JPH0792641B2 - Color image display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in the following order.

A Industrial field B Outline of invention C Conventional technology D Problems to be solved by the invention E Means for solving problems (Fig. 1) F Action G Example G ₁ Description of display unit (No. 1) 1 to 9) Description of G ₂ display device (FIGS. 10 to 17) H Effect of the invention A Industrial field of application The present invention is a trio unit consisting of a combination of red, green and blue pixels. Relates to a color image display device in which a screen is formed by two-dimensionally arranging a plurality of trios.

B Outline of the Invention The present invention is a color image display device in which one trio unit consisting of a combination of red, green and blue pixels is two-dimensionally arranged in a plurality of trio units to form a screen, and the red and green pixels emit light. By using a diode and a blue pixel as a fluorescent display tube or the like, it is possible to obtain a pixel with low power consumption and no problem in brightness and cost.

C Prior Art A display device in which fluorescent display tubes are two-dimensionally arranged to form a large screen is described in, for example, Japanese Patent Application Laid-Open No. 60-32239. That is, one trio unit composed of a combination of red, green, and blue pixels is composed of a fluorescent display tube, and these units are two-dimensionally arranged to form a color screen.

D. Problems to be Solved by the Invention According to such a display device, since the fluorescent display tube is used for the configuration of the red, green and blue pixels, it consumes a lot of power and can be driven at a high voltage. There was also a problem.

Therefore, it is conceivable to use a light emitting diode that consumes less power and can be driven at a low voltage for the configuration of the red, green, and blue pixels. In this case, the red light emitting diode and the green light emitting diode can be mass-produced easily, and the light emitting efficiency is relatively good, and the light emitting diode can be practically used. there were.
For example, a display device in which a pixel is composed of only light emitting diodes has been proposed as described in Japanese Utility Model Laid-Open No. 56-22572, but it is inevitably limited to two colors.

In view of this point, the present invention has been made to obtain a device which has relatively low power consumption and which has no problem in brightness and cost.

E Means for Solving Problems In order to solve the above problems, the red and green pixels are composed of light emitting diodes (11R) and (11G), and the blue pixels are fluorescent display tubes (10). Etc.

F action Red and green pixels are composed of light emitting diodes (11R) and (11G), so power consumption is reduced. Further, since the blue pixel is composed of the fluorescent display tube (10), there is no problem in brightness and cost.

G Embodiment One embodiment of the present invention will be described below with reference to the drawings.

Description of G ₁ Display Unit (FIGS. 1 to 9) FIG. 1 shows the display unit (100) as a whole. The screen of this display unit (100) has light emitting diodes (LEDs) (11R) and (11G) for emitting red and green light.
As shown in FIG. 2, a plurality of horizontal lines and a plurality of horizontal end faces (12a) of the light guides (12a) are alternately arranged in the vertical direction. It is arranged and configured. The other end face of the light guide (12) is fixed on the display segment of one fluorescent display tube (10) for emitting blue light for each line, and the display segment on the end face (12a) of the light guide (12) is fixed. Is displayed as it is, that is, it is displayed in blue. In this case, the pair of light emitting diodes (11R) and (11G) and the end face (12a) of one light guide (12) have corresponding sizes as shown in FIG. 3, and the screen of the display unit (100) is , These 1
One trio unit consisting of a pair of light emitting diodes (11R) and (11G) and an end face (12a) of one light guide (12) is arranged by arranging, for example, 24 horizontally and 24 vertically, for example. . This one trio unit corresponds to one pixel. For example, the sizes of the light emitting diodes (11R) and (11G) are length = 4 mm and width = 4 mm, and the size of the end face (12a) of the light guide (12) is length = 4 mm and width = 8 mm, The size of one trio unit is 8 mm in length and 8 mm in width. Therefore, the size of the screen of the display unit (100) is 192 mm in length and 192 mm in width.

