JPH0350554Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a fluorescent display device for graphic display, and in particular to a fluorescent display device that enables high-quality graphic display without causing brightness unevenness or reduction in brightness within a pixel. It is.

In general, fluorescent display devices for graphic display are different from conventional fluorescent display tubes that display end numbers and characters using a combination of segments. It is displayed by a combination of minute anodes such as shape. The minute anodes are called dots, and these dots are arranged in a plane in multiple columns and rows, and are driven to emit light in a matrix manner, so this type of display device is called a dot matrix type display device. There is.

A conventional example of a dot matrix type display device in which the anode is improved and formed into a band shape to increase the density is a fluorescent display device disclosed by the present applicant in Japanese Utility Model Application No. 162692/1983. In this fluorescent display device, as shown in FIG. 1, strip-shaped anodes A ₁ to A _o are arranged on a substrate in either the column direction or the row direction, in this embodiment, in the column direction. The band-shaped anodes A ₁ to A _o are formed by forming a band-shaped anode conductor on an insulating substrate, for example, a glass substrate, and depositing a phosphor layer on the anode conductor to form the band-shaped anodes A ₁ to A _o . was. A direction perpendicular to this band-shaped anode A ₁ ~A _o ,
In Figure 1, multiple control electrodes are arranged in the row direction.
G ₁ to G _o and a cathode (not shown) stretched above the control electrode, and electrons emitted from the cathode are controlled by each of the two adjacent control electrodes. The display device includes a fluorescent display tube section that emits light as one pixel by colliding with a region on the anode conductor, and a drive circuit that simultaneously applies a control voltage to each of the two adjacent control electrodes.

In this way, a control pulse is simultaneously applied to the two control electrodes G ₁ , G _{2 .} The part A _o emits light to form a pixel. This driving state will be explained with reference to the timing chart shown in FIG.

Control electrodes G ₁ to G _o shown in FIG. 1 are sequentially connected to adjacent control electrodes G ₁ and G ₂ by a control circuit (not shown).
A control voltage is applied to G ₂ and G ₃ , G ₃ and G ₄ . That is, after applying a control voltage to the control electrode G ₁ as shown in FIG. 2 AG ₁ , after a predetermined period of time, as shown in FIG _.
By applying _a control voltage to control electrode G ₂ as _shown in _FIG .
At the same time, a control voltage is applied to the

And during this period T ₁ , the anode of the first row
As shown in FIG. _2FA1 , when the switch is closed to apply an anode voltage to _the anode _A1 , the electrons emitted from the cathode impinge on the pixel _P1 . The phosphor layer ₁ is excited and emits light.

Next, a control voltage is continuously outputted to the control electrode _G2 even after the period _T1 , and a control voltage is outputted to the control electrode _G3 during the period _T2 . Therefore, in period _T2 , control voltages are applied to control electrodes _G2 and _G3 at the same time, and in synchronization with this, an anode voltage is applied to anode _A2 , causing pixel _P2 to emit light.

Furthermore, the same effect causes the pixel P ₃ to emit light during the period T ₃ .

In this way, the adjacent control electrodes G _o-1 ,
By scanning the G _o simultaneously and applying an anode voltage according to the display signal to the anodes A ₁ to A _o in synchronization with this scanning, it is possible to obtain detailed displays of characters, figures, etc. It is what it is.

By the way, this conventional fluorescent display device has a driving method in which a control voltage is simultaneously applied to two adjacent control electrodes, and the portion of the anode sandwiched between the two control electrodes is caused to emit light. Therefore, since the method uses the electric field created by the two control electrodes to focus the electrons onto the target anode, if the pixel size is circular or quadrilateral with a diameter of 0.5 mm or less, the electrons will be emitted evenly. Uniform and good light emitting conditions can be obtained all of a sudden, but if the diameter of one pixel is circular or quadrilateral with a diameter of 0.5 mm or more, the potential will drop in the center between the two control electrodes. had the following problems.

In the center of the pixel, the density of electrons decreases, resulting in decreased luminance and unevenness. Furthermore, the average luminance of the pixels as a whole also decreases.

In the non-emitting part, the control electrode is set to a negative potential,
This prevents electrons from being attracted to the positive potential of the anode and emitting light. This operation is called cut-off, and the voltage that causes the cut-off is called cut-off voltage.
In this case, as the size of one pixel increases, the area of the anode to which a positive potential is applied increases, so there is a problem that cut-off cannot be achieved unless the cut-off voltage is increased.

