JPH09270896A - Image reader and