JP2000296636A - Fluorescent print head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent print head particularly suitable for low resolution, to reduce component cost and mounting cost of a driving element and to reduce the head in size. SOLUTION: A fluorescent light print head comprises a box-shaped housing of which the inner section is maintained in a high vacuum condition, light emitting dot arrangements 26, 27 formed such that a plurality of light emitting dots 25 are arranged in a staggered fashion in the main scanning direction at an inner face of an anode substrate forming a part of the housing, plane face control electrodes 32 formed on the anode substrate each being flush with the light emitting dot arrangements 26, 27 such that they surround the circumference of each of the light emitting dots 25, and a filament-type cathode 34 provided along the light emitting dot arrangements 26, 27 in the inside of the housing. Wire type conductors 30 each being drawn straight from the respective light emitting dot 25 are collected to one side of the anode substrate to be connected to driving elements such that the conductors pass through gaps between the light emitting dots and plane face control electrodes 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fluorescent print head used in an optical printer for forming a desired image on a recording medium such as a photosensitive film or photographic paper.

[0002]

2. Description of the Related Art An optical printer equipped with a fluorescent print head using light emission by the impact of electrons on a phosphor is used as a light source for forming a desired image on a recording medium such as a photosensitive film or photographic paper. Already known.

FIG. 5 is a partially cutaway perspective view of a conventional fluorescent print head mounted on this type of optical printer, and FIG. 6 is a plan view showing a wiring structure of an anode conductor in the fluorescent print head.

[0006] The fluorescent print head 5 shown in FIGS.
1 has an envelope 52 whose inside is kept in a high vacuum state. On the inner surface of the anode substrate 53 constituting the envelope 52, a rectangular anode conductor 54 having a through hole and a linear anode wiring 55 connected to each anode conductor 54 are formed. A dot-shaped phosphor layer 5 is provided in the through hole of each anode conductor 54.
6 are formed to form the light emitting dots 57. The light emitting dots 57 are arranged in two rows in a staggered manner, and the light emitting dot row 5
8,59.

More specifically, the pitch of the light emitting dots 57 in the two parallel light emitting dot rows 58 and 59 is the same, and the light emitting dots of one of the rows are orthogonal to the longitudinal direction of the row of the light emitting dots 57. 57A is adjacent to a position between the light emitting dots 57B in the other row. Then, in the light emitting dot rows 58 and 59, the light emitting dots 57
Is the main scanning direction when data is stored on the recording medium, and the direction orthogonal to this is the sub-scanning direction.

In the fluorescent print head 51, 200
Since it has a resolution of about 300 dpi,
Since the pitch between the wires 7 and 57 is narrow and the wiring density is large, a wiring structure as described below has been adopted.

That is, a bar-like connecting portion 60a like a tree trunk is provided between the two light emitting dot rows in parallel with the main scanning direction, and further, the light emitting dot rows 58, on both sides like branches and leaves from the connecting portion 60a. The plane control electrode 60 is formed so as to extend in the direction of 59 and surround each light emitting dot 57. Then, from each light emitting dot 57, the anode wiring 55 is drawn out to both outer sides between the two light emitting dot rows 58 and 59, and the CIG,
Each light emitting dot 57 is connected to the driver IC 61 by a mounting method such as COG and TAB.

[0008]

As described above, the above-described conventional fluorescent print head 51 is 200 to 300 dp.
i, and the pitch of the light emitting dots 57 is very narrow.
Through the gap of the plane control electrode 60 to both sides and connected to the driver IC 61.

For this reason, as shown in FIG. 5, at least two driver ICs 61 are required irrespective of the number of anode wirings 55, which is disadvantageous in terms of component cost and IC mounting cost. In addition, there is a disadvantage in miniaturizing the package (the envelope 52) in order to secure an IC mounting area.

Incidentally, the conventional fluorescent print head 51
In order to take cost measures and miniaturization measures in the structure of
If an attempt is made to concentrate the anode wiring 55 on one side of the anode substrate 53, a wiring structure as shown in FIG. 7 is conceivable.

