JP2000115474A - Reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve processing speed by relieving a load of a read means required for its movement that reads an original image, while scanning an original image. SOLUTION: When back-scanning is conducted with this reader, a drive belt 4 pulls a belt-fixing part 3c to the left to drive a carriage. A moment exerted to a mount member caused by a tractive force of the belt is larger than a moment by a compression spring 6, the mount member is turned clockwise around a turning shaft 3a till a boss 3b of a compressed part of the mount member strikes on a bottom of the carriage 2, resulting that the attitude of the mount member in the carriage is determined. Since back scanning is conducted in this state, a positioning member 7 is separated from an original glass plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a reading apparatus for reading an image of a document, and more particularly to a flat bed type reading apparatus using a contact image sensor.

[0002]

2. Description of the Related Art Conventionally, a scanner which is a reading device mounted on a copying machine, a facsimile, a scanner, etc.
Many book-reading scanners that read document image information while the document is fixed have a CCD image sensor.

However, in recent years, as shown in FIG. 7, in a multifunction machine in which the functions of a printer, a copier, a facsimile, and a scanner are all-in-one, the close contact type image sensor 101 is mounted for reasons such as cost advantages. In many cases.

That is, the contact type image sensor 101
In the case of the configuration using, compared to the configuration of an imaging system using three mirrors and lenses like a half optical system,
This is because there are the following advantages.

The dimension of the reader in the thickness direction can be substantially reduced by half (in the case of the above-described imaging system, two scanning units are required in a direction overlapping the thickness direction. This is because the configuration using the image sensor 101 can be configured with one scanning unit.)

[0006] Fewer adjustments are required to achieve proper imaging.

The drive system can be simplified by reducing the mechanical load and simplifying the configuration.

For the above reasons, it is possible to greatly reduce the cost.

However, since the contact type image sensor is an optical system of the same magnification image forming system, the size of one pixel is larger than that of the conventional CCD image sensor.

For example, while the image size of a general CCD image sensor is 7 μ, the contact type image sensor has a size of 63.5 μ in the case of 400 dpi in the main scanning direction.

Therefore, the accumulation time becomes long.

In order to shorten this, a combination of a bright light source and a bright short focus lens is often adopted as a configuration.

Therefore, it is difficult to optimize the focus and it is difficult to accurately read image information without "blur".

Therefore, in order to solve such a disadvantage, a configuration as described below has been considered.

FIG. 8 is a diagram showing a conventional contact sensor configured to solve this drawback.

As shown in FIG.
01 is held in the carriage 102 via a spring 106.

A lead shaft 105 passes through the center of the carriage 102, and a slider 110 is provided at the lower surface of one end.

With the above arrangement, the carriage 102 is pulled by a driving wire (not shown), and moves on the leader housing as shown in FIG.
In the left and right directions.

In the scanner of this type, since the carriage 102 holds the contact image sensor 101 while energizing it, the abutting portion 107 of the contact image sensor 101 follows the back surface of the original glass 108 even in the reading operation. By performing the scanning while reading, the problem of the focal length, which is the above-mentioned disadvantage, has been solved.

[0020]

However, in the case of the above-described prior art, the following problems have occurred.

As described above, the scanning is performed while the abutting portion of the close contact image sensor is in contact with the back surface of the original glass, so that the distance between the original image surface and the close contact image sensor is stabilized. Is improved,
Since the abutting portion 107 of the contact sensor 101 rubs against the back surface of the document glass 108, an adverse effect due to an increase in load is caused.

This increase in load does not cause any particular problem during reading scanning. However, when the contact image sensor 101 completes reading scanning and turns back, that is, when it moves at a high speed during so-called back scanning. Had the adverse effect of hindering the stable running of the car.

The problem in increasing the back scan speed is as follows.
Although it was inconspicuous in applications as a scanner or a facsimile, it has been considered to be mounted on a multifunction peripheral in which it is important to have a certain high-speed copy speed, and it has begun to be considered important.

