JPH10161401A - Picture reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a picture reader which is miniaturized and whose cost is reduced. SOLUTION: As for the picture reader reading an image from an original by moving an optical unit constituted of plural photoelectric converting elements 3d reading the entire width of the original 1 in a main scanning direction and an optical system 3c, a scanning means obtained by folding back wire to be extended 4 plural times and fixing at least two points 3e and 3f of the wire moving in the same direction and spatially disposed in parallel out of the wire folded back and scanning and reading the image by moving the optical unit by moving the wire is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus used for a scanner, a facsimile, a copying machine, and the like, and more particularly to an improvement in a scanning mechanism of the image reading apparatus.

[0002]

2. Description of the Related Art FIG. 9 is a perspective view of a conventional image reading apparatus, which is a so-called flat head scanner equipped with a reading optical system unit. FIG. 10 is a perspective view of the optical system unit.

In FIG. 9 and FIG. 10, reference numeral 51 denotes an optical unit having a long focal point SELFOC lens (not shown) therein so as to focus on a platen glass having a thickness of 3 mm. Is set. In addition, a cold-cathode tube (Xe tube) (not shown) is provided inside, and a high-speed scan with a long focal length of about 0.7 msec / line is possible. This cold cathode tube is controlled by an inverter circuit 52 provided outside the optical unit.

Reference numeral 53 denotes a holding member for holding the optical unit 51, and reference numeral 54 denotes a carriage that supports the holding member 53 rotatably in a vertical direction at a fulcrum 54a. Fulcrum 54
“a” is provided substantially at the center of the optical unit 51 in the main scanning direction to balance left and right. It is desirable that the distance from the fulcrum 54a to the reading line 51b be long in order to prevent the optical unit 51 from tilting in the sub-scanning direction due to dimensional variations or the like, thereby preventing the illumination angle from shifting or changing the focal length. Further, an inverter circuit 52 is also provided on the carriage 54, and the carriage 54 moves the optical unit 51 and the inverter circuit 52 together, so that the cable length from the optical unit 51 to the inverter circuit 52 can be shortened. It has the effect of preventing the emission of high frequency noise.

[0005] Reference numeral 55 denotes a height adjustment unit, which is provided on the housing of the optical unit 51 in a pair of right and left. This is so that when the tip of the height regulating member 55b moves while contacting the lower surface of the platen glass 62, even if the contact portion is worn and a contact mark is generated on the lower surface of the glass, the image is not affected. To do that. The biasing spring 56 elastically supports the optical unit 51 supported on the fulcrum 54a on the carriage 54.

The carriage 54 is slidably supported on a guide shaft 57 via a bearing 54b. This bearing position is determined by the optical unit 51, the inverter circuit 5,
2, provided at a position shifted from the center of gravity in the main scanning direction of the optical master unit 50 including the holding member 53, the carriage 54, the adjustment unit 55, and the urging spring 56. A sliding member 54c is provided below the end of the carriage 54 in the direction opposite to the direction in which the bearing position is shifted. That is, the center of gravity is located between the bearing 54b and the sliding member 54c, and the optical master unit 50 slidably supported by the guide shaft 57 is configured to be inclined in the direction of the sliding member 54c.

[0007] Both ends of the guide shaft 57 are frame 5
9, a frame 59 is provided with a bent portion raising 59a parallel to the guide shaft.
When the carriage 54 moves in the sub-scanning direction along the guide shaft 57, the height is set so that the horizontal direction of the contact-type image sensor 51 is maintained by the contact of c with the bent portion 59a. The sliding member 54c moves on contact with the raised portion 59a.

Reference numeral 60 denotes a timing belt for moving the carriage 54 in the sub-scanning direction, and reference numeral 61 denotes a driving stepping motor. The contact type image sensor 51 is urged to the lower surface of the platen glass 62, and is located between the contact image sensor (optical unit) 51 on the optical master unit 50 that moves in the sub-scanning direction and the upper surface of the platen glass 62. The distance is always kept constant.

When reading an image, a sheet document or a book is urged from above by a pressure plate (not shown) which can be opened and closed up and down and placed on a platen glass 62 to read the image of the document. Is brought into close contact with the original table glass 62, the stepping motor 61 is driven, and the contact sensor (optical unit) 51 is moved to read an image.

[0010]

However, in the above conventional example, the optical carriage shaft (carriage 5
4, there is a problem that the size of the device is increased due to the presence of the guide shaft 57).

