JP3483393B2 - Image reading device and image forming device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applicable to an image reading apparatus and an image forming apparatus, and is characterized by a structure for adjusting a main scanning direction of an optical unit equipped with an image reading unit. Specific examples of applicable products include a scanner, a facsimile machine, and a copying machine.

[0002]

2. Description of the Related Art Conventionally, as an image reading device for reading an image of a document, various image reading devices have been proposed.
It is used in facsimile machines and copiers. Figure 6
Is a schematic configuration of the image reading apparatus. An automatic document feeder (hereinafter referred to as AD
F103 (called an automatic document feeder) is installed.

In the image reading apparatus 101, only the image reading apparatus main body 102 allows the operator to place the document on the platen 104, which is the image reading area, so that the image information 1
Stop-reading method for reading sheet by sheet, fast reading of a plurality of sheet-like originals, and flow-reading method for reading an original having a size larger than the length of the platen 104 in the sub-scanning direction or a long original while being conveyed by the ADF 103 It is possible to perform the two reading methods of.

The image reading apparatus main body 102 has an image reading means 105 for reading image information of a document in the main scanning direction. The image reading unit 105 is the rail unit 106.
The configuration is such that it can move upward in the sub-scanning direction of the arrow A101 direction.

On the other hand, the ADF 103 has a document tray 107.
The original G placed on the sheet is fed from below by the pickup roller 108, and the original G is conveyed to the nip portion between the separation roller 109 and the friction plate 110. Reference numeral 111 denotes a weight plate, which presses the leading end of the document G placed on the document tray 107 and rotationally drives the pickup roller 108 so that the document G can be stably fed. After the registration is adjusted by the registration roller pair 112, it is conveyed to the flow reading unit at the end of the platen 104. Reference numeral 113 denotes a platen 104 for copying the original at the flow reading unit.
Is a reading and conveying roller that conveys the sheet at a constant speed while pressing the surface of the sheet. Then, it is discharged onto the discharge tray 115 by the discharge roller pair 114.

Here, in the case of flow reading using the ADF 103, the image reading means 105 moves to the flow reading portion indicated by P101 and reads the image information in a stopped state. Further, in the stop reading method in the case where the image of the original such as a book which cannot be scanned by the operator is placed on the platen 104, the image reading area of the platen 104 from P102 to P103 is set in the image reading means. 105 moves in the direction of arrow A101 (sub-scanning direction) to read image information.

The image reading means 105 is constructed as a flat head type having an optical system unit in which a reading element arranged in a line in the main scanning direction and a lens member corresponding to the reading element are integrated. The image reading means 105 is used, and various technical improvements have been made to the image reading means 105.

For example, in Japanese Utility Model Publication No. 5-43561, a guide plate is arranged between a flat head type image reading means and an original pressing roller which faces the flat head type image reading means to reduce the distance between the image reading means and the original. A configuration that guarantees the focal length is described.

Further, in Japanese Patent Laid-Open No. 61-149920, in order to keep the distance between the fixed platen glass and the optical system unit moving in the sub-scanning direction constant, the optical system unit is provided on the back surface of the platen glass. On the other hand, a device has been proposed in which a roller is projected and urged against the platen glass (the focal length becomes constant along the shape of the platen.

[0010]

However, in the prior art as described above, in order to guarantee the right angle accuracy of the main scanning and the sub-scanning at the time of reading an image of the optical system unit, each component of the optical system unit is required. It is necessary to improve the dimensional accuracy of the support housing and the image reading means.

In particular, in the structure for reading an original placed on the original glass table, the number of intermediate parts interposed between the original and the image reading means increases, and the reading right-angle property deteriorates with general parts processing accuracy. Therefore, many copiers and image scanners perform complicated position adjustment in a number of assembling steps, and there is a drawback that the production cost due to the adjusting step increases.

Further, if the right-angle accuracy of the main scanning and the sub-scanning goes wrong during the use of the user, it is necessary to use a special tool or the like to make an adjustment, which improves the maintainability and maintainability. Was wanted.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and its object is to simply determine the right-angle accuracy of the main scanning and the sub-scanning without depending on the accuracy of parts or complicated assembly adjustment. An object of the present invention is to provide an image reading apparatus that can be performed with high accuracy and that does not require jigs and tools during adjustment.

