JPH0712711B2 - Fluorescent printer head - Google Patents

Description

The present invention relates to a light source to which a vacuum fluorescent tube having a multi-pole tube structure is applied, and particularly useful as a light source for facsimiles, a light source for electronic copying machines, and a light source for optical printers. The present invention relates to a fluorescent printer head.

[Conventional technology]

FIG. 6 is a partially cutaway plan view showing a part of a fluorescent printer head having a quadrupole tube structure proposed by the present applicant. As shown in the figure, a plurality of linear (or strip-shaped) anode conductors 2 are arranged in parallel with each other on the surface of the substrate 1, and the phosphor layer 3 is provided on the upper surface of each anode conductor 2. A plurality of anodes 4 are formed by successively depositing each. An insulating layer 5 is deposited on the substrate 1 around the anode 4. The end of each anode conductor 2 under the insulating layer 5 is
Is extended toward the end of the substrate 1 and is connected to and electrically connected to the connecting portion 6 provided at the end of the substrate 1. The inner ends of the outer leads 7 are connected to the connecting portions 6, respectively. The outer lead 7 is led out to the outside of the envelope 8 by hermetically penetrating a sealed portion between the container portion 9 and the substrate 1 which form the envelope 8.

A plurality of second control electrodes 10 are provided above the anode 4 via an insulating layer 5 provided in the peripheral portion of the substrate 1. The second control electrode 10 is formed of a flat plate member that obliquely intersects the arrangement direction of the anode conductor 2, and is provided in parallel with each other and electrically separated from each other. Also,
Slits 11 are formed in the center of each second control electrode 10 in a direction that diagonally crosses the anode conductor 2, and only a portion of the phosphor layer 3 defined by the slit 11 is formed. It is a light-emitting dot that emits light upon being hit by electrons.

Next, insulating spacers (not shown) are provided on both edges of the second control electrode 10, and the first control electrode 12 is provided above the second control electrode 10 with the spacers interposed therebetween. It is provided. The first control electrode 12 is formed of a single plate material, and a slit 13 slightly larger than the slit 11 is formed at a position corresponding to each slit 11 of the second control electrode 10. Therefore, the portion of the phosphor layer 3 of the anode 4 that appears in the gap between the second control electrodes 10 is hidden by the first control electrode 12, and the effective light emitting portion is, as described above, the light emitting dot of the light emitting dot. Only part. It is not necessary to continuously deposit the phosphor layer 3 on the anode conductor 2 as described above, depending on the manufacturing convenience, etc., and the phosphor layer 3 is deposited on at least the portion viewed through the slit 11. You just have to be present.

Next, cathode supports 14, 14 are provided near both ends of the substrate 1. In the figure, reference numeral 15 denotes an anchor frame, both ends of which are led out of the envelope 8, and a base portion 14a of the cathode support 14 is welded and fixed to the anchor frame 15 from below. As shown in FIG. 5, one end edge of the base portion 14a on the control electrode side is bent vertically upward and serves as a locking portion 14b for positioning with respect to the anchor frame 15. A pair of band-shaped anchors 14c having an elastic force for tensioning the filamentary cathode 16 is provided at the other end of the base 14a.
The anchor 14c is paired with the base portion 14a and is bent vertically upward, and the rectangular mounting portion 14d at the tip thereof is bent horizontally. And filament cathode 16
Is the mounting portion 14d with the anchor 14c elastically deformed.
The filamentous cathode 16 is welded and fixed at a predetermined position inside, and is pulled from both ends by the elastic force of the anchor 14c, and is provided at a predetermined position above the substrate 1 with a predetermined tension.

A container portion 9 composed of a side plate and a front plate is sealed to the substrate 1 via a sealing material, and the inside thereof is kept in a high vacuum atmosphere.

Next, when the fluorescent printer head having the above configuration is mounted as a light source for an optical printer or the like, the fluorescent printer is arranged so that the rotation axis direction of the photosensitive drum as a recording medium and the longitudinal direction of the anode 4 are parallel. Install the head near the photosensitive drum. The diagonal arrangement direction of the light emitting dots divided by one slit 11 is inclined with respect to the axial direction of the photosensitive drum. However, the width of each light emitting dot determined by the width of the slit 11 in the longitudinal direction of the anode 4 (that is, the axial direction of the photosensitive drum) is set appropriately, and the light emitting timing of each light emitting dot is set to the light emitting timing of the photosensitive drum by appropriate electric signal processing. By appropriately adjusting according to the rotation speed, the light emitted from each light emitting dot can continuously reach the position on a straight line parallel to the axis of the photosensitive drum surface.