It is desired that the back scan speed be at least seven times the scan (reading scan) speed for the copy speed UP. To achieve this, it is necessary to at least reduce the mechanical load at the time of backing. Had become.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. It is an object of the present invention to reduce the load of moving a reading means while scanning an image on a document while reducing the processing load. It is an object of the present invention to provide a reading device that improves speed.

[0026]

In order to achieve the above object, according to the present invention, scanning is performed while contacting a light-transmitting plate.
In a reading device provided with reading means for reading an image of an original placed on the opposite side via the light transmitting plate, the reading means is provided rotatably, and the reading means is moved in a reading scanning direction. The reading means is moved while being in contact with the light transmitting plate, and when the reading means is moved in the direction opposite to the scanning direction, the reading means is moved while being separated from the light transmitting plate. It is characterized by making it.

Also, in a reading apparatus provided with reading means for scanning while contacting the light transmitting plate and reading an image of an original placed on the opposite side via the light transmitting plate, the reading means is provided with a light transmitting means. The reading means is provided so as to be able to freely contact and separate from the plate, and when the reading means is moved in the reading scanning direction, the reading means is urged in a direction in which the reading means comes into contact with the light transmitting plate, and is opposite to the reading scanning direction. When moving in the direction, the urging force is reduced so that the reading unit is separated from the light transmitting plate.

Further, scanning is performed while contacting the light-transmitting plate,
In a reading device provided with reading means for reading an image of a document placed on the opposite side via the light transmitting plate, the reading means is provided rotatably, and the reading means is brought into contact with the light transmitting plate. An urging means for applying a rotational force in a direction in which the reading means is brought into contact with the reading means; The positional relationship between the acting part of the biasing force and
When the reading means is moved in the reading scanning direction, the force is increased in the same direction as the rotation direction given by the urging means, and when the reading means is moved in the direction opposite to the reading scanning direction. Are characterized in that they are arranged so as to increase the force in the direction opposite to the rotation direction given by the urging means.

Further, in a reading apparatus provided with reading means for scanning while abutting on the light transmitting plate and reading an image of an original placed on the opposite side via the light transmitting plate, the reading means is rotated. A switching lever is provided so as to be movable, and a switching lever is provided for switching between a direction in which the reading unit is brought into contact with the light transmitting plate and a direction in which the reading unit is separated from the light transmitting plate.

Here, the switching lever includes a direction in which the reading unit is brought into contact with the light transmitting plate, a direction in which the reading unit is separated from the light transmitting plate,
It is convenient to have a toggle mechanism for switching the direction of action of each force.

The switching lever may be switched by bringing the switching lever into contact with a contact portion provided on a frame that slidably supports the reading unit.

Further, the contact portions provided on the frame may be arranged at positions corresponding to a position where the reading means starts reading and scanning and a position where the reading is turned back.

It is preferable that the reading means comes into contact with the light transmitting plate via a positioning member.

[0034]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The material, shape, relative arrangement, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

The reading apparatus according to the present invention is applied to, for example, a copying machine, a facsimile, a scanner, and a multifunction machine in which these functions are all-in-one as described above. Since the configuration and the like are well-known technologies, the description thereof will be omitted, and only the characteristic components will be described in the following embodiments.

(First Embodiment) A reading apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a perspective view schematically showing the structure of a main part (a contact sensor and a carriage that holds the contact sensor and travels to scan a document) of the reading apparatus according to the first embodiment of the present invention. FIG. 2 and FIG. 3 are explanatory views of the operation of the main part (a contact sensor and a carriage that holds the contact sensor and travels to scan a document) of the reading apparatus according to the first embodiment of the present invention.

First, each component will be described with reference to FIG.

In the figure, reference numeral 2 denotes a box-shaped housing containing members required for image reading for image reading, and a carriage for scanning the original image while traveling.

The carriage 2 has a guide shaft 5 laid in the scanning direction at a substantially central portion of a frame of the reader section (a frame on the side of the reading device) via a bearing.