[0014]

In order to achieve the above object, according to the present invention, there are provided an image reading means for performing main scanning of image information of a document and a base on which the image reading means is mounted. In an image reading apparatus having an optical unit that has a sub-scanning direction, the image reading unit includes a rotating shaft that can change an angle of the main scanning direction with respect to the sub-scanning direction, and the image reading unit has a predetermined angle. And fixing means for fixing the image reading means.

According to this, the angle of the main scanning direction with respect to the sub scanning direction can be easily changed by the rotating shaft, and can be fixed by the fixing means when a right angle is formed.

The image reading means has a linear image reading area which is parallel to the main scanning direction, and an arm member which extends from the image reading area in the sub scanning direction and has a rotary shaft at its tip end which is parallel to the main scanning direction. The base includes a bearing portion that supports the rotation shaft of the arm member, and a biasing unit that biases the image reading unit in the platen direction that supports the document. A pair of abutting positioning parts parallel to the main scanning direction are provided on both sides of one end in the sub-scanning direction, and the image reading means sets the main scanning direction by abutting on the abutting positioning parts. It is characterized in that it is provided with a contact portion.

According to this, the image reading means is rotated about the rotation axis and is biased following the platen, so that good image reading is performed, and the main scanning direction is achieved without using an adjusting jig. The position can be set.

It is also preferable that the abutment positioning portion is a mounting reference for the platen. According to this, by rotating the image reading means about the rotation axis, it becomes possible to align the positions of the abutting portion and the platen mounting reference, and the main scanning direction is made parallel to the platen mounting reference. Is possible.

It is also preferable to provide a driving means for moving the optical unit and a driving force connecting means capable of selectively connecting the driving force by the driving means.

According to this, the optical unit can be easily moved during the adjustment work, and the adjustment work can be performed smoothly.

An image forming apparatus is characterized by including the above-mentioned image reading apparatus and an image forming means for forming image information read by the image reading apparatus on a recording medium.

[0022]

DETAILED DESCRIPTION OF THE INVENTION

(Embodiment 1) FIG. 1 is a top view of an optical unit U1 of an image reading apparatus to which the present invention is applied, and FIG. 2 is a perspective view of a facsimile apparatus F1 equipped with the optical unit U1.

In FIG. 1 and FIG. 2, 28 is a contact type image sensor as an image reading means, which is equipped with an internal (not shown) long focus SELFOC lens and is focused on the platen glass 20 as a platen. It is set to meet. In addition, a light source (not shown) is provided inside,
It has a long focus and enables high-speed scanning up to 0.7 msec / line for main scanning.

Reference numeral 16 denotes a first supporting the image sensor 28.
Of the holding arm having the rotating shaft 5 at a position deviated from the center in the main scanning direction, and the fixing portion 17 on the opposite side to the center of the main scanning.
have. Reference numeral 15 denotes a second holding arm, which is pivotally supported on the carriage 3 at a fulcrum 15a and is connected to the first holding arm 16 by a rotating shaft 5 so that the image sensor 28 can rotate in a horizontal plane.

Reference numeral 17 denotes a fixing portion for fixing the first holding arm 16 and the second holding arm 15, and at the time of assembling this unit, a guide shaft 6 and an image sensor centering on the rotating shaft 5 by an unillustrated assembly jig. The right angle accuracy with 28,
The fixing portion 17 fixes the first holding arm 16 and the second holding arm 15.

Reference numeral 3 denotes a carriage that supports the first holding arm 16 at a fulcrum 15a so that the first holding arm 16 is rotatable in the vertical direction.
The fulcrum 15a is provided substantially in the center of the contact type image sensor 28 in the main scanning direction to balance the left and right. The distance from the fulcrum 15a to the reading line 28b is such that the contact type image sensor 28 is tilted in the sub-scanning direction and the illumination angle is deviated or the focal length is changed due to variations in dimensions. A fulcrum 15a is provided at a position 30 mm or more away from.

Reference numeral 1 denotes a height regulating portion, which is provided in a pair on the left and right sides of the casing of the contact image sensor 28. The height regulating member 1 made of a slidable resin defines a gap between the back surface of the platen glass 20 and the image sensor 28, and is always on the lower surface of the platen glass 20 even if the image sensor moves in the sub-scanning direction. Since they are in contact, the focal length can always be kept constant.

Further, with this configuration, it is possible to guarantee the focal length without requiring an assembly adjustment jig for assuring the focal length of the image sensor or a highly accurate component size.