However, when such a wiring structure is employed, there is a problem that the substrate becomes large in order to secure a sufficient area for forming the anode wiring 55, and as a result, the head itself also becomes large. In addition, there is a problem that the larger the number of light-emitting dots, the larger the number of anode wirings 55 drawn to one side. Further, since the length of the anode wiring 55 drawn to one side becomes longer and the variation in the length also becomes larger, there is a problem that the luminance variation becomes larger due to the influence of the wiring resistance. This is because the longer the wiring, the higher its electrical resistance and the light emitting dots 5
This is caused by a decrease in the potential at the portion 7; however, this causes a luminance difference between the light emitting dot rows 58 and 59, and the wiring lengths at the same light emitting dot rows 58 and 59 are also greatly different. A luminance difference also occurs between the light emitting dots 57.
Then, there is a problem that the quality of the output image is deteriorated due to the luminance variation.

By the way, as a fluorescent print head,
While there is a demand for a high resolution product, there is also a demand for a low resolution product in which the price is given priority over the quality of the output image.

Accordingly, the present invention has been made in view of the above problems, and is particularly useful for low-resolution products, and aims to reduce the component cost and mounting cost of a driving element (driver IC) and to reduce the size. Another object of the present invention is to provide a fluorescent print head capable of reducing the luminance variation by making the electric field surrounding the light emitting dots substantially uniform.

[0014]

In order to achieve the above object, a first aspect of the present invention provides a box-shaped envelope whose inside is maintained in a high vacuum state, and a substrate forming a part of the envelope. A plurality of light emitting dots formed in a staggered manner in the main scanning direction on the inner surface of the light emitting dot array, and a planar control formed on the substrate in the same plane as the light emitting dot array so as to surround the light emitting dots. In a fluorescent print head having electrodes and a cathode provided along the light emitting dot row inside the envelope, a linear wiring conductor drawn linearly for each light emitting dot includes the light emitting dot and It is characterized in that it passes between the planar control electrodes and is concentrated on one side of the substrate and connected to a driving element.

According to a second aspect of the present invention, in the fluorescent print head according to the first aspect, a linear dummy wiring conductor is drawn out of the light emitting dot in a straight line with the wiring conductor of the light emitting dot. Both ends of the planar control electrode including an end of the dummy wiring conductor are covered with an insulating layer.

[0016]

FIG. 1 is a schematic structural view of an optical printer having a fluorescent print head according to the present invention. FIG. 2 is a partially cutaway perspective view showing a first embodiment of the fluorescent print head.
FIG. 3 is a plan view showing a wiring structure of an anode conductor which is a main part of the fluorescent print head.

Before describing the structure of the fluorescent print head 2 of each embodiment, an optical printer 1 will be described with reference to FIG.
Will be described.

The optical printer 1 includes a fluorescent print head 2 as a light source. The light of three primary colors R, G, and B obtained from the fluorescent print head 2 is used to record a recording medium such as a color film or photographic paper. The writing to W is performed by three scans to form a full-color image.

The optical printer 1 is driven by a digital color image signal obtained from a video device or the like, and is used as a color printer that prints an image on a recording medium W in full color. In addition, it can be used for an electrophotographic printer, a silver halide printer, a label printer, and the like.

As shown in FIG. 1, an optical printer 1 has a fluorescent print head 2 which moves along a sub-scanning direction indicated by an arrow A with respect to a recording medium W positioned and fixed at a predetermined position.
In addition, a single optical system 6 as a light imaging unit including a lens 4 for reflecting light from the light emitting unit 3 of the fluorescent print head 2 on the surface of the recording medium W and a reflecting mirror 5 is provided as a housing. 7 is built in.

As shown in FIG. 1, the fluorescent print head 2
Is reciprocated with respect to the recording medium W in the sub-scanning direction by a moving mechanism 8 as moving means. The moving mechanism 8 includes a guide unit (not shown) for movably guiding the housing 7 containing the fluorescent print head 2 in the sub-scanning direction, and a pair of pulleys 1 around which a driving belt 9 is wound.
0, 10 and a drive motor 11 for rotating one of the pulleys 10, 10.

When the drive belt 11 is circulated by driving the drive motor 11, the housing 7 having the fluorescent print head 2 built therein and fixed to the drive belt 9 is guided by guide means (not shown) to perform sub-scanning. Can move along the direction. A plurality of color films as the recording medium W are held at predetermined positions, and when writing by light is completed, the discharge mechanism 12 performs development and discharges the color film to the outside.