A slider 10 is provided on the lower surface of the end of the carriage 2 so as to slide on the base surface of the frame of the leader portion. The carriage 2 is configured to maintain a posture substantially parallel to the original glass. ing.

The carriage 2 is reciprocated by the movement of the belt 4, which is a traction means, by a drive motor (not shown), and scans the original image.

The pulling member is not limited to a belt, but may be, for example, a wire.

Next, the configuration inside the reading means will be described in more detail with reference to the operation explanatory diagram of FIG.

Reference numeral 1 denotes a contact-type image sensor as reading means.

The contact type image sensor 1 has a longitudinal dimension corresponding to the width of the document, and reads an image by scanning in the left-right direction in FIG. 2 (A direction in FIG. 1).

The contact type image sensor 1 includes a light source 11 that emits light in a range corresponding to the width of a document, an optical sensor array 13 that converts optical information into an electric signal with the same width, and a short focus imaging element array 12. Become.

It is preferable to use a cold-cathode tube such as a xenon tube as the light source 11 because external heat generation is small.

The above parts are integrated to form a contact image sensor.

Reference numeral 7 denotes a positioning member fixed to the contact sensor with screws.

A part of the positioning member 7 protrudes toward the original glass from the contact sensor, and contacts with the lower surface of the original platen glass 8 as a light-transmitting plate. It functions to keep the depth of focus of the image element array 12 constant.

The positioning member 7 is a platen glass 8
It is formed of a material having good slidability, such as polyacetal, in consideration of the rubbing with the material.

The object distance at the time of reading in the sub-scanning direction of the contact type image sensor 1 is such that the positioning means 7 follows the platen glass 8 even if the carriage 2, the leader frame lower surface 9, and the lead shaft 10 are deformed. Is determined by

Therefore, the change in distance can be neglected to the extent that it is determined by the flatness of the platen glass 8.

Therefore, by performing reading scanning while the positioning member 7 is in contact with the lower surface of the document table glass 8, stable reading can be performed.

Here, the contact type image sensor 1 is held by the mount member 3.

The mount member 3 is incorporated so as to be rotatable with respect to the carriage 2 about pivot shafts at both ends in the longitudinal direction.

The mount member 3 has a compression spring 6 serving as an urging means at the lower boss 3b disposed between the mount member 3 and the carriage 2, and the contact type image sensor 1 and the positioning member are positioned via the mount member 3. The means 7 is urged against the original glass surface.

The urging force and the like of the compression spring 6 are set so that the contact force of the positioning means 7 against the glass does not become larger than the mechanical load at the time of moving the carriage at a constant speed.

The portion 3c extending downward is the drive belt 4
It is fixed to.

The circuit board 14 that drives and controls the light source 11 and the optical sensor array 13 is disposed alone in the carriage 2.

Reference numeral 15 denotes a flat cable for supplying electricity or the like.

With the reading apparatus configured as described above, the original image is read and scanned by reciprocating movement in FIG.

It should be noted, however, that scanning is performed when moving in one direction, and reading is not performed when returning in the other direction (so-called back scan).

Then, the read image information is converted into a video signal by the optical sensor array 13 and then sent to a control board disposed in a printer section at the lower part of the apparatus main body.
Processing such as D conversion, shading correction, and density processing is performed, and output for recording by the printer unit.

FIG. 3 shows the operation of each unit at the time when the original scanning is completed and the back scan is started after the reversal.

The drive belt 4 drives the carriage by pulling the belt fixing portion 3c to the left in the drawing.

Then, the moment acting on the mount member 3 is greater than that due to the compression spring 6 due to the pulling force of the belt.

Therefore, the mount member 3 rotates clockwise about the rotation support shaft 3a.

The mounting portion rotates until the compression portion boss 3b of the mounting member comes into contact with the bottom of the carriage 2 to determine the posture in the carriage.

The back scan is performed in this state.