Further, since it is necessary to slide the carriage on which the optical unit 51 is mounted and the guide shaft 57, a material having good abrasion resistance must be used, which raises a problem of increasing the cost.

Further, since the guide shaft 57 slides with respect to the central axis in the longitudinal direction of the guide shaft 57 in the rotational direction, rattling in the rotational direction occurs in a plane parallel to the scanning plane of the optical unit 51. There is a problem.

Further, since components such as pressing means for the optical master unit 50 and the optical unit 51 are added, there is a problem that the cost is increased.

Further, since the height regulating member 55b is not on the extension of the reading line 51b of the optical unit 51, in order to secure a depth of focus which can guarantee an image, the relative position between the height regulating member 55b and the optical unit 51 is required. The target height naturally needs to be managed with high accuracy, and the relative height between the fulcrum 54a and the optical unit 51 needs to be managed with high accuracy.

Therefore, the object of the invention described in claim 1 is:
An object of the present invention is to provide an image reading apparatus in which the size of the apparatus is reduced and the cost is reduced by eliminating guide members of an optical unit such as a guide shaft of a carriage.

Further, an object of the present invention according to claim 2 is to dispose the optical unit so that the wire and the optical unit do not needlessly contact with each other.
An object of the present invention is to provide an image reading apparatus capable of accurately performing scanning by an optical unit with low load.

It is a further object of the present invention to provide an image reading apparatus capable of forming a scanning mechanism simply and at low cost.

A fourth object of the present invention is to provide a simple and inexpensive mechanism for preventing erroneous scanning of an optical unit due to slackness of a wire rod and performing accurate scanning to achieve high-quality reading. It is an object of the present invention to provide an image reading device which enables the above.

It is a further object of the present invention to provide an image reading apparatus which can prevent rattling of the optical unit in the rotation direction in the mechanism according to the fourth or fifth aspect.

It is a further object of the present invention to provide an image reading apparatus capable of reducing the size of the optical unit.

A further object of the present invention is to provide an image reading apparatus which is low in cost and has little variation in input sensitivity between pixels.

A further object of the present invention is to eliminate a guide member such as a guide shaft so as to reduce the size and cost of the apparatus, and to accurately position the optical unit to prevent erroneous scanning. An object of the present invention is to provide an image reading apparatus capable of suppressing the occurrence.

Further, the object of the invention described in claim 10 is that:
It is an object of the present invention to provide an image reading apparatus capable of reducing the size and cost of the apparatus by using a height regulating member capable of securing the distance between the optical unit and the document to be read with the minimum required accuracy. .

Still another object of the present invention is to provide an image reading apparatus capable of eliminating erroneous scanning and enabling high-quality reading by a main scanning direction positioning mechanism having a simple and low-cost structure. It is in.

Further, the object of the invention described in claim 13 is:
It is an object of the present invention to provide an image reading apparatus capable of realizing an urging of an optical unit on a platen glass by a simple and low-cost mechanism for applying tension to a folded wire.

Further, the object of the invention described in claim 14 is to
It is an object of the present invention to provide an image reading apparatus capable of realizing biasing of an optical unit in a main scanning direction by a simple and low-cost mechanism for applying tension to a folded wire.

[0027]

According to a first aspect of the present invention, a plurality of photoelectric conversion elements capable of reading the entire width of a document in the main scanning direction, a light source, and an optical system are provided. In an image reading apparatus that reads an image from a document by moving an optical unit consisting of a plurality of non-stretchable wire rods, at least one of the folded wire rods that move in the same direction and are spatially arranged in parallel. An image reading apparatus, comprising: a scanning unit that fixes two places to the optical unit, moves the optical unit by moving the wire, and scans and reads an image.

According to this configuration, since the wire is non-stretchable, the wire is naturally connected even if it is bent back plural times, and the moving speed of the wire in the wire length direction is the same at any wire portion. By fixing two places of the wires moving in the same direction and spatially parallel to the optical unit, it is possible to move the optical units in the scanning direction by moving in parallel to the direction in which the wires are stretched.

A specific configuration for realizing the object of the invention according to the present application is an optical system comprising a plurality of photoelectric conversion elements capable of reading the entire width of a document in the main scanning direction, a light source, and an optical system. In an image reading apparatus that reads an image from a document by moving a unit, a plurality of non-stretchable wire rods are folded back a plurality of times, and at least two of the folded wire rods that move in the same direction are arranged in parallel in space. Scanning means fixed to the optical unit and moving the optical unit by moving the wire to scan and read an image, wherein the scanning means is in a direction opposite to a moving direction of the wire fixed to the optical unit. An image reading apparatus is characterized in that a folded wire rod that moves to a position apart from a space in which the optical unit moves is disposed.