4 to 7 show a fluorescent display tube. FIG. 4 is a perspective view, FIGS. 5 and 6 are sectional views showing the internal electrode structure thereof, and FIG. 7 is a front view. In the figure, (1)
Is a glass tube consisting of a front panel (1a), a rear panel (1b), and four side panels (1 _C1 ) to (1 _C4 ). This glass tube (1) is constructed by sealing a front panel (1a), side panels (1 _C1 ) to (1 _C4 ) and a back panel (1b) with a frit (not shown). . In this case, the front panel (1a) and the rear panel (1b) are arranged so as to be sandwiched between the side panels (1 _C1 ) to (1 _C3 ). Further, the exhaust pipe (2) is fixed to the side panel (1 _C4 ) with a frit.

Further, a blue fluorescent material layer is applied to the inside of the front panel (1a) of the glass tube (1) to form ₂₄ fluorescent display segments A _{1 to} A ₂₄ . These display segments A _{1 to} A
_A metal back layer (4) made of, for example, aluminum is applied to the inside of ₂₄ . Reference numeral (5) is an anode lead, which is led out to the outside through a sealing portion between the front panel (1a) and the upper end surfaces of the side panels (1 _C2 ) and (1 _C4 ). The metal back layer (4) through the anode lead (5),
Therefore, a high voltage is applied to the display segments A _{1 to} A ₂₄ .

Further, in the glass tube (1), display segments A ₁ ~
A cathode (heater) K is arranged so as to face A ₂₄ . Also, the cathode K and display segments A _{1 to} A ₂₄
A second grid G ₂ forming an accelerating electrode is arranged between the and. Further, between the cathode K and the second grid G ₂ , there is provided a first grid G ₁ , _{1 to} G ₁ , ₂₄ which constitutes a control electrode in a one-to-one correspondence with each display segment A _{1 to} A _24. Will be placed. Leads k ₁ , k _{2 of} cathode K, first grid G ₁ , _{1 to} G
_{1, 24} leads g ₁ of, ₁ to g _{1, 24,} the second lead grids G ₂
g ₂₁ and g ₂₂ are side panel (1 _C3 ) and rear panel (1b), respectively.
Is led out to the outside through a sealing portion between the upper end surface of the.

In such a configuration, an anode voltage of, for example, about 10 KV is applied to the display segments A _{1 to} A ₂₄ through the anode lead (5). In addition, each first grid G ₁ , ₁ ~
A voltage of 0 V or 30 V, for example, is applied to G ₁ and _24, and 300 V, for example, is applied to the second grid G ₂ . In this case, the anode side and the second grid G ₂ have a fixed voltage, and are selectively turned on and off by the voltage applied to the first grids G ₁ , _{1 to} G ₁ , ₂₄ . That is, the first grid G ₁ , ₁ ~
When 0 V is applied to G ₁ and ₂₄ , the electron beam from the cathode K is shielded and its corresponding display segment A ₁
~ A ₂₄ is not illuminated. On the other hand, the first grid G ₁ , _{1 to} G
_When 30V is applied to ₁ and ₂₄ , the electron beam from the cathode K passes through the first grids G ₁ , _{1 to} G ₁ , ₂₄ and is accelerated by the second grid G ₂ to correspond to the corresponding display segments A _{1 to} A _24. It reaches the fluorescent body and is illuminated and displayed. And at this time the first
The emission brightness is controlled by controlling the application time of the voltage (30 V) applied to the grids G ₁ , _{1 to} G ₁ , ₂₄ . As described above, by selectively controlling the voltage and the application time of the first grids G ₁ , _{1 to} G ₁ , ₂₄ , the respective display segments A _{1 to} A _1
24 are selectively illuminated and displayed with a predetermined brightness.

FIG. 8 shows 24 light guides (12) arranged for each horizontal line. These light guides (1
2) is formed by, for example, integral molding. In this case, one end face (12
The lateral width of a) is made wider than the width of the other end face (12b) fixed to the display segments A _{1 to} A ₂₄ of the fluorescent display tube (10). Thus, the end face (12a) of the light guide (12)
As described later, when the display units (100) are two-dimensionally arranged to form a screen, it is possible to prevent a gap between the screens of the display units (100) by expanding the horizontal direction. it can.

