JPH05136955A - Moving structure of scanning member in picture reader - Google Patents

Abstract

PURPOSE:To improve the moving driving of a scanning unit and a mirror unit interlocking with it at high accuracy and to enable accurate reading. CONSTITUTION:A lamp unit 10 for reflection original with a first mirror 14 reflecting the original image light on an original platen in an opposite direction from the scanning movement direction and a mirror unit 20 introducing the original image light from the first mirror 14 with second mirror 22 and the third mirror 23 arranged by making an angle between them the right angle and opposing mutally in the upper and lower parts are supported to rotate freely by guide shafts 51 and 52. The lamp unit 10 is driven in the scanning direction by the rotation of a ball male screw 53. By an interlocking wire 61 whose one end is fixed to a chassis 2A and the other end is fixed to the lamp unit 10 while winding a wire wheel 26 mounted on the mirror unit 20 to rotate freely, the mirror unit 20 is connected to move by the half of the movement amount accompanying the scanning movement of the lamp unit 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving structure of a scanning member in an image reading apparatus for reading character / image information on an original by converting it into an electric signal.

[0002]

2. Description of the Related Art An image reading apparatus for converting character / image information on an original into an electric signal and reading it is a so-called image scanner in which a linear sensor in which pixels are arranged in a row is fixedly arranged and an optical image for guiding an original image to the linear sensor is provided. There is a system in which a linear sensor is moved by scanning in a direction orthogonal to the pixel arrangement direction, and main scanning is performed by the linear sensor and sub-scanning is performed by moving the optical system.

In such a configuration in which the linear sensor is fixedly arranged, the optical path length of the document image from the scanning position of the document by the scanning unit that scans and moves to the linear sensor must be kept constant regardless of the scanning movement of the scanning unit. Therefore, for this reason, in the optical path of the original image from the original scanning position to the linear sensor, a mirror unit that interlocks with the scanning unit and keeps the optical path length constant is provided. The mirror unit is arranged such that two mirrors are arranged at a right angle and the movement of the scanning unit moves in the same direction by half the amount, and scanning is performed by a mirror fixed to the scanning unit. The optical path of the original image refracted in the opposite direction is inverted by two mirrors, refracted to the same side as the scanning direction, and guided toward the linear sensor. As a result, the change in the optical path length of the original image due to the scanning movement of the scanning unit is canceled by the movement of the mirror unit, and the optical path length of the original image from the original scanning position to the linear sensor can always be kept constant. The movement drive of the scanning unit is carried out by interlocking the interlocking string member such as an endless belt or a wire between the pulleys by aligning the linear portion of the circulating track with the moving range of the scanning unit and fixing the interlocking string member to the scanning unit. However, it is common that the interlocking string member is driven to rotate by rotationally driving the pulley.

[0004]

In the image reading apparatus as described above, the reading accuracy depends on the scanning movement accuracy of the scanning unit, and the movement of the scanning unit is controlled with high accuracy in order to perform highly accurate reading. There is a need to. Further, the interlocking structure of the mirror unit and the scanning unit also requires high accuracy. As described above, in the configuration in which the scanning unit is moved and driven by the interlocking string member hung between the pulleys, if the driving pulley has eccentricity, the scanning is periodically performed for each rotation no matter how accurately the driving pulley is rotated. There is a problem that the speed fluctuates.

[0005]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a scanning member in an image reading apparatus, which makes it possible to highly accurately move and drive a scanning unit and a mirror unit interlocked with the scanning unit and to perform highly accurate reading. Of mobile structure,
With the goal.

[0006]

