JPH04371065A - Original scanner - Google Patents

Abstract

PURPOSE:To obtain a sliding surface having excellent flatness by providing a panel-shaped member whose panel thickness face is used as the sliding surface of a running optical system as a running guide member. CONSTITUTION:Besides a light source a mirror, etc., not shown in the figure is mounted on a stand 3 of a light source unit U1, a panel-shaped sliding member 21 is fixed on the bottom face of the stand near its both ends, and the panel-shaped sliding member 12 slides on panel rails 10 and 11. Another panel- shaped sliding member is fixed on the bottom of the mirror unit not shown in the figure near its both ends and the sliding member slides on the panel rails. The panel rails 10 and 11 consist of a rectangular-shaped sheet metal formed by press working, and the panel thickness face formed by the press working not by bending has excellent flatness. Thus, since the panel thickness face is used as the sliding surface of the scanning optical system without applying bending to the sheet metal formed by press working, excellent straightness can be maintained for the scanning guide by making good use of the straightness of the cutting face in press working.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention illuminates an original placed on a glass original table with a light source, and the reflected image light is reflected by a mirror to form an image on a line image sensor or photoreceptor. The present invention also relates to a document scanning device that reads a document by moving and scanning a scanning optical system including a light source, a mirror, and the like.

0002

[Prior art] Copying machine, OCR (optical character recognition device)
Among the image exposure apparatuses that input image information such as computer input devices and the like, a document scanning device which is a computer input device has conventionally had a schematic configuration as shown in FIG.
1 is a light source, 102 is a mirror, 103 is a base, and V1 is a light source unit composed of these. Also, V2 is 2
This is a mirror unit composed of two mirrors 104 and 105, a base 106, and the like. (Hereinafter, V1 and V2 are collectively referred to as a scanning optical system.) The original 107 is irradiated by the light source 101, and the reflected image light is reflected from the mirrors 102, 104, 1
05 and is imaged by an imaging lens 108 onto a line image sensor 109. In the above optical path, the light source unit V1 and mirror unit V2 are moved in the direction of the arrow (hereinafter referred to as the sub-scanning direction) at a speed ratio of 1:1/2 based on the principle of a movable pulley. By moving and scanning in the longitudinal direction of the stand (referred to as the main scanning direction), the optical path length from the original to the line image sensor is always kept constant, so that the original can be read uniformly. (Hereinafter, a scanning optical system having such a configuration will be referred to as a 1:1/2 type scanning optical system.) By the way, the moving scanning of the light source unit V1 and the mirror unit V2 is usually carried out near both longitudinal ends of the bases 103 and 106. This is done along a provided scanning guide. As shown in the side view of FIG. 7, the scanning guide uses a cylindrical shaft 110 on one side and a plate-like member (hereinafter referred to as a plate rail) 111 on the other. The most common method is to provide a thrust bearing 113 that moves and a member 114 that rotates or slides on a plate rail. In this method, the shaft is used to position the base in the longitudinal direction, so the shaft 110 is set parallel to the document in the sub-scanning direction, and the plate rail 111 is also set parallel to this. Ru.

0003

[Problems to be Solved by the Invention] However, in the conventional configuration described above, the plate rail 111 is usually bent into an L-shape or a U-shape as shown in FIG. 7 to increase rigidity in order to support the weight of the scanning optical system. Since the plate rail 111 is used in a shape, there is a problem in that the flatness of the plate rail 111 is inferior to that of the shaft 110 as a result of the bending process.

If the flatness of the plate rail is not guaranteed, an image exposure apparatus with a 1:1/2 type traveling optical system will suffer from the problem shown in FIG. 8(a).
), as shown in (b), when reading a grid-like document in which the straight lines intersect perpendicularly as shown in FIG. 8(a), the straight lines drawn in the main scanning direction as shown in FIG. 8(b) A phenomenon occurs in which parallelism deteriorates.

On the other hand, in an image exposure apparatus with a so-called integrated scanning optical system, a light source, a mirror, an imaging lens, a line image sensor, etc. are arranged in one frame, and this is moved and scanned as a unit. Also, if the flatness of the plate rail is not guaranteed, a phenomenon occurs in which the magnification in the main scanning direction changes.