However, in recent years, various fluorescent display devices have been required.
One of these is the enlargement of the display screen. Increasing the number of pixels is also effective in increasing the display screen size, but this requires a complicated control method. In order to easily enlarge the resignation screen, it is required to increase the size of one pixel.

In addition, there is a strong demand for color display screens, and research is being conducted on forming one pixel with two or three anodes, each coated with two or three types of color phosphors that emit light in different colors. In this case as well, the pixels may become larger than before.

As one pixel becomes larger in this way, there is a higher possibility that the above-mentioned problem will occur.

Therefore, the present invention was developed in view of the above-mentioned circumstances. Even if the pixels are large, the luminance is uniform, the cut-off voltage can be lowered, and the cut-off is not impossible and no leakage occurs. It is an object of the present invention to provide a fluorescent display device that can prevent such problems.

In order to achieve the object of the present invention, the configuration of the present invention includes a band-shaped anode having a phosphor coated on the upper surface of an insulating substrate, and a plurality of strip-shaped anodes spaced apart in a direction crossing the band-shaped anode. It has a control electrode and an anode stretched above the control electrode, and a region on each strip-shaped anode that is controlled by simultaneously applying a control voltage to each of the two adjacent control electrodes is defined as a pixel. In a fluorescent display device for displaying a display, the fluorescent display tube section includes a reinforcing control electrode between the two adjacent control electrodes, and a drive for applying a control voltage to the reinforcing control electrode at the same time as the two adjacent control electrodes. It is characterized by comprising a circuit.

Hereinafter, embodiments of a fluorescent display device according to the present invention will be described with reference to the drawings.

FIG. 3 is an explanatory diagram of an embodiment of the fluorescent display device according to the present invention. In this embodiment, the anodes A are arranged from A ₁₁ to A _o in the column direction, but they can also be arranged in the row direction. Control electrodes G ₁₁ to _{G o+1} are arranged in a direction perpendicular to this anode A. One auxiliary control electrode G _11a to _Goa is arranged between the control electrodes.
This auxiliary control electrode G _11a has a wire shape and is configured to be stretched between the control electrodes G ₁₁ and G ₁₂ .

The anodes A ₁₁ to _{A o} are strip-shaped and have a width of 0.5 mm or more. The embodiment shown in FIG.
The width of A _{11 to o} is 0.75 mm, and since it is desirable for the aspect ratio of pixels to be 1:1 in graphic display, the distance between the control electrodes is also 0.75 mm, and the auxiliary control electrode G _11a is arranged in between. Therefore, the pitch interval between the control electrode and the auxiliary control electrode is 0.375 mm, which can be reduced to 0.5 mm or less.

Therefore, in FIG. 3, SA ₁₁ to SA _o are switches provided for each anode A ₁₁ to _{A o} , and are opened and closed according to display signals, and SG ₁₁ , SG ₁₃ ,
SG _2o+1 with an odd number such as SG ₁₅ ... is provided for each control electrode G ₁₁ , G ₁₂ ...G _o+1 , and sequentially scans the control electrodes G ₁₁ to G _o+1. This is a switch for Switches with even numbers such as SG ₁₂ , SG ₁₄ , etc. are connected to each auxiliary control electrode G _11a , G _12a , and each auxiliary control electrode G _11a is synchronized with the upper and lower control electrodes so that both overlap. A switch configured to apply a control voltage at certain times. In addition, Rg (Rg ₁₁ , Rg ₁₂ ...) is the control electrode that is not selected.
This is a grid resistance to maintain G _o and the auxiliary control electrode G _o a below the cathode voltage. Further, Eg is a control power source for applying a control voltage to the selected control electrode G _o and auxiliary control electrode G _oa , and Eb is
Ek is an anode power supply for applying an anode voltage to the selected anode A _o , and Ek is a bias power supply for maintaining unselected control electrodes and auxiliary control grids below the cathode potential via a frid resistor Rg. . In addition, filament-shaped oxide cathodes F ₁ to _{F o} are stretched over the anode A _11-o in the same direction as the anode A _11-o . Furthermore, Ef is a heating power source for heating the oxide cathode F _1-o .

With the configuration shown in FIG _. 3, the control electrode switches _{SG 11} , SG _{13 ,} . ₁₂ , _G13, and so on are scanned sequentially.

This driving state will be explained with reference to the timing chart shown in FIG.

