.

In addition, when a condensing lens is arranged between the end of the optical fiber serving as a light guide on the photodetector 9 side and the photodetector 9, a condensing lens can be used in the conventional arrangement as shown in FIG. Compared to the case where lenses are arranged, this has the advantage that the mechanical arrangement size tolerance is larger.

In other words, when arranging the condensing lens as shown in Fig. 15, the relative positions of the condensing lens, photodetector, and index tube had to be optimized in consideration of the overall light intensity. When placing a condensing lens in front of the photodetector 9, the optical fiber 8
*1. Since this can be ensured by multiple arrangements such as 8*i, 8Ll+8La, etc., it is only necessary to pay attention to the relative positional relationship between the optical fiber end and the photodetector 9.

FIG. 4(a) is a graph showing the index signal strength detected in the vertical period, and FIG. 4(b) is a graph comparing the detected index signal strength with the horizontal period in the case of the tree invention and that of the conventional method. A solid line indicates a case where a photodetector is installed near the deflection yoke 6 to collect light as shown in FIG. 15 using a conventional technique.

It will be understood that according to the present invention, the index signal intensity can be increased over the entire surface of the phosphor screen, and the variation in index signal intensity change can be reduced, so that a stable color reproduction image can be obtained.

The number of light guide paths is not limited to four as explained in the above embodiment, and it is possible to use a plurality of light guide paths other than four.

FIG. 5 shows another embodiment using four or more light guide paths. That is, the light guide array 8. ．． 8L each has a large number of optical fibers arranged in parallel in a straight line to form an array, and the light guide paths constituting each array 811.8L are branched midway, one by one. 8 from l
．． , and 81 from 8L to the photodetector 9, and 8. 8. from l. ' and 8 from 8L. ' is guided to a photodetector 9'.

In this way, the optical index signals from the entire surface of the phosphor screen 3 can be effectively collected in each of the photodetectors 9 and 9', and each index signal thus collected is added to the adder AD. The sum is added and the result is supplied to the index signal processing circuit 10. In this way,
The reason why the adder AD adds the values will be described later.

FIG. 6 shows a phosphor screen structure of a beam index tube that uses two types of index phosphors already proposed and disclosed by the present inventors to stabilize the operation of a beam index type color image reproducing device. This is what is shown.

As shown in FIG. 7, the two types of index phosphors 11+I in the same figure are invisible YAfi03:C whose emission peak is in the ultraviolet region.

Phosphor (hereinafter abbreviated as YAP), I2 is Y, which has an emission spectrum similar to that of a green phosphor, /1m! s: C or Y3
A! ! , G-z:C-phosphor (hereinafter abbreviated as P46) is used.

A first index phosphor stripe I, is placed between the B and R phosphor stripes, and a second index phosphor IN is mixed with the G phosphor to form a G color vision photon-cum-second index phosphor stripe L. It was applied as.

Note that the reason why the (G+12) phosphor stripe width is made wider than the phosphor stripe widths of other colors is to compensate for the decrease in the amount of light emitted by the green phosphor and obtain a white color with an appropriate white balance. -One set of G-B color light stripes has one set of each index phosphor stripe i+, rz1
/1 system is shown in FIG.

If the phase of the arrangement of a pair of R-G-B color light stripes is 360°, the index phosphors T+ and It have a phase difference of 1806 degrees, so after inverting the phase of one index signal, , by adding 1
One index signal can be obtained.

The index signal obtained in this way can solve the problem of the conventional 1/1 method in which the index signal cannot be obtained when reproducing a specific hue, and can further reduce the phase error of the index signal. Color images with stable hue can be reproduced.

When using the two types of index phosphors mentioned above,
Since it is necessary to collect each optical index signal independently, in FIG.
．． Optical filters 12 and 12' each having transmittance characteristics as shown by dotted lines in FIG. 7 are provided between the filters 9'.

After collecting two types of optical index signals independently, one index signal is inverted by an inverting circuit INV,
The operation after the addition by the adder AD is the same as that in the embodiment shown in FIG. 1, so a description thereof will be omitted.

Note that in FIG. 5, the light guide array 8. ．． 8F by branching each light guide path that makes up 8L.
, 8n to the photodetector 9, 8rZ8Jl' to the photodetector 9'
The reason for this is to reduce the variation in the index signal intensity ratio from the two types of index phosphor stripes II+I2 regardless of the horizontal deflection position of the electron beam, and the number of dividing light guide paths is It is not limited to each piece.