Next, the configuration of the fluorescent print head 2 according to the first embodiment will be described with reference to FIGS.

The fluorescent print head 2 according to each of the embodiments described below has a driver IC for responding to a demand for a low-resolution product in which a low price is prioritized over an image quality.
The present invention is characterized by the wiring structure of the anode conductor, which can reduce the component cost and the mounting cost of the device and reduce the size.

As shown in FIG. 2, the fluorescent print head 2
Has an envelope 24 in which a positive electrode substrate 21, a side plate 22, and a rear substrate 23 are assembled in a box shape by sealing glass, and the inside is in a high vacuum state.

On the inner surface of the anode substrate 21 of the envelope 24, the first and second light emitting dot rows 2 each including a plurality of light emitting dots 25 are formed along the longitudinal direction of the anode substrate 21.
6 and 27 are provided to constitute the light emitting section 3 (anode). Each of the light emitting dots 25 includes a frame-shaped anode conductor 28 formed of a conductive film such as an aluminum thin film formed on the anode substrate 21, and a phosphor layer 2 covered on the anode conductor 28.
9 is provided.

The phosphor layer 29 is made of, for example, a phosphor such as ZnO: Zn, and is applied so as to be wider than the rectangular opening of the anode conductor 28 and not to protrude from the frame. Light emitted from the phosphor layer 29 is emitted from the opening of the frame-shaped anode conductor 28 to the outside of the anode substrate 21 through the anode substrate 21.

Therefore, the area of the light emitting dots 25 of the fluorescent print head 2 indicates the effective light emitting area of the phosphor layer 29 divided by the opening of the frame-shaped anode conductor 28.

First and second light emitting dot rows 26 and 27
Is one in which a plurality of light emitting dots 25 are arranged in the main scanning direction. The light emitting dots 25 adjacent to each other in the main scanning direction in each row have a pitch corresponding to the resolution, for example, a resolution of 1
In the case of 00 dpi, they are arranged at a pitch of 254 μm.

First and second light emitting dot rows 26 and 27
Are parallel to each other and are arranged at a predetermined pitch in the sub-scanning direction orthogonal to the main scanning direction. The positions in the main scanning direction are displaced by one pitch of the light emitting dots 25 and are arranged in a staggered manner. . That is, the pitch of each light emitting dot 25 in the two light emitting dot rows 26 and 27 parallel to each other is the same, and in the direction orthogonal to the longitudinal direction of the row of the light emitting dots 25, the light emitting dot 25A of one row is replaced by the other. It is located adjacent to between the light emitting dots 25B. The pitch in the sub-scanning direction between the two light emitting dot rows 26 and 27 is set to an integral multiple of the pitch of the light emitting dots 25 in the main scanning direction.

The first and second light emitting dot rows 26,
At 27, the longitudinal direction in which the light emitting dots 25 are arranged is the main scanning direction during the recording operation by the fluorescent print head 2,
The direction orthogonal to this is the sub-scanning direction.

The anode conductor 28 of each light emitting dot 25 is integrally formed with a linear wiring conductor (anode wiring) 30 which is drawn to one side perpendicularly to the direction in which the light emitting dots 25 are juxtaposed and collected. . Each wiring conductor 30 is connected to a driver IC 31 as a driving element for each light emitting dot 25, and an anode voltage is applied to each light emitting dot 25 via the driver IC 31.

On the inner surface of the anode substrate 2, a plane control electrode 32 made of a conductive film such as an aluminum thin film is provided in the same plane as the anode conductor 28 and the wiring conductor 30. A plurality of planar control electrodes 32 are provided in parallel with the sub-scanning direction, and are patterned so as to surround the anode conductor 28 and the wiring conductor 30 of each light emitting dot 25. Each of the plane control electrodes 32 is drawn out to the opposite side to the drawing direction of the wiring conductor 30, and is integrally and commonly connected to a rod-shaped connecting part 32b parallel to the main scanning direction via a linear lead part 32a. A positive control voltage is always applied to the plane control electrode 32,
The electric field is kept uniform, and the flow of electrons emitted from a cathode 34 described later is controlled. Both end portions of the plane control electrode 32 are covered with an insulating layer 33 as shown by a dashed line in FIG.