The light emitting diodes (11R) and (11G) are, as shown in FIG. 9, an insulating layer (13b) on an aluminum plate (13a).
Is placed on an aluminum substrate (13) on which a predetermined wiring pattern (13c) made of copper foil is formed. That is, the end portion of the aluminum substrate (13) is bent in a convex shape, the insulating layer (13b) of the portion forming the vertical surface of the tip is removed, and the LED chip (14) is mounted on this portion. . The + electrode of the LED chip (14) is connected to the wiring pattern (13c) via the gold wire (15), and the-electrode is connected to the ground via the aluminum plate (13a). The aluminum plate (13a) is also used as a heat sink, and the portion on which the LED chip (14) is mounted is made a mirror surface and is also used as a reflection surface. In the figure, (16) is a cap made of transparent resin. In addition, a plurality of light emitting diodes (11R) and (11G) that form one horizontal line
Are arranged on one aluminum substrate (13). Also, the ninth
As shown in the figure, the light emitting diodes (11R), (11G) and the light guides (12) are arranged alternately in the vertical direction in a so-called sandwich shape, but between the two horizontal lines of the light guides (12). The drive circuit (17) for the light emitting diodes (11R) and (11G) is arranged on the aluminum substrate (13) in the space that can be formed.

In addition, the light emitting diodes (11R) and (11G) thus arranged on the aluminum substrate (13) and the other end face are fixed to the display segments A _{1 to} A ₂₄ of the fluorescent display tube (10). With the light guides (12) arranged alternately in a sandwich, as shown in FIG. 1, the aluminum substrate (13) and the fluorescent display tube (10) are sandwiched and fixed by the frame (18) to be integrated. It is said that In this case, the size of the frame (18) is at least such a size that the frame (18) does not protrude from the front surface of the display unit (100).
When a plurality of 0) are arranged two-dimensionally to form a screen, the screens of the respective display units (100) are connected without a gap.

Further, in FIG. 1, (19) is a printed circuit board arranged corresponding to each fluorescent display tube (10), and a drive circuit for the fluorescent display tube (10) is provided on this printed circuit board (19). Has been formed. Further, as will be described later, (20) is a vertical plate used for screwing and fixing the display unit (100) to the steel frame, and is inserted between the frame (18) and the printed circuit board (19). To be done.

G ₂ Display device description (Figs. 10 to 17) The above display unit (100) is only 20 vertical x 26 horizontal = 520 2
A display device (200) having a large screen as shown in FIG. 10 is configured by being arranged in a dimension. In this case, each display unit (100) has a steel frame (21) as shown in FIGS. 11 and 12.
Then, the display device (200) is configured by being fixed with a screw (22) and having an outer frame (23) provided on an unnecessary portion other than the display screen.

The screen of this display device (200) is composed of 20 units in the vertical direction and 26 units in the horizontal direction = 520 units of the display unit (100), and the length is about 3.8 m (480 lines) and the width is about 5 m (629 trio). Of about 300,000 trio units.

Next, the circuit configuration of this display device (200) will be described.

In FIG. 13, a video signal from a signal source such as a camera (30), a VTR (31) and a tuner (32) is selected by an input selector switch (33). This video signal is, for example, a composite signal of NTSC system, and this video signal is supplied to the decoder (34) to be the three primary color signals R, G, B of red, green and blue. These three primary color signals R, G, B are supplied to the A / D conversion circuits (35R), (35G), (35B), respectively, and are converted into 8-bit parallel digital signals, for example.

Each of these digital signals is one field of memory (36R ₁ ), (36G ₁ ), (36B ₁ ), and (36R ₂ ), (36G ₂ ),
(36B ₂ ) and are alternately supplied. In these memories,
Scanning line conversion is performed on 240 lines in each field.
A total of 20 (× 8 bit parallel) outputs are extracted for each book.

Here, the order of taking out is the display unit (100) described above.
The signal is completed every time. That is, when there are two adjacent display units as shown in FIG. 14, in one field, the digital signals of the pixels corresponding to the respective trio units are extracted from one memory in the order of numbering. , 12 scan lines (1 to 24) (25 to 48) of the left display unit (25 to 48) ... 24) (25 ~ 48) ... (265 ~ 28
Pixel data corresponding to 8) is taken out and sequentially moved to the display unit on the right side. Note that the scan line with a dash is fetched from the other memory to the next field by interlaced scanning. The data of each of these pixels is stored in each memory (36R ₁ ), (36G ₁ ), (36B ₁ ) or (36B ₁ ).
R ₂ ), (36G ₂ ), and (36B ₂ ) are simultaneously extracted. In addition, 20 out of every 12 lines are taken out at the same time.

