CN103226926A

CN103226926A - Vacuume fluorescent display module and driving method thereof

Info

Publication number: CN103226926A
Application number: CN2013100288461A
Authority: CN
Inventors: 刈谷真
Original assignee: Futaba Corp
Current assignee: Futaba Corp
Priority date: 2012-01-26
Filing date: 2013-01-25
Publication date: 2013-07-31
Anticipated expiration: 2033-01-25
Also published as: TW201331927A; CN103226926B; KR101437519B1; TWI521501B; JP5515068B2; KR20130086963A; JP2013152394A

Abstract

The invention relates to a fluorescent display module and a driving method, with a view to disclosing a VFD with brightness adjusting function, especially is used for preventing display flicker. A fixed filament driving signal is generated at a difference of the edge position to start timing of a head anode lighting period which is placed at a head of each scan period of a grid in each scan period, and the driving signal drives the filament, thereby preventing the filament driving signal in the anode brightening period (grid signal and anode signal are in the conduction period) differs according to length of H level period in each scan, or even the difference is generated, the difference is regular. As a result, the observed brightness reduction in each scan can be prevented, and display flicker can be prevented.

Description

Fluorescent display tube module and driving method

Technical field

The invention relates to the driving method of a kind of fluorescent display tube module (module) and fluorescent display tube, this fluorescent display tube module is to possess fluorescent display tube and driving circuit portion thereof and constitute.

Background technology

(background technology document)

(patent documentation)

Patent documentation 1: Japanese kokai publication hei 8-278763 communique

Figure 15 is the general structural map of VFD (Vacuum Fluorescent Display, vaccum fluorescent tube).

In addition, in Figure 15, be the structure of extracting and show the information of one digit number only out about the part that shows about the structure of VFD.

As the VFD of prior art, be in vacuum tank, to dispose filament (filament) 100 (direct heating type negative electrode), grid (grid) 101, anode (segment) 102.In VFD, be filament 100 to be applied alternating voltage make its heating and thermoelectron is emitted, and this thermoelectron quickened and the fluorophor that collides on the anode 102 makes this light-emitting phosphor in grid 101, show and carry out desired figure (pattern).

Described thermionic acceleration is to be undertaken by grid 101 is applied DC voltage.Grid 101 is actually corresponding to figure place showing and is provided with, and by applying DC voltage and the figure place that can select to show to which grid 101.

Moreover, when the display device (device) that anode 102 is made as for example about alphameric characters, be as shown to have the mode of a plurality of sections for a grid (figure place) and to form.At this moment, the selection of anode (section) 102 is to be undertaken by the anode 102 that meets is applied DC voltage.

When making set information be shown in set figure place showing, be that the grid 101 that forms corresponding to this figure place showing and the anode 102 of reservation are applied DC voltage.Whereby, only the fluorophor on the set anode 102 of this figure place showing can and be realized set information demonstration because filament 100 thermoelectron of being emitted bring out luminously.

Figure 16 is signal g, the figure that anode signal a describes when showing at information.

In this, for convenience of explanation, be shown in Figure 16 A, the quantity (quantity of figure place showing) of grid to be made as four of G1 to G4.Moreover, in each figure place showing (grid G), with regard to anode A, be to be made as seven of the A1 to A7 that is formed with shown in Figure 16 B.

Figure 16 C, Figure 16 D are signal g1 to g4, the anode signal a1 to a7 when showing as the illustrated demonstration of Figure 16 A as " 4321 " of the numerical value of four figures respectively.

In addition, signal g1 to g4 shows respectively that about the grid G 1 drive signal person to G4 anode signal a1 to a8 shows respectively about the anode A 1 drive signal person to A8.

For example, when only describing at the grid G 1 corresponding to the figure place showing of front, in the example when this situation, the numerical value that should be shown in the figure place of this grid G 1 is " 4 ", and anode A that therefore should movable (active) is anode A 2, A3, A6, A7 four.Therefore, during the selection of grid G 1 in (signal g1 be conducting (ON) during), be that conducting respectively is corresponding to these anode A 2, A3, A6, anode signal a2, the a3 of A7, a6, a7.

Whereby, the demonstration of the numerical value " 4 " of the figure place of realization grid G 1.

In addition, explain, become conducting in regular turn from grid G 1 beginning grid G 2, G3, G4 for affirmation, and the grid G 1 that arrives become once again till the conducting during, be to be made as during the one scan.So scan grid G (promptly selecting each grid G in regular turn) with the set cycle,, and can show set information by each figure place simultaneously with the suitable set anode A of conducting of set sequential (timing) by one side.

Yet, in VFD, be to make the person that can adjust the display brightness.

With regard to the gimmick of the brightness adjustment of VDF, the gimmick of load (duty) of conducting/shutoffs (OFF) of change anode signal a can be arranged for example, or change the gimmick of load of conducting/shutoff of signal g.

According to Figure 17, at the change of the conducting/shutoff by anode signal a, and the gimmick of carrying out the brightness adjustment describes.

In this Figure 17, only illustration has the signal g1 of the drive signal that belongs to signal G1, with the relation of the anode signal a1 of the drive signal that belongs to anode A 1.That is, for illustration only relevant for the brightness adjustment person of the anode A 1 of grid G 1.

As shown in the figure with regard to the gimmick of this situation, corresponding to high brightness the time conduction period lengthening with anode signal a, corresponding to low-light level the time, then the ON time of anode signal a is shortened.

If the ON time of anode signal a is set at longer, then the anode of anode A can be elongated during shinny.On the other hand, if the ON time of anode signal a is set at shorter, then the anode of anode A can shorten during shinny.

So adjust the length of anode during shinny, and realize the adjustment of brightness whereby by the conduction period of change anode signal a.

In addition, explanation according to described Figure 16 also can be understood, so-called " during anode is shinny ", be meant about corresponding to the signal g of the grid G (being G1 this moment) of the formation position of this anode A, and about the anode signal a (being anode signal a1 this moment) of this anode A become simultaneously conducting during the person.

So " during anode is shinny " if of considering the decision display brightness for signal g and anode signal a be all conducting during, then adopt be not the gimmick of conduction period of change anode signal a but change signal g the time, can realize that also same brightness adjustment is not say to explain.

Yet, in VFD, with regard to the key element of decision brightness, though the length of its main person during be described anode shinny, with regard to other key element, the driving voltage of filament 100 also can become the essential factor that makes the brightness variation.Particularly, in during anode is shinny the filament driving voltage become the accurate position of H (level) during length be the key element that can become decision brightness.This is because during the filament driving voltage became during the accurate position of H in during anode is shinny, filament 100 diminished with the potential difference (PD) of grid 101 and anode 102, and is decline to the brightness that should change anode 102.

In view of the above, in the past, with regard to filament driving voltage (filament drive signal), be to be set as the signal that generation and signal and anode signal are asynchronous (frequency and phase place).This is because in order from filament 100 thermoelectron to be emitted, and only needs to drive filament 100 with both alternating voltages of fixed cycle and gets final product.

