JPH0564504B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD This invention relates to a dot array fluorescent tube recording head for use in optical printers and the like.

PRIOR ART In recent years, as an electrophotographic optical printer that records the output from a computer, etc., an optical printer has been developed in which a dot array fluorescent tube recording head is configured with a dot array fluorescent tube as an optical writing device that converts the output into an optical signal. .

Such a dot array fluorescent tube recording head is
A large number (for example, 2,560) of anode electrodes coated with phosphor on the surface are arranged in a vacuum container, a cathode electrode is provided corresponding to the anode electrode, and one anode electrode is provided between the anode electrode and the cathode electrode. It consists of a dot array fluorescent tube with a grid electrode interposed therebetween, a dot array fluorescent tube that selectively applies a driving voltage to each anode electrode of the dot array fluorescent tube, and a drive circuit mounted on a separate substrate.

However, in the conventional dot array fluorescent tube recording head, one grid electrode is interposed between the anode electrode and the cathode electrode, so it is not possible to drive a large number of anode electrodes separately. First, a drive IC with a built-in drive circuit.
There is a disadvantage that the number of .

Purpose This invention has been made in view of the above points, and provides an IC for driving a dot array fluorescent tube recording head.
The aim is to reduce the number of

Configuration The configuration of the present invention will be described below based on one embodiment.

FIG. 1 is a schematic configuration diagram showing an example of an optical printer equipped with a dot array fluorescent tube recording head embodying the present invention.

In this optical printer, when printing starts, the belt photoreceptor 1 is rotated in the direction of arrow P, and the surface of the belt photoreceptor 1 is uniformly charged by the charging charger 2.

Then, each light-emitting segment of the dot-array fluorescent tube recording head 3 is made to selectively emit light according to the recorded image signal, and the light emitted from the dot-array fluorescent tube recording head 3 is converted into a same-magnification condenser made of, for example, a focusing optical fiber array. The light is focused by the image element 4 and irradiated onto the belt photoreceptor 1 to form an electrostatic latent image on the belt photoreceptor 1 according to the recorded image.

After that, the electrostatic latent image on the belt photoreceptor 1 is
A developing device 5 applies a developer and visualizes the image.
The image is transferred by the transfer charger 6 onto recording paper fed from the paper feeder 7 .

Then, this recording paper is passed through a fixing device 8, subjected to a fixing process, and then discharged to an external paper output tray, etc., while the residual charge on the belt photoreceptor 1 is removed by a static elimination lamp 9.
After erasing the developer, the remaining developer is removed by a cleaner 10 such as a magnetic brush cleaning device, in preparation for the next recording process.

In this way, the recorded image is recorded on the recording paper.

FIG. 2 is a plan view showing an example of the dot array fluorescent tube recording head 3. As shown in FIG.

This dot array fluorescent tube recording head 3 consists of a dot array fluorescent tube 11 and two substrates 12 on which a driving IC for selectively applying a driving voltage to each anode electrode of this dot array fluorescent tube 11 is mounted.

Referring also to FIGS. 3 and 4, the dot array fluorescent tube 11 is constructed by placing a face glass 2 on a substrate 21 made of glass or the like via a spacer glass 22.
3 to form a vacuum container 24.

A transparent electrode film 25 is formed on the inner surface of the face glass 23 in order to prevent the influence of an external electric field and to prevent disturbance of the electric field distribution due to charging of the surface by thermionic beams. 25 is given a cathode potential or grid potential.

On the substrate 21 inside the vacuum vessel 24, anode electrodes 26 are arranged in a row in the longitudinal direction of the vacuum vessel 24, and the tips of the anode electrodes 26 are coated with a dot-shaped phosphor 27 to form minute dots. The light emitting segments 28 are arranged in a line.

Note that the anode electrode 26 is formed on the substrate 21 by photo-etching a metal thin film such as Al, and high resolution can be achieved by forming the anode electrode 26 in this manner.