In order to achieve the above object, the moving structure of the scanning member in the image reading apparatus according to the present invention is supported so as to be capable of scanning and moving the original image light in the direction opposite to the scanning and moving direction. A scanning unit having a reflecting first mirror and a second mirror and a third mirror which are movably supported in a direction parallel to the scanning movement direction of the scanning unit and which are vertically opposed to each other, are used to scan the original image light from the first mirror. And a mirror unit that reflects the light in the same direction as the scanning movement direction of the scanning unit and guides the linear sensor to the linear sensor. Scanning movement is driven by rotation of the ball male screw, and one end of the scanning unit and the mirror unit is fixed to the main body of the device, and the sliding unit is rotatably mounted on the mirror unit. By interlocking stringers other end by winding the member is fixed to the scanning unit, the amount of movement of the half mirror unit is connected to be driven moves with the scanning movement of the scanning unit.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram corresponding to a vertical section of an image reading apparatus to which an embodiment of a moving structure of a scanning member in an image reading apparatus according to the present invention is applied. The illustrated image reading apparatus 1 is provided with an original table 3 formed of a transparent glass plate on the upper surface of a main body 2, and an upper side of the original table 3 is provided with an axis 6 at one end (right end in the figure) of the main body 2. It is openably and closably covered by a cover 4 pivotally attached so as to be swingable. The main body 2 includes a lamp unit 10 for a reflection original as a scanning unit, a mirror unit 20, and a filter 3
1, a sensor unit 30 in which a lens 32 and a CCD linear sensor 33 are integrated is provided. On the other hand, the cover 4 is provided with a light diffusing plate 5 made of translucent acrylic resin on the lower surface thereof corresponding to the document table 3 of the main body 2, and a lamp unit 40 for a transparent document inside.
Is provided.

Inside the main body 2, as shown in a plan view of FIG. 2, guide rails 5 are provided at both lateral ends of the chassis.
1,52 are arranged in parallel on both ends in the width direction,
The guide rails 51 and 52 movably support the lamp unit 10 for the reflection original and the mirror unit 20. Also, on the outside of one guide rail 51,
The ball male screw 53 is provided in parallel, and the ball male screw 5
3, a toothed belt 55 is stretched between a toothed pulley 53A fixed to the front end thereof and a toothed pulley 54A fixed to a spindle of a motor 54 provided on the front end side of the chassis 2A, and a motor 3 is provided. It is adapted to be rotationally driven by 54.

The lamp unit 10 for the reflection original is shown in FIG.
The cross-sectional view is shown in FIG. 4, and the front view corresponding to the arrow A view in FIG. 2 is shown in FIG. 4, respectively. As shown in FIG. Halogen lamp 13 is installed inside 12,
Further, the first mirror 1 is provided on the side adjacent to the open side of the reflection plate 12.
4 are supported. A cover glass 15 is attached to the open portion of the reflector 12 so that the light emitted from the halogen lamp 13 passes through the cover glass 15 and irradiates the original surface of the original placed on the original table 3 downward. Is becoming
The first mirror 14 is located below the original portion illuminated by the halogen lamp 13 and is provided at an angle of 45 ° so that the original image is reflected toward the left side in the horizontal direction with the reflecting surface facing upward. ..

In the lamp unit frame 11, a slide bearing portion 16 provided at one end portion in the width direction is slidably fitted on the guide rail 51, and a support leg 17 provided at the other end portion is provided. The guide rail 52 is supported by the guide rail 52 in a mounted state via the sliding member 17A.
It is possible to move along 1,52. A ball female screw 18 is fixed to the outer side surface of the slide bearing portion 16 via a bracket 19, and the ball female screw 18 is screwed with a ball male screw 53. As a result, the lamp unit 10 for the reflective original is driven by the motor 54 to rotate the ball male screw 53, so that the guide rails 51, 52 can be rotated.
It is driven to move in the horizontal direction in FIG.

The mirror unit 20 is provided with a second mirror 22 and a second mirror 22 by a mirror unit frame 21 as shown in its sectional view in FIG. 5 and a rear view corresponding to the arrow B view in FIG. Below the second mirror 22, the third mirror 23
Is supported. The second mirror 22 has a reflection surface on the lower side in a position horizontal to the first mirror 14 supported by the lamp unit 10 for the reflection original, and the third mirror 23 has a reflection surface on the lower side of the second mirror 22. Are arranged to face each other at an angle of 45 ° with the upper side as the upper side, and the first mirror 14
The original image reflected by the second mirror 22 is reflected downward, and the third mirror 23 is reflected horizontally in the right direction in the drawing.

In the mirror unit frame 21, a slide bearing portion 24 provided at one end portion in the width direction is slidably fitted on a guide rail 51, and a support leg 25 provided at the other end portion is provided. The guide rail 52 is supported by the guide rail 52 via the sliding member 25A in a mounted state.
It is possible to move along 1,52. Further, an interlocking wire pulley 26 as a pulley member is rotatably mounted on the inner side surface of the slide bearing portion 24 with its rotation axis perpendicular to the moving direction. Hook unit 6 fixed to the inner surface at the tip of the slide bearing portion 16 of the lamp unit 10 for automobiles
An interlocking wire 61 as an interlocking string member, which is engaged with and fixed to No. 2 and whose other end is engaged and fixed to a hook fitting 63 fixed to the front side of the chassis 2A, is wound.