The control electrode is closed by closing switch SG ₁₁ in Figure 3.
At G ₁₁ , the control voltage is set to the period as shown in Figure 4 AG ₁₁ .
Grant up to T ₁₁ . Then, by closing switch S ₁₃ , control electrode G ₁₂ is switched from period T ₁₁ as shown in CG _12.
Control voltage is applied up to T ₁₂ . Further control electrode
G ₁₁ and G ₁₂ switches SG ₁₁ and SG ₁₃ synchronized,
The auxiliary control electrode G _11a is switched on by closing the switch SG ₁₂ during the period when both regime voltages overlap, ie during the period T ₁₁ .
A control voltage is applied to the That is, the scanning is performed sequentially so that a total of three electrodes, two control electrodes G ₁₁ and G ₁₂ and one auxiliary electrode G _11a , are closed at the same time.

And in this period T ₁₁ , the pixel of the first row
P ₁₁ , P ₁₂ ... are selected and the switch connected to the anode is closed according to the display signal within this period T ₁₁ .
The pixel P on the anode A selected by SA ₁₁ to _{SA o} emits light. For example, this period
Switch SA ₁₁ in T ₁₁ as shown in Figure 4 HA ₁₁
is closed and anode voltage is applied to anode A ₁₁ ,
Electrons emitted from cathode F hit pixel _P11 ,
The phosphor in this image _P11 is excited and emits light. That is, the control electrodes G ₁₁ and G ₁₂ located on both sides above the pixel P ₁₁ are both at a positive potential, and the auxiliary control electrode G _11a located between them is also at a positive potential _. A positive electric field is formed in the upper covering position, and the electrons emitted from the cathode F can directly impact the pixel _P11 without being bent. Therefore, there is no region in the center of the pixel P ₁₁ where electrons do not collide, and uneven brightness can be reliably prevented and a high-quality display can be obtained.

Next, switches SG ₁₃ , SG ₁₄ , SG ₁₅ are closed to apply a control voltage to control electrodes G ₁₂ , G ₁₃ and auxiliary control electrode G _12a , and in synchronization with this, switch SA ₁₂ of anode A ₁₂ is closed. By doing so, it becomes possible to selectively display pixel P ₂₂ during period T ₁₂ .

Furthermore, the same effect causes the pixel _P33 to emit light during the period _T13 .

In this way, the adjacent control electrodes G _o+1 ,
The auxiliary control electrode G _oa located between G _o and its control electrodes G _o+1 and G _o is simultaneously scanned, and in synchronization with this scanning, an anode voltage is applied to the anode A _o according to the display signal. By doing so, it becomes possible to display detailed characters, figures, etc. evenly.

Next, a second embodiment shown in FIG. 5 will be described.

This embodiment is a color graphic fluorescent display device in which the anode is divided into two parts and each part is coated with two types of phosphors that emit light of different colors.

FIG. 5 is an explanatory diagram showing the relationship between the anode A and the control electrode G of this embodiment, and FIG. 6 is a timing chart showing the driving state of this embodiment.

The anode A ₁₁ is composed of band-shaped anode segments A _11a and A _11b each having a width of, for example, 0.3 mm in the column direction, and the slit width between the anodes is very narrow, for example, 0.075 mm. _11a and A _11b are two strip-shaped anode segments forming one pixel.
A _11a is coated with a green-emitting phosphor, and the adjacent band-shaped anode A _11b is coated with phosphors of different luminescent colors, such as a red-emitting phosphor. Since one pixel consists of two colors, the anode pitch is
Although it is 0.375mm, the pixel pitch is 0.75mm, which is larger than 0.5mm.

The aspect ratio of one pixel is generally 1:1 in graphic displays, so if the width is 0.75 mm, the vertical direction is also 0.75 mm, but in the conventional method, the control electrode is also stretched every 0.75 mm. Just hang it up. If this is done, the electrons emitted between the two control electrodes will be bent directly below the control power source due to the influence of the electric field, creating a region with low electron density on the anode between the control electrodes. This results in a decrease in brightness. This invention uses two control electrodes.
Since the auxiliary control electrode G _11a is provided between the control electrodes G ₁₁ and G ₁₂ , electrons in the intermediate portion between the control electrodes G ₁₁ and G ₁₂ travel straight without being bent due to the electric field created by the auxiliary control electrode G _11a . Therefore, the electrons are evenly bombarded onto the anode, and uneven brightness can be completely prevented.

Next, the driving state of the fluorescent display device of the second embodiment will be explained with reference to the timing chart shown in FIG.