Inside the envelope 24, one position is provided above each of the light emitting dot rows 26 and 27 along the direction in which the light emitting dot rows 26 and 27 are arranged (main scanning direction). Two filament cathodes 34 are stretched.

As described above, in the first embodiment, the wiring conductors 30 drawn from the first and second light emitting dot rows 26 and 27 do not largely detour as shown in FIG. The driver I is integrated on one side of the anode substrate 21
Can be connected to C31.

As a result, the required number of driver ICs can be reduced to half that of the conventional configuration while minimizing the luminance variation caused by the variation in the wiring length. As a result, there is a great effect in terms of the component cost and the mounting cost of the driver IC, and further, the miniaturization of the envelope.

FIG. 4 is a plan view showing a wiring structure of an anode conductor which is a main part of the fluorescent print head according to the second embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

The fluorescent print head according to the second embodiment has
As shown in FIG. 4, the first and second light emitting dot rows 26,
The dummy wiring conductor 35 is provided integrally with the anode conductor 28 of each of the 27 light emitting dots 25. The dummy wiring conductor 35 is in the opposite direction to the wiring conductor 30 and
Are drawn out of the respective anode conductors 28 in parallel with the sub-scanning direction. The wiring of the wiring conductor 30 and the dummy wiring conductor 35 for each light emitting dot 25 is formed to have the same length.

A plurality of plane control electrodes 32 are provided in parallel with the sub-scanning direction, and are patterned so as to surround the anode conductor 28, the wiring conductor 30, and the dummy wiring conductor 35 of each light emitting dot 25. Each plane control electrode 32 is drawn out in parallel with the drawing direction of the dummy wiring conductor 35,
It is integrally and commonly connected to a rod-shaped connecting portion 32b parallel to the main scanning direction via a linear lead portion 32a.

As shown by the alternate long and short dash line in FIG.
0 and the plane control electrode 3 including the end of the dummy wiring conductor 35
2 are located at intervals H between adjacent light emitting dot rows.
1 and H2 are covered with the insulating layer 33 so as to be the same. As a result, only the periphery of the light emitting dot 25 is exposed. The shape of this portion is substantially symmetrical in the upper, lower, left, and right directions, and the wiring resistance of each light emitting dot 25 is also equal. Therefore, the electric field surrounding each light emitting dot 25 is made uniform, and as a result, luminance variation is suppressed. Can be.

As described above, when the desired resolution is low, the fluorescent print head 2 of the present embodiment has the anode conductor 28.
Wiring conductor 30 and the plane control electrode 32
The wiring conductors 30 are drawn out to one side while being formed with an appropriate width between 5, 5 and 25, and are connected to the driver IC 31 for each light emitting dot 25.

Here, the appropriate width is assumed to be a width of 20 μm or more. The reason is that, considering the process variation in the aluminum thin film pattern manufacturing process, 2
It is very difficult to control the wiring width below 0 μm, and when it exists as an electrode for controlling thermoelectrons,
If the thickness is less than 20 μm, the electric field control ability is reduced.

Further, in the patterning process of several tens of μm or more, the proximity exposure method using ultraviolet rays is popular, and the gap between the mask and the substrate is maintained at several tens μm to prevent the mask from being stained by contact with the photoresist. I'm dripping. As a result, light diffraction occurs and the resolution deteriorates. In addition, there is also a variation factor in the etching process. In order to manage a fine wiring of 20 μm or less, it is necessary to perform a higher level of process management that requires time and expense, or to pattern in a semiconductor manufacturing process. .

Therefore, the fluorescent print head 2 of this embodiment is
For example, although a low-resolution product of about 100 dpi has a meaningful configuration, the cost of parts and mounting of the driver IC can be reduced in the demand for a low-resolution product in which the price is given priority over the quality of the output image. , It is a configuration suitable for demand.

Specifically, assuming a fluorescent print head having a light emitting width of 1 inch and a resolution of 100 dpi, if a conventional configuration is used to design a fluorescent print head, 1
Wiring conductors are drawn out from the 00 light-emitting dots to both outer sides by 50 lines. As a result, a total of two driver ICs each having 50 or more outputs are mounted on both outer sides.

On the other hand, when designing with the configuration of this example,
From 100 light emitting dots arranged in a zigzag pattern, 100 wiring conductors are gathered and pulled out on one side. As a result, it is only necessary to mount one driver IC having 100 or more outputs.