Further, a tension wire 65 whose one end is engaged and fixed to a hook metal fitting 64 fixed to an outer surface on the rear side of the slide bearing portion 24 is rotatably mounted on a rear outer surface of the chassis 2A by a bracket 66. A hook metal fitting 6 in which a tension wire wheel 67 is wound and the other end is fixed to the chassis 2A via a tension spring 68.
9 is engaged and fixed to the front end of the tension wire 65.
The mirror unit 20 is urged to move to the rear end side by the urging force of the tension spring 68 acting via the. The movement of the mirror unit 20 due to the urging force of the tension spring 68 is restricted by the interlocking wire 61 wound around the interlocking wire pulley 26.
A predetermined tension acts on 1 to put it in a tensioned state.

The sensor unit 30 includes a filter 31,
The lens 32 and the CCD linear sensor 33 are formed by being combined in series, and the third mirror 23 of the mirror unit 20 is formed.
The filter 31 is fixed on the chassis 2A at the lower center of the scanning movement range of the lamp unit 10 for the reflected original so that the original image light reflected by the unit is incident on the rear side of the apparatus (mirror unit 20). .. The lens 32 is a fixed focus lens and is set so as to form an original image on the upper surface of the original plate on the photosensitive surface of the CCD linear sensor 33. Although not shown, the CCD linear sensor 33 is provided horizontally so that the pixel array direction is the width direction of the document placed on the document table.

With the above-described structure, the original image light illuminated by the reflecting original lamp unit 10 is in a direction opposite to the scanning movement direction (the right side in FIG. 1) of the reflecting original lamp unit 10 by the first mirror 14. After being reflected by
It is inverted by the second mirror 22 and the third mirror 23 and enters the sensor unit 30 in the same direction as the scanning movement direction of the lamp unit 10 for the reflective original. By converting the incident original image light into an electric signal by the CCD linear sensor 33,
Main scanning in the width direction of the document is performed, and at the same time, the first mirror 14 is moved in the vertical direction with respect to the document by the scanning movement drive of the lamp unit 10 for the reflective document to the right side in the drawing, and the sensor unit 30 is moved. A portion of the original light to be guided moves to perform sub scanning.

Here, the ball male screw 5 by the motor 54
When the lamp unit 10 for the reflective original is driven to scan and move to the right side in the figure along the guide rails 51 and 52 by the rotation of 3, the interlocking wire is accompanied by the scanning movement of the lamp unit 10 for the reflective original. The fixed end of the lamp unit 10 of 61 is pulled, and the interlocking wire 6
Since the other end of 1 is fixed to the chassis 2A, the mirror unit 20 is moved and driven via the wire wheel 26 by half the amount of movement of the lamp unit 10 against the biasing force of the tension spring 68. As a result, the original image optical path length that reaches the sensor unit 30 after being reflected by the first mirror 14, the second mirror 22, and the third mirror 23 is also affected by the scanning movement of the lamp unit 10 for the reflected original. The lamp unit 10 for the reflection original will be constantly maintained by the movement.
The image on the document surface is always C by the lens 32 regardless of the position of
The image can be read by forming an image on the photosensitive surface of the CD linear sensor 33.