The data fetched from the memories (36R ₁ ) and (36R ₂ ) is supplied to the data selector (37R), and in this data selector (37R), red data R ₁ from the memory on the side not being written is written for each field. ~ R ₂₀ is taken out.
And the red data R ₁ is 26 display units (100)
P corresponding to the first horizontal unit row composed of [u _{1 to} u ₂₆ ]
It is supplied to CM / PWM converter circuit (38R _1). In the conversion circuit (38R _1), the red data R _1, each display unit
Converted to a PWM signal that drives the light emitting diode (11R) of u _{1 to} u ₂₆ . That is, in the odd field, twelve scanning lines (1 to 2 in FIG. 14) of each display unit u _{1 to} u ₂₆ .
4,25~48, ···, PWM signal r ₁ ~r _{28 8} for driving the light emitting diode (11R) constituting the support) to 265 to 288 is obtained,
In the even field, _{1 of} each display unit u _{1 to} u ₂₆
Two scanning lines (1'-24 ', 25'-48' in FIG. 14,
..., corresponding to 265 'to 288'), PWM signals ▲ r ^' ₁ ▼ to r ₂₈ ' ₈ for driving the light emitting diodes (11R) are obtained. These PWM signals r _{1 to} r _{28 8} and ▲ r ^′ ₁ ▼ to r ₂₈ ′
₈ is supplied to the drive circuit of the corresponding light emitting diode (11R). As shown in FIG. 15, the PWM signal r ₁ is supplied to the base of an npn-type transistor (40R), the emitter of this transistor (40R) is grounded, and its collector is connected to a DC voltage via a resistor (41R). It is connected to a power supply terminal (42R) to which + B (for example, + 12V) is supplied. Also, the connection point between the collector of the transistor (40R) and the resistor (41R) is connected to the base of the npn-type transistor (43R), the collector of this transistor (43R) is connected to the power supply terminal (42R), and its emitter Is a resistor for brightness adjustment (44R)
Also, it is grounded through a series circuit of a light emitting diode (11R). In this case, the transistor (40R) is turned off and the transistor (43R) is turned on according to the pulse period of the PWM signal r ₁ , so that the light emitting diode (11R) emits light with the brightness corresponding to the pulse width of the PWM signal r _1. Done PWM signal r _{2
^{~r 28 8, ▲ r '1}} ▼ ~r 28' emitting diodes corresponding in the same manner with respect to ₈ (11R) is emitted.

In addition, red data R _{2 to} R ₂₀ from the data selector (37R)
Similarly to the case of the red data R ₁ described above, the red data R ₁ is also supplied to the PCM / PWM conversion circuit (not shown) corresponding to the second to twentieth horizontal unit rows each including 26 display units (100). The light emitting diodes (11R) corresponding to the PWM signals output from these conversion circuits emit light with a luminance corresponding to the pulse width of the PWM signal. This allows
A red image is displayed on the screen of the display device (200).

Further, the data taken out from the memories (36G ₁ ) and (36G ₂ ) is supplied to the data selector (37G), and in this data selector (37G), the green color from the memory on the side not being written is written for each field. The data G _{1 to} G ₂₀ are retrieved. Then, the green data G ₁ is supplied to the PCM / PWM conversion circuit (38G ₁ ) corresponding to the first horizontal unit row composed of 26 display units (100) [u _{1 to} u ₂₆ ]. In this conversion circuit (38G ₁ ), the green data G ₁ is the PWM that drives the light emitting diode (11G) of each display unit u _{1 to} u _26.
Converted to a signal. That is, in the odd field,
PWM signal for driving the light emitting diode (11G) that composes 12 scanning lines (corresponding to 1 to 24, 25 to 48, ..., 265 to 288 in FIG. 14) of each display unit u _{1 to} u ₂₆ g ₁ to g _{28 8} is obtained, in the even field, the display unit u ₁
~ U ₂₆ 12 scanning lines (1'-24 ', 25' in Fig. 14)
~48 ', ···, 265'~288' PWM signal g ₁ '~g _{28' 8} for driving the light emitting diodes constituting the support) to (11G) is obtained. These PWM signals ^{_{g 1 ~g 28 8, ▲ g}} '1 ▼ ~
The g ₂₈ ′ ₈ is supplied to the drive circuit of the corresponding light emitting diode (11G).