[Problems to be solved by the invention]

In the fluorescent printer head having the above-described structure, it is necessary to accurately set the position of the filament cathode 16 as an electron emission source at a predetermined position in order to make the light emission brightness of each light emitting dot uniform.

However, the cathode support 14 on which the filamentary cathode 16 is stretched is manufactured by complicated press bending as described above, and the bending position and bending angle of the anchor 14c with respect to the base 14a, and the anchor 14c. An error is likely to occur in the bending angle and the like of the attachment portion 14d with respect to, and the welding position of the filamentary cathode 16 may deviate from a predetermined position. Further, the attachment portion 14d is a portion having an area of, for example, about 1 mm ² , and the filament cathode
Since the diameter of 16 is 30 to 40 μm, which is quite small, the mounting portion 14d
An error is likely to occur in the welding position of the filament cathode 16 with respect to. Further, during welding, the anchor 14c and the mounting portion 14d may be deformed by heat or may be mechanically deformed. As described above, according to the conventional stretched structure using only the anchor 14c having the elastic force, it is unavoidable that the attachment position accuracy of the filament cathode 16 varies.

Next, the filament cathode 16 expands due to heating during lighting. Therefore, the anchor 14c of the cathode support 14 which stretches the filamentary cathode 16 with elastic force is also deformed. That is, according to the above-described conventional tension structure, variations in the mounting position of the filament cathode 16 occur not only during manufacturing but also during use (lighting).
In the structure pulled by c, the variation becomes large.

In particular, in a fluorescent printer head having a long filament cathode, which is different from an ordinary fluorescent display tube, the filament cathode has a large positional deviation, and the mounting position varies.
It may exceed 200 μm. In particular, if there is such a positional shift in the height direction (vertical direction) of the filamentary cathode, the light emission luminance of each light emitting dot varies. As a result, in the fluorescent printer head, the sizes of the printed dots become uneven, so that uniform printing cannot be performed and the printing quality deteriorates.

[Object of the Invention]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the mounting position accuracy of a filament cathode in a fluorescent printer head and to improve the printing quality of the printer due to the low mounting position accuracy.

[Means for solving problems]

The fluorescent printer head of the present invention includes a plurality of strip-shaped anodes formed on an inner surface of a substrate forming a part of an envelope, a control electrode having a slit provided above the anodes, and the control electrode. In a fluorescent printer head having a filamentary cathode stretched over a pair of cathode supports above the positioning pattern provided at both ends of the substrate, and positioning pattern having substantially the same shape as the positioning pattern. Guide holding plates provided with both ends of the substrate with a through hole pattern, guide plates fixed with the guide holding plate with guide portions supporting the ends of the filamentary cathode, and the guide plate And an anchor for stretching and supporting the end portion of the filamentous cathode so that the filamentous cathode is supported by the guide portion.

[Action]

The filament cathode is stretched in the envelope by a pair of cathode supports, and both ends of the filament cathode are supported by a pair of guide plates. Since the guide plate is positioned at a predetermined position on the substrate on which the anode is formed, the position of the filamentary cathode with respect to the anode and the control electrode is set accurately. Even if the filamentous cathode and the cathode support are thermally deformed during lighting, the supporting state of the guide plate with respect to the filamentous cathode does not change, so that the filamentous cathode is not displaced.

〔Example〕

 An embodiment of the present invention will be described with reference to FIGS.

The fluorescent printer head 20 of this embodiment has substantially the same structure as the conventional structure except for the structure for supporting and positioning the filament cathode 21. Therefore, in this section, a description will be given centering on the guide plate and the like which are the main parts, and the other components shown in the figure are denoted by the same reference numerals as in FIG.