According to this configuration, since the wire rod, which is returned in the direction opposite to the moving direction of the optical unit, is disposed outside the space in which the optical unit moves, the wire rod interferes with the movement of the optical unit. Therefore, the movement of the optical unit becomes accurate and the image quality of the read image can be improved without increasing the load on the driving means of the wire.

According to another specific configuration for realizing the object of the invention according to the present application, as set forth in claim 3, the scanning means includes a plurality of pulleys as means for turning back the non-slip wire. 3. The pulley according to claim 1, wherein a rotating shaft of the pulley is axially supported in a direction perpendicular to a plane inclined from a plane in which the optical unit moves.
The image reading device described in the above.

According to this structure, the wire rods are turned back by the tilted pulley, and the spatial positions of the wires input to and output from the tilted pulley are shifted without increasing the number of parts. In other words, if the inclination of the inclined pulley is managed, a wire that moves in the opposite direction to the moving direction of the optical unit can be provided at a position that is separated from the space in which the optical unit moves and does not interfere.

[0033] In another specific configuration for realizing the object of the invention according to the present application, as described in claim 4, the scanning means has means for applying tension to the folded wire. An image reading apparatus according to claim 1.

According to this structure, the wire is not loosened even if the precision concerning the length of the wire is not specially managed, and the moving position of the optical unit is determined only by the position of the pulley serving as the folding means. Can be.

According to another specific configuration for realizing the object of the present invention according to the present invention, the means for applying tension is constituted by an elastic member. The image reading device described in the above.

According to this structure, the means for applying tension is constituted by a simple elastic member such as a spring, so that low cost can be realized.

According to another specific configuration for realizing the object of the invention according to the present application, as described in claim 6, the means for applying tension is provided at a position other than at least between two fixed positions of the wire. The image reading device according to claim 4, wherein the image reading device is disposed at a place.

According to this configuration, even if an excessive tension is generated in the wire at the moment when the optical unit starts to move and the tension generating means moves, only the start of the movement of the optical unit is delayed, and the image quality such as the inclination of the optical unit is reduced. High-quality reading can be maintained without causing deterioration.

According to another specific configuration for realizing the object of the invention according to the present application, the optical system of the optical unit is a contact sensor of the same magnification optical system. The image reading device according to claim 1.

According to this configuration, the space required for the movement of the optical unit can be reduced by reducing the size of the optical unit.

In another specific structure for realizing the object of the invention according to the present application, the photoelectric conversion element of the optical unit is a CCD as described in claim 8. The image reading device described in the above.

According to this configuration, the variation in sensitivity between pixels is reduced, and the quality of a read image can be improved.

According to another configuration for realizing the object of the invention according to the present application, the image reading apparatus according to any one of the first to eighth aspects is provided with positioning means for the optical unit. An image reading apparatus according to the present invention.

According to this configuration, the optical unit is fixed to two places of the spatially arranged wires that are moved in the same direction and are bent back plural times by the non-stretchable wire, and the optical unit is moved by the movement of the wires. By performing positioning necessary for scanning the original with the optical unit in an image reading apparatus constituted by a low-cost scanning means for scanning by moving the scanner, stable scanning and higher-quality reading can be performed.

A specific configuration for realizing the object of the invention according to the present application is that, as set forth in claim 10, the positioning means includes at least three positioning members positioned by the platen glass on the optical unit side. The plane formed by the optical axis formed between the photoelectric conversion element and the pixel to be read on the document to be read mounted on the platen glass intersects with the back surface of the platen glass. 10. The image reading apparatus according to claim 9, wherein the positioning is performed by contacting at least two or more of the positioning members and the platen glass on a straight line formed by the scanning.

According to this configuration, since the positioning of the optical unit changes centering on the optical axis, the rate at which the change in the height of the third positioning member affects the change in the optical path length of the optical unit is small. Therefore, the arrangement distance of the three positioning members is small, and the depth of focus can be easily secured.

In another specific configuration for realizing the object of the invention according to the present application, as described in claim 11, the positioning unit includes a positioning unit in a main scanning direction of a document and the optical unit. 10. The image reading apparatus according to claim 9, further comprising: means for positioning by a positioning means in the main scanning direction.

According to this configuration, the positioning in the main scanning direction with respect to the size index on the platen glass can be realized at a low cost without performing a process such as adjustment or increasing the precision of parts.