As shown in FIG. 16, the PWM signal g ₁ is supplied to the base of the npn-type transistor (40G), and this transistor (40G)
Has its emitter grounded and its collector a resistor (41G)
Is connected to a power supply terminal (42G) to which a DC voltage + B (for example, + 12V) is supplied via. In addition, the transistor (40
The connection point between the collector of G) and the resistor (41G) is connected to the base of the npn transistor (43G), the collector of this transistor (43G) is connected to the power supply terminal (42G), and its emitter is brightness adjusted. It is grounded through a series circuit of a resistor (44G) and a light emitting diode (11G). In this case, the transistor (40G) is turned off and the transistor (43G) is turned on in accordance with the pulse period of the PWM signal g ₁ , so that the light emitting diode (11G) emits light with the brightness corresponding to the pulse width of the PWM signal g _1. Done PWM signals g ₂ ~g _{28 8,}
The corresponding light emitting diode (11G) emits light in the same manner for g ^′ ₁ ˜g ₂₈ ′ ₈ .

Also, green data G _{2 to} G ₂₀ from the data selector (37G)
Similarly to the case of the green data G ₁ described above, the green data G ₁ is also supplied to the PCM / PWM conversion circuit (not shown) corresponding to the second to twentieth horizontal unit rows each including 26 display units (100). A light emitting diode (11G) corresponding to each of the PWM signals output from these conversion circuits emits light with a luminance corresponding to the pulse width of the PWM signal. This allows
A green image is displayed on the screen of the display device (200).

Further, the data fetched from the memories (36B ₁ ) and (36B ₂ ) is supplied to the data selector (37B), and this data selector (37B) supplies blue data from the memory on the side not writing for each field. B _{1 to} B ₂₀ are taken out. Then, the blue data B ₁ is displayed on 26 display units (10
0) The signal is supplied to the PCM / PWM conversion circuit (38B ₁ ) corresponding to the first horizontal unit row composed of [u _{1 to} u ₂₆ ]. In this converter (38B _1), the blue data B ₁ is, is converted into a PWM signal for driving the fluorescent display tube (10) corresponding to the light guide (12) of the respective display units u ₁ ~u _26. That is, in the odd field, 12 scanning lines of each display unit u _{1 to} u ₂₆ ( _{1 to 24} , 25 to 48, ..., 265 to 28 in FIG. 14).
The PWM signals b _{1 to} b _{28 8} for driving the fluorescent display tubes (10) corresponding to the light guides (12) constituting the display units u _{1 to} u in the even field are obtained.
Twelve scanning lines of ₂₆ (1'-24 ', 25'-4 in FIG. 14)
PWM for driving the fluorescent display tube (10) corresponding to the light guide (12) constituting 8 ', ..., 265'-288')
The signals ▲ b ^′ ₁ ▼ to b ₂₈ ′ ₈ are obtained. These PWM signals b _{1
^{~b 28 8, ▲ b '1}} ~b 28' 8 is supplied to the drive circuit of each corresponding fluorescent display tube (10).

As shown in FIG. 17, the PWM signals b _{1 to} b ₂₄ are supplied to the bases of the npn transistors (51 ₁ ) to (51 ₂₄ ), respectively.
The emitters of these transistors (51 ₁ ) to (51 ₂₄ ) are grounded, and the collectors of the transistors (51 ₁ ) to (52 ₂₄ ) are connected to the fluorescent display tube (10) through resistors (52 ₁ ) to (52 ₂₄ ) of high resistance, for example, ₁₀₀ KΩ. It is connected to the first grid _{G 1, 1 ~G 1, 24} . Further, a voltage source (53) of, for example, + 50V is applied to the commonly connected second grid G _2, and each of the voltage sources (53) has a high resistance, for example, 100K.
Ω resistors (54 ₁ ) to (54 ₂₄ ) through the transistor (5
1 ₁ ) to (51 ₂₄ ) connected to the collector. The display segments A _{1 to} A ₂₄ have a higher voltage than the terminal (55), for example 10K.
V is applied. Further, the cathode K is heated by the voltage source (56) of, for example, + 1.4V.

