JPH08274946A - Image processor - Google Patents

Abstract

PURPOSE: To make the interval between a scanning head and an object sheet constant in the subscanning direction by connecting the scanning head with connecting members supported turnably. CONSTITUTION: While a nut 235 and a 1st auxiliary connecting member 252 are coupled, the nut 235 is set nearly in the middle of a valid screw length of the nut 235 so that a spring pin press fit hole 252d of the member 252 hardly receives rocking in the subscanning direction. Thus, the mount seat face of the member 252 is tilted from the proper direction and the member 252 is fitted to a holder 215 via the connecting member 250, then the tilt is absorbed through the proper amount of turning of supports 270, 275 between a main connection member 251 and 1st and 2nd auxiliary connecting members 252, 253. Thus, a torsional force owing to the tilt is not propagated to the holder 215. Since the connecting member 250 is tilted depending on the tilt direction and tilt amount of the mount seat face of the nut 235, the mount between the nut 235 and the holder 215 is facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus, and more particularly to an image processing apparatus such as an input / output scanner or an inkjet printer used for plate making.

[0002]

2. Description of the Related Art In an output scanner, for example, a drum type scanner, a rod for guiding the output head in the sub-scanning direction and a rod for guiding the output head in the sub-scanning direction substantially parallel to the axis of the drum on which the photosensitive material is mounted. And a feed screw for driving and driving, and a holder holding an output head is slidably inserted into the rod, and a holder-side mounting seat surface is closely attached to the nut-side mounting seat surface. Are doing

In the output scanner, since the depth of focus of the head is shallow, it is strictly required that the distance between the output head and the drum surface be equal at any position in the sub-scanning direction. That is, if the distance between the output head and the drum surface changes while the output head is running, the focus of the output head deviates from the drum surface, so the size of the halftone dot becomes large in the halftone dot drawing, and the print image is locally printed. There are problems such as blurring and disorder.

The above problem is not limited to the drum-type output scanner, but also exists in the flat-type output scanner. In the input scanner, the read image is blurred due to the change in the distance between the input head and the document mounting surface. There is a problem that occurs. Further, in an image forming apparatus such as an inkjet printer, when the distance between the head and the recording paper changes, ink droplets flying from the head are affected by gravity and are displaced in the sub-scanning direction on the recording paper, resulting in image quality. There is a problem that is worse.

However, in reality, since the machining accuracy and the assembly accuracy are limited, the nut swings as the nut moves in the sub-scanning direction. Since the holder (or the output head) is conventionally attached in close contact with the nut as described above, the swing of the nut causes a change in the distance between the output head and the drum surface. It was

In view of the above problems, the present invention provides a useful image processing apparatus capable of ensuring that the distance between the scanning head and the sheet-shaped member to be read or written is constant in the sub-scanning direction. The purpose is to do.

[0007]

In order to achieve the above object, an image processing apparatus according to claim 1 is a sheet-shaped body mounting member for mounting a sheet-shaped body to be read or written, A scanning head for reading an image from the sheet-shaped body or writing an image on the sheet-shaped body, and a linear motion guide for guiding the scanning head in a sub-scanning direction in parallel with the mounting surface of the sheet-shaped body. A mechanism, a feed screw mechanism for rotationally driving the feed screw to reciprocate the nut along the sheet-shaped body mounting surface, and a mechanism for rotatably rotating about a first axis intersecting with the axis of the feed screw. A connecting member pivotally supported by the nut and pivotally supporting the scanning head around a second axis intersecting both the axis of the feed screw and the first axis. To do.

The image processing apparatus according to claim 2 is different from the image processing apparatus according to claim 1 in that the scanning head optically reads an image from a sheet-like body or optically. It is characterized by being either an optical head for writing or an inkjet head for ejecting ink droplets. The image processing device according to claim 3 is different from the image processing device according to claim 1 in that in the connecting member, the first shaft and the second shaft are substantially at the center of the effective screw length of the nut. It is characterized by crossing the axis of the feed screw.

[0009]

According to the configuration of the image processing apparatus of claim 1,
Depending on the direction and degree of rocking of the nut, the connecting member is first
Rotate a proper amount around the axis of and the second axis. Therefore, it is desirable that the first axis and the second axis are substantially orthogonal to each other in order to smoothly rotate the connecting member with respect to the swing in all directions. Further, in this specification, the term “axis intersects” with respect to two axes is used as a concept including so-called three-dimensional intersection in which both axes do not intersect in the same plane.