FIG. 8 is an explanatory diagram showing an example of the structure of a light guide used in the present invention.

In FIG. 8(a), the light guide path 8 is made of two types of glass, and the refractive index n has a stepped refractive index characteristic as shown in the figure, and a convex lens 20 is provided at the incident end of the optical index signal 7'. The optical index signal is focused and guided to the light guide path 8 (thus increasing the optical detection sensitivity).

Note that instead of the convex lens 20, the light guide may be formed so that the tip of the light guide itself has a convex shape.

As shown in FIG. 8(b), the light guide path 8 is composed of a parabolic refractive index characteristic in which the refractive index n gradually increases toward the center, and has a lens-like function by itself. Therefore, the optical index signal can be focused and the optical detection sensitivity can be increased.

FIG. 9 is a perspective view showing the main part of another embodiment of the present invention, in which a convex lens 21 is disposed between the bundled part of the output end of the light guide path 8 and the photodetector 9, so that the optical index signal can be Since the light is focused and incident on the light-receiving surface of the photodetector 9, a photodiode element with a small light-receiving area can be used as the photodetector 9.

When a photodiode with a small light-receiving area is used in this way, the junction capacitance MC of the element becomes small, so when detecting a high-frequency index signal, the noise from the index signal amplifier can be reduced, and the S of the index signal can be reduced.
/N ratio is increased, and the stability of color image reproduction can be further improved.

FIG. 10 is a sectional view showing a main part of still another embodiment of the present invention, in which a case 22 is provided between the bundled output end of the light guide path 8 and the photodetector 9, and the refractive index is A transparent material 23 with a large n value, such as oil, epoxy, acrylic, etc., is filled. The optical index signal 7 is generated by a substance with a high refractive index n.
' forms an image on the light-receiving surface of the photodetector 9 with a small area, so a photoelectric conversion element with a small light-receiving area can be used as the photodetector 9.

FIG. 11 is a sectional view showing still another embodiment of the present invention, in which a convex portion 24 is formed on the side surface of the glass container 1 of the flat index tube.
is formed inside, and a light guide path 8 (8+++, 8., . . .
. . . 8L, , 8° . . . )), the light guide path 8 is fixed to the glass container 1 with silicone resin, etc., and the incident end of the light guide path is This prevents dust from entering the lens and reduces changes in optical performance over time.

Further, since the glass container 1 is formed with a convex shape 24 on the inside, the convex portion 24 has the function of a convex lens and condenses the optical index signal, so that the light detection sensitivity can be increased.

The embodiment described above is intended for a front-lighting type flat beam index tube in which three primary color phosphor stripes and index phosphor stripes are formed in the same layer, and the phosphor screen is arranged diagonally with respect to the electron gun. However, the present invention is not limited to this, and for example, as shown in FIG.
After being deflected by the deflection yoke 6, the electron beam 5 emitted from the electron beam 5 is bent at a nearly right angle by the electrostatic field formed in the space between the sub-electrode 25 and the phosphor screen 3, and enters the phosphor screen, causing the three primary color phosphors to It is also possible to apply it to an index tube having a structure that emits visible light 7 in front of the face plate 1'.

FIG. 12(b) is an explanatory diagram of the phosphor screen structure of the embodiment shown in FIG. 12(a), in which the index phosphor I is arranged opposite to the three primary color phosphor stripes through the metal back film 2. coated on the side, excited by the electron beam 5,
The emitted light index signal 7' is emitted into the glass container 1. A plurality of light guide paths 8 are installed outside the glass container 1, and it is possible to stably illuminate the optical index signal over the entire surface of the phosphor screen.

In this way, the present invention can be applied to a flat beam index tube that collects optical index signals from the back side as shown in FIG. 12, and if FIG. 1 and FIG. It is easy to understand that the present invention can be applied to the flat beam index tube of FIG. 1 in which the phosphor screen and the phosphor screen are arranged diagonally, and the phosphor screen structure is suitable for a rear lighting system.

It should be noted that the optical fiber bundle used in the present invention does not need to form an image by itself, and only needs to transmit optical information, so there is no restriction on the order in which the optical fibers in the bundled portion are mutually arranged. Therefore, the cost of the optical fiber bundle is not high, and there is no need to pay attention to the arrangement order of the optical fiber ends when assembling the color image reproducing device, so there is no risk of significantly increasing the manufacturing cost of the entire device.

