JPH0321916B2 - - Google Patents

Description

[Detailed description of the invention]

[Object of the Invention] (Industrial Application Field) The present invention relates to a large color display device that displays information such as characters and images in color on a stadium, the roof of a building, or on a wall. (Prior art) Generally, this type of large color display device is required to be visible as a color television image from a long distance, for example, 200 meters away, so the entire display surface is formed in a rectangular shape of 5 meters or more on each side. . Then, as shown in FIG. 1, on the display surface 2 of the display device 1, picture elements 3 consisting of three or four display elements exhibiting at least red, green, and blue luminescent colors are provided.
are arranged in a matrix. This large-sized color display device is designed to provide images with color tones and image resolution comparable to those of general color television images, as well as sufficient brightness and brightness contrast even under daytime outdoor viewing conditions. It is desirable that the elements 3 are small and provided as many as possible. In general color televisions, picture elements consisting of a set of red, green, and blue phosphor dots are arranged at a pitch of 0.6 mm to 0.8 mm and can be seen as a sufficiently good color television image at a normal viewing distance of about 2 m. The pixel pitch of a large color display device is preferably a size that satisfies viewing conditions equivalent to those of a general color television. Now, if the pixel pitch of the display element is X mm when the viewing distance is 200 m, then if the pixel pitch of a general color TV is 0.6 mm, then 0.6 mm: 2 m = X mm: 200 m In this case, 0.8mm:2m=Xmm:200mX=80mm, and the pixel pitch of a large color display device is 60.
It is desirable to have it closer to mm~80mm. Therefore, since this picture element is made up of a set of multiple display elements, for example four display elements, it is desirable that each side be 80 mm or less. Therefore, for example, if rectangular picture elements of 80 m on a side are arranged on a rectangular display surface of 6 m in height and 8 m in width, a total of 7500 pixels will be arranged in 75 columns by 100 columns. (Problem to be Solved by the Invention) By the way, display elements for each color that constitute a picture element include an incandescent light bulb, a cathode ray tube, a light emitting diode,
Fluorescent lamps and the like have been proven, and some have already been put into practical use. However, using these display elements alone has advantages and disadvantages, and poses a practical problem. That is, in the case of a device using a fluorescent lamp as a display element, for example, the device described in Japanese Utility Model Publication No. 48-23343, it is a straight tube fluorescent lamp bent into a U-shape. When viewed from above, the light-emitting display section is almost I-shaped, and the light-emitting area (hereinafter referred to as effective light-emitting area) that can be used as a display surface of the fluorescent lamp's arc tube is small, and therefore the amount of light is small. However, there is a drawback that the required power does not decrease as much as expected. Furthermore, the device described in Japanese Patent Publication No. 51-12239 has straight tube fluorescent lamps that emit red, green, blue, and white colors arranged side by side, and is housed in a translucent case to form a unit or picture element. However, since a pair of sockets supporting each end of the straight tube fluorescent lamp are also arranged within the display surface, the picture elements become larger and
There is an inconvenience that the brightness decreases. Therefore, it is not suitable for displaying television images as in the present invention, and can only be used for displaying mosaic images at most. Furthermore, since this device requires a light-transmitting case, it has the disadvantage that the brightness of the display surface further decreases. Furthermore, as shown in FIGS. 10 and 11, there is a tubular fluorescent lamp in which the intermediate portion 15 is bent into a U-shape, and the tip end of the light emitting portion is bent toward the base portion. Japanese Unexamined Patent Publication No. 1983-83147, Utility Model Publication No. 1983-
There is a fluorescent lamp as shown in Publication No. 22762,
This item was published in Utility Model Publication No. 51-28773 and Utility Model Publication No. 45-
Even if it were possible to combine it with a display panel like the one shown in Publication No. 33465, it would only result in a monochromatic display device.Moreover, this fluorescent lamp was originally for illumination, and the entire kobe was used as light. It is. When this device is disposed on a display surface, the pair of light emitting portions are arranged in an 11-character shape such that both ends of the light emitting portions are parallel to each other and spaced apart within the display surface. Therefore, the occupancy rate of the light emitting parts within the display surface becomes low. Furthermore, with this configuration, not only is the light emitted from the middle portion 13 of the lamp wasted, but depending on the viewing angle of the display surface, the portion located further back than the display surface becomes invisible and no longer contributes to display light. Next, it is also possible to use light-emitting diodes as display elements, but at present, although red and green can provide a practical amount of light, blue light-emitting diodes cannot provide a practical amount of light, so it is difficult to maintain color balance. I can't compose a good picture element. In addition, a device using a cathode ray tube as a display element is already in practical use, and as shown in Figure 2, this device can emit light of two green G, one red R, and blue B colors. One picture element 3 is composed of a set of four cathode ray tubes 4. However, in this case, the shape of the light emitting display section 5 of the cathode ray tube 4 is circular and high voltage is required for energization, so the socket section 6 becomes large due to electrical insulation. It becomes difficult to arrange them close to each other. Therefore, the effective light emitting area is small at about 22%, and since the picture elements 3 are large, the mounting density on the display surface 1 is also small. Therefore, there is a risk that image resolution will deteriorate and visibility at short distances will also deteriorate. Also,