In addition, in an image exposure device using a scanning optical system that uses a 1-magnification type line image sensor and an erect 1-magnification imaging lens, the depth of focus of the erect 1-magnification imaging lens is shallow and the plane of the scanning guide is Since performance is the most stringent requirement, there has been a system in which shafts are used as scanning and guides on both sides, and a plate-shaped sliding member 112 is fixed to the bottom surface of the base for sliding, as shown in the side view of FIG. Although this configuration certainly improves the flatness, there are problems such as an increase in weight due to the increase in the shaft and a significant increase in cost.

[0007]

[Means for Solving the Problems] The present invention takes the above-mentioned conventional problems into consideration, and provides an optical system for scanning the thick surface of the plate rail using a plate rail without bending on both sides of the base as a scanning guide. By using it as a sliding surface, the flatness of the scanning guide can be improved at a very low cost.

[0008]

【Example】

First Embodiment FIGS. 1 and 2 show a first embodiment of the present invention, in which FIG. 1 is a side view of a document scanning device, and FIG. 2 is a top view of the document scanning device. In this embodiment, the document scanning device has roughly the same configuration as the conventional example, so the different parts will be explained below.

In FIG. 1, 1 is a light source, 3 is a base of a light source unit U1, 7 is a document, 10 and 11 are strip-shaped flat plate rails, and 12 is a plate-shaped sliding member. In addition to the light source, a mirror (not shown) is mounted on the base 3 of the light source unit, and plate-shaped sliding members 1 are mounted on the bottom near both ends.
2 is fixed, and the plate-shaped sliding member 12 slides on the plate rails 10 and 11. Similarly, plate-shaped sliding members are fixed to the bottom surface near both ends of the mirror unit (not shown) and slide on the plate rails. The base 3 is also provided with a stopper 3' that suppresses movement in the longitudinal direction of the base within a certain range.

[0010] The plate rails 10 and 11 are press-formed rectangular sheet metal or the like, and the plate thickness surfaces, which are press-formed without bending or the like, have good flatness.

As shown in FIG. 2, the plate rail is set parallel to the scanning direction of the scanning optical system, and is fixed to the frame of the apparatus.

Therefore, according to this embodiment, by using the thick side of the press-formed sheet metal as the sliding surface of the scanning optical system without bending the sheet metal, the linearity of the press-formed cut surface can be utilized. Therefore, it is possible to maintain sufficiently good linearity as a scanning guide. Also, for example, compared to a conventional L-shaped scanning guide, the conventional horizontal plane is simply deleted.
Rigidity as a scanning guide can also be maintained. In addition, significant cost reductions can be achieved.

Although the shape of the plate rail is a rectangular shape in this embodiment, it is not limited to this, and may be of any shape as long as the scanning optical system is configured to slide on the thick surface of the plate. . Also, the material is not limited to sheet metal,
Any material may be used as long as it has good linearity in terms of thickness.

Second Embodiment FIGS. 3 and 4 show a second embodiment of the present invention, in which FIG. 3 is a top view of the document scanning device, FIG. 4(a) is a bottom view of the base of the light source unit, and FIG. ) is a bottom view of the base of the mirror unit. This embodiment differs from the first embodiment only in the positioning of the plate rail to the device, and the same members will be described with the same numbers.

In FIG. 3, 3 is the base of the light source unit U1, 6 is the base of the mirror unit, and 20 and 21 are plate rails. A plate-shaped sliding member that slides on the plate rail is fixed to the base and bottom of each of the two units, as in the first embodiment. As shown in the figure, the plate rails 20 and 21 are set straight and non-parallel to the scanning direction of the scanning optical system.

With this setting, the position of the plate rail in the light source unit changes from S1 at the start of reading to E1 at the end of reading, as shown in FIG. 4(a), so that the entire scanning of the scanning optical system is In the range, the plate rail slides on the plate-shaped sliding member of the base while moving up and down (in the direction of the arrow) in the figure within the shaded area. That is, compared to the embodiment described above, the contact position of the plate-shaped sliding member with the plate rail changes, so that wear of the plate-shaped sliding member can be reduced.

Similarly, in the mirror unit, as shown in FIG. 4(b),
The plate rail moves within the shaded area as shown in . This amount of movement is smaller than that of the light source unit, but since the mirror unit has a moving scanning range and a moving speed that are both 1/2 that of the light source unit, wear on the plate-shaped sliding member can be kept low.