Formation about the generation system of in the past filament driving voltage (below be attached with symbol Ef) is to be disclosed in for example described patent documentation 1 (particularly Fig. 3).

Fig. 3 with reference to this patent documentation 1 can understand, filament driving voltage Ef in the past is the secondary coiling that applies special use at the secondary side of the transformer with DC/DC converter (converter) (transformer), and obtain the alternating voltage that winds the line as this secondary, and the anode signal a and the signal g that make and produce according to set clock signal are asynchronous signal.

Summary of the invention

(problem that invention institute desire solves)

Therefore, as described in using the VFD in the past that is made to respect to signal g and anode signal a to asynchronous filament drive signal, especially in the state of controlling in the mode that shortens during anode is shinny in the brightness adjustment in response in low-light level the time, can produce the problem of the flicker of experiencing demonstration.

Figure 18 is the figure that describes in order at the generation principle that so shows flicker.

In this Figure 18, be to be prerequisite with m grid G that in VFD, has grid G 1 to Gm and n the anode A that has anode A 1 to An, and the waveform of illustration signal g1 to gm, anode signal a1 to an.

Moreover, in Figure 18,, be the brightness that is directed to the anode A 1 of grid G 1 about the brightness adjustment.In the drawings, " A1 of G1 shinny during " be the anode of anode A 1 of the grid G 1 when being presented at high brightness comparatively shinny during (signal g1 and anode signal a1 all become conducting during).And in the drawings, be the anode signal a1 of the anode A 1 of the grid G 1 when being presented at low-light level, and the anode signal of the anode A 1 of grid G 1 that will be when this low-light level is shown as " A1 of the G1 during low-light level shinny during " during shinny.

In Figure 18, with regard to " Ef in the past ", though show the waveform of filament driving voltage Ef in the past, but with reference to should " Ef in the past " understanding, filament driving voltage (drive signal) Ef in the past is signal g and the anode signal a that does to become with respect to during shinny in order to the decision anode, and it is asynchronous signal that the position reaches frequency mutually.Therefore, the beginning sequential during shinny is not consistent to the edge sequential of filament driving voltage Ef (edge timing) (marginal position) with respect to the anode of foundation signal and anode signal, and the relation of these sequential is to change along with each scanning (scan).That is, the relation of the marginal position of these filament driving voltages Ef and the anode beginning sequential during shinny is variant along with each scanning.

When each scanning of the beginning sequential during the marginal position of like this filament driving voltage Ef is shinny with anode produces difference, during anode is shinny in filament driving voltage Ef become accurate of H during (be the potential difference (PD) of filament and grid and anode diminish and brightness decline during) length also can produce difference by each scanning.

In the drawings, with oblique line be presented at anode shinny during in during filament driving voltage Ef becomes the accurate position of H, if during with reference to this oblique line portion, can confirm during anode is shinny in filament driving voltage Ef become accurate of H during length be variant by each scanning.

Can understand from described explanation, by being that asynchronous filament driving voltage Ef drives in the background technology of filament 100 for signal g or anode signal a, be that its anode brightness meeting produces difference by each scanning.

So the difference of brightness is to become to make to show the reason that produces flicker.

Yet, so the difference of brightness (flicker of demonstration) corresponding to high brightness the time so that anode shinny during under the state controlled of mode of lengthening, be to become to be difficult to discover.Promptly, under the state that extends corresponding to high brightness the time and during making anode shinny, because that pulse (pulse) number of the filament driving voltage Ef in during this anode is shinny becomes is many (potential difference (PD) during anode is shinny between inner grid-filament diminish during shared ratio change many), so the marginal position of the filament drive signal of the beginning sequential with respect to described anode during shinny difference caused by the difference of the brightness of each scanning, be to tail off in response to this variation.Therefore, when high brightness, be the flicker that is difficult to discover by the demonstration of each scanning.

With respect to this, corresponding to low-light level the time so that during the situation that the mode that anode shortens during shinny is controlled, as shown, because the umber of pulse of the filament driving voltage Ef in during this anode is shinny tails off, so the marginal position of the filament driving voltage Ef of the beginning sequential with respect to described anode during shinny difference caused by the measures of dispersion of the brightness of each scanning, comparing during with high brightness is to become big, and the result can become and discover flicker by the demonstration of each scanning easily.

In fact, become roughly in the situation below three with the umber of pulse of the filament driving voltage Ef in confirming during anode is shinny, can be observed so the flicker that shows (in addition, though the umber of pulse of the filament drive signal in during the anode in Figure 18 corresponding to high brightness the time is shinny is below three, but this is owing to the illustrated state person of causing).

The present invention is because described problem and developer, and its problem is the VFD at brightness-adjusting, especially is to seek to prevent the generation of the demonstration flicker that can discover when low-light level.

(in order to solve the means of problem)

In order to solve described problem, the present invention constitutes the fluorescent display tube module in the following manner.

That is, fluorescent display tube module of the present invention is to comprise the fluorescent display tube that is formed with anode, grid, filament.

Moreover, possessing has the filament drive signal that produces the filament drive signal to produce means, the filament drive signal that is produced, it is positioned at this marginal position poor of the beginning sequential during shinny with respect to the front anode of front of each scan period of described grid, is fixing person in each scan period.

Moreover, possess the filament driving means that drives described filament according to described filament drive signal is arranged.

Moreover the present invention is that motion has following method as driving method.

Promptly, driving method of the present invention is the driving method that includes the fluorescent display tube of anode, grid, filament in order to driving, be to have the filament drive signal generating routine that produces the filament drive signal, the filament drive signal that is produced, it is positioned at this marginal position poor of the beginning sequential during shinny with respect to the front anode of front of each scan period of described grid, is fixing person in each scan period.

Moreover, have the filament driver that drives described filament according to described filament drive signal.

Being worse than of this marginal position according to the beginning sequential during shinny with respect to the front anode is fixing filament drive signal in each scan period as described, be can prevent terminating in anode shinny during in, the filament drive signal become the accurate position of H during length by each scanning difference.Perhaps, even if produce difference, also can make this difference have systematicness.

During anode is shinny, if can prevent the filament drive signal become the accurate position of H during the difference by each scanning of length, can prevent lowering of luminance, and can seek to prevent the flicker that shows by each scanning.

Perhaps, by making difference have systematicness, also can prevent to perceive the flicker of demonstration as described by the length during the accurate position of H of the filament drive signal of each scanning.

At this, for example at certain anode, the filament drive signal in will be during the anode of scanning for the first time is shinny becomes accurate lowering of luminance amount that is caused of H and is made as " N ".At this moment, if can make difference have systematicness by each scanning, then for example the filament drive signal can be become the lowering of luminance amount that the accurate position of H caused in the shinny time and be made as " 0 ", and in the shinny time of this anode of the scanning of odd number time, the filament drive signal can be become the lowering of luminance amount that the accurate position of H caused and be made as " N " at the anode of this anode of the scanning of even number time.If can make difference have so systematicness, human vision ground is discovered less than the flicker that shows by the brightness of each scanning.Promptly, because cycle that scans of grid is for example to be made as comparatively high speed person such as 120Hz, even if so produce by each scanning as described brightness bright/dark because " bright " " secretly " brightness separately is identical, so discover flicker less than demonstration with can making human vision.