Further, the anode electrodes 26 are extended alternately (staggered) on both sides of the outside of the vacuum container 24 .

Further, the phosphor 27 has, for example, zinc oxide ZnO doped with Zn as a main component.

Note that in this dot array fluorescent tube 11, the recording (printing) density is set to 300DPI (dot/print), for example.
(inch), the pitch of each anode electrode 26 is 85μ
m, and the dot size of the phosphor 27 (light-emitting segment 28) is 40 to 50 μm square.

In addition, in order to make it possible to print on recording paper with a maximum width of 210 mm (A4 size), this dot array fluorescent tube 11 has a length of the light emitting segment 28 in the column direction of 210 mm.
mm, its anode electrode 26 (light emitting segment 2
8), 2560 pieces are formed.

The portion of each anode electrode 26 other than the phosphor 27 is covered with an insulating paste layer 30 made of low-melting point glass using a thick film printing method, and as shown in FIG. A first grid electrode 3 having a mesh structure made of a thin metal film is disposed on the layer 30.
1. A second grid electrode 32 is provided, and a grid terminal 3 is provided on the substrate 21 in order to apply a grid voltage to each of the first and second grid electrodes 31 and 32.
3 and 34 are formed.

Note that these first and second grid electrodes 31,
32 may be formed directly on the insulating paste layer 30 by vapor deposition or the like, or may be formed by a thick film printing method.

In addition, these first and second grid electrodes 31,
32, slits 31a, 32a are formed corresponding to the rows of light emitting segments 28, so that the emitted light from each minute light emitting segment 28 is not blocked by the first and second grid electrodes 31, 32. This improves the effectiveness of the emitted light and suppresses variations in the brightness of the emitted light.

These first and second grid electrodes 3
As shown in FIG. 2, a filament (cathode electrode) 35 formed by coating a thin tungsten wire with an oxide is placed above the supports 36, 36 along the arrangement direction of the light emitting segments 28, as shown in FIG. and applying tension with spring members 37, 37,
In order to apply a cathode voltage to the filament 35, filament terminals 38, 38 are formed on the substrate 21.

That is, in this dot array fluorescent tube 11, the grid electrode interposed between the anode electrode 26 (light emitting segment 28) and the filament 35 is
The anode electrode 26 is divided into two parts in the arrangement direction. Note that the grid electrode may be divided into three or more pieces.

In the dot array fluorescent tube 11 constructed in this manner, thermoelectrons are emitted by heating the filament 35 by supplying an AC voltage of, for example, 10 to 20 V.

At this time, by applying a voltage of, for example, +20 V to the first grid electrode 31 or the second grid electrode 32, and applying a voltage of, for example, +40 V to the anode electrode 26, the thermoelectrons are transferred to the first grid electrode 31 or the second grid electrode.
It hits the phosphor 27 while being accelerated by the grid electrode 32, and the light-emitting segment 28 of the phosphor 27 emits light.

At this time, the emission spectrum when the phosphor 27 is ZnO:Zn has a peak at 505 nm, and has a wide characteristic of 410 nm on the short wavelength side and 650 nm on the long wavelength side.

Therefore, the first grid electrode 31 or the second
By selectively applying a grid voltage to one of the grid electrodes 32 and then selectively applying a driving voltage to each anode electrode 26 according to a print signal (information signal), a desired light emitting segment 28 is generated. It can be printed by emitting light.

On the other hand, a driving IC 41 for selectively applying a driving voltage to each anode electrode 26 of the dot array fluorescent tube 11 is mounted on the substrate 12.

This substrate 12 is made of, for example, glass, ceramic,
It can be formed from epoxy, glass epoxy, polyimide, polyester, etc.

The driving IC 41 is, for example, a one-chip IC capable of driving 32 anode electrodes 26, as shown in FIG.
The print signal of the 32-bit shift register 42 is latched to the 32-bit latch 43 by the latch signal,
When each AND gate 44 is opened by the strobe signal, each anode electrode 26 is output.