As shown in FIGS. 1 to 3, inside the envelope 8 of the fluorescent printer head 20, a guide holding plate 22 made of 426 alloy is positioned and fixed on the inner surface of the end portion of the substrate 1. The fixed portion 23 of the guide holding plate 22 has a substantially rectangular shape, and a dozen shaped through hole pattern 24a is provided at a substantially central portion thereof, and one shaped through hole patterns 24b and 24b are provided near both ends thereof by photoetching. Is formed by. At a predetermined position on the substrate 1,
The insulating layer 5 is provided with three non-deposited square regions, and the through-hole patterns 24a and 24b are provided in each of the three regions.
Smaller than a dozen or one type of minute positioning patterns 25a and 25b for positioning are adhered and formed. Therefore, a pattern for positioning the substrate 1 is used by using a microscope in the manufacturing process.
The guide holding plate 22 can be precisely positioned with respect to the substrate 1 by aligning the through hole patterns 24a and 24b of the fixing portion 23 with the holes 25a and 25b. Further, in the fixing portion 23, mesh-shaped attachment portions 26 are formed as two through-hole attachment portions by photoetching. At a predetermined position on the substrate 1, there is provided a substantially square adhesive region where the insulating layer 5 is not adhered, and the position of the mounting portion 26 of the guide holding plate 22 positioned with respect to the substrate 1 is It is designed to coincide with this adhesive area. A crystalline frit glass 27 as an adhesive material is applied to the mounting portion 26 from the upper surface side of the fixing portion 23, and is baked and solidified to position and fix the guide holding plate 22 to the substrate 1. The structure of the through hole-shaped mounting portion 26 is not limited to the mesh shape, and may be, for example, a slit shape, or one or a plurality of through holes may be provided. Next, a guide attachment portion 28 is integrally provided on one long side of the fixed portion 23. The guide mounting portion 28 is formed by bending so as to be perpendicular to the fixed portion 23 and the substrate 1. Insertion holes for the rivets 29 are formed at both ends of the guide attachment portion 28, and a pair of escape grooves 28a are provided inside the insertion holes so that the filament cathode 21 does not come into contact with the guide attachment portions 28. A guide plate 30 is attached to the guide attachment portion 28 positioned at a predetermined position on the substrate 1 by a rivet 29. At the upper edge of the guide plate 30, V-shaped introducing portions 31 are formed at two positions as shown in FIG. 4 corresponding to the pair of escape grooves 28a, 28a.
Straight groove-shaped guide portions 32, 32 for surely supporting the filamentary cathode 21 are formed on the bottoms of 31, 31. Further, as shown in FIG. 4A, the introduction part 31 may have a tapered cross section having a radius, and the guide part 32 may have a groove having a wedge-shaped cross section. The groove width of the guide portion 32 is set to be equal to or slightly larger than the outer diameter of the filamentary cathode 21. The guide plate 30 is made of ceramics as a wear resistant material. In this embodiment, for example, zirconia-based or alumina-based ceramics having a coefficient of thermal expansion close to that of glass and good workability are used. As the material of the guide plate 32, in addition to this, a wear resistant metal can be used, and for example, Cr, Ti, W or the like can be adopted. The entire guide plate 32 may be made of the same kind of wear-resistant material, but since only the guide portion 32 is in constant contact with the filament cathode 21, the wear-resistant material as described above is used. It may be used as a part so that at least the guide portion 32 has abrasion resistance. Further, the means for attaching the guide plate 30 to the guide attaching portion 28 is not limited to the rivet 29, and may be a mechanical attachment structure such as caulking that does not easily deteriorate the attachment state due to heat generated during lighting.