(effect of invention)

According to described the present invention, at the VFD (fluorescent display tube) of brightness-adjusting, the demonstration that can perceive in the time of especially can preventing to be created in low-light level flicker.

Description of drawings

Fig. 1 is the figure in order to describe at the driving gimmick as the 1st example.

Fig. 2 is the figure of demonstration as the inside formation of the VFD module of the 1st example.

Fig. 3 is the sequential chart about generation filament drive clock frequency for the 1st example.

Fig. 4 is the figure of demonstration as the inside formation of the VFD module of the 2nd example.

Fig. 5 is the sequential chart about generation filament drive clock frequency for the 2nd example.

Fig. 6 is the figure for the effect in order at the filament drive signal of using the 2nd example the time.

Fig. 7 is the figure of demonstration as the inside formation of the VFD module of the variation of the 2nd example.

Fig. 8 is the figure of demonstration as the inside formation of the VFD module of the 3rd example.

Fig. 9 is the sequential chart about generation filament drive clock frequency for the 3rd example.

Figure 10 is the figure for the effect in order at the filament drive signal of using the 3rd example the time.

Figure 11 is when being presented at umber of pulse during each grid is selected in generation and being made as the filament drive signal of odd number, the figure of the configuration example of the filament drive clock frequency generating circuit that should possess.

Figure 12 is the figure in order to describe at the filament drive clock frequency that is produced by filament drive clock frequency generating circuit shown in Figure 11.

Figure 13 is the figure of demonstration as the inside formation of the VFD module of the variation of the 3rd example.

Figure 14 is the figure that describes in order to the variation at the AC driving of filament.

Figure 15 is the general structural map for VFD.

Figure 16 is the signal (g) when showing at information, the figure that anode signal (a) describes.

Figure 17 is the figure that describes in order to the brightness adjustment at VFD.

Figure 18 is the figure in order to describe at the generation principle that shows flicker.

The primary clustering symbol description

1 VFD

The 1a filament

2、10 CPU

3 controllers

4 drivers

5,11 filament drive clock frequency generating circuits

The 5a reverser

6 filament driving circuits

The 11a OR circuit

A1 to An anode

A1 to an anode signal

The G1Gm negative electrode

The g1gm cathode signal

The Vd DC voltage

CK clock frequency terminal

Q, Q (going up graticule) lead-out terminal

Q1 to Q5 changeover module

F_CLK, F_CLK1, F_CLK2 filament drive clock frequency

Ef filament driving voltage

Receive diode ZD season

The VHA anode voltage

The VHG grid voltage.

Embodiment

Below describe at example of the present invention.

In addition, explanation is to carry out with following order.

＜1. the 1st example (the filament drive signal that is synchronized with the INT signal)＞

＜2. the 2nd example (the filament drive signal that is synchronized with the BK signal)＞

＜3. the 3rd example (the filament drive signal that is synchronized with the GCP signal)＞

＜4. variation＞

Fig. 1 is the figure that describes in order at the driving method as the 1st example.

At this, comprise this Fig. 1 interior and in the following description, as being formed at VFD (Vacuum Fluorescnet Display, fluorescent display tube) grid G, anode A, be m (m is the natural number more than the 2) grid G that has grid G 1 to Gm, and the n of anode A 1 to An (n is the natural number more than 2) anode A.Moreover, be that souvenir is signal g1 to gm respectively at the drive signal of grid G 1 to Gm, be that souvenir is anode signal a1 to an respectively at the drive signal of anode A 1 to An.

In Fig. 1,, be that illustration has the waveform same with described Figure 18 as the example of the waveform of these signal g1 to gm and anode signal a1 to an.At anode signal a1, be that the signal during also with low-light level shows in the lump.

Moreover, " Ef in the past " among the figure be with the situation of Figure 18 similarly for showing filament drive signal (driving voltage) person in the past.

In this Fig. 1, identical with described Figure 18, be the brightness that is directed to the anode A of grid G 11 at brilliance control.Among the figure, " A1 of G1 shinny during " be the anode of anode A 1 of the grid G 1 of the situation with Figure 18 when similarly being presented at high brightness comparatively shinny during (signal g1 and anode signal a1 are all conducting during).Moreover " A1 of the G1 during low-light level shinny during " is person during anode A 1 shinny of grid G 1 when being presented at low-light level among the figure.

As explanation at Figure 18, when to use with signal g and anode signal a be asynchronous " Ef in the past ", since as signal g and anode signal a all become conducting during the beginning sequential of anode during shinny, with the pass of the edge sequential (marginal position) of filament driving voltage Ef be can be by each scanning difference, so in during anode is shinny filament driving voltage Ef become the accurate position of H during (potential difference (PD) of filament and grid and anode diminish and brightness decline during: the length oblique line portion among the figure) also can produce the difference by each scanning, as a result, become by the difference of each scanning generation brightness.

Though the luminance difference of so each scanning can become the essential factor that shows flicker, but as described, the flicker that shows is corresponding to high brightness the time so that anode is difficult to discover under the state controlled of the mode of lengthening during shinny, and corresponding to low-light level the time so that discover especially easily under the state that the mode that anode shortens during shinny is controlled.

In in this " A1 of G1 shinny during " during relatively corresponding to high brightness " Ef in the past " become accurate of H during length, with in " A1 of the G1 during low-light level shinny during " in " Ef in the past " become the accurate position of H during length, be that during this period the measures of dispersion (the variation ratio of the length of this period of each scanning) of each scanning of length becomes bigger during than high brightness in the time of can finding out low-light level significantly.

In the present invention, in preventing so when the low-light level, produce perceptible demonstration flicker, with regard to the filament drive signal, be to use a kind of signal, this signal is this marginal position poor of the beginning sequential during shinny with respect to the front anode of the front of each scan period that is positioned at grid, is fixing person in each scan period.Promptly, in example shown in Figure 1, with with respect to the difference of the marginal position that all becomes front anode during the conducting beginning sequential during shinny as signal g1 and anode signal a1 in each scan period for fixing mode, produce filament drive signal (driving voltage) Ef.

Particularly, in the 1st example, be to produce a kind of signal as filament drive signal Ef, for making its marginal position unanimity (synchronously) in the signal (more specifically being to be INT signal described later) of the scan period that shows grid.

In Fig. 1, be that the filament drive signal Ef that the 1st example is produced is shown as " Ef that this is routine ".This routine filament drive signal Ef is the signal that reverses by scanning each time that becomes grid as shown.