According to another specific configuration for realizing the object of the invention according to the present application, the positioning means is provided in the optical unit, and the positioning means in the main scanning direction is provided. 12. The image reading apparatus according to claim 11, wherein the rib guide is a rib guide fitted into a groove guide of the frame.

According to this configuration, the means for positioning the document in the main scanning direction can be realized by a simple and low-cost mechanism such as a groove guide of a frame fitted with a rib guide provided on the optical unit.

According to another specific configuration for realizing the object of the invention according to the present application, the positioning means biases the optical unit to the platen glass by the folded wire. 11. The image reading apparatus according to claim 10, wherein said urging force is generated by means for applying a tension to said wire.

According to this configuration, the optical unit can be biased against the platen glass with a simple and low-cost configuration.

In another specific configuration for realizing the object of the invention according to the present application, the positioning means performs biasing of the optical unit in the main scanning direction by the wire. 12. The image reading apparatus according to claim 11, wherein said urging force is generated by means for applying tension to said wire.

According to this configuration, the urging of the optical unit in the main scanning direction can be performed with a simple and low-cost configuration.

[0055]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. 1 to 4 are diagrams according to the first embodiment. FIG. 1 is a central sectional view of the image reading apparatus according to the first embodiment of the present invention. FIG. 2 is a plan view of the image reading apparatus shown in FIG. 3 is a side view of the image reading apparatus shown in FIG. 2 as viewed from the direction C. FIG. 4 is a side view of the image reading apparatus shown in FIG. 2 as viewed from the direction D.

In FIG. 1, reference numeral 1 denotes a reading original (hereinafter abbreviated as an original), and 2 denotes an original platen glass made of a material having a high light transmittance such as acrylic, polycarbonate, glass, and the like, and an original platen pressure plate (not shown). As a result, the original 1 is brought into close contact with the original platen glass 2. Reference numeral 3 denotes an optical unit, which is formed of a material having a high light transmittance similarly to the original platen glass 2 to prevent dust from entering a photoelectric conversion element unit and the like described later. Reference numeral 3b denotes an LED as a light source, 3c denotes an equal-magnification optical imaging lens, and 3d denotes a photoelectric conversion element.

In the present embodiment, the LED is used as the light source 3b. However, a halogen lamp, a hot cathode tube, a cold cathode tube, a xenon tube or the like may be used. Also, the photoelectric conversion element 3d may be a CCD element. Also 3c
May be a reduction optical lens, and it is desirable that the optical path length is as short as possible. To make the apparatus compact, if the optical path length is long, it may be folded back by a mirror or the like.

Regarding the configuration on the electric board, the photoelectrically converted electric signal passes through the I / O port and then performs image processing and the like using the RAM according to the contents written in the ROM. Unit, a transmission unit (neither is shown) or the like.

Here, in order to read the entire image reading range of the original 1, it is necessary to move the optical unit 3, and in this embodiment, the image is read by moving in the direction of arrow A in FIG. . At this time, the CPU 13 in FIG. 1 synchronizes the image reading timing with a motor 13 described later.

Next, the optical unit 3 which is the core of the present invention
Will be described in detail with reference to FIGS.

First, in the plan view of FIG.
FIG. 1 is a diagram viewed from the direction, FIG. 3 is a diagram viewed from the C direction, and FIG. 4 is a diagram viewed from the D direction.

In FIG. 2, reference numeral 13 denotes a motor, which transmits a driving force to a driving pulley 5 to be described later by a driving transmission means such as a gear, a timing belt, a belt, and a wire (not shown). In the present embodiment, a pulse motor is used as the motor 13 and the motor 13 is driven by open loop control.
Encoder means may be provided using a DC motor to perform closed loop control.

The driving pulley 5 is rotatably supported around a driving pulley shaft 5a.
As shown in the figure, the optical unit 3 is disposed at right angles to the plane on which the optical unit 3 moves.

The wire 4 is wound around the pulley 5, and the material of the wire 4 is metal and non-stretchable. However, the wire 4 may be formed of glass fiber, carbon fiber, Kepler, or other inorganic or organic material. Further, if the core portion is stretchable, the surrounding portion may be impregnated or covered with a stretchable material such as rubber or nylon. The winding of the wire 4 around the driving pulley 5 requires winding and rewinding the wire 4 around the driving pulley 5 without slipping.
A portion having a partly different wire diameter is provided at a predetermined midpoint of the wire 4, and a portion having a different wire diameter is fixed to the drive pulley 5 to prevent the drive pulley 5 and the wire 4 from slipping. In the present embodiment, the wire 4 is caulked with a small steel ball having a cut to provide a portion having a different wire diameter.