The average brightness when emitting white light (hereinafter simply referred to as average brightness) is as low as 900 cd/m ² , and when outdoors in the daytime, the display brightness contrast decreases and visibility may deteriorate. Furthermore, in the case of an incandescent light bulb as a display element, three color incandescent light bulbs 7 emitting red R, green G, and blue B are arranged in a triangular shape as shown in FIG. It is known that one picture element consists of three pixels. However, in this case, the shape of the light emitting display section 8 of the incandescent light bulb 7 is approximately circular;
In addition, because of the large amount of heat generated, incandescent light bulbs7
It becomes difficult to arrange them in close proximity. Therefore, the effective effective area is as small as about 44%, and the picture elements 3 are also relatively large, resulting in a low mounting density on the display surface 1. Therefore, there is a risk that the image resolution will deteriorate and the visibility at short distances will deteriorate. Also,
The incandescent light bulb 7 consumes a lot of power, and in order to obtain the amount of light required for a picture element, the power consumption for one picture element is approximately
The output power is 61W, which is about 8 times the 8W for one pixel of a cathode ray tube, and because it generates a lot of heat, the display panel needs to be cooled, which requires additional power consumption and equipment costs, making it uneconomical. There are drawbacks. Furthermore, as shown by the dotted line in FIG. 14, incandescent light bulbs have the disadvantage that the blue color is biased toward the green side, so that the display range of the blue color is narrowed and the white color also has a reddish tinge. The present invention has been made in consideration of the above-mentioned circumstances, and it requires relatively less power, generates less heat, and increases the amount of light that contributes to display compared to the total amount of light emitted, and is at least as effective as an incandescent bulb. A large color display device that has an average luminance of the same level or higher, has a high luminance by increasing the effective light emitting area as much as possible, and also has small picture elements so that the density of mounting on the display surface can be increased. The purpose is to provide [Structure of the Invention] (Means for Solving the Problems) Next, an outline of the present invention will be explained. For the reasons mentioned above, this kind of large-sized color display device has a display surface that is formed in a rectangular shape with one side of 5 m or more. The size of one picture element is preferably 80 mm or less on one side, and the number of picture elements is preferably as large as possible. That is, it is desirable that the image can be viewed not only as a color television image from a long distance of 200 m, but also as a color television image from a short distance. Therefore, in order to improve visibility, it is necessary to increase the average brightness of the picture elements so that the brightness contrast with the surroundings is large, and to make the picture elements small by arranging the display elements close to each other. It is sufficient to increase the mounting density and arrange a large number of them. However, using an incandescent light bulb or cathode ray tube as a display element has practical problems as described above, and using a conventional fluorescent lamp as a display element has practical problems as described above. . The inventor of the present invention has discovered that fluorescent lamps generate less heat, consume relatively less power, and have high brightness, making it possible to widen the effective light emitting area and make the lamp more compact when viewed from the viewing direction. The present invention was made based on the knowledge that a fluorescent lamp can be used as a display element. The large-sized color display device of the present invention is a large-sized color display device that displays information in color by arranging a plurality of picture elements composed of three types of display elements that emit light in red, green, and blue. The display device is a color display device in which the picture element is a sealed container whose display surface side is translucent at least, mercury and an inert gas are sealed inside the container, and a phosphor film is formed on the inner surface. The discharge path is bent in a U-shape within the display surface of the display screen to form a substantially rectangular light-emitting display section for each color,