The tip of the height regulating member 1 that comes into contact with the rear surface of the platen glass 20 is provided at a position outside the reading line in the main scanning direction. This prevents the image from being affected even when the tip of the height regulating member 1 comes into contact with the lower surface of the document table glass 20 and moves when the contact portion is worn and a contact mark is generated on the lower surface of the glass. This is because.

Reference numeral 7 is a timing belt for moving the carriage 3 in the sub-scanning direction, and 8 is a drive unit having a stepping motor. Reference numeral 2 denotes a fixing member (which is below the carriage 3 and is not shown) for fixing the timing belt 7 to the carriage 3. By attaching or detaching this fixing member 2, it becomes a driving force connecting means for connecting or disconnecting the driving force of the driving unit. Also, the frame 30
Is provided with a glass reference 30c as an abutting position determining portion that abuts the platen glass 20 to determine the position.

Since the entire width of the image sensor 28 in the main scanning direction is narrower than the width of the frame 30, when the original table glass 20 is detached, the image sensor stands still at a position where it springs out from the glass mounting surface of the frame 30 due to the spring force.

Since the image sensor 28 can be lifted by removing the platen glass 20, the belt fixing member 2 can be attached and detached.

After removing the belt fixing member 2, the carriage 3 can be moved on the guide shaft 6 by a small manual force, so that the belt fixing portion and the gear of the drive unit 8 are not destroyed. Therefore, a control board can be provided under the bottom surface of the frame 30 below the carriage 3, and consumable items such as an adjustment unit, ROM, and batteries necessary for maintenance of the apparatus can be arranged, and the apparatus has excellent maintainability. be able to.

10 is a flat cable, which is a frame 30
The contact type image sensor 28 is controlled by connecting a control board provided below the bottom surface of the image sensor 28 to the image sensor 28.

A contact type image sensor 28 is urged from below by the spring 4 on the back surface of the document table glass 20, and the contact type image sensor 28 on the optical unit and the upper surface of the document table glass 20 move in the sub-scanning direction. The distance between them is always kept constant.

In this structure, the optical unit U1 such as the height of the guide shaft 6 and the height of the rails 14 of the frame 30 is set.
It is possible to eliminate the influence of the focal length deviation by eliminating the factor that the position of fluctuates in the vertical direction. As a result, the component accuracy can be designed at the level of general intersection, so that the cost can be kept low.

The carriage 3 is supported slidably in the thrust direction (that is, the sub-scanning direction) with respect to the guide shaft 6 via bearings 3b and 3c. The bearing position is the contact type image sensor 28, the carriage 3, the height regulating portion 1,
It is provided at a position deviated from the center of gravity of the optical unit U1 composed of the biasing spring 4 in the main scanning direction.

A sliding member 13 is provided below the end of the carriage 3 in the direction opposite to the direction in which the bearing position is displaced. Both ends of the guide shaft 6 are frame 30
Fixedly supported horizontally. A slide rail 14 is provided on the frame 30 in parallel with the guide shaft 6,
When the carriage 3 moves along the guide shaft 6 in the sub scanning direction, the sliding member 13 comes into contact with the slide rail 14 and moves.

The focal length of the image sensor is the height control unit 1.
Therefore, the horizontal accuracy of the slide rail 14 and the guide shaft 6 is sufficient to be coarse.

Reference numeral 32 denotes a pressure plate, which can be opened and closed up and down, and a sheet document or a book placed on the document table glass 20 is biased from above to bring the read image surface of the document into close contact with the document table glass 20. It is what makes me.

Reference numeral 40 denotes a photo interrupter, which is a home position sensor (HPS: Home Posision Sensor) for detecting the reference position of the optical unit U1, and 41 is also a photo interrupter, which reaches the rightmost end after the optical unit U1 completes the sub-scanning. A right end position detection sensor (hereinafter, RES: Right End Sensor) that detects the limit position detects the infrared light shielding portion 3C provided on the carriage 3 together.

Reference numeral 42 denotes a sheet original feeding portion provided on the pressure plate 32, which moves up and down when the pressure plate 32 is opened and closed. The sheet document transport unit 42 sequentially separates a plurality of sheet documents stacked on the pressure plate 32 from the bottom and transports them to the sheet document reading position.