〔Effect of the invention〕

According to the present invention, the optical index signal from the flat beam index tube can be stably and reliably illuminated over the entire surface of the phosphor screen using a light guide, and the optical detection sensitivity can be increased by focusing the optical index signal. Therefore, it becomes possible to stabilize the operation of the beam index type flat color image reproducing apparatus, and there is an effect of promoting practical use.

In particular, since the diameter of each input end of the optical fiber is much smaller than the size of the photodetector 9, by applying the present invention to a flat input tube, the conventional structure shown in FIG. In comparison, the original advantage of the flat color image reproducing device, which is that the overall depth of the cent can be significantly reduced, can be fully utilized.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a sectional view of the same side, FIG. 3 is an explanatory diagram of the phosphor screen structure in the same embodiment, and FIG. A graph showing a comparison between the case according to the invention and the case according to the conventional technology,
FIG. 5 is a perspective view showing another embodiment of the present invention, FIG. 6 is an explanatory view showing the phosphor screen structure of a beam index tube according to an existing proposal by the present inventors, and FIG. 7 is similar to FIG. Graphs showing the characteristics of the two types of index phosphors shown, FIG. 8 is an explanatory diagram showing an example of the structure of the light guide used in the present invention, and FIG. 9 shows the main part of another embodiment of the present invention. FIG. 10 is a sectional view showing essential parts of still another embodiment, FIG. 11 is a sectional view showing still another embodiment of the present invention, and FIG. 12 (a
) is a sectional view showing still another embodiment of the present invention, No. 12
12(b) is an explanatory diagram of the phosphor screen structure in the embodiment shown in FIG. 12(a), FIG. 13(a) is a plan view showing a conventional example of a beam index type color image reproducing device,
Figure (b) is a sectional view of the same side, Figure 14 is an explanatory diagram showing the structure of the fluorescent screen of the flat index tube shown in Figure 13, Figure 15 is
The figure is a side sectional view showing another conventional example of a beam index type color image reproducing device. Explanation of symbols 1... Flat glass container, 1'... Face plate, 3... Fluorescent screen, 4... Electron gun, 5... Electron beam, 6... Deflection yoke, 7...・Visible light, 7'...
Optical index signal, 8. 8R, L, , 8-
, 8r', 8Jl, aj'... light guide path, 9.
9'... Photodetector, I, II+ It... Index phosphor, 12. 12'... Optical filter, 20
．． 21...Convex lens agent Patent attorney Akio Namiki g+ Figure 2 Tsuno Figure 3 Wi4 Figure Cd) (b) (I)
(1 site = 27 squares 10 ↑ zero light 1 standing) Figure 5 Figure 6 Figure 7B 8B ((2) (b) 10th
Figure 11 Figure 1112 Figure (α) (b) Figure 13 Figure 14 N ←Z1 contradiction film 7/ ,,=,. -cam 15th FM Former I) Te=, Guess No. 11

Claims (1)

[Scope of Claims] 1) The electron beam is projected from an angle other than a right angle to a phosphor screen formed by three primary color phosphor stripes of red, green, and blue and an index phosphor stripe. In a beam index type flat color image reproducing device using a flat beam index tube that enables a reduction in the thickness dimension as seen from the phosphor screen, a plurality of guides are installed at desired positions on the optical index signal emitting surface near the tube surface of the index tube. One end of each optical path is arranged, each other end of the light guide path is guided together to a common photodetector, and the optical index signal from the index phosphor stripe is captured via the light guide path and the photodetector. , a beam index type flat color image reproducing device characterized in that it uses: 2) In the beam index type flat color image reproducing device according to claim 1, by providing a convex lens at one end of the light guide path facing the optical index signal emitting surface, or by forming the one end into a convex lens shape, A beam index type flat color image reproducing device characterized in that an optical index signal from the index phosphor stripe is focused on one end of the light guide path. 3) In the beam index type flat color image reproducing device according to claim 1, by disposing a convex lens between the other end of the light guide and the photodetector, light from the other end of the light guide is A beam index type flat color image reproducing device characterized in that an index signal is focused on the photodetector. 4) In the beam index flat color image reproducing device according to claim 1, a transparent material having a refractive index larger than that of air is used to connect the other end of the light guide and the photodetector. A beam index method flattened color image reproducing device characterized in that it is formed by filling. 5) In the beam index type flat color image reproducing device according to claim 1, a part of the flat glass container constituting the tube surface of the index tube is formed to be convex inward, and the convex portion 1. A beam index type flat color image reproducing device, characterized in that one end of said light guide path facing the optical index signal emitting surface is attached to said light guide path.