In this case, the transistors (51 ₁ ) to (51 ₂₄ ) are turned off corresponding to each pulse period of the PWM signals b _{1 to} b ₂₄ , and + 50V
The voltage from the voltage source (53) of the resistors (54 ₁ ) to (5
4 ₂₄ ), (52 ₁ )-(52 ₂₄ ) through the first grid, respectively
It is applied to the _{G 1, 1 ~G 1, 24} , electrons from the time the cathode K is supplied to the display segment A ₁ to A ₂₄ each. Therefore, the display segments A _{1 to} A _{24 respectively} have the PWM signals b _{1 to} b.
It emits light with a brightness corresponding to a pulse width of ₂₄ . PWM signal _{b 25 ~b 28 8, ▲ b} '1 ▼ ~b 28' display segment A ₁ to A ₂₄ of the corresponding fluorescent display tube in the same manner with respect to ₈ (10) is emitted.

In addition, blue data B _{2 to} B ₂₀ from the data selector (37B)
Is also supplied to the PCM / PWM conversion circuit (not shown) corresponding to the second to twentieth horizontal unit rows each including 26 display units (100), as in the case of the blue data B ₁ described above. The display segments of the fluorescent display tube (10) corresponding to the PWM signals output from these conversion circuits emit light with brightness corresponding to the pulse width of the PWM signal. As a result, a blue image is displayed on one end face (12a) of the light guide (12) whose other end face is fixed to the display segment of the fluorescent display tube (10).

Thus, on the screen of the display device (200), the light emitting diodes (11R) and (11G) display the red image and the green image, respectively, and the light guide (12) displays the blue image, and thus the color image. Is displayed. That is, a high-definition color screen of about 300,000 trio (300,000 pixels) is displayed.

As described above, according to this example, since the red and green pixels are composed of the light emitting diodes (11R) and (11G), it is possible to reduce power consumption as compared with the case where all of them are composed of the fluorescent display tube. . Further, since the blue pixel is composed of the fluorescent display tube (10), it is possible to obtain the one having sufficient brightness and no problem in cost.

In the above embodiment, the blue pixel is the fluorescent display tube (1
However, it is also conceivable to use a liquid crystal display element, a plasma display tube, or the like. Further, the size of the display screen of the display device (200), the size of the display unit (100), and the like are examples, and the present invention is not limited to these.

H According to the present invention described above, since the red and green pixels are composed of light emitting diodes, power consumption can be reduced, and the blue pixel is composed of a fluorescent display tube. It is possible to obtain a display having no problem in brightness and cost.

[Brief description of drawings]

FIG. 1 is a perspective view of a display unit in an embodiment of the present invention, FIGS. 2 to 9 are views for explaining the same, FIG. 10 is a perspective view of a display device, and FIGS. The assembly explanatory drawing,
FIG. 13 is a circuit configuration diagram of a display device, FIG. 14 is a diagram for explaining the same, FIGS. 15 and 16 are drive circuit diagrams of light emitting diodes, and FIG. 17 is a drive circuit diagram of a fluorescent display tube. is there. (10) is a fluorescent display tube, (11R) and (11G) are light emitting diodes, (12) is a light guide, (100) is a display unit, and (200) is a display device.

Claims (1)

[Claims] 1. In a color image display device in which one trio unit consisting of a combination of red, green and blue pixels is two-dimensionally arranged in a plurality of trio units to form a screen, and the red and green pixels are light emitting diodes. The blue pixel is composed of a fluorescent display tube disposed behind the light emitting diode and a light guide connected to the fluorescent display tube, and the screen area ratio of the red, green and blue pixels is 1: 1. A color image display device, wherein one trio unit is configured to be pair 2.