Next, the operation of this device will be described. First, after the power is turned on, the optical unit U1 is moved in the right direction (direction of the RES 41) regardless of the position of the optical unit U1. At this time, HPS
If 40 detects the presence of the optical unit U1, it is determined that "the optical unit U1 is between the HPS 40 and the RES 41", so the optical system is stopped with the detection position of the HPS 40 as the initial position. In addition, when the RES 41 detects the presence of the optical system, it is determined that “the optical unit U1 is at the RES 41 (book reading end position)”, so the drive unit 8 is reversed and the optical unit U1 is moved toward the HPS 40. After returning, when the HPS 40 detects the optical unit U1, the operation is stopped. As described above, regardless of the position of the optical unit U1, the initial position setting operation can be performed by first moving the optical unit U1 in the direction of the RES 41.

The RES 41 is provided for the carriage 3 in case the carriage 3 does not stop at the right end of the reading.
I'm watching overshoot. Even if it cannot be detected or the movement of the carriage 3 is hindered on the way, the belt fixing member 2 is elastically deformed to open the belt connecting portion, so that the device can be prevented from being destroyed.

Particularly, as a problem at the time of installation, a fixed part for transportation (not shown) is mounted on the carriage 3 when the apparatus is packed for transportation.
The belt fixing member 12 is elastically deformed so that the belt connecting portion may be damaged by forgetting to remove the fixing member for transportation before turning on the power at the time of installation. Since it is opened, destruction of the device can be prevented.

Further, the elastic deformation of the belt fixing member 12 prevents the inertial load generated during the movement of the carriage 3 from being transmitted to the gear of the drive unit 11 and generating the impact noise of the gear.

The amount of movement from the reference standby position HPS 40 to the reading front end position is determined by driving the drive unit from the HPS 40 by a predetermined number of steps stored in advance in the memory.

Further, the contact-type image sensor 1 which has moved has a possibility of being displaced due to an external impact, a vibration of the sheet scanner motor, the recording portion, etc., and therefore, the stepping used in the drive unit 11 is performed. Excitate (hold) the motor. At this time, if the maximum current is applied to each of the two phases, heat generation will increase.
At the time of holding and exciting, the current is reduced to about 30% to excite.

This method is required when the dedent torque of the stepping motor is small or the gear ratio of the drive system is small. When the dedent torque is large or the gear ratio is large. Since there is a large static force due to the moment of inertia of the contact-type image sensor 1 and the urging force to the platen glass 20, the hold due to motor excitation can be omitted.

In this case, since the motor control is released, the system only needs to control the sheet scanner motor (not shown), that is,
Since it is not necessary to control both motors at the same time, it is possible to perform control by having only one control circuit and switching the motors to be controlled, and it is possible to reduce costs compared to the case where two control circuits are provided.

When the destination dial number or the preset destination is selected by the one-touch key from the operation unit 33 (FIG. 3A), the contact image sensor 28 first sets a white background at the reference standby position. Prescan is performed, and the contact image sensor 28 starts moving in the document reading direction. When the HPS 40 is turned on, the number of motor steps is started to be counted, and after the contact image sensor 28 reaches the front end of the original to which the original is attached (the number of pulses is counted and stored in the nonvolatile memory in advance). (Judge by comparing with the number of pulses) Start reading and store in memory. After the reading is completed, the contact image sensor 28 is returned to the detection position of the HPS 40.

When the reading of the first page is completed, the display section displays the options of "a display prompting an instruction to read the next original" and "a display prompting an instruction to finish reading and send the data on the memory". If there is a second or subsequent page,
After the user replaces the original, the second page of the original is read by pressing the read instruction key. When the reading is completed and the data on the memory is transmitted, the data is transmitted by pressing the key for instructing the document transmission.

Further, when a plurality of sheet-shaped originals are continuously read, image information is read by the flow reading method using the ADF and the data is continuously transmitted.

(Second Embodiment) FIGS. 3 and 4 show a second embodiment of the present invention.
It is an embodiment of. The height regulating portions 1 provided at both ends of the image sensor 28 are further provided with protrusions 1b. The image sensor 28 projects from the upper surface of the frame 30 by the reaction force of the spring 4 when the document table glass 20 is removed. When the image sensor 28 is moved in this state, the protrusions 1b at both ends correspond to the glass reference 30c. When the platen glass 20 is placed, the protrusions are located below the glass butting part and therefore do not hit.

Since the belt fixing member 2 is removable,
After the belt fixing member 2 is removed to release the drive transmission of the carriage 3, the carriage 3 is moved to abut the projection 1b against the glass abutting portion 30c, whereby the image sensor 28 causes the first holding arm 16 and the second holding arm 16 to move. Holding arm 1
It rotates about the joint rotation shaft 5 of 5, and the parallel accuracy in the main scanning direction is obtained following the glass reference 30c.