According to the structure of the image processing apparatus of the second aspect, in the case where the scanning head is an optical head which optically reads an image from the sheet-shaped body, the image is read without blurring. In the case where the scanning head is an optical head for optically writing, halftone dots can be drawn in a desired size, and in the case where the scanning head is an inkjet head, it is possible to print on recording paper. Ink droplets can be made to fly to a target position.

According to the structure of the image processing apparatus of the third aspect, even if the nut swings due to traveling in the sub-scanning direction, there is a high possibility that it will become the center of the swing, and the effective screw length of the nut is substantially at the center. Since the first axis and the second axis of the connecting member intersect with the axis of the feed screw in the section, the scanning head is hardly displaced in the sub-scanning direction due to its swing.

[0012]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows an embodiment of the present invention.
The schematic configuration of the output scanner is shown.
Drive system 100 for driving the output head 210 in the main scanning direction Y, and drive system 2 for driving the output head 210 to reciprocate in the sub scanning direction X.
It consists of 00 and.

The drum drive system 100 includes a pulse motor 12
0 and a rotary shaft 130 connected to the motor rotary shaft. A pulse encoder 1 is provided at the shaft end of the rotary shaft 130.
40 is connected and the rotation speed is detected. The detection result is fed back to the traveling control unit 150, and is used for generation of a drive pulse necessary for driving the pulse motor 120 in the control unit 150.

The output head drive system 200 includes the rotary shaft 1
Rod 220 and feed screw 23 installed in parallel with 30
0 and a pulse motor 240 that drives the feed screw 230 to rotate.
Mainly composed of and. The drive pulse of the pulse motor 240 is also generated by the traveling control unit 150. The output head 210 is, as shown in the figure, a holder for a rectangular housing.
215, and this holder-215 holds the rod 2
20 is slidably inserted and the connecting member 2
Nut 2 screwed into the feed screw 230 via a screw 50
It is attached to 35.

The output head 210 uses, for example, a laser diode, and the light emission is controlled based on the halftone dot signal processed and generated by the image processing section 260. The connecting member 250 has a main connecting member 25, as shown in FIG.
1, the first auxiliary connecting member 252, and the second auxiliary connecting member 253
, And the first auxiliary connecting member 252 and the second auxiliary connecting member 253 have bolts 280 ... Or bolts 285.
Is connected and fixed to the nut 235 or the holder-215 with
The connecting members are pivotally supported by spring pins 270 and 275.

As shown in the sectional view of FIG. 3, the first auxiliary connecting member 252 has a uniform inner diameter Dc over the entire length Lc and an outer diameter formed in two steps of a small diameter portion 252a and a large diameter portion 252b. Has a cylindrical shape, and the large diameter portion 252b is provided with screw holes 252c for the bolts 280.
2a is a position 2 where press-fitting holes 252d of spring pins 270 are opposed to each other on a linear axis C1 intersecting with the cylindrical axis Nc1.
It is provided in the place. Further, the positions of the press-fitting holes 252d ... In the direction of the cylinder axis Nc1 are set in the nut 23 as shown in FIG.
5 and the first auxiliary connecting member 252 are connected and fixed,
It is the approximate center of the effective screw length LH of the nut 235. This is because, as will be described in detail later, this position is the least affected by the swing of the nut while traveling in the sub-scanning direction. Here, the "effective screw length" refers to the length in the screw axial direction of the portion where the screw and the nut are completely screwed together.

The main connecting member 251 has a ring shape in which a part of the outer periphery of the cylinder is chamfered in parallel with the axial center Ncm, and press-fitting holes for press-fitting the spring pins 275 and 270 are formed. Cylindrical axis Nc substantially perpendicular to the chamfered surface 251c
2 positions (25 points) facing each other on the first axis S1 intersecting with m.
1a, 251a) and the first axis S1 and the cylindrical axis Nc.
Two positions (251b, 251b) facing each other on the second axis S2 that intersect with both m are provided at a total of four positions.

The second auxiliary connecting member 253 has a gate shape as shown in FIG.
The insertion holes 253a of 5 ...
5, press-fitting holes 253b ... Are provided and connected and fixed to the mounting seat surface 215a of the holder-215 by bolts 285.
In addition, the position of the press-fitting hole 253b in the vertical direction is the axial center C2
Is a position that passes near the axial center N of the feed screw in the assembled state, as shown in FIG.