The foundation conduct is the filament drive signal Ef of the 1st example of " Ef that this is routine " so, be as shown, filament drive signal Ef in during anode is shinny can be become the accurate position of H during length, when the scanning of odd number time, be made as both fixed length (being made as " N "), and when the scanning of even number time, be made as " 0 ".That is, though in during anode is shinny filament drive signal Ef become the accurate position of H during length can produce difference by each scanning, but can make this difference have systematicness.

At this, the scan period of grid is for example to be made as comparatively high speed person such as 120Hz.Therefore, even if produce by each scanning as described brightness bright/dark, also can make the mankind can sense of vision ground not discover the flicker of demonstration because these " bright " " secretly " brightness separately are identical (" N " or " 0 ").

In addition, though in Fig. 1 only at the anode A 1 of grid G 1, and illustration have " in during anode is shinny filament drive signal Ef become the accurate position of H during length ", but according to filament drive signal Ef as described the 1st example, for the anode A of all other, " in during anode is shinny filament drive signal Ef become the accurate position of H during length, when the scanning of odd number time, become " N ", and become when the scanning of even number time " 0 " " be also to set up.That is, be the demonstration flicker to seek to prevent to produce low-light level the time, for whole anode A.

Fig. 2 is the figure that shows that the inside of the VFD module of conduct the 1st example that drives in order to the filament of realizing by described illustrated conduct the 1st example constitutes.

In addition, the VFD module is to become, in response to carry out the module that required information shows from the indication of main frame (host) machine that is connected in this VFD module carrying out the mode of data communication.

Be to include in the VFD of the 1st example module as shown: VFD1; CPU (Central Processing Unit, center processing unit) 2; Controller (controller) 3; Driver (driver) 4; Filament drive clock frequency generating circuit 5; And filament driving circuit 6.

VFD1 is a fluorescent display tube, and is formed with n anode A and the filament 1a of grid G 1 to m the grid G of grid G m, anode A 1 to anode An in this vacuum tank.

CPU2 constitutes to comprise: calculation portion; ROM (Read Only Memory, ROM (read-only memory)); And RAM (Random Access Memory), and described calculation portion is according to being stored in the program (Program) of described ROM and performing calculations.Described RAM is used for temporarily being stored in the data (data) that CPU2 handles.

CPU2 is in response to from the indication of host machine (about the indication of the information that should show), by carrying out processing according to the program (program) that is predetermined, and produce the grid data that belong to about each person's of how driving m the grid G that is formed at VFD1 information, and produce the anode data that belong to about each person's of how driving n anode A information (is to be " data " with these souvenirs at figure).

CPU2 is that the generation of carrying out these grid data, anode data according to the coming the INT signal (signal that shows the scan period of grid) that self-controller 3 supplies with of then explanation is handled with output.

Controller 3 is that various clock signals such as described INT signal are produced, and supplies with the grid data of the m system that corresponds respectively to grid G 1 to Gm and the anode data that correspond respectively to the n system of anode A 1 to An for driver 4.

At this, with regard to the clock signal that controller 3 is produced, be that described INT signal, BK signal and GCP signal can be arranged for example.

The BK signal is in the scanning motion that is undertaken by each grid G of selecting grid G 1 to Gm in regular turn, becomes the signal in the cycle that shows the selection of switching grid G.

Moreover the brightness adjustment that the GCP signal carries out for the length during shinny by the adjustment anode is the periodic signal that becomes the section that shows this adjustment width.

The INT signal that controller 3 is produced is that CPU2 is supplied with.Moreover in this routine situation, this INT signal is also to supply with for filament drive clock frequency generating circuit 5 as graphic.

On the other hand, the BK signal that produced of controller 3 and GCP signal are that driver 4 is supplied with.

In driver 4 is to import respectively by the graphic grid voltage VHG (DC voltage) that power circuit produced of omission, and anode voltage VHA (DC voltage).

Driver 4 is grid data that correspond respectively to grid G 1 to Gm of being supplied with according to slave controller 3, and conducting/shutoff grid voltage VHG (carrying out change action (switching)) produces and export signal g1 to gm whereby respectively.

Moreover driver 4 is anode data that correspond respectively to anode A 1 to An of being supplied with according to slave controller 3, and switches anode voltage VHG, produces respectively whereby and output anode signal a1 to an.

Be used for confirming and describing that signal g1 to gm is in order to driving the signal of the grid G 1 to Gm that is formed at VFD1 respectively in this, and anode signal a1 to an is in order to drive the signal of the anode A 1 to An that is formed at VFD1 respectively.

Filament drive clock frequency generating circuit 5 is in order to produce the circuit for the required filament drive clock frequency F_CLK of the drive signal that produces filament 1a.

The filament drive clock frequency generating circuit 5 of this moment is to constitute the flip-flop 5a that comprises D flip-flop (flip-flop).DC voltage Vd is the data terminal (D) that inputs to this flip-flop 5a, and is the INT signal of importing self-controller 3 for clock frequency terminal (CK).

Whereby, (Qbar (going up graticule) can obtain the filament drive clock frequency F_CLK1, the F_CLK2 that reverse by each position, rising edge of INT signal respectively in the lead-out terminal (Q) of flip-flop 5a, inversion output terminal.

In addition, produce two kinds of clock frequencies of the F_CLK1, the F_CLK2 that belong to inverse relation respectively as filament drive clock frequency F_CLK, be in order to make it corresponding to possessing in this example as described later filament driving circuit 6 be arranged, this filament driving circuit 6 is to carry out the driving of filament 1a by so-called AC driving mode.

In Fig. 3 is the sequential chart (timing chart) about generation filament drive clock frequency F_CLK that shows the 1st example.

In addition, be to show signal g1 to gm, INT signal, filament drive clock frequency F_CLK and filament drive signal Ef at this Fig. 3.

At first, also can understand from explanation up to the present, during the one scan be mean into, in the scanning motion of turn-on grid electrode signal g1 to gm (promptly selecting grid g1 to gm in regular turn) in regular turn, from signal g1 become conducting back to this signal g1 become once again till the conducting during.

INT signal used in this example is as shown, and this position, rising edge is to be configured to the signal that shows the beginning sequential during the one scan.

Illustrated as described, the filament drive clock frequency F_CLK of the 1st example (with reference to F_CLK1 in graphic) is produced the signal that reverses by the position, rising edge of each this INT signal.That is be to be configured to the signal person who reverses by each scanning.

Follow in this, as the filament drive signal Ef that is produced according to this filament drive clock frequency F_CLK, also as described shown in Figure 1 becomes the signal that reverses by each scanning.

Getting back to Fig. 2 goes on to say.

Filament drive clock frequency F_CLK1, F_CLK2 that filament drive clock frequency generating circuit 5 is produced are supplied to filament driving circuit 6.

Filament driving circuit 6 is to constitute according to these filament drive clock frequencies F_CLK1, F_CLK2 to drive filament 1a by the AC driving mode.