The display screen is characterized in that it is constituted by a fluorescent lamp having a power supply section disposed substantially perpendicularly to the display surface. In the present invention, the closed container may be made of any material, for example, transparent glass, and the mercury enclosed therein is in an appropriate amount necessary for the fluorescent lamp to exhibit a low-pressure mercury vapor discharge when the lamp is energized. Yes, inert gases include argon, neon,
or consisting of one or more krypton;
A pressure of about 0.3 to 6 mmHg is sealed. Use of one or more of various phosphors that emit blue, green, and red light as the phosphor. Furthermore, a white phosphor may be used if necessary. In the latter case, a color filter having desired color transmission characteristics is also used. About the shape of the display element A tubular fluorescent lamp is used as the display element, the middle part of which is bent into a U-shape within the display surface, and one end of a pair of light-emitting display parts is connected to each other within the display surface. Can be configured. Alternatively, both ends of the discharge path may be bent and extended toward the back side of the light-emitting display section, and the connection terminal may be located behind approximately the center of the discharge path of the light-emitting display section. In this way, by arranging the connecting device such as a socket connected to the fluorescent lamp in the center of the lamp, the directionality can be reduced or the connecting device can be easily attached. In order to make the effective light emitting area as wide as possible and obtain as high an average brightness as possible, the dimensional relationship between the width of the light emitting display section and the gap formed between the pair of light emitting display sections is as follows.
The width should be smaller than the width of the light emitting display section. However, in the case where it is sufficient to obtain an average brightness comparable to that of an incandescent lamp, the effective light emitting area may be small, so the gap may be made wider than the width of the light emitting display section. Furthermore, the space may be closed with glass by constructing the display side portion of the airtight container with a molded plate glass.
In addition, when it is necessary to downsize the light-emitting display section,
What is necessary is to minimize it to the extent that the division of the discharge path can be maintained. Regarding the configuration of the picture element, the picture element consists of one display element each that emits red and blue light, and two display elements that emit green light.
The display elements can be arranged in a rectangular shape as a set. This embodiment is effective when the amount of green light emission is small. Three picture elements exhibiting each luminescent color of red, blue, and green
The display element may be arranged in a triangular shape as one display element. When the display elements are composed of fluorescent lamps as in the present invention, it is relatively easy to ensure a sufficient amount of light for the green display elements, so a picture element is composed of three display elements as described above. Then, 1
The number of display elements per picture element can be minimized.
Moreover, since the display elements of adjacent picture elements can be arranged at equal intervals, color balance is improved. A picture element can be constructed by integrating four or three display elements. in this case,
Display elements can be easily mounted on a picture element basis. Further, a picture element can also be constructed by attaching each display element individually and removably to the display surface. In this case, the display elements can be replaced individually, which is economical. The arrangement of each picture element is preferably such that display elements of each color are distributed at regular intervals. Regarding the emitted light color of the display element It is desirable that the display element be constructed so that the desired emitted color is emitted by a fluorescent lamp itself formed with a phosphor film that emits red, green, and blue colors. This would be easy to manufacture and also advantageous in terms of implementation since it does not require a filter or the like. However, if the display element that emits blue and green light is composed of a fluorescent lamp formed with a phosphor film that emits blue and green light, and the display element that emits red light is composed of a fluorescent lamp that has a phosphor film that emits blue and green light, the display element that emits red light is replaced by a fluorescent lamp. It may also be configured by using a filter in combination. When the display element is composed of a fluorescent lamp as in the present invention,
Since it is difficult to obtain a fluorescent lamp with a phosphor film that emits the desired red color compared to green or blue, display elements that emit the desired red light can be easily provided by using a red filter together. can do. In this case, by using a fluorescent lamp formed with a phosphor film that emits a reddish color, light loss in the filter can be reduced. Note that the filter may be formed integrally with the display element, or may be separately provided in front of the display element. To form the filter integrally with the display element, the filter may be integrally attached to the surface of the fluorescent lamp, or it may be integrally fixed at a distance in front of the fluorescent lamp. Regarding lighting of the display element Since the display element is the discharge path of the fluorescent lamp,