As a result, in FIG.
In a state where a wire having a length corresponding to a and 4d is always wound around the drive pulley 5, a part of the wound portion having a different wire diameter is fixed to the pulley 5. At this time, if the wire is further wound on the wire once wound, the apparent outer diameter of the pulley 5 changes, and the inclination of the pulley 6 and the pulley 10 described later causes the wire 4 not to wind on the wire 4. Or the diameter of the drive pulley 5 may be increased so as not to be wound a plurality of times. Also,
Here, the pulley 5 is used so that a part of the wire 4 is fixed, but the wire is wound around the pulley without fixing, and the driving force of the pulley 5 is transmitted to the wire 4 only by frictional force. Is also good. In the case of a transmission system using frictional force, the pulley 6 and the pulley 10 must be arranged so that the wire is not wound around the wire on the pulley 5 due to the inclination of the pulley 6 and the pulley 10.

The wire 4 wound around the driving pulley 5 is wound around the pulley 6 and folded as shown in FIG. The wire 4 between the driving pulley 5 and the pulley 6 is referred to as a wire 4a. Then, it is fixed to the optical unit 3 at the portion 3e in the middle of the wire 4a. The pulley 6 is rotatably supported around a pulley shaft 6a.
Are fixed to the frame 14 at an angle as shown in FIG.

Similarly, the direction of the wire 4 turned back by the pulley 6 is changed by the pulley 7, and the wire 4 is wound around the pulley 9 via the pulley 8. This pulley 7
The pulley 8 is rotatably supported around pulley shafts 7a and 8a, respectively. The pulley shafts 7a, 8a
Is also fixed to the frame 14 in an inclined manner, as shown in FIG.

Next, the direction of the wire 4 changed by the pulley 8 is reversed by the pulley 9, the direction is changed by the pulley 10, and the wire 4 returns to the driving pulley 5. The pulleys 9 and 10 are also rotatably supported by pulley shafts 9a and 10a, respectively. FIG. 3 shows how the pulley shaft 9a is tilted, and FIG. 4 shows how the pulley shaft 10a is tilted. Pulley 8 and pulley 9
The wire 4 between them is denoted by 4d, and the wire 4 is fixed to the optical unit 3 at 3f also at 4d as in the case of 4a.

The position of the optical unit 3 is determined by the position of the wires 4a and 4d.
The arrangement positions of a and 4d are on the line connecting the side where the wire 4 is separated on the outer circumference of the pulleys 5 and 8 and the side where the wire 4 is wound on the outer circumference of the pulleys 6 and 9, respectively, in a straight line. In other words, in FIG. 2, 4a is a line connecting the 5b portion of the pulley 5 and the 6b portion of the pulley 6, and the straight line connecting the 8b portion of the pulley 8 and the 9b portion of the pulley 9 is the wire 4d. It will be the disposition position.

Pulleys 5, 6, 8, and 9 are arranged such that 5b, 6b, 8b, and 9b are arranged in a plane parallel to platen glass 2, and 4a and 4d are provided in a space. The parts 5b, 6b, 8b, 9b are arranged so as to be parallel to each other. Further, wires 4a and 4d are arranged in parallel or at right angles to a document size index (not shown) on the document table glass 2.

Further, 4a, 4d in the direction of arrow K shown in FIG.
Is disposed so that the optical unit 3 forms an image of the original 1 to be read on the photoelectric conversion element 3d.
The fixing positions of the wires 4a and 4d of the optical unit 3 are fixed such that the size index and the optical unit 3 are perpendicular or parallel.

Next, among the pulley shafts, only the pulley shaft 10a is not fixed to the frame 14 but to the idler plate 11, as shown in FIG. As shown in FIG. 4, the idler plate 11 is slidably disposed on the frame 14 while maintaining an inclination, and further has a spring member 12 stretched between the idler plate 11 and the frame 14. Thus, the tension of the wire 4 is adjusted by the strength of the spring member 12 so that the portions 4a and 4d are sufficiently straight.

In this embodiment, as described above, 5
Although the positions of b, 6b, 8b, and 9b are adjusted and arranged according to the precision of each component, they may be arranged so as to satisfy the same condition by adjusting the height of each pulley on each pulley shaft.