Particularly, filament driving circuit 6 is to constitute to comprise: first circuit that is connected in series is be connected in series the changeover module Q1 of Pch (ch:channel, channel) MOS-FET and the changeover module Q2 of NchMOS-FET; Second circuit that is connected in series is be connected in series the changeover module Q3 of PchMOS-FET and the changeover module Q4 of NchMOS-FET; And receive diode (Zener diode) ZD season.

As shown, the source electrode of the source electrode of changeover module Q1 (source) and changeover module Q3 is the positive potential side that all is connected in filament E_f, and the drain electrode of changeover module Q1 is the drain electrode that is connected in changeover module Q2, and the drain electrode of changeover module Q3 is the drain electrode that is connected in changeover module Q4.

Moreover the source electrode of the source electrode of changeover module Q2 and changeover module Q4 is the negative potential side (E_f-) that all is connected in thread terminal voltage E_f.

Moreover, be the end that is connected with the side of filament 1a for the tie point of changeover module Q1 and changeover module Q2, be the end that is connected with the opposing party of filament 1a for the tie point of changeover module Q3 and changeover module Q4.

At this,, also need not limit especially about this generation gimmick as long as thread terminal voltage E_f is configured in order to drive the DC voltage of the required accurate position of wanting of filament 1a.In this example,, be to be made as the voltage of abridged survivor that power circuit produces in diagram being imported filament driving circuit 6 at thread terminal voltage E_f.

The diode ZD that receives in season is under the state with its plus earth, negative electrode (cathode) is connected in the tie point (being E_f) of the source electrode of the source electrode of changeover module Q2 and changeover module Q4.

In addition, the diode ZD that receives in season so-called leaks luminously in order to prevent, and blocks bias voltage and person's of setting (for example with reference to following list of references 1,2) for grid G and anode A are applied.

List of references 1... Japanese kokai publication hei 2-190893 communique

List of references 2... Japanese kokai publication hei 2007-72323 communique

In addition, replace and receive diode ZD season, also can apply the described bias voltage that blocks by resistance is set.

The filament drive clock frequency F_CLK1 that is supplied to filament driving circuit 6 is imparted to first be connected in series the changeover module Q1 of circuit and the grid (gate) of changeover module Q2.

Moreover filament drive clock frequency F_CLK2 is imparted to second be connected in series the changeover module Q3 of circuit and the grid of changeover module Q4.

In the filament driving circuit 6 of described formation, filament drive clock frequency F_CLK1 become the accurate position of H during, promptly filament drive clock frequency F_CLK2 become the accurate position of L during, be the conducting that is combined into of changeover module Q2 and changeover module Q3, and changeover module Q1 and changeover module Q4 be combined into shutoff.In this period, heater current is to flow via changeover module Q3 → filament 1a → changeover module Q2.The heater current of this moment is called along the direction heater current.

On the other hand, filament drive clock frequency F_CLK1 become the accurate position of L during in (F_CLK2 become the accurate position of H during), then be the shutoff that is combined into of changeover module Q2 and changeover module Q3 conversely, and changeover module Q1 and changeover module Q4 be combined into conducting, heater current is to flow via changeover module Q1 → filament 1a → changeover module Q4 whereby.That is, flow rightabout heater current is arranged.

In filament driving circuit 6, be to drive filament 1a (even thermoelectron is emitted), and carry out so-called AC driving as described by the mutual rightabout heater current that flows.

Then, describe at the 2nd example.

The 2nd example is to produce its marginal position to be synchronized with show to follow in the signal of the switching cycle of selecting grid in regular turn of scanning motion, and as filament drive signal Ef.

Particularly, produce the signal that makes the synchronous signal of its marginal position for a wherein side the marginal position of the rising/decline of described BK signal, and as filament drive clock frequency F_CLK.

In addition, in the explanation after headed by this Fig. 4, be additional same-sign and omit explanation at the part identical with the part that had illustrated.

In Fig. 4, the VFD module of the 2nd example is compared with the VFD module of the 1st example, and difference is: be the BK signal of self-controller 3 in the future but not the INT signal is inputed to filament drive clock frequency generating circuit 5 (the clock frequency terminal of reverser 5a).

Fig. 5 shows the sequential chart of the generation of the 2nd example about filament drive clock frequency (F_CLK).

At first, the used BK signal of this example is that its position, drop edge is the signal that is configured to the selection switching sequence that shows grid G as shown.The pulse width of BK signal is to be configured to very short person, and the marginal position of rise and fall signal is very approaching as shown.

In addition, explain in order to be confirmed to be, the pulse width of BK signal is for fixing.

Explanation as described by filament drive clock frequency generating circuit 5 (reverser 5a), is to produce the signal reverse by the position, rising edge of each input signal as filament drive clock frequency F_CLK.

Therefore, with regard to the filament drive clock frequency F_CLK1 of this moment, as shown in Figure 5, can obtain the signal that reverses by the position, rising edge of each BK signal, moreover, follow in this situation, as the filament drive signal also have as shown a waveform that reverses by the position, rising edge of each BK signal.

Fig. 6 is the figure of the effect in order at the filament drive signal EF that uses the 2nd example the time.

In addition, be for illustrated convenience at Fig. 6, and only be formed with three of G1 to G3 as grid G (promptly only having g1 to g3) as signal g.Moreover, with regard to Fig. 6, be only to be directed to anode A 1, the anode signal a1 that belongs to the drive signal of this anode A 1 is as shown, illustration have select grid G 1 time=conducting, select grid G 2 time=conducting, when selecting grid G 3=situation of shutoff (, only the anode A 1 of the anode A 1 of grid G 1 and grid G 2 is shinny).

In view of the above, be directed to the anode A 1 (anode A of the shinny object of odd number grid G) of the grid G 1 that is configured to shinny object, and the anode A 1 (anode A of the shinny object of even number grid G) of grid G 2, then in the one scan, know with respect in during shinny about the anode of the anode A 1 of grid G 1, have filament drive signal Ef become the accurate position of H during (" having " among the figure), and do not have in during shinny about the anode of the anode A 1 of grid G 2 filament drive signal Ef become the accurate position of H during (among the figure " nothing ").

And, in scanning for the second time, then conversely during the anode of the anode A 1 of grid G 1 is shinny filament drive signal Ef become the accurate position of H during become " nothing ", and in during the anode of the anode A 1 of grid G 2 is shinny filament drive signal Ef become the accurate position of H during become " having ", and in scanning for the third time, then closing is to switch once again, with scanning for the first time similarly during the anode of the anode A 1 of grid G 1 is shinny filament drive signal Ef become the accurate position of H during become " having ", and in during the anode of the anode A 1 of grid G 2 is shinny filament drive signal Ef become accurate of H during become " nothing ".

In addition, in the drawings, about filament drive signal in during anode is shinny become the accurate position of H during have or not, be to show the having or not of this period of the anode A 1 of grid G 1 by the circle mark, and show the having or not of this period of the anode A 1 of grid G 2 by the square mark.