The lighting may be dimmed using a light current or a DC power source. Further, the lighting may be dimmed using a high frequency lighting device. This high-frequency lighting device that performs dimming lighting has high efficiency and can be made lightweight and compact, making it easy to incorporate into a display device. Regarding attachment of the display element to the display surface The display element can be attached by providing a connection device such as a socket on the display surface and connecting the display element to the connection device. Moreover, each display element can be partitioned by a shield light plate to prevent the lights of adjacent display elements from undesirably mixing together. Further, a light transmitting plate may be provided in front of the display element to protect the display element and prevent dust, water, etc. from entering. Furthermore, this transparent plate may also be configured to serve as a color filter. (Function) According to the present invention, the effective light-emitting area of the display element as a light-emitting display section can be made longer by bending the discharge path in a U-shape within the display surface, so that the display area can be enlarged. At the same time, since one discharge path is bent only once within the display surface, the effective light emitting area can be increased to approximately 45% to 75% relative to the area occupied by one picture element, which is approximately 45% to 75% of the area occupied by one picture element, which is approximately
44%, which is a significant improvement over the approximately 22% for cathode ray tubes. In addition, since the contour shape of the display surface of the display element is approximated to a rectangular shape as much as possible, it is possible to increase the mounting density of one picture element and configure the desired size of about 8 mm or less on one side, and each picture element Since the packaging density of the array can be increased, the effective light emitting area can be increased and the arrangement of picture elements can be facilitated. In addition, since the power supply part is positioned perpendicular to the display surface, connection devices such as sockets that also attach connection terminals connected to the power supply part are not exposed on the surface, and furthermore, it is easy to attach and detach the display element. be able to. As a result, an observation state in which display elements emitting red, green, and blue light colors are fused, and a good color television image with sufficiently mixed colors can be visually recognized. Furthermore, the average brightness is 3900~ per pixel.
4600cd/m ² , which is significantly higher than the 1800cd/m ² of incandescent bulbs and 900cd/m ² of cathode ray tubes, and visibility during daytime can also be significantly improved. (Example) Hereinafter, an example of the present invention will be described with reference to the drawings. 4 to 6 show a first embodiment of the present invention. FIG. 4 shows the display surface 2 of the display device 1 shown in FIG.
A plurality of picture elements 11 are arranged in a matrix and serve as one display unit. The picture element 11 is composed of four display elements 12. As shown in FIG. 6, this display element 12 is installed inside a closed container 13 made of a translucent tubular glass container with a phosphor film P formed on the inner surface in advance at a temperature of 0.005 to 0.006 mmHg.
of mercury and argon gas at a pressure of several mmHg, and for example, filament electrodes 14, 1 are placed at both ends.
It consists of a tube-shaped fluorescent lamp in which power supply parts 17, 17 connected to 4 are protruded from both ends 16, 16 of the discharge path, and the single discharge path is locked, and the middle part is connected to the display surface 2. The display surface 2 is bent into a U-shape inside the
A pair of light emitting display portions 15, 15 are formed in parallel arrangement inside. The pair of light-emitting display sections 15, 15 are configured such that one end thereof is connected to each other within the display surface 2 via a gap 〓A. Moreover, each of the display elements 12 has an electrode 1
Both end portions 16, 16 where the light emitting display portions 4, 14 are provided are bent at a substantially right angle to the back side of the light emitting display portions 15, 15, and extending to one end portion of the light emitting display portions 15, 15. ing. The protruding element 12 formed in this manner is configured to emit red, green, and blue luminescent colors. For example, it consists of a fluorescent lamp formed with a phosphor film that emits blue and green colors,
A display element that emits red light is constructed by using a red fluorescent lamp together with a red filter 61. Thus, the display element 12 has a total of four display elements, one each of display elements R and B that emit red and blue light, and two display elements G and G that emit green light. As shown in FIG. 4, with the light emitting display parts 15 and 15 respectively located on the display surface side,
One picture element 11 is arranged in a substantially regular square shape in two stages, upper and lower, in a display element storage section 19 of the display surface 2 partitioned into a lattice shape by a light plate 18. In configuring this picture element 11, the display elements 12 located above and below can have both end portions 16, 16 disposed close to each other. By arranging the display elements 12 in this way, it becomes possible to integrally provide the sockets 20 for four display elements on the back side of the display surface 2, which makes it easy to attach the sockets 20 and also facilitate manufacturing. becomes. Each of the display elements 12 displays a color television image as a whole by being dimmed and lit according to the image signal by alternating current lighting or high frequency lighting. FIG. 12 shows an example of a circuit for AC lighting.