By fixing the first holding arm 16 and the second holding arm 15 with the fixing portion 17 between them, the parallel accuracy of the glass abutting portion 30a and the image sensor 28 is guaranteed. Compared with the first embodiment, a jig / tool for obtaining the right angle accuracy between the guide shaft 6 and the image sensor 28 is not required, and the parallelism of the image sensor 28 can be easily adjusted even during maintenance at the user's site. effective.

(Third Embodiment) In contrast to the first and second embodiments in which the angle between the image sensor 28 and the carriage 3 is adjusted, in the third embodiment, the angle between the carriage 3 and the guide shaft 6 is adjusted. To do.

In FIG. 5, reference numeral 31 denotes a bearing, which has a fulcrum 31a at one end and a fixing portion 31b for the carriage 3 at the opposite end. At the fulcrum 31a of the bearing 31, the carriage 3 can be displaced by a small angle with respect to the guide shaft 6 in the horizontal plane, and after the right angle accuracy of the main scanning and the sub scanning is obtained, the carriage 3 to which the image sensor 28 is attached is attached. The small angle displacement is fixed by the fixed part 31b of the bearing.

[0059]

According to the present invention described above, the angle of the main scanning direction with respect to the sub-scanning direction can be easily changed by the rotating shaft, and the angle can be freely set and fixed. It can be fixed by means.

Since the image reading means is rotated about the rotation axis and is biased following the platen, good image reading is performed, and the perpendicularity in the main scanning direction is set without using an adjusting jig. Can be adjusted easily.

Since the abutting positioning portion serves as the platen mounting reference, the abutting portion and the platen mounting reference can be aligned, and the main scanning direction can be made parallel to the platen mounting reference. is there.

By providing the driving force connecting means, the optical unit can be easily moved during the adjustment work, and the adjustment work can be performed smoothly.

[Brief description of drawings]

FIG. 1 is a top view of an optical unit according to a first embodiment to which the present invention is applied.

FIG. 2 is an explanatory diagram of an image reading apparatus to which the present invention has been applied.

FIG. 3 is a diagram of an optical unit according to a second embodiment of the present invention.

FIG. 4 is a diagram of an optical unit according to a second embodiment of the present invention.

FIG. 5 is a perspective explanatory view of an optical unit according to a third embodiment.

FIG. 6 is a sectional configuration explanatory diagram of a conventional image reading apparatus.

[Explanation of symbols]

1 height regulation section 1b Abutment part 2 fixing members 3 carriage 3b, 3c bearings 4 biasing spring 5 rotation axis 6 Guide shaft 7 Timing belt 8 drive units 14 rails 15 Second holding arm 16 First holding arm 17 Fixed part 20 Platen glass 28 Image sensor (image reading means) 30 frames (device support case) 30c Glass standard (abutting positioning part) 32 pressure plate F1 facsimile machine U1 optical unit

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI H04N 1/107 (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 1/04-1/207

Claims (4)

(57) [Claims] 1. An image reading apparatus comprising an image reading unit for performing main scanning of image information of an original document and an optical unit having a base for mounting the image reading unit and moving in a sub-scanning direction. The image reading means is a line-shaped parallel to the main scanning direction.
The image reading area and the area extending from this image reading area in the sub-scanning direction.
It has a rotating shaft parallel to the main scanning direction at the tip end
An arm member, and the base is a bearing portion that supports a rotation shaft of the arm member.
The image reading means in the direction of the platen supporting the original.
In addition to the urging means for urging the device support housing , the device support housing is mounted on both sides of one end in the sub-scanning direction.
The image reading means includes a pair of abutting positioning portions that are parallel to the scanning direction, the image reading unit is configured to change the angle of the main scanning direction with respect to the sub-scanning direction, and the abutting position.
Abutment part whose main scanning direction is set by abutting on the deciding part
When the image reading apparatus, characterized in that a fixing means for fixing the image reading means at a predetermined angle. 2. The image reading apparatus according to claim 1 , wherein the abutting positioning portion is a platen attachment reference. And drive means for causing wherein moving the optical unit, or claim 1, characterized in that a driving force connection means making it possible to selectively connect the drive force by the drive means 2. The image reading device described in 2 . 4. An image comprising: the image reading device according to claim 1 , 2 or 3 , and an image forming means for forming image information read by the image reading device on a recording medium. Forming equipment.