Filament drive signal Ef according to the 2nd example that is so produced according to the BK signal, anode A about shinny object, be made as " having "/" nothing " (promptly the brightness slippage being made as " N "/" 0 ") by each scanning during filament drive signal in during this anode is shinny can being become the accurate position of H by each scanning, therefore, becoming the brightness that the accurate position of H caused about filament drive signal Ef in during anode is shinny and descend, is to make its difference by each scanning have the systematicness same with the 1st example.

Therefore, also can prevent to produce the flicker of demonstration according to the 2nd example.

Moreover, with regard to described explanation, since be configured to generation by the signal of the position, rising edge of each BK signal counter-rotating as filament drive signal Ef (filament drive clock frequency F_CLK), though so not consistent beginning sequential during anode is shinny of the marginal position of filament drive signal Ef, but the signal that generation is reversed by the position, drop edge of each BK signal is as filament drive clock frequency F_CLK, and obtain making the filament drive signal Ef of the beginning sequential of its marginal position unanimity during anode is shinny, make luminance difference have systematicness similarly, discover less than showing flicker and can reach by each scanning.

At this, can understand with reference to Fig. 6, in order to prevent produce to show the more important person of flicker, be poor (mistiming) of the marginal position of the filament drive signal Ef of the beginning sequential during shinny with respect to anode, be in each scan period, to be fixing (also comprising poor=0 is the situation of unanimity).Promptly, so if the difference of marginal position of filament drive signal Ef that makes with respect to anode the beginning sequential during shinny in each scan period for fixing, then as Fig. 6 or shown in Figure 1, can make " in during anode is shinny filament drive signal Ef be the accurate position of H during " the difference by each scanning have systematicness (that is, will descend be made as " N "/" 0 ") by the brightness of each scanning.

Perhaps, also can become prevent to produce as after the 3rd example illustrated " in during anode is shinny filament drive signal Ef become the accurate position of H during " the difference person by each scanning.

As described in order to reach " being worse than in each scan period of the marginal position of the filament drive signal Ef of the beginning sequential with respect to anode during shinny " to fixing, as long as at least during the anode of the front of each scanning is shinny, the difference of its marginal position that begins sequential and filament drive signal Ef is got final product for fixing.

Because as filament drive signal Ef is the signal person who produces the fixed cycle, so as long as make with respect to the front anode of each scanning the difference of the marginal position of the beginning sequential during shinny be made as fixing in mode so, even if then about the anode A of each grid G after the grid G (grid G 1) of front, also can make the difference of its marginal position of filament drive signal Ef of the beginning sequential during shinny be made as fixing by each scanning with respect to this anode.

Yet, in described Fig. 6 (and Fig. 5), since illustration the formation number of grid G is made as the situation of odd number, the pass that event becomes by the waveform counter-rotating of each scanning filament drive signal Ef is, and can make the anode A brightness slippage of brightness slippage and the inferior grid G of even number of anode A of the grid G of odd number time alternatively become " N "/" 0 " whereby by each scanning, as a result, can prevent to produce the demonstration flicker for whole anode A.

Yet, when the formation number with grid G is made as the situation of even number, waveform in each scan period filament drive signal Ef can become identical, and follow in this, the brightness slippage of the anode A of the grid G of odd number time can be fixed as " N " in each scan period, and the brightness slippage of the anode A of even number time grid G can be fixed as " 0 ", the result, be formed at odd number time grid G anode A and the grid G that is formed at even number time anode A between can produce brightness and blur.That is, can become and to realize the appropriate brightness adjustment.

Therefore, when the formation number with grid G is made as even number, as long as by inserting virtual pulse (dummy pulse) for the BK signal that is input into filament drive clock frequency generating circuit 5, get final product and make waveform by each scanning filament drive signal Ef become counter-rotating person.Particularly, as long as insert (odd number) virtual pulse by each scanning for the BK signal.

Moreover, in explanation up to the present, though have the controller 3 of utilization hardware (hardware), and the BK signal that this controller 3 is exported be made as for filament drive clock frequency generating circuit 5 and the importer, omit controller 3 but with regard to the VFD module, also can constitute.

Fig. 7 is that the inside of VFD module of variation that shows conduct the 2nd example of the controller 3 omitted hardware constitutes.

In this situation, the function that controller 3 is had is by CPU10 install software (software) is realized.The formation of so omitting controller 3 is when using the higher CPU of arithmetic capability as CPU10 and adopted.

In this formation shown in Figure 7, the BK signal of slave controller 3 outputs and GCP signal are to become from CPU10 for driver 4 outputs in described Fig. 4 and Fig. 2.

Corresponding to this,, be that input has the BK signal of so exporting from CPU10, and carry out the generation of filament drive clock frequency F_CLK1, F_CLK2 according to this BK signal in the filament drive clock frequency generating circuit 5 of this situation.

Then, describe at the 3rd example.

The 3rd example is to show that with this marginal position is synchronized with by this marginal position the signal of signal of the boundary of the adjustment width of anode during shinny is produced as filament drive signal Ef.Particularly, will make the synchronous signal of this marginal position, be produced as filament drive clock frequency F_CLK for the either party's of the rising/decline of described GCP signal marginal position.

In Fig. 8, the VFD module of the 3rd example is compared with the VFD module of the 2nd example shown in Figure 4, difference is: import the GCP signals to filament drive clock frequency generating circuit 5 (the clock frequency terminal of reverser 5a) by controller 3, and be not the BK signal.

Fig. 9 is the sequential chart that shows the generation filament drive clock frequency F_CLK of the 3rd example.

In addition, in this Fig. 9, waveform about signal g1, BK signal, filament drive clock frequency F_CLK1 and the filament drive signal Ef of grid G 1, though only mainly extract the waveform during the selection of grid G 1 out, but the waveform after during the selection of grid G 1 of these each signals is the repetitions that become the waveform during the selection of this grid G 1.

At first with regard to prerequisite, in this example, the gradient of brightness adjustment is to be made as 16bit, and corresponding to this with regard to the GCP signal, be that the umber of pulse that is made as during grid is selected as figure is 14.

Foundation is the GCP signal so, from marginal position, select set marginal position, the width of the conduction period of the anode signal a in the time of can setting the briliancy adjustment by set quantitative (gradient) whereby (even being the width of anode during shinny) with this GCP signal.

Can understand with reference to Fig. 8, the filament drive clock frequency generating circuit 5 of this moment is just also exported the signal that reverses by the position, rising edge of each input signal as filament drive clock frequency F_CLK.Therefore, as shown in Figure 9, with regard to the filament drive clock frequency F_CLK of this moment, can obtain the signal that reverses by the position, rising edge of each GCP signal.

Moreover, follow in this, as filament drive signal Ef, have the waveform person who reverses by the position, rising edge of each GCP signal as scheming also to become.

Figure 10 is the figure of the effect in order at the filament drive signal Ef that uses the 3rd example the time.