Third Embodiment FIG. 5 shows a third embodiment of the present invention. This embodiment also differs from the first embodiment only in the position setting of the plate rail to the original scanning device, and the same members are used. shall be explained using the same numbers.

FIG. 5 is a top view of the apparatus, in which 3 is the base of the light source unit U1, 6 is the base of the mirror unit, and 30 and 31 are plate rails. A plate-shaped sliding member that slides on the plate rail is fixed to the bottom surface of each base of the two units as in the first and second embodiments. The plate rails 30 and 31 are fixed in a curved manner as shown in the figure. This may be manufactured by making the plate rail itself into a curved shape, but
Fix the straight board rail to the board rail (hatched area in the diagram)
It may be forced to curve by fixing it to. In this case, the rigidity of the plate rail in the vertical direction of the device can be increased.

[0020] Also, by bending, for example, the member 3
2 can also be arranged in the illustrated position (if the plate rails are arranged straight, they will interfere), and the space inside the device can be used effectively. In addition, the rate of curvature increases as you go to the left in the figure, so if you start reading with the scanning optical system at the solid line position and finish reading at the broken line position as shown in the figure, the wear of the plate-shaped sliding member on the reading start side can be reduced. can be reduced. As a result, even when small-sized originals, such as so-called service version photographic originals, are frequently read, the above-mentioned friction can be effectively reduced.

[0021]

Effects of the Invention As described above, according to the present invention, by providing a plate-like member whose thick surface serves as a sliding surface of the traveling optical system as a scanning guide member, a sliding surface with good flatness can be achieved. can be obtained very cheaply.

Furthermore, by arranging the sliding surface of the plate-shaped member so that it is parallel to the document placement surface and non-parallel to the scanning direction of movement of the scanning optical system, the sliding surface of the plate-shaped member and the scanning optical system base can be Even when the contact area of the plate-shaped sliding member is small, there is an effect that wear of the plate-shaped sliding member can be reduced.

Furthermore, by arranging the sliding surface of the plate-like member parallel to the document placement surface and curved with respect to the scanning optical system traveling direction, the rigidity of the plate rail in the vertical direction of the apparatus can be increased, and the The inner space can be used effectively, and wear of the plate-like sliding member on the reading start side can be reduced. Therefore, even when small-sized originals are read frequently, the above-mentioned friction can be effectively reduced.

[Brief explanation of drawings]

FIG. 1 is a side view of a document scanning device according to a first embodiment of the present invention.

FIG. 2 is a top view of the document scanning device according to the first embodiment of the present invention.

FIG. 3 is a top view of a document scanning device according to a second embodiment of the present invention.

FIG. 4(a) is a bottom view of the base of the light source unit according to the second embodiment of the present invention.

FIG. 4(b) is a bottom view of the base of the mirror unit according to the second embodiment of the present invention.

FIG. 5 is a top view of a document scanning device according to a third embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a conventional document scanning device.

FIG. 7 is a side view of a conventional document scanning device.

FIG. 8(a) is a diagram showing a grid-like original.

FIG. 8(b) is a diagram showing a scanned grid document.

FIG. 9 is a side view of another conventional document scanning device.

[Explanation of symbols]

1. Light source 3. Base 10 Plate rail 11 Plate rail 12 Plate sliding member U1 Light source unit V1 Light source unit V2 Mirror unit

Claims (4)

[Claims] 1. A scanning optical system including a light source that illuminates a document placed on a document table and a mirror that guides image light from the document to a light receiving section, and a scanning guide member that guides movement of the scanning optical system. A document scanning device that reads a document by moving and scanning the document, characterized in that the scanning guide is composed of a plate-like member, and the thickness surface of the plate is used as the sliding surface of the scanning optical system. Document scanning device. 2. The plate-like member has a sliding surface parallel to the document placement surface and disposed non-parallel to the scanning direction of the scanning optical system. original scanning device. 3. The plate-like member has a sliding surface parallel to the document placement surface and disposed non-linearly with respect to the scanning direction of the scanning optical system. original scanning device. 4. The plate-like member has a sliding surface located parallel to the document placement surface and perpendicular to the scanning direction of the scanning optical system from the scanning optical system reading end side to the scanning optical system reading starting side. 4. The document scanning device according to claim 3, wherein the document scanning device is arranged non-linearly so that the amount of deviation increases.