Next, an anchor frame 33 is provided next to the guide holding plate 22.
There is provided a cathode support 34 attached to the. These structures are similar to those described in the [Prior Art] section, except that the mounting portion of the anchor frame 33 and the base portion of the cathode support 34 are
A rectangular through hole 35 is provided in 34a, and the guide attaching portion 28 of the guide holding plate 22 to which the guide plate 30 is attached is inserted into the through hole 35. Then, one ends of the pair of filamentary cathodes 21, 21 are welded and fixed to the mounting portions 34c, 34c provided at the tips of the pair of anchors 34b, 34b having elastic force. Although not shown,
The other end of the filament cathode 21 is also attached to a similar cathode support 34, and the filament cathode 21 is given a predetermined tension. Both ends of the filament cathode 21 are inserted into the guide portions 32 of the guide plate 30 positioned with respect to the substrate 1 via the guide holding plate 22. First
As shown in FIG. 2 and FIG. 2, the filament cathodes 21, 21 are arranged farther than the space between the guide portions 32, 32 of the one guide plate 30.
The distance between the welding points is larger, and the height of the welding points is lower than the height of the bottom of both guide portions 32, 32. Therefore, as shown in FIG. 4, the end of the filament cathode 21 is
The filamentous cathode 21 is accurately positioned at a predetermined position on the substrate 1 because the filamentous cathode 21 is supported by coming into contact with the position of the positioned guide portion 32 near the bottom. Fig. 4-
Also in the embodiment shown in A, it is possible to accurately position the filament cathode 21 by forming the wall surface 32b of the groove that is in contact with the outer side of the groove vertically.

Reference numeral 36 in the figure is a getter integrally provided with the cathode support 34, and 37 is a contact lead of a transparent conductive film provided on the inner surface side of the front plate.

Next, a manufacturing process of the fluorescent printer head 20 having the above configuration will be briefly described.

As shown in FIG. 1, the anchor frame 33 on which the filamentary cathode 21 is stretched by welding, the frame of the contact lead 37, the control electrode (not shown) and the external lead 7 of the anode 4 are provided on the frame 38. And forms a frame structure as a whole. According to the present embodiment, since the positioning of the filamentary cathode 21 is performed by the guide plate 30, the setting of the welding position for the attachment portion 34c of the filamentous cathode 21 may be rougher than in the past, and the workability can be improved. .

Next, an aluminum anode pattern and a positioning pattern are formed on the substrate 1 by a photolithography method,
The insulating layer 5 is printed on the substrate 1 so as to surround both the patterns, and then baked. Then, a glass sealing material is printed around the substrate 1 and fired again, and then silver is printed on the connection portion 6 of the anode 4 at the end of the substrate 1. Then, the phosphor layer 3 is applied to the strip-shaped anode pattern by the electrodeposition method to form the anode 4.

Next, the guide holding plate 22 with the guide plate 30 riveted
Are fixed to both ends of the substrate 1, respectively.
First, using the microscope, the through hole pattern 24 of the guide holding plate 22
The guide holding plate 22 is accurately positioned with respect to the substrate 1 by aligning a and 24b with the positioning patterns 25a and 25b provided on the substrate 1, and the two are temporarily fixed with an adhesive material. And mounting part
A crystalline frit glass 27 is applied to 26 and then baked to permanently fix the guide holding plate 22 to the substrate 1. Then, the first and second control electrodes 12 and 10 are positioned and fixed on the substrate 1.

Next, the frame structure is placed on the substrate 1, and two ends of each of the two filament cathodes 21, 21 are connected to the two guide plates 3.
It is inserted into each guide portion 32 of 0 and 30 and supported. The guide plate 30 is accurately positioned via the guide holding plate 22 with respect to the substrate 1 provided with the strip-shaped anode 4 serving as a light emitting portion. Therefore, the filament cathode 21 stretched between the guide portions 32, 32 of the guide plate 30 is accurately positioned at a predetermined position set in advance with respect to the anode 4. Since the guide portion 32 is provided with the introduction portion 31, the filament cathode 21 can be easily set in the guide portion 32. Further, the portion where the guide portion 32 comes into contact with the filamentous cathode 21 is a portion within a range where a so-called end cooling effect is produced in the filamentous cathode 21, and the filamentous cathode 21
Do not unnecessarily reduce the electron emission capacity of.

Next, the box-shaped container portion 9 is sealed and fixed on the substrate 1 to form the envelope 8, and the inside thereof is evacuated, and the various electrodes and the like arranged in the envelope 8 are raised. Place in a vacuum atmosphere.