In addition, also because illustrated convenience, and similarly only form G1 to G3 as grid G (that is, only having g1 to g3) in this Figure 10 as signal g with the situation of described Fig. 6.Moreover, also identical in this situation with described Fig. 6, be made as and only be directed to anode A, and the anode signal a1 that belongs to the drive signal of this anode A 1 be shown with as legend select grid G 1 time=conducting, select grid G 2 time=conducting, when selecting grid G 3=shutoff.

In this, when being directed to the anode A that the is made as shinny object anode A 1 of the anode A 1 of grid G 1 and grid G 2 (in this legend for), in can understanding during the anode of these anode A is shinny, begin sequential for this, the position, rising edge of filament drive signal Ef is consistent, and for finishing sequential, the position, drop edge of filament drive signal Ef is consistent.This is to be as described the signal in order to the width of conduction period of setting anode signal a owing to become the GCP signal in the generation source of filament drive signal Ef.

Can understand thus, by the 3rd example, in whole scan periods,, can make about whole anode A " in during anode is shinny filament drive signal Ef become the accurate position of H during length " for fixing.Promptly, about whole anode A, can prevent from fully to produce " during anode is shinny in filament drive signal Ef become the accurate position of H during length " the difference (preventing the difference of the brightness of each scanning itself fully) of each scanning, the result can prevent to produce demonstration and glimmer.

In addition, according to the 3rd example,, also can make to show that flicker is not easy to be discovered even if also mean for the scan period with grid is made as lower situation (for example 60Hz etc.).

Therefore, in described, owing to use the umber of pulse during each grid selection is made as the signal of even number (14) as the GCP signal, so the umber of pulse during a grid is selected of filament drive signal Ef also becomes even number, and follow select in this in each grid during the waveform of filament drive signal Ef be become identical, the result, though make as Figure 10 and to prevent from fully to produce " during anode is shinny in filament drive signal Ef become accurate of H during length " the difference of each scanning, but with regard to the 3rd example, also according to identical the considering of situation of described the 2nd example, and the umber of pulse of making the filament drive signal Ef during each grid selection is made as odd number, and the waveform of counter-rotating filament drive signal Ef during selecting by each grid, whereby, also can make the difference of the brightness of each scanning have systematicness and make the demonstration flicker be not easy to discover.

Figure 10 is an illustration when having umber of pulse during the selection that produces each grid to become the filament drive signal Ef of odd number, the formation of the filament drive clock frequency generating circuit 11 that should possess.

With regard to regard to the gimmick of filament drive signal Ef that produces umber of pulse during each lattice is selected and become odd number, can take the gimmick of the logical "or" (OR) of GCP signal and BK signal for example.

Corresponding to this gimmick, filament drive clock frequency generating circuit 11 shown in should figure, be to include the OR grid circuit 11a of input GCP signal and BK signal as figure, and include the reverser 5a that the output of this OR grid circuit 11a is inputed to the clock frequency terminal.

Figure 12 is the figure that describes in order at the filament drive clock frequency F_CLK that is produced by filament drive clock frequency generating circuit 11 shown in Figure 11.

In addition, the waveform that in this Figure 12, also shows signal g1, BK signal, GCP signal in the lump.

In this in this routine situation, be during using this decline sequential to become to select as figure than a grid the beginning sequential a little the signal in the place ahead as the BK signal.

Can understand with reference to this Figure 12, if the logical "or" of doing to become according to GCP and BK signal produces filament drive clock frequency F_CLK person, then with regard to this filament drive clock frequency F_CLK1, be as figure during a grid is selected in umber of pulse become odd number, and the signal that its waveform reverses during obtaining selecting by each grid.

If use so filament drive clock frequency F_CLK1, then the waveform by filament drive signal Ef during selecting by each grid reverses, and with the situation of described Fig. 6 in the same manner, filament drive signal Ef in making during the anode of the anode A of the grid G of odd number time is shinny become accurate of H during become " having ", and the filament drive signal Ef during the anode of the anode A of the grid G of even number time is shinny become the accurate position of H during become " nothings " etc., then can give set " bright " for the brightness of the anode A of the inferior grid G of the brightness of the anode A of the grid G of odd number time and even number, " secretly ".

And, be odd number if also make the formation number of grid G this moment, " bright ", " secretly " of the brightness of the grid G of the grid G that then can make odd number so time and even number time concern reverses by each scanning, the result, with the situation of the 2nd example similarly, can make the difference of the brightness of each scanning have systematicness.That is, the result can prevent to perceive the demonstration flicker.

In addition, this moment is when the formation number with grid G is made as even number, identical with the situation of the 2nd example, as long as by inserting virtual pulse, and get final product with the mode adjustment that the waveform of filament drive signal Ef reverses by each scanning with respect to each scanning of BK signal.

Yet, can understand with reference to described Figure 10 etc., comparing with signal g and anode signal a at the employed GCP signal of the 3rd example is the frequency higher signal.

So for the 3rd example that produces filament drive signal Ef according to more high-frequency signal, therefore, and the loss and the 1st, the 2nd example that expend electric power are compared the tendency that becomes big are arranged.Particularly, the loss that expends electric power is to become big according to the 1st example＜the 2nd example＜the 3rd example.

This is changed speech, also mean the loss that expends electric power is reduced, therefore with regard to deleting the aspect that expends electric power, the 1st example that produces the minimum filament drive signal Ef of frequency is for the most favourable.

In addition, the variation of the 2nd example as described is illustrated, and the situation of the controller 3 that omits output BK signal and GCP signal is also arranged.

Though Figure 13 shows the figure as the inside formation of the VFD module of the variation of the 3rd example of the controller 3 that has omitted hardware, but this moment, also become by software CPU10 is installed the function that controller 3 is had, BK signal and GCP signal are to driver 4 outputs from this CPU10.

Corresponding to this, be that input has from the GCP signal of CPU10 output as figure in the filament drive clock frequency generating circuit 5 of this situation, and carry out the generation of filament drive clock frequency F_CLK1, F_CLK2 according to this GCP signal.

＜4. variation＞

Though more than at the explanation of having advanced shape of each example of the present invention, but the present invention is not by the hereto illustrated concrete example person of qualification.

For example, when AC driving filament 1a, formed the commutation circuit that is constituted by changeover module Q1 to Q4, but the AC driving of filament 1a is also can for example realize by formation shown in Figure 14 though be set as with regard in the explanation hereto.

In formation shown in Figure 14, be to be formed with when producing filament drive signal (driving voltage) Ef, carry out the DC/DC converter of change action by the commutation circuit of primary side according to filament drive clock frequency F_CLK1.Particularly, be to have input side capacitor (condenser) Ci, changeover module Q5, transformer TR, commutation diode Do1, commutation diode Do2, outgoing side capacitor Co1, the outgoing side capacitor Co2 among the figure and receive the DC/DC converter of diode ZD season.