The display element 12 is connected to an AC power source 27 via a ballast 23 including a leakage transformer 21 and a filament transformer 22, a dimmer 26 including a phase control element 24, and a gate signal generator 25. Then, the AC power source 27 is phase-controlled by the dimmer 26 and energizes the display element 12 via the leakage transformer 21 of the ballast 23, but since the phase is controlled according to the image signal, the image signal The display element 12 will be dimmed accordingly. By this dimming, a color television image can be obtained. FIG. 13 shows an example of a circuit for high frequency lighting. The display element 12 is connected to a DC power source 60 via a light control device 31 and a high frequency generator 41. The light control device 31 includes a clock signal generator 32, a control transistor 33, a pulse width control device 34, and the high frequency generator 41 includes an input chain 42, an inverter transformer 43, a resonant capacitor 44, a switching transistor 45, and a pulse width controller 34. A first transistor inverter 46 consisting of a starting resistor 46 and connected to the dimming output terminal of the dimming device 31, and similarly to the first transistor inverter 46, an inverter yoke 47, an inverter transformer 48, and a resonant capacitor. 49, consisting of a switching transistor 50 and a starting resistor 51,
Dimmer 31 directly connected to DC current 60
and a second transistor inverter 52 connected to the terminal of the transistor. The inverter transformer 43 of the first transistor inverter 46 constitutes a leakage transformer, the output of which supplies a lamp current between the electrodes 14, 14 of the display element 12. Further, the second transistor inverter 52
is applied to both ends of the electrodes 14, 14 of the display element 12, respectively. Then, the light control device 31 controls the power in accordance with the required amount of light control, and the first transistor inverter 46 converts the power into high-frequency power to energize the display element 12. On the other hand, the second transistor inverter 52
Since a constant direct current is always supplied to heat the filament, the filament is heated continuously with a constant high-frequency power regardless of the amount of dimming, and stable discharge is maintained during dimming. Further, the light control device 31 generates a pulse width controlled output in this signal cycle using an arbitrary clock signal as a reference, and generates high frequency DC power corresponding to the light control amount via the control transistor 33 based on this pulse width signal. It can be sent to the device 41. Therefore, by arbitrarily changing the pulse width control amount of the dimming device 31 according to the image signal, the display element 12 is dimmed, and a color image can be obtained by this dimming. Note that a dimmer, a ballast, or a high-frequency generator as a lighting device can be installed on the back side of the display element 12 in the display device 1 in correspondence with each display element 12. According to the embodiment of the present invention described above, red R,
By forming the picture elements 11 with the display elements 12 exhibiting the respective luminescent colors of blue B and green G, the first
As shown in Figure 4, the chromaticities of red R, blue B, and green G (indicated by solid lines) are almost the same as those of cathode ray tubes (indicated by double-dot chain dots), and display good colors. can. In addition, the display element 12 has a small amount of heat generated, and since the light emitting display parts 15, 15 are formed as a pair by bending a single discharge path, the effective light emitting area is smaller than the area occupied by one display element. We were able to increase the percentage to approximately 75%. Furthermore, even if one pixel is formed into a small 80 mm square, the effective light emitting area is 4800.