By closing a switch provided in a control circuit (not shown) to the control electrode _G11 in FIG. 5, a control voltage is applied until the period _T21 as shown in FIG. 6 _AG11 .
Next, control electrode G ₁₂ is connected to the control electrode G 12 for a period of time as shown in Figure 6 CG ₁₂ .
A control voltage is applied from T ₂₁ to T ₂₂ . Therefore, during the period _T21 , the control voltage is applied to both the control electrodes _G11 and _G12 . In synchronization with this overlapping period _T21 , a control voltage is applied to the auxiliary control electrode _G11a to select the first row. Then, during this period T ₂₁ , the pixels of the first column, that is, the band-shaped anode segments A _11a and A _11b are selected, and the switches are closed according to the display signal within this period T ₂₁ , as shown in FIG.
Anode voltage is applied as shown in FA _11a and GA _11b . In this way, the electrons emitted from the cathode emit yellowish light, with the part _P11 sandwiched between the control electrodes _G11 and _{G12 on the band-shaped anode segments A11a and A11b as one} pixel, emitting both green and red light. Becomes a color. In addition, by changing the pulse width and voltage of the timing chart FA _11a and GA _11b of the band-shaped anode segments A _11a and A _11b shown in FIG. 6, the ratio of green and red components can be changed, and by changing the mixing ratio It is possible to emit various colors other than yellow.

Next, by closing the switches of the control electrodes G ₁₂ and G ₁₃ and the auxiliary control electrode G _12a during the period T ₂₂ , and synchronously closing only the band-shaped anode segment A _12a as shown in FIG. 6 HA _12a . strip anode segment
Only the green component of the pixel P ₂₂ consisting of A _12a and A _12b can be displayed by emitting light.

In this way, the adjacent control electrodes G _o+1 and G _o and the auxiliary control electrode G _oa sandwiched between the control electrodes G _o+1 and G _o are simultaneously scanned, and in synchronization with this scanning, the strip anode is By applying an anode voltage according to the display signal to the segments A _oa and A _ob , it is possible to display fine characters, figures, etc. in color without any unevenness.

FIG. 7 shows the third embodiment, in which the anode A ₁₁ is composed of three strip-shaped anode segments A _11R , A _11G , and A _11B , these three segments form one pixel, and the auxiliary control electrode
Two G _11a , G _11b , G _12a , and G _12b are stretched between adjacent control electrodes. Three strip anode segments A _11R , A _11G , A _11B are regularly red,
A phosphor that emits green and blue light is deposited. 7th
In the embodiment shown in the figure, from the left end, the band-shaped anode segments A _11R coated with a red-emitting phosphor are arranged, followed by the green-emitting band-shaped anode segments A _11G , and next to them, the blue-emitting band-shaped anode segments A _11B . has been done.

The area between the control electrode G ₁₁ and the adjacent control electrode G ₁₂ is one pixel, and is configured to be approximately equal in width to the anode A. Auxiliary control electrodes G _11a and G _11b are stretched between the control electrodes G ₁₁ and G ₁₂ to make the electric field distribution uniform.

Although the full-color fluorescent display device constructed in this way is basically the same as the first and second embodiments, its driving state will be explained with reference to the timing chart shown in FIG.

The control electrode G ₁₁ has a period of time as shown in FIG. 8 AG ₁₁ .
The switch is closed so that the control voltage is applied up to T ₃₁ . Next, the period T ₃₁ is applied to the adjacent control electrode G ₁₂ ,
The switch is closed so that a control voltage is applied to T ₃₂ , and the adjacent control electrode G ₁₃ is sequentially scanned so that a control voltage is applied to it as well. And an auxiliary control electrode sandwiched between the control electrodes G ₁₁ and G ₁₂
The switches are closed so that a control voltage is applied to G _11a and G _11b in synchronization with the period T ₃₁ in which the control electrodes G ₁₁ and G ₁₂ overlap. Therefore the control electrode
Control voltages are simultaneously applied to the four electrodes G ₁₁ , G ₁₂ and the auxiliary control electrodes G _11a , G _11b to select the first row. Then, in synchronization with this control voltage, an anode voltage is applied to the band-shaped anode segments A _11R , A _11G , and A _11B during the period T ₃₁ , so that the band-shaped anode segments A _11R ,
The portion on A _11G and A _11B and sandwiched between control electrodes G ₁₁ and G ₁₂ serves as one pixel P ₃₁ and emits all three colors of red, green, and yellow to display white. Further, as in the second embodiment, the band-shaped anode segments A _11R , A _11G , A _11B
By changing the pulse width for emitting light and the anode voltage, it is possible to display light emission in various colors by changing the ratio of each light-emitting color component.
For example, as in the pixel P ₃₂ , a control voltage is applied to the control electrodes G ₁₂ , G ₁₃ and the auxiliary control electrodes G _12a , G _12b during the period T ₃₂ , and the band-shaped anode segments have green-emitting A _12G and blue-emitting A By applying the same anode voltage to _12B only, a sky blue luminescent color can be obtained.