Input side capacitor Ci is that its positive terminal is connected with input voltage Vcc in this DC/DC converter, and negative terminal is ground connection as shown.And, between the tie point of this input side capacitor Ci and input voltage Vcc and ground connection (earth), be the circuit that is connected in series that is inserted with once wind the line N1 and changeover module Q5 that transformer TR has.

Changeover module Q5 does to become NchMOS-FET, and its drain electrode is to be connected with the N1 that once winds the line, and source electrode is a ground connection.

Grid in changeover module Q5 is to give filament drive clock frequency F_CLK1 as shown, and is to flow the primary side current that switched according to this filament drive clock frequency F_CLK is arranged in the N1 that once winds the line whereby.

In transformer TR, in response to flowing described primary side current is arranged and produce alternating voltage for the coiling that is wound in its secondary side in the N1 that once winds the line.

At this moment, the secondary side for transformer TR is to be wound with secondary coiling N2 and secondary coiling N' as shown.

Be formed with first rectifier smoothing circuit that is constituted by commutation diode Do1 and outgoing side capacitor Co1 for secondary coiling N2, and second rectifier smoothing circuit that is constituted by commutation diode Do2 and outgoing side capacitor Co2.

Particularly, secondary coiling N2 is the anode that one square end portion is connected in commutation diode Do1, and the opposing party end is a ground connection.The negative electrode of commutation diode Do1 is the positive terminal that is connected in outgoing side capacitor Co1, and the negative terminal of this outgoing side capacitor Co1 is a ground connection.

Moreover, bestowed middle tap (tap) in secondary coiling N2, be the anode that is connected with commutation diode Do2 for this centre tap.And the negative electrode of commutation diode Do2 is to be connected with the positive terminal of outgoing side capacitor Co2, and the negative terminal of this outgoing side capacitor Co2 is a ground connection.

In view of the above, if will be made as first winding section from wind the line winding section till the tap in the middle of described, end of a described side of N2 of secondary, and residual winding section is made as second winding section, then described first rectifier smoothing circuit is to carry out smoothly moving according to the rectification that results from the alternating voltage of described first winding section, and produces first VD in the two ends of smmothing capacitor Co1 whereby.This first VD is to be supplied to driver 4 as anode voltage VHA.

Moreover described second rectifier smoothing circuit is to carry out smoothly moving according to the rectification that results from the alternating voltage of described second winding section, and produces second VD in the two ends of smmothing capacitor Co2 whereby.This second VD is to be supplied to driver 4 as grid voltage VHG.

Moreover secondary coiling N2' is the end that the end of one side is connected the side of the filament 1a that is formed at VFD1 inside, and the opposing party end is the end that is connected in the opposing party of this filament 1a.

Tap in the middle of also being applied with as this secondary coiling N2', this centre tap are as shown via receiving diode ZD (negative electrode → anode) and ground connection season.In addition, receiving the effect of diode ZD season is with identical the illustrated person of described the 1st example.

By so constituting, can be by in response in the cycle of filament drive clock frequency F_CLK1 AC driving filament 1a.Particularly, filament drive clock frequency F_CLK1 become the accurate position of H during, in secondary coiling N2', the end side from described the opposing party can be flowed for filament 1a toward the mobile electric current of a described side's end side (suitable directional current: corresponding to figure " Ef+ "), and on the other hand, filament drive clock frequency F_CLK1 become the accurate position of L during, the electric current (contrary directional current: corresponding to figure " Ef-") that the end side from a described side's end side toward described the opposing party can be flowed in secondary coiling N2' is mobile for filament 1a.

In view of the above, though described illustrated DC/DC converter becomes the power circuit person who constitutes the VFD module, but according to the formation of DC/DC converter shown in Figure 14, then have with in order to the power circuit that produces filament drive signal Ef with common in order to the power circuit that produces anode voltage VHA and grid voltage VHG be one advantage.

Claims

1. fluorescent display tube module comprises:

Fluorescent display tube comprises anode, grid, filament;

The filament drive signal produces means, produce the filament drive signal, the filament drive signal that is produced, it is positioned at this marginal position poor of the beginning sequential during shinny with respect to the front anode of front of each scan period of described grid, is fixing person in each scan period; And

The filament driving means drives described filament according to described filament drive signal.

2. fluorescent display tube module according to claim 1 is characterized in that, described filament drive signal generation means are according to the signal that shows the scan period of described grid by this marginal position, produce described filament drive signal.

3. fluorescent display tube module according to claim 1, it is characterized in that, described filament drive signal generation means are according to the selection grid switching cycle signal that shows the switching cycle of selecting described grid in regular turn by this marginal position, produce described filament drive signal.

4. fluorescent display tube module according to claim 3, it is characterized in that, described selection grid switching cycle signal is the marginal position that is configured to by the side in rising or the position, drop edge, shows the signal of the switching cycle of selecting described grid in regular turn;

Described filament drive signal generation means are signals that generation is reversed by a described side's of each described selection grid switching cycle signal marginal position, are used as described filament drive signal.

5. fluorescent display tube module according to claim 4 is characterized in that the quantity of described grid is established even number;

And described filament drive signal generation means are by the virtual pulse of insertion with respect to described selection grid switching cycle signal, and result from the described filament drive signal that each scan period has the odd number pulse.

6. fluorescent display tube module according to claim 1, it is characterized in that, described filament drive signal generation means are according to the brightness width signal of the boundary that shows the adjustment width of anode during shinny by this marginal position, produce described filament drive signal.

7. fluorescent display tube module according to claim 6 is characterized in that, described brightness width signal be configured to by rise or the position, drop edge in a side marginal position, show the signal of the boundary of the adjustment width of described anode during shinny;

Described filament drive signal generation means are signals that generation is reversed by a described side's of each described brightness width signal marginal position, are used as described filament drive signal.

8. fluorescent display tube module according to claim 7, it is characterized in that, described filament drive signal generation means be the described brightness width signal of input and by rise or the position, drop edge in a side marginal position show the selection grid switching signal of the switching cycle of selecting described grid in regular turn, and according to these brightness width signal and select the logical "or" of grid switching signal to produce described filament drive signal.

9. fluorescent display tube module according to claim 1 is characterized in that, described filament driving means is to carry out the driving of described filament by the AC driving mode.

10. fluorescent display tube module according to claim 9, it is characterized in that, described filament drive signal generation means are alternating voltages that produced according to the coiling of the secondary of DC/DC converter and obtain described filament drive signal, this DC/DC converter is to be fixing signal in each scan period in response to being worse than of this marginal position of the beginning sequential during shinny with respect to described front anode, and its primary side commutation circuit is carried out the change action person.

11. a driving method is the driving method that includes the fluorescent display tube of anode, grid, filament in order to driving, comprising:

Filament drive signal generating routine, produce the filament drive signal, the filament drive signal that is produced, it is positioned at this marginal position poor of the beginning sequential during shinny with respect to the front anode of front of each scan period of described grid, is fixing person in each scan period; And

The filament driver drives described filament according to described filament drive signal.