Accordingly, as shown in FIG. 3, the positioning member 7 is separated from the original glass.

Therefore, even when moving at a high speed, a more stable running than before can be obtained.

Further, the contact / separation operation of the contact sensor can be achieved without adding a dedicated drive actuator, so that a configuration having no adverse effect such as increasing the weight of the carriage can be achieved.

The reading means (mount member 3)
The configuration of the contacting / separating operation of the contact type image sensor 1) held on the platen glass 8 as a light transmitting plate will be further described.

The reading means is provided rotatably as described above, and is urged by the urging means (compression spring 6) so as to rotate in the direction in which the reading means contacts the light transmitting plate.

Here, in the following description, for convenience of explanation, the above-mentioned rotation direction is changed to the first rotation direction (FIGS. 2 and 3).
(A counter-clockwise direction), and the opposite rotation direction is a second rotation direction (the clockwise direction in FIGS. 2 and 3).

When the reading means is stopped, the reading means is brought into contact with the light transmitting plate by the urging force of the urging means.

In the case where the reading means is moved in the reading scanning direction, the action part of the force for driving the reading means, the action part of the force to be urged by the above-mentioned urging means, and the position of the center of rotation. From the relation, the direction of the driving force acting on the reading unit when the reading unit is moved acts so as to further apply a force in the first rotation direction.

Accordingly, since both of this force and the urging force of the urging means apply a force in the first rotation direction, the scanning can be performed while the reading means is properly in contact with the light transmitting plate. .

On the other hand, when the reading means returns after finishing the reading (so-called back scan), the direction of the driving force acting on the reading means when the reading means is moved is the second direction based on the above positional relationship. It acts to generate a force in the rotating direction.

Here, the positional relationship between the components and the bias of the biasing means are set such that the force of the reading means in the second rotating direction by this force is greater than the force of the biasing means in the first rotating direction. A force (spring force), a driving force for moving the reading unit, and the like are set.

Therefore, at the time of back scanning of the reading means, the reading means moves while being separated from the light transmitting plate.

As described above, the processing speed can be improved, and the structure for achieving the contact / separation operation is realized by a special member for contact / separation (for example, a dedicated actuator or the like).
Can be achieved by setting the positional relationship, the force relationship, and the like of each member without the need for the above, so that it can be achieved with a simple configuration.

Further, during back scanning, the sliding contact with the light-transmitting plate is not performed, so that the durability and wear resistance can be improved.

(Second Embodiment) FIGS. 4 to 6 show a second embodiment of the present invention. In the present embodiment, the configuration in the case where the operation of contacting / separating the reading unit from / to the light transmitting plate is performed using the switching lever is shown.

The other configuration and operation are the same as those of the first embodiment, so that the same components are denoted by the same reference characters and description thereof is omitted.

FIG. 4 is a schematic perspective view of a main part of a reading device according to a second embodiment of the present invention, and FIGS. 5 and 6 are diagrams of the reading device according to the second embodiment of the present invention. It is operation | movement explanatory drawing.

As shown in FIG. 4, a switching lever 20 is supported on the outside of the carriage 2 so as to be rotatable around a boss unit integrated with the carriage 2.

The switching lever 20 has a spring hook 20d.

A spring hook 2a is also provided on the outer surface of the carriage 2.

The spring hook 2a on the side surface of the carriage 2 is arranged such that the line connecting to the center of rotation of the lever 20 extends in the vertical direction.

Since the tension springs 21 are erected on both hook portions, the switching lever 20 is moved to the tension springs 21.
Thus, the biasing force in both the clockwise direction and the counterclockwise direction is configured to act by a toggle effect.

As shown in FIG. 5, at the other end of the switching lever 20, an engaging portion 20c for engaging with the mounting member is formed, and the mounting member 3a projecting out of the carriage 2 through the square hole is operated. By rotating the mount member 3a, the reading unit (contact type image sensor 1) is moved toward and away from the light-transmitting plate (document table glass 8).