On the other hand, the cover 4 is provided with a light diffusing plate 5 made of translucent acrylic resin on the lower surface thereof corresponding to the document table 3 of the main body 2, and a lamp unit 40 for a transparent document is provided therein. It is provided. The lamp unit 40 for the transparent original has a substantially symmetrical shape with the lamp unit 10 for the reflective original, and includes the lamp unit frame 4
1, a reflecting plate 42 that is open obliquely downward is supported, a halogen lamp 43 is internally provided in the reflecting plate 42, and a cover glass 44 is attached to the opening of the reflecting plate 42. There is. Lamp unit frame 41
Is guided by a guide rail (not shown) and movably supported in the left-right direction in the figure, and is driven and driven by a driving means (not shown). As a result, the lamp unit 40 for the transparent original is shown in the figure. It is capable of reciprocating a predetermined stroke in the left-right direction. In the above structure, the light emitted from the halogen lamp 43 is emitted from the cover glass 4
4 and illuminates the diffuser plate 5, and the light transmitted through the diffuser plate 5 is transmitted through the transparent document placed on the document table 3 facing downward. The light transmitted through the transparent original (original image light) is the first mirror of the lamp unit 10 for the reflective original, which is located at a lower symmetrical position with the diffuser plate 5 of the lamp unit 40 for the transparent original and the original table 3 separated. The light is reflected at 14, and is incident on the sensor unit 30 via the second mirror 22 and the third mirror 23 of the mirror unit 20 as in the case of the reflected original.

In the image reading apparatus 1 configured as described above, in the case of a reflective original, the original is placed on the original table 3 with its original surface facing down, and the main body 2 is used for the reflective original. The halogen lamp 13 of the lamp unit 10 irradiates the original surface of the original, and the lamp unit 10 for the reflective original is scanned and moved at a predetermined speed.
The CCD linear sensor 33 reads the image information. At this time, the lamp unit 40 for the transparent original in the cover 4 does not operate. On the other hand, in the case of a transparent original, the original is placed on the original table 3
The original surface is placed on the upper side, the original is illuminated by the halogen lamp 43 of the transparent original lamp unit 40 in the cover 4, and the transparent original lamp unit 40 and the reflective original lamp unit 10 are provided. To scan and move at a predetermined speed in synchronization with the CCD of the sensor unit 30.
Image information is read by the linear sensor 33. At this time, the light (original image light) transmitted through the transparent original is the second mirror 22 and the third mirror 23 of the mirror unit 20 as in the case of the reflective original.
To the sensor unit 30. The halogen lamp 13 of the lamp unit 10 for the reflection original is not turned on.

[0019]

As described above, according to the moving structure of the scanning member in the image reading apparatus according to the present invention, since the scanning unit is driven by the rotation of the ball-screw, the scanning speed of the component processing accuracy can be increased. The influence is small and the scanning unit can be moved and driven with high accuracy. Therefore, the driving movement of the mirror unit interlocking with the scanning unit also becomes highly accurate, and highly accurate reading can be performed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram corresponding to a longitudinal section of an image reading apparatus to which an embodiment of a moving structure of a scanning member in an image reading apparatus according to the present invention is applied.

FIG. 2 is a plan view of a scanning member portion.

FIG. 3 is a cross-sectional view of a reflective original lamp unit.

FIG. 4 is a front view of a reflective original lamp unit corresponding to a view taken along the arrow A in FIG.

FIG. 5 is a sectional view of a mirror unit.

FIG. 6 is a rear view of the mirror unit corresponding to the arrow B view in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Image reading device 10 ... Lamp unit (scanning unit) for reflective originals 14 ... First mirror 18 ... Ball female screw 20 ... Mirror unit 22 ... Second mirror 23 ... Third mirror 26 ... Interlocking wire wheel (pulley member) 33 ... CCD linear sensor (linear sensor) 53 ... ball male screw 61 ... interlocking wire (interlocking cord member)

Claims (1)

[Claims] 1. An image reading apparatus for reading character / image information on an original by converting it into an electric signal, wherein a linear sensor is fixedly installed, and a scanning member is arranged in a direction orthogonal to a pixel array direction of the linear sensor. In the case of moving and performing sub-scanning, a scanning unit having a first mirror which is movably supported and reflects document image light in a direction opposite to the scanning movement direction, and a scanning movement direction of the scanning unit. The original image light from the first mirror is reflected in the same direction as the scanning movement direction of the scanning unit by a second mirror and a third mirror which are movably supported in a parallel direction and are arranged to face each other in the vertical direction. A mirror unit for guiding to a sensor, wherein the scanning unit is screwed onto a ball female screw fixed to the scanning unit and is rotated by a rotation driving means. The scanning unit and the mirror unit have one end fixed to the apparatus main body, a pulley member rotatably mounted on the mirror unit, and the other end fixed to the scanning unit. The interlocking string member is connected so that the mirror unit is moved and driven by half of the movement amount of the scanning unit in accordance with the scanning movement of the scanning unit. ..