Further, in the structure of the conventional fluorescent print head, if the wiring of the anode conductor is drawn out to one side for cost reduction, a problem occurs as shown in FIG. On the other hand, the fluorescent print head 2 of the present example has an effect of minimizing the luminance variation caused by the variation of the wiring resistance while responding to the cost. In addition, the size of the fluorescent print head and its module can be reduced, which is a great advantage particularly when applied to portable products.

In particular, since the fluorescent print head 2 of the second embodiment has a configuration in which the dummy wiring conductor 35 is added,
This has the effect of making the electric field uniform. At this time, both ends of the plane control electrode 32 including the ends of the wiring conductor 30 and the dummy wiring conductor 35 are covered with the insulating layer 33, and only the periphery of the light emitting dot 25 is exposed, and the shape at that portion is substantially symmetrical in up, down, left and right. Since the shape becomes the same and the wiring resistance of each light emitting dot 25 becomes equal, there is an effect that the electric field surrounding each light emitting dot 25 is made uniform, and as a result, the luminance variation can be suppressed.

Incidentally, the configuration of the above-described embodiment is as follows.
This is also effective when a plurality of driver ICs are mounted on one side. For example, a fluorescent print head having a resolution of about 100 dpi and a long emission width has a structure as shown in FIG. 2 extended in the longitudinal direction, and a required number of driver ICs are mounted on one side according to the number of wirings.

[0050]

As is apparent from the above description, according to the fluorescent print head of the present invention, it is particularly useful for low-resolution products, and reduces the component cost and the mounting cost of the driving element (driver IC) and reduces the size. Can be achieved.

In particular, according to the fluorescent print head of the second aspect, it is possible to make the electric field surrounding the light emitting dots substantially uniform and suppress the luminance variation.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an optical printer including a fluorescent print head according to the present invention.

FIG. 2 is a partially cutaway perspective view showing a first embodiment of a fluorescent print head.

FIG. 3 is a plan view showing a wiring structure of an anode conductor which is a main part of the fluorescent print head.

FIG. 4 is a plan view showing a wiring structure of an anode conductor which is a main part of a fluorescent print head according to a second embodiment.

FIG. 5 is a partially cutaway perspective view of a conventional fluorescent print head mounted on an optical printer.

FIG. 6 is a plan view showing a wiring structure of an anode conductor in the fluorescent print head of FIG. 5;

FIG. 7 is a plan view showing a wiring structure when the anode wiring is concentrated on one side in the arrangement of the light emitting dots of the fluorescent print head of FIG. 5;

[Explanation of symbols]

2 Fluorescent print head, 21 Anode substrate, 24 Envelope, 25 Light emitting dot, 26 First light emitting dot row, 2
7 ... second light emitting dot row, 30 ... wiring conductor, 31 ... driver IC (drive element), 32 ... plane control electrode, 33 ...
Insulating layer, 34: cathode, 35: dummy wiring conductor.

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Kinya Ueda 629 Oshiba, Mobara-shi, Chiba Futaba Electronics Co., Ltd. (72) Inventor Tomoji 629 Oshiba, Mobara-shi, Chiba Futaba Electronics Co., Ltd. Reference) 2C162 AH33 AH34 AH40 FA19

Claims (2)

[Claims] 1. A box-shaped envelope whose inside is maintained in a high vacuum state, and a plurality of light emitting dots formed in a zigzag pattern in a main scanning direction on an inner surface of a substrate forming a part of the envelope. A light emitting dot row, a plane control electrode formed on the substrate on the same plane as the light emitting dot row so as to surround the light emitting dot, and provided along the light emitting dot row inside the envelope. In the fluorescent print head having a cathode formed, a linear wiring conductor that is linearly drawn out for each light emitting dot is passed between the light emitting dot and the plane control electrode and is collected on one side of the substrate. A fluorescent print head connected to a driving element. 2. A line-shaped dummy wiring conductor is drawn out of said light emitting dot in a straight line with a wiring conductor of said light emitting dot, and said planar control electrode including end portions of said wiring conductor and said dummy wiring conductor. The fluorescent print head according to claim 1, wherein both ends are covered with an insulating layer.