The present invention is not limited to the embodiments shown in the drawings, but can be implemented with various modifications without changing the gist of the claims for utility model registration. For example, there may be embodiments in which one pixel includes three or more strip-shaped anode segments, or two or more auxiliary control electrodes. Further, the shape of the control electrode is not limited to a linear shape, but may also be a planar shape control electrode disposed on a substrate.

As described above, the fluorescent display device according to the present invention has an anode, the upper surface of which is coated with a phosphor layer, arranged in parallel along one direction on one surface of a substrate made of an insulating material. A fluorescent display tube section is provided in which a control electrode is disposed in a direction intersecting at the top and an auxiliary control electrode is disposed between two adjacent control electrodes, and the area on the anode controlled by the control electrode is defined as one pixel. By simultaneously applying control electrodes to the adjacent control electrodes of the fluorescent display tube section and the auxiliary control electrodes sandwiched therebetween, a selected pixel is made to emit light to perform display.

Therefore, even if the area of one pixel becomes large, the electric field is made uniform by the action of the auxiliary control electrode, and the electrons emitted from the cathode can evenly hit the pixel, eliminating uneven brightness and emitting light uniformly. It becomes possible to display it.

In addition, since an auxiliary control electrode was installed in the control electrode tube,
When applying a cut-off voltage in the case of non-lighting, the control area of one control electrode becomes narrower. Therefore, the cut-off voltage may be small, and cut-off is not impossible, and the phenomenon of leakage light emission can be completely prevented.

Furthermore, since it is possible to make one pixel larger, it also has the effect of providing a fluorescent display device with a large display area.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of a conventional fluorescent display device;
The figure is a timing chart showing the driving state of a conventional fluorescent display device, FIG. 3 is an explanatory diagram of the first embodiment of the fluorescent display device of the present invention, and FIG. 4 is a timing chart showing the driving state of a conventional fluorescent display device. A timing chart showing the driving state, FIG. 5 is an explanatory diagram of the second embodiment of the present invention,
FIG. 6 is a timing chart showing the driving state of the second embodiment, FIG. 7 is an explanatory diagram of the third embodiment of the present invention, and FIG. 8 is a timing chart showing the driving state of the third embodiment. A ₁₁ , A ₁₂ ...A _o ... strip anode, G ₁₁ , G ₁₂ ...
G _o ... Control electrode, G _11a , G _12a ... G _oa , G _ob ... Auxiliary control electrode, F ₁ , F ₂ , F _o ... Cathode.

Claims (1)

[Claims for Utility Model Registration] (1) A strip-shaped anode having a phosphor coated on the upper surface of an insulating substrate, a plurality of control electrodes spaced apart in a direction intersecting the strip-shaped anode, The control electrode has a cathode stretched above the control electrode, and by applying a control voltage to the adjacent control electrodes simultaneously and sequentially shifting them one by one, the plurality of control electrodes can be scanned, and the control electrodes can be scanned. In a fluorescent display device in which a display signal is applied to each band-shaped anode in synchronization with the scanning of a control electrode, and each area on each band-shaped anode divided by the control electrode to which a control voltage is applied is treated as one pixel to display a display. , a configuration comprising: auxiliary control electrodes disposed between the adjacent control electrodes; and a drive circuit that applies a control voltage to the auxiliary control electrodes in synchronization with the scanning of the control electrodes sandwiching the auxiliary control electrodes. Fluorescent display device. (2) A utility model registration claim described in paragraph 1 in which a strip anode constituting one pixel is divided into a plurality of strip anode segments to form strip anode segments, and each segment is coated with a phosphor of a different luminescent color. Fluorescent display device. (3) The band-shaped anode constituting one pixel is divided into three, and each band-shaped anode segment has a red-emitting phosphor.
A fluorescent display device according to claim 1 or 2, which is coated with a green-emitting phosphor and a blue-emitting phosphor. (4) The fluorescent display device according to claim 1, 2, or 3, wherein the auxiliary control electrode is in the form of a wire, and a plurality of auxiliary control electrodes are arranged between two control electrodes.