The operation will be described with reference to FIGS.

FIGS. 5A and 5B show a state at the time of reading scanning. FIG. 5A shows a state in which the reading means (contact type image sensor 1 held by the mount member 3) is at the home position, and FIG. FIG. 3C shows a state immediately before reaching the reversal position during the reading scan of the means, and FIG. 4C shows a state where the reading scan is completed (a state where the reversal position is reached).

As shown in FIG. 5A, when the reading means is at the home position, the position of the lever 20 is restricted by the block 22 fixed to the frame of the reader section.

That is, at this time, the tension spring 21 gives the lever 20 a clockwise moment in the drawing due to the toggle effect.

Therefore, the mount member 3 holding the close contact type image sensor 1 is urged by the engaging portion 21c.

In addition, the mounting member 2 operates so that the contact type image sensor 1 abuts on the original glass 8 by the action force of the compression spring 6.

Accordingly, the positioning member 7 is kept in contact with the original glass, and the scanning of the original by the reading apparatus is started.

Then, as shown in FIG. 5B, during the reading scan, the positioning member 7
Moves while sliding on the platen glass 8.

Therefore, since the scanning operation is performed while the predetermined focal length is secured, stable reading is performed.

Then, immediately before the scanning operation is stopped, the block 23 fixed to the leader frame (not shown) hits (contacts) the lever 20, thereby causing the lever 20 to move.
Rotates counterclockwise (the state shown in FIG. 5C).

Here, when the switching lever 20 is rotated until the spring hooking portion 20d is located on the right side in the drawing at the center of rotation, the tension spring 21 urges the lever 20 counterclockwise in the drawing by a toggle effect. Work to do.

The compression spring 6 in the state shown in FIG.
And the operating length of the tension spring 21 are set such that substantially the same operating force can be obtained.

Therefore, the mount member 3 receives a clockwise moment about the rotation center 3a.

Therefore, the contact sensor and the positioning member 7 are separated from the original glass 8.

After this operation is completed, a back operation (back scan) is started.

FIGS. 6A and 6B show the state at the time of the back scan. FIG. 6A shows a state in which the reading means (contact type image sensor 1 held by the mount member 3) is at the reverse position, and FIG. A state during the back scan of the means is shown, and (c) shows a state where the back scan is completed (a state where the home position is reached).

The back scan starts from the state shown in FIG. 6A, and performs the back scan while keeping the positioning member 7 separated from the original glass 8 as shown in FIG. 6B.

When returning to the home position again, the block 2 fixed to the leader frame (not shown)
After 2 has hit (contacted) lever 20, the reader finishes a predetermined amount of backscan.

At this time, the spring hook portion 20d of the switching lever 20 is located on the left side of the rotation center in the drawing, and the biasing force of the tension spring 21 is turned to rotate the lever 20 clockwise by the toggle effect. Be replaced.

Thus, the lever 20 rotates, and the positioning member 7 of the close contact sensor again strikes the original glass.

As described above, at the time of the back scan of the reading means, the reading means moves while being separated from the light transmitting plate, so that the processing speed can be improved, and further, the contact / separation operation can be achieved. Without the need for special components (such as dedicated actuators)
It can be achieved with a relatively simple configuration, and since it does not slide on the light-transmitting plate during back scan, it is possible to improve the durability and wear resistance.

[0116]

As described above, according to the present invention, when the reading means is moved in the direction opposite to the scanning direction, the reading means is moved while being separated from the light transmitting plate. The load at the time of movement is reduced, the processing speed is improved, and the durability and abrasion are also improved.

An urging means for applying a rotating force in a direction in which the reading means is brought into contact with the light transmitting plate is provided, and a portion for applying a force to the reading means when the reading means is driven; The processing speed can be improved with a simple configuration by causing the reading unit to move toward and away from the light transmitting plate depending on the positional relationship between the urging force and the acting part.