Note that the driving ICs 41 of each board 12 are connected in cascade as shown in FIG.

This driving IC 41 and each anode electrode 26
As shown in FIG.
(hereinafter referred to as "anode electrode 26bn (n= ₁ to ₈ )") is a non-matrix wiring.

On the other hand, each anode electrode 2 that is not located near the dividing point between the first grid electrode 31 and the second grid electrode 32
6 (hereinafter referred to as "anode electrode 26a"), matrix wiring is used.

This matrix wiring is a multilayer wiring on the substrate 12, that is, a 2.5 μm thick wiring on a substrate such as a ceramic substrate.
Pattern a thick first Al layer conductive layer and then 5μm thick glass (Corning #7059) on top of this.
A 100μΦ hole is etched into the glass layer for the through-hole part, and a 6μΦ hole is etched on top of this.
m second Al conductive layer is deposited to form an underlying first Al conductive layer.
It is constructed by stacking Al conductive layers such that they are connected to a conductive layer.

This driving IC 41 and this driving IC
41 and each anode electrode 26 mounted on the substrate 1
2 and each anode electrode 26 of the dot array fluorescent tube 11 are wire bonded or flexible tape (a pattern is wired on a polyimide substrate).
Connect by etc.

This dot array fluorescent tube 1 configured in this way
1, when applying a grid voltage to the first grid electrode 31 to cause the light emitting segment 28 corresponding to the first grid electrode 31 to emit light in response to a print signal (information signal), the first grid electrode 31 Each anode electrode 26 (anode electrode 2
A driving voltage is selectively applied to the anode electrodes 6a and anode electrodes _26b1 to _26b4 ) according to the information signal to cause the required light emitting segments 28 to emit light.

At this time, for the anode electrodes 26b ₅ to 26b ₈ near the dividing point corresponding to the second grid electrode 32,
Apply 0V.

Further, when a grid voltage is applied to the second grid electrode 32 to cause the light emitting segment 28 corresponding to the second grid electrode 32 to emit light in response to a print signal (information signal), the light emitting segment 28 corresponding to the second grid electrode 32 A drive voltage is selectively applied to each anode electrode 26 (anode electrode 26a and anode electrodes 26b ₅ to 26b ₈ ) according to the information signal to cause a required light emitting segment 28 to emit light.

At this time, for the anode electrodes 26b ₁ to 26b ₄ near the dividing point corresponding to the first grid electrode 31,
Apply 0V.

When driving the light emitting segment 28 on the first grid electrode 31 side in this way, 0V is applied to the anode electrode 26 located near the dividing point on the second grid electrode 32 side, and the light emitting segment 28 on the second grid electrode 32 side is driven. When driving the segment 28, 0V is applied to the anode electrode 26 located near the dividing point on the first grid electrode 31 side.

As a result, when the grid electrode is divided and driven, the light emitting segments near the division point corresponding to the grid electrode to which the grid voltage is applied and which are adjacent to the grid electrode to which the grid voltage is not applied are affected by the grid voltage ( It is possible to prevent the light from turning on due to crosstalk).

A control example for driving one line (for example, 2560 dots) of the anode electrode 26 will be briefly described with reference to FIG. 5 described above.

First, when controlling the lighting of the light emitting segment 28 corresponding to the first grid electrode 31, a 4-dot "0" signal is added to the end of half (1280 dots) of the information signal for one line.

Then, the odd-numbered dot data in the information signal is set in the shift register 42 of the odd-numbered dot driving IC by an odd-numbered clock generated by dividing the reference clock, and similarly, the even-numbered dot data in the information signal is set in the shift register 42 of the odd-numbered dot driving IC. is set in each shift register 42 of the even-numbered dot driving IC by an even-numbered clock signal generated by frequency-dividing the reference clock.