It was confirmed that it can be made as wide as mm ² and that high average brightness can be obtained. Furthermore, it is possible to increase the mounting density by arranging a large number of picture elements 11 on the display surface 2, and it is also possible to improve visibility as a color television image even at short distances. Next, the second embodiment will be explained with reference to FIG. 7. In this embodiment, a picture element 11 is constructed by arranging a set of three display elements 12 in a triangular shape, and the same parts as those in the first embodiment are given the same reference numerals and explanations are omitted. do. That is, in this device, display elements 12 each emitting red R, green G, and blue B are arranged in a triangular shape, with each display element 12 being positioned on the front side. In this case, the light emitting area is smaller because there is less green compared to the first embodiment, but since the picture elements 11 are arranged close to each other, the effect on the area occupied by one picture element is The ratio of the light emitting area can be increased to about 75% as in the first embodiment. Table 1 shows a comparison of power consumption per pixel, brightness, and light emitting area between the first and second embodiments of the present invention and the conventional one.

【table】

[Table] As is clear from Table 1, the power consumption of the present invention is slightly higher than when using a cathode ray tube, but it is lower than when using an incandescent lamp, and the brightness is lower than that using a cathode ray tube and an incandescent lamp. Becomes higher. Furthermore, as mentioned above, in the present invention, the ratio of the effective light emitting area to one pixel increases, making it possible to downsize the pixel, so the degree of modification can be improved by arranging a large number of pixel elements at high density. can be done. FIGS. 8 and 9 are a perspective view and a side view of another embodiment of the display element 12 when it is attached to a display device. It should be noted that the same parts as in the previous embodiment are given the same reference numerals and the explanation thereof will be omitted. In the display element 12 of this embodiment, both ends 16, 16 of the discharge path are bent and extended toward the back side of the light-emitting display parts 15, 15, and the power supply parts 17, 17 are connected to the light-emitting display parts 15, 15.
It is located approximately at the back of the center of the 15 discharge paths. This one includes the power feeding section 17,
17 is located approximately at the center of the back of the light-emitting display units 15, 15, so there is no upward or downward direction, and as shown in FIG. This makes it easy to implement and is advantageous in terms of implementation. [Effects of the Invention] As detailed above, the present invention makes it possible to lengthen the discharge path by bending the discharge path of the display element in a U-shape within the display surface of the display device, and the bending is performed only once. Therefore, the effective light-emitting portion can effectively contribute to light emission, so it has an average brightness at least as high as that of an incandescent bulb, and the outline shape on the display surface can be approximated to a rectangular shape. Since the power supply part is arranged approximately perpendicular to the display surface, it is easy to attach the fluorescent lamp to the display board, and when looking at the display surface, the power supply part is within the area of the light emitting display part. As a result, it is possible to increase the occupation rate of the light-emitting display section to the display surface, so the mounting density of one picture element can be increased and the size can be smaller than the required size, and the mounting density of the array of each picture element can also be reduced. The height can be increased, and the arrangement of picture elements is also easier.

[Brief explanation of the drawing]

FIG. 1 is a front view schematically showing a large color display device, FIGS. 2 and 3 are front views schematically showing picture elements of a conventional color display device, and FIGS. 4 to 6 are The first embodiment of the present invention is shown, FIG. 4 is a front view showing one picture element, FIG. 5 is a side view,
FIG. 6 is a partially cutaway perspective view showing a display element, FIG. 7 is a front view of one picture element showing a second embodiment of the present invention,
FIGS. 8 and 9 are perspective views showing other embodiments of the display element and side views showing the state in which it is attached to a display device, and FIGS. 10 and 11 are perspective views and front views showing conventional fluorescent lamps. 12 and 13 are circuit diagrams showing examples of lighting circuits for display elements, respectively, and FIG. 14 is a chromaticity diagram. 1... Display device, 2... Display surface, 3, 11...
Picture element, 12... Display element, 13... Transparent tubular body part, 14, 14... Electrode, 15, 15... Light emitting display section, 16, 16... End of discharge path, 17... Power supply Department.

Claims (1)

[Scope of Claims] 1. A large color display device configured to display information in color by arranging a plurality of picture elements each consisting of three types of display elements emitting red, green, and blue luminescent colors. The picture element is a sealed container whose display surface side is translucent at least, mercury and an inert gas are sealed inside the container, and a phosphor film is formed on the inner surface of the container, and the display surface of the display device is The discharge path is bent into a U-shape within the display to form a substantially rectangular light-emitting display section for each color, and has a power supply section disposed substantially at right angles to the display surface. A large color display device characterized by comprising a fluorescent lamp.