The processing speed can be improved with a relatively simple configuration by providing switching levers for switching the reading means between the direction in which the reading means is brought into contact with the light transmitting plate and the direction in which the reading means is separated from the light transmitting plate. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic configuration perspective view of a main part of a reading device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation of a main part of the reading device according to the first embodiment of the present invention.

FIG. 3 is an operation explanatory diagram of a main part of the reading device according to the first embodiment of the present invention;

FIG. 4 is a schematic configuration perspective view of a main part of a reading device according to a second embodiment of the present invention.

FIG. 5 is an operation explanatory diagram of a reading device according to a second embodiment of the present invention.

FIG. 6 is an operation explanatory diagram of a reading device according to a second embodiment of the present invention.

FIG. 7 is an overall configuration diagram of a reading device according to a conventional technique.

FIG. 8 is a schematic configuration diagram of a main part of a reading device according to a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Contact image sensor 2 Carriage 3 Mounting member 4 Drive belt 5 Guide shaft 6 Compression spring 7 Positioning member 8 Original glass 9 Lower surface of a leader frame 10 Lead shaft 11 Light source 12 Short focus imaging element array 13 Optical sensor array 14 Circuit board 15 Flat cable 20 Lever 21 Tension spring 22, 23 Block

Claims (8)

[Claims] A scanning device for scanning an image of a document placed on the opposite side through the light transmitting plate while scanning while contacting the light transmitting plate; When the reading means is moved in the reading scanning direction, the reading means is moved while being in contact with the light transmitting plate, and when the reading means is moved in the direction opposite to the reading scanning direction. And a reading device for moving the reading means while moving the reading means away from the light transmitting plate. 2. A reading device provided with reading means for scanning while abutting on a light transmitting plate to read an image of an original placed on the opposite side via the light transmitting plate, wherein the reading means transmits light. Along with being provided so as to be able to contact and separate from the plate, when the reading unit is moved in the reading scanning direction, the reading unit is urged in a direction in which the reading unit comes into contact with the light transmitting plate, and
A reading device, comprising: an urging means for reducing an urging force when moving the reading means in a direction opposite to the reading scanning direction and separating the reading means from the light transmitting plate. 3. A reading device provided with reading means for scanning while abutting on a light transmitting plate and reading an image of an original placed on the opposite side via the light transmitting plate, wherein the reading means is rotated. A biasing means for arbitrarily providing the rotating means in a direction in which the reading means is brought into contact with the light transmitting plate; and when the reading means is driven in a reading scanning direction and in a direction opposite to the reading scanning direction. When the reading unit is moved in the reading scanning direction, the positional relationship between the acting unit of the force on the reading unit and the acting unit of the biasing force by the biasing unit is given by the biasing unit. When the force is increased in the same direction as the rotating direction and the reading means is moved in the direction opposite to the scanning direction, the force is increased in the direction opposite to the rotating direction given by the urging means. A reading device, wherein the reading device is arranged so that 4. A reading device provided with reading means for scanning while abutting on a light transmitting plate and reading an image of an original placed on the opposite side via the light transmitting plate, wherein the reading means is rotated. A reading device, which is freely provided, and further includes a switching lever that switches and moves the reading unit in a direction in which the reading unit contacts the light transmitting plate and a direction in which the reading unit moves away from the light transmitting plate. 5. A switching mechanism according to claim 1, wherein said switching lever has a toggle mechanism for switching a direction in which a force is applied between a direction in which said reading means is brought into contact with said light transmitting plate and a direction in which said reading means is separated from said light transmitting plate. Item 5. The reading device according to Item 4. 6. The switching lever according to claim 5, wherein said switching lever is brought into contact with a contact portion provided on a frame body slidably supporting said reading means, thereby switching said switching lever. Reading device. 7. A contact portion provided on the frame body is disposed at a position corresponding to a position where the reading means starts reading and scanning and a position corresponding to a turn-back position.
A reading device according to claim 1. 8. The reading apparatus according to claim 1, wherein said reading means contacts the light transmitting plate via a positioning member.