The press-fitting hole 25 of the spring pin 270
1b and 252d and the press-fitting hole 25 of the spring pin 275
3b and 251a have substantially the same diameter. this is,
When there is a large difference in the diameter, when the spring pin is press-fitted, the spring pin shrinks to the diameter of the smaller press-fit hole, preventing play between the large-diameter press-fit hole and the spring pin. This is because

In the above structure, it is assumed that the mounting seat surface 235a on the nut 252 side is tilted by an angle θ1 from the proper direction, as shown in FIG. This nut 252
When attached to the holder-215 via the connecting member 250, the inclination θ1 of the mounting seat surface 235a on the nut side is determined by the inclination between the main connecting member 251 of the connecting member 250 and the first and second auxiliary connecting members 252, 253. The support portions 270, 275 are absorbed by the proper rotation and are absorbed (see FIG. 5), and the torsional force due to the inclination angle θ1 does not propagate to the holder-215.

As described above, the mounting seat surface 215a of the holder is
Even if the mounting seat surface of the nut 235 is not parallel to the mounting seat surface of the nut 235, the connecting portion 250 can be tilted according to the tilt direction and the tilt amount of the mounting seat surface of the nut 235.
It is easy to attach 35 and holder-215. In the above, the case where the mounting seat surface 235a of the nut 252 is tilted from the normal direction has been described, but in addition, when the holder-side mounting seat surface is tilted or both mounting seat surfaces are tilted. However, in any case, according to the above-mentioned configuration, the connecting member is rotated about its pivot axis by an appropriate amount according to the direction and the degree of non-parallelism between the two mounting surfaces, and the holder is attached to the holder. The nut can be installed easily.

Next, the pivotal positions of the main connecting member 251 and the first and second auxiliary connecting members 252, 253 are set substantially at the center of the effective thread length LH of the nut 235, as described above. Therefore, even if the nut 235 swings while moving on the feed screw 230, the holder-215 is fed at a constant speed without causing fluctuations in the speed in the sub-scanning direction. That is, if the pivotal position of the main connecting member 251 and the first and second auxiliary connecting members 252, 253 is near the end of the nut 252, as indicated by P1 in FIG. As indicated by the chain line in FIG. 6, when 252 tilts with respect to the axial center N of the feed screw by swinging, the pivot position P1 is displaced to Q1. Since this displacement is an arcuate movement whose radius is the length from the swing center X of the nut 252 to P1, the pivotal support position Q1 after displacement is as shown in FIG. 6 (b). The position P1 is shifted in the direction of the feed screw shaft center N by the length E1. This shift in the direction of the feed screw shaft center N is not absorbed by the pivotal support structure in the connecting member 250, and is thus transmitted to the holder-215 as it is. Since the swing of the nut 235 changes the tilt angle with time, the shift amount E1 in the direction of the feed screw shaft center N transmitted to the holder-215 also changes with time. Therefore, if the nut 235 swings while being conveyed by the feed screw 230, the holder 215 cannot travel at a constant speed in the sub-scanning direction, and the travel speed changes within the range of the shift amount E1. Of. In the output scanner, this change appears as a change in the recording density in the sub-scanning direction, which causes deterioration of the image quality.

The pivotal position of the connecting member 250 is shown in FIG.
As shown by P2, if the nut 252 is provided closer to the center than the end portion, the shift of the nut 252 in the direction of the feed screw axis N becomes E2, which is slightly improved as compared with E1, but still. It will remain. On the other hand, if the pivot position of the connecting member 250 is set to the swing center X of the nut 252, the pivot position theoretically does not shift in the N direction of the feed screw axis. Since the swing center center X of the nut 252 is generally the center of the effective screw portion of the nut 252, the pivotal position of the connecting member 250 is set to the approximate center of the effective screw length LH of the nut 252 as in this embodiment. Then, even if the nut swings during traveling, the holder-21
No. 5 is fed at a constant speed in the sub-scanning direction without uneven speed.

Although the present invention has been described above based on the embodiments, it goes without saying that the present invention is not limited to the above embodiments. That is, (1) In the above embodiment, the connecting members are pivotally supported by the spring pins, but the pivoting method is not limited to this. For example, a pivot shaft having a conical portion 290b at the tip of the hexagon socket head screw portion 290a as shown in FIG. 7A may be pivotally supported. The pivotal state when the pivot shaft is used is shown in FIGS. 7 (b) and 7 (c). Note that FIG. 7B
Is a side view of the first auxiliary connecting member 252 and the main connecting member 251 seen from the direction of the first axis S1, and FIG.
The second auxiliary connecting member 253 and the main connecting member 251 from two directions
It is the side view which looked at, and the same number is attached to the same member as the said Example. In this case, as shown in FIG. 7B, in the main connecting member 251, a screw-in hole 251c of the pivot shaft 290 is provided in place of the press-fitting hole 251b of the spring pin 270 of the above embodiment, and the first auxiliary connecting member is provided. 25
2, the conical chamfered portion 252 is located at the position of the opening of the press-fitting hole 252d of the spring pin 270 of the above embodiment.
e is provided. Further, also in the pivotal support of the main connecting member 251 and the second auxiliary connecting member 253, as shown in FIG.
The configuration is similar to the above case. (2) In the above embodiment, the connecting member 250 includes the first auxiliary connecting member 252, the main connecting member 251, and the second auxiliary connecting member 2.
It is composed of three members 53. However, since the second auxiliary connecting member 253 is a member for forming a press-fitting hole in the mounting seat surface 215a of the holder-215 in a direction orthogonal to the axis N, the press-fitting hole in the holder-215 in that direction is formed. If formed directly, the second auxiliary connecting member 253 becomes unnecessary.