As described above, according to the fluorescent printer head 20 of the present embodiment, the filament cathode 21 can be accurately positioned and arranged at a predetermined position by the guide plate 30 positioned with respect to the substrate 1. And when lit, anchor 34
Even if b or the like is thermally deformed, the guide plate 30 that determines the position of the filamentary cathode 21 is hardly displaced, so that the arrangement position of the filamentous cathode 21 is not displaced. Since the guide portion 32 of the guide plate 30 has abrasion resistance, repeated lighting of the fluorescent printer head 20 causes repeated friction between the filament cathode 21 and the guide portion 32. Also, the guide part
32 does not wear out. Therefore, even if the filament cathode 21 is used for a long period of time, the arrangement position of the filament cathode 21 hardly changes. As described above, in this embodiment, since the filament cathode 21 is correctly set at a predetermined position and there is almost no change in position, the variation in the brightness of each light emitting dot is small, and the characteristics are stable even during long-term and long-term use. Is obtained. Therefore, the printing quality of the printer using the fluorescent printer head 20 can be improved.

Although the present embodiment has a quadrupole structure, the present invention is not limited to the first embodiment.
It can be applied to a fluorescent printer head having a triode structure without the control electrode 12.

〔The invention's effect〕

In the fluorescent printer head of the present invention, the guide holding plate is positioned in accordance with the through hole pattern provided on the guide holding plate in accordance with the positioning pattern provided on both ends of the substrate, and the filament cathode which gives tension from both ends by the anchor is used. The filament cathode is positioned by being supported by the guide portion of the guide holding plate. Therefore, the positioning of the guide holding plate is easy, and the position of the filamentary cathode can be set to be always constant by a simple operation. Further, since the filament cathode is applied with tension from both ends, it is possible to sufficiently absorb the amount of thermal expansion of the member generated when the fluorescent printer head is driven. Therefore, according to the fluorescent printer head of the present invention, it is possible to reduce variations in light emission luminance and improve the quality of printer printing.

[Brief description of drawings]

1 is a plan view of an essential part showing an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a view seen from the direction of arrow III in FIG. 4 and 5 are enlarged views of the IV portion in FIG. 3, FIG. 4A is an enlarged view of another embodiment of the IV portion in FIG. 3, and FIG. 5 is a cathode support in a conventional fluorescent printer head. FIG. 6 is a diagram showing a fluorescent printer head having a quadrupole structure, which is an example of a conventional fluorescent printer head, and is a partial plan view with a part cut away. 1 ... Substrate, 4 ... Anode, 8 ... Envelope, 10 ... Second control electrode, 11 ... Slit, 12 ... First control electrode, 13 ... Slit, 20 ... Fluorescent printer head, 21 …… Filament cathode, 22 …… Guide holding plate, 24a, 24b …… Penetration pattern, 25a,
25b …… Positioning pattern, 26 …… Through hole mounting part, 3
0 …… Guide plate, 32 …… Guide part, 34 …… Cathode support.

Claims (8)

[Claims] 1. A plurality of strip-shaped anodes formed on an inner surface of a substrate forming a part of an envelope, a control electrode having slits provided above the anodes, and a control electrode above the control electrodes. In a fluorescent printer head having a filamentary cathode stretched by a pair of cathode supports, a positioning pattern provided on both ends of the substrate and a positioning through-hole pattern having substantially the same shape as the positioning pattern. A guide holding plate provided at both ends of the substrate, a guide plate fixed to the guide holding plate having a guide portion for supporting the end portion of the filamentary cathode, and a guide portion of the guide plate. A fluorescent printer head, comprising: an anchor that stretches and supports an end of the filament cathode so that the filament cathode is supported by the anchor. 2. The fluorescent printer head according to claim 1, wherein at least the guide portion of the guide plate is made of an abrasion resistant material. 3. The fluorescent printer head according to claim 2, wherein the abrasion resistant material is an abrasion resistant metal. 4. The fluorescent printer head according to claim 2, wherein the abrasion resistant material is ceramics. 5. The fluorescent printer head according to claim 1, wherein the guide portion has a straight groove shape or a triangular shape. 6. The fluorescent printer head according to claim 1, wherein the guide plate is fixed to a guide holding plate which is positioned and fixed on the substrate. 7. The fluorescent printer head according to claim 6, wherein the guide holding plate is provided with a through hole pattern having a shape matching a positioning pattern provided on the substrate. 8. The fluorescent printer head according to claim 6, wherein the guide holding plate is provided with a through-hole-like mounting portion fixed to the substrate with an adhesive material.