And (1280+4) dots (odd number dots 640+
2. Even-numbered dots 640 + 2) data are driven by an IC.
41 shift register 42,
The content of the shift register 42 is latched in each latch 43 by the latch signal, and the strobe signal is applied to each AND gate 44, so that the first grid electrode 3
A driving voltage is selectively applied to each of the anode electrodes 26 corresponding to the grid electrodes 26 to cause the required light emitting segments 28 to emit light.
is applied to prevent crosstalk.

Similarly, when controlling the lighting of the light emitting segment 28 corresponding to the second grid electrode 32, a 4-dot "0" signal is added to the beginning of half (1280 dots) of the information signal for one line. Thereafter, by performing the same control as described above, a drive voltage is selectively applied to each anode electrode 26 corresponding to the second grid electrode 32 to cause the required light emitting segment 28 to emit light, and at this time, the first grid electrode 31 The anode electrode 26 for four dots near the dividing point corresponding to
Apply 0V to prevent crosstalk.

In this way, in this dot array fluorescent tube recording head, the grid electrode is divided into a plurality of parts in the direction in which the anode electrodes are arranged, and the wiring between the drive circuit and the anode electrodes that are not located near the grid electrode division points is required. is a matrix wiring, and the wiring between the drive circuit and the anode electrode located near the dividing point of the grid electrode is a non-matrix wiring.

Thereby, one row of light emitting segments can be divided and driven into a predetermined number corresponding to each grid electrode, so the number of driving ICs can be reduced.

At the same time, since it is possible to prevent lighting due to crosstalk of non-lighting segments that may occur with split driving, it is possible to improve printing quality when used in an optical printer or the like.

Furthermore, by controlling the grid voltage applied to each grid electrode according to the luminance of the luminescent segment group corresponding to each grid electrode, it is possible to make the luminance of all luminescent segments approximately constant. , variations in the density of recorded images can be suppressed.

Note that the dot array fluorescent tube recording head according to the present invention is not limited to those used in optical printers.
For example, it can also be used as a display device.

Effects As explained above, according to the present invention, the number of driving ICs in a dot array fluorescent tube recording head can be significantly reduced, and erroneous lighting due to crosstalk can be prevented.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an optical printer equipped with a dot array fluorescent tube recording head embodying the present invention, FIG. 2 is a plan view of a dot array fluorescent tube recording head showing an embodiment of the present invention, and FIG. 4 are a sectional view and an enlarged plan view of essential parts of an example of the dot array fluorescent tube of the dot array fluorescent tube recording head, and FIG. 5 is an example of a driving IC for the dot array fluorescent tube recording head. The block diagram, FIG. 6, is an enlarged schematic plan view of the main parts for explaining the wiring between the dot array fluorescent tube recording head and the drive circuit. 3...Dot array fluorescent tube recording head, 11...
...Dot array fluorescent tube, 12...Driver IC board,
21... Substrate, 26... Anode electrode, 27... Phosphor, 28... Light emitting segment, 31... First grid electrode, 32... Second grid electrode, 35...
Filament (cathode electrode).

Claims (1)

[Claims] 1. A dot array fluorescent tube in which a large number of anode electrodes whose surfaces are coated with phosphor are arranged in a vacuum container, and a grid electrode is interposed between the anode electrode and the cathode electrode corresponding to the anode electrode; In a dot array fluorescent tube recording head comprising the dot array fluorescent tube and a drive circuit mounted on a separate substrate for selectively applying a driving voltage to the anode electrode of the dot array fluorescent tube, the grid electrode of the dot array fluorescent tube is connected to the anode electrode. The electrodes are divided into a plurality of parts in the arrangement direction, and the wiring between the drive circuit and anode electrodes other than the anode electrode located near the division point between the drive circuit and the grid electrode is matrix wiring, A dot array fluorescent tube recording head characterized in that the wiring between the head and the anode electrode located nearby is non-matrix wiring.