Similarly, if a press-fitting hole corresponding to the press-fitting hole 252d in the first auxiliary connecting member 252 is directly formed in the nut 235, the first auxiliary connecting member 252 becomes unnecessary.
In this way, the connecting member 250 may be formed only by the main connecting member 251. (3) In the above embodiment, the linear motion guide mechanism is constituted by the rod provided in parallel with the drum rotation axis and the insertion hole of the rod provided in the head holder, but the present invention is not limited to this. For example, a rolling guide such as a linear motion ball bearing may be used. (4) In the above embodiment, the output scanner has been described as an example, but it goes without saying that it can be realized by an input scanner, an inkjet printer, or the like.

[0026]

As described above, according to the image processing apparatus of the first aspect of the present invention, the nut and the scanning head are rotatable about the first axis which intersects the axial center of the feed screw with respect to the nut. The nut is oscillated because the scanning head is connected by a connecting member that is rotatably supported around a second shaft that intersects both the shaft center of the feed screw and the first shaft. In this case, the distance between the scanning head and the sheet-shaped mounting member to be read or written is constant in the sub-scanning direction.

According to the image processing apparatus of the second aspect of the invention, in the case where the scanning head is an optical head which optically reads an image from a sheet-shaped body, the image is not blurred. Can be read, and when the scanning head is an optical head for optically writing, halftone dots can be drawn in a desired size, and when the scanning head is an inkjet head, It is possible to make the ink droplets fly to a desired position on the recording paper.

According to the image processing apparatus of the third aspect of the present invention, in the connecting member, the first shaft and the second shaft are substantially in the center of the effective screw length of the nut, and the shaft of the feed screw. Since it intersects with the heart, it is possible to minimize the uneven feeding caused by the swing of the nut during traveling.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of an output scanner that is an embodiment of the present invention.

FIG. 2 is an exploded view of the connecting member of the above embodiment.

FIG. 3 is a cross-sectional view showing an assembled state of the connecting member of the above embodiment.

FIG. 4 is a diagram for explaining the operation of the above embodiment.

FIG. 5 is a diagram for explaining the operation of the above embodiment.

FIG. 6A is a diagram for explaining the operation of the above embodiment. (B) is a diagram for explaining the operation of the above embodiment.

FIG. 7A is a half sectional view showing a pivot shaft as another pivot shaft in the above-mentioned embodiment. (B) is a sectional view showing a pivotal support state of the main connecting member and the first auxiliary connecting member using the pivot shaft. FIG. 7C is a sectional view showing a pivotally supported state of the main connecting member and the second auxiliary connecting member using the pivot shaft.

[Explanation of symbols]

 230 Feed screw 235 Nut 215 Holder-251 Main connecting member 252 First auxiliary connecting member 253 Second auxiliary connecting member 270 Spring pin 275 Spring pin 280 Bolt 285 Bolt

Claims (3)

[Claims] 1. A sheet to be read or written.
A sheet-shaped body mounting member for mounting the sheet-shaped body, a scanning head for reading an image from the sheet-shaped body or writing an image on the sheet-shaped body, and the scanning head for the sheet-shaped body. A linear motion guide mechanism that guides travel in the sub-scanning direction parallel to the mounting surface, a feed screw mechanism that rotationally drives the feed screw to reciprocate the nut along the seat-shaped body mounting surface, and a shaft of the feed screw. The nut is rotatably supported on the nut so as to be rotatable about a first axis intersecting with the core, and the first axis of the feed screw and the first axis.
An image processing apparatus comprising: a connecting member that rotatably supports the scanning head around a second axis that intersects with both of the axes. 2. The scanning head is any one of an optical head for optically reading an image from a sheet-like body, an optical head for optically writing an image, and an inkjet head for ejecting ink droplets. The image processing device according to claim 1. 3. The connecting member, wherein the first shaft and the second shaft intersect the shaft center of the feed screw at substantially the center of the effective screw length of the nut. The image processing apparatus according to item 1.