With the above configuration, when the drive in the direction of the arrow E is transmitted to the drive pulley 5 by the motor 13, each pulley also rotates in the direction E and is fixed to the optical unit 3 of the wires 4a, 4d by the portions 3f, 3e. Is the motor 1 while maintaining the relative position.
According to the rotation angle of 3, the robot moves in the direction of arrow F in FIG. That is, an image can be read by synchronizing the movement of the motor 13 with the reading by the optical unit 3 by the CPU. Further, since the wires 4e and 4b are arranged apart from each other, even if the optical unit 3 moves, there is no possibility that the wires 4e and 4b contact the optical unit 3 or affect the movement.

As described above, according to the present embodiment, a simple and low-cost scanning means which does not take up space and is constructed such that the non-stretchable wire 4 is bent back plural times by using the pulleys 5 to 10. , The size and cost of the image reading apparatus can be reduced.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to the drawings. 5 to 8
FIG. 4 is a diagram according to a second embodiment. FIG. 5 is a central sectional view of the image reading apparatus according to the second embodiment of the present invention. FIG. 6 is a plan view of the image reading apparatus shown in FIG. FIG. 7 is a side view of the image reading apparatus shown in FIG. FIG. 8 is a side view of the image reading apparatus shown in FIG.

The second embodiment is different from the first embodiment in which the pulleys 5 to 10 and the wire 4 shown in FIGS. As shown in the figure, positioning members 3g to 3j positioned by the document table glass 2 on the optical unit 3, a rib guide 3k for positioning in the main scanning direction, and a groove guide 14a fitted to the rib guide 3k on the frame 14 are newly added. It is provided in.

The positioning members 3g, 3 of the optical unit 3
The materials h, 3i and 3j desirably have a low frictional force with respect to the platen glass 2 and a good abrasion. Here PO
Although an organic material such as M is used, other materials may be used. In addition, if a portion that comes into contact with the document table glass 2 is configured as a separate member such as a roller so as to be in rotational contact with the document table glass 2, improvement in wear resistance and reduction in frictional load can be achieved. As shown in FIG. 5, the positioning members 3g, 3
h, 3i, 3j have a circular or spherical contact surface with the platen glass 2, and the positions of the members 3g, 3h, 3i, 3j in the direction of the arrow K with respect to the optical unit 3 are the members 3g, 3
When h, 3i, and 3j come in contact with the back surface of the document glass 2, the image of the document 1 to be read is formed on the photoelectric conversion element 3d.

The positions of the members 3g and 3h in the direction A in FIG. 5 are such that the contact points of the members 3g and 3h with the platen glass 2 are just the optical axes from the original 1 to be read to the photoelectric conversion element 3d. It is arranged to be the center. Here, 3
Although two positioning members other than i, 3j and 3g, 3h are arranged, the plane is determined by three points.
h may be omitted. Note that a rib guide 3k is provided on the optical unit 3 as a positioning member in the main scanning direction, and a groove guide 14a to be fitted is formed on the frame 14.
5 and FIG. 6, FIG. 7 is FIG. 3, FIG. 7 is FIG. 3, and FIG.
FIG. 8 corresponds to FIG. 4 and has exactly the same configuration. Therefore, a duplicate description of the configuration and the operation of the scanning unit will be omitted, and only different points from the first embodiment will be described.

The specific positioning newly added in the second embodiment in this case will be described.

The arrangement position of the optical unit 3 shown in FIG. 5 in the direction of the arrow K is determined by the positioning members 3 g, 3 h, 3 i, 3 j abutting on the platen glass 2. As for this contact force, the wires 4a and 4d in FIG. 5 have a linear shape if the tension is originally sufficient, that is, the wires 4a and 4d have a linear shape if the tension is sufficiently high with respect to the weight of the optical unit 3. Is pressed down together with the optical unit 3 on the platen glass 2 in the direction of the arrow K in the drawing. Thereby, the wires 4a,
An external force in the directions of arrows L and M in FIG. 5 is received by the tension of 4 d, and as a result, in the drawing in the direction of arrow K, it receives an upward component and is urged against the platen glass 2.

The frame 14 is provided with a groove guide 14a having a groove shape. The cross-sectional shape of the groove guide 14a is shown in FIGS. 7 and 8, and a rib guide 3k provided on the optical unit 3 is fitted into the groove guide 14a. As shown in FIG. 6, the groove guide 14a and the rib guide 3
The relative positions of the k in the directions of the arrows B and J are arranged relative to an index (not shown) of the original size on the original platen glass 2. It is determined.

The groove guide 1 with respect to the frame 14
The relative arrangement position of 4a is arranged substantially at the center of the plurality of photoelectric conversion elements, but may be anywhere as long as it is not affected by wires and pulleys. However, it is necessary to arrange at right angles or parallel to the document size index, and to manage the straightness in the longitudinal direction of the groove guide 14a. Otherwise, the read image may be bent.

Further, as shown in FIG.
The optical unit 3 is urged against the tension of d by the groove guide 14a and the rib guide 3k in the arrow J direction. This eliminates the gap between the groove guide 14a and the 3ka side of the rib guide 3k as shown in FIG. 7, and the optical unit 3 receives external forces in the directions indicated by the arrows O and N shown in FIG. The optical unit 3 receives a biasing force in the B direction.

As described above, according to the second embodiment,
Stretchable wire 4 and pulley 5 shown in the first embodiment
In addition to the simple and space-saving low-cost scanning means of (10) to (10), the optical unit 3 is provided with positioning members 3g to j for abutting the platen glass 2 for positioning and a rib guide 3k for positioning members in the main scanning direction. Since the positioning of the optical unit 3 is performed accurately, the size of the apparatus can be reduced and the cost can be reduced while maintaining the reading accuracy.

(Correspondence between Claims and Embodiments) The scanning means of the present invention comprises a stretchable wire 4 operated by CPU instead of an optical master unit, a guide shaft, a timing belt and the like controlled by a conventional CPU. It comprises pulleys 5 to 10 and an optical unit 3.

The positioning means of the present invention has two types of positioning means, one of which is the platen glass 2 of the optical unit 3.
The other is a positioning mechanism in the main scanning direction by means of positioning members 3g to 3j arranged at the contact portion with the surface, and the other is by a rib guide 3k fitted into the groove guide 14a of the frame.

(Other Embodiments) As an embodiment, an example of a facsimile having a printer unit and a transmission unit has been described as an embodiment, but the present invention is not limited to this. Equipment used,
Of course, the present invention can be applied to a film scanner, a copying machine, and the like.

[0089]

As described above, according to the first aspect of the present invention, the non-stretchable wire is bent a plurality of times and moved in the same direction. Since the optical unit is fixed to the scanner and the optical unit is moved by the movement of the wire for scanning, the size and cost of the image reading apparatus can be reduced.

Further, according to the second aspect of the present invention, since the folded wire rod moving in the opposite direction to the wire rod fixed to the optical unit is arranged away from the space in which the optical unit moves, scanning by the optical unit is performed. And the image quality can be improved without increasing the load on the wire driving means.

Further, according to the third aspect of the present invention, a pulley is used for driving the wire rod, and the pulley shaft is axially supported at right angles to a plane inclined from the plane on which the optical unit moves. A simple and low-cost scanning mechanism capable of performing smooth scanning without the wires overlapping on the pulley can be configured.

Further, according to the fourth or fifth aspect of the present invention, since the means for applying tension to the folded wire by the elastic member is provided, slack of the wire is prevented, and high quality image is obtained by accurate scanning. Can be read.

Further, according to the invention of claim 6, since the means for applying tension to the wire is disposed apart from two places fixed to the optical unit, it is possible to prevent rattling in the rotation direction of the optical unit. it can.

Further, according to the present invention, since the contact sensor is used in the optical system of the optical unit, the size of the optical unit can be further reduced.

Further, according to the invention of claim 8, since a CCD is used as the photoelectric conversion element, an apparatus having less variation in input sensitivity between pixels can be constructed.

Further, according to the ninth aspect of the present invention, since the positioning means of the optical unit is added to the scanning means having the wire turned back, a higher quality image can be obtained by accurately positioning the optical unit. Reading becomes possible.

Further, according to the tenth aspect of the present invention,
The optical unit has three or more positioning members that are positioned in contact with the platen glass. A height regulating member that ensures the minimum required distance between the optical unit and the document to be read is provided. By doing so, the size and cost of the device can be reduced.

According to the eleventh or twelfth aspect of the present invention, since the means for positioning the optical unit in the main scanning direction is provided, it is possible to perform more accurate scanning and perform high-quality reading.

Further, according to the thirteenth aspect of the present invention, since the optical unit is urged to the platen glass by the means for applying tension to the wire, the urging of the optical unit to the platen glass is simplified. The mechanism is implemented to enable high-quality reading.

Furthermore, according to the invention of claim 14,
Since the optical unit is urged in the main scanning direction by means for applying tension to the wire, the optical unit is urged in the main scanning direction by a simple mechanism, and high-quality reading is enabled.

[Brief description of the drawings]

FIG. 1 is a central sectional view of an image reading apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view of the image reading apparatus shown in FIG.

FIG. 3 is a side view of the image reading apparatus shown in FIG.

FIG. 4 is a side view of the image reading apparatus shown in FIG.

FIG. 5 is a central sectional view of an image reading device according to a second embodiment of the present invention.

FIG. 6 is a plan view of the image reading apparatus shown in FIG.

FIG. 7 is a side view of the image reading apparatus shown in FIG.

FIG. 8 is a side view of the image reading apparatus shown in FIG.

FIG. 9 is a perspective view of a conventional image reading apparatus.

FIG. 10 is a perspective view of the optical unit shown in FIG. 9;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 original to be read 2 platen glass 3 optical unit 3b light source 3c 1 × optical imaging lens 3d photoelectric conversion element 3e, 3f fixing point 3g, 3h, 3i, 3j positioning member 3k rib guide 4 wire 5 driving pulley 6-10 folding pulley Reference Signs List 11 idler plate 12 spring member 13 motor 14 frame 14a groove guide

Claims (14)

[Claims] 1. An image reading apparatus for reading an image from a document by moving an optical unit including a plurality of photoelectric conversion elements, a light source, and an optical system capable of reading the entire width of the document in the main scanning direction, wherein the non-stretchable wire is folded back a plurality of times. Fixing at least two locations of the folded wire rods moving in the same direction and arranged in a spatially parallel manner to the optical unit, and moving the optical rod to move the optical unit, thereby forming an image. An image reading apparatus comprising a scanning unit for scanning and reading. 2. An image reading apparatus for reading an image from a document by moving an optical unit comprising a plurality of photoelectric conversion elements, a light source, and an optical system capable of reading the entire width of the document in the main scanning direction, wherein the non-stretchable wire is folded back a plurality of times. Fixing at least two locations of the folded wire rods moving in the same direction and arranged in a spatially parallel manner to the optical unit, and moving the optical rod to move the optical unit, thereby forming an image. Scanning means for scanning and reading, wherein the scanning means arranges a folded wire rod moving in a direction opposite to a moving direction of the wire rod fixed to the optical unit at a position away from a space in which the optical unit moves. An image reading apparatus comprising: 3. The scanning means uses a plurality of pulleys as a means for turning the wire material subjected to a non-slip process, and a rotating shaft of the pulley is perpendicular to a plane inclined from a plane on which the optical unit moves. The image reading device according to claim 1, wherein the image reading device is supported by a shaft. 4. The image reading apparatus according to claim 1, wherein the scanning unit has a unit that applies tension to the folded wire. 5. An image reading apparatus according to claim 4, wherein said means for applying tension is constituted by an elastic member. 6. The image reading apparatus according to claim 4, wherein the means for applying tension is disposed at a place other than at least two fixing positions of the wire. 7. The optical system according to claim 1, wherein the optical system of the optical unit is a contact sensor of an equal-magnification optical system.
The image reading device according to claim 1. 8. The photoelectric conversion element of the optical unit,
The image reading device according to claim 1, wherein the image reading device is a CD. 9. The image reading apparatus according to claim 1, further comprising a positioning unit for positioning the optical unit. 10. The positioning means is provided with at least three or more positioning members positioned by the platen glass on the optical unit side, and the photoelectric conversion element and a document to be read loaded on the platen glass are arranged on the optical unit. At least two or more positions of the positioning member and the platen glass on a straight line formed by intersecting a plane formed by an optical axis formed between pixels to be read and the back surface of the platen glass. The image reading device according to claim 9, wherein positioning is performed by: 11. An image according to claim 9, wherein said positioning means comprises means for positioning the document in the main scanning direction, and means for positioning said optical unit in said main scanning direction. Reader. 12. The image reading apparatus according to claim 11, wherein said positioning means is a rib guide provided in said optical unit and fitted into a groove guide of a frame as positioning means in a main scanning direction. apparatus. 13. The positioning unit biases an optical unit to the platen glass with the folded wire,
11. The image reading apparatus according to claim 10, wherein the urging force is generated by means for applying a tension to the wire. 14. The positioning device according to claim 1, wherein the optical unit is urged in the main scanning direction by the wire, and the urging force is generated by means for applying tension to the wire. 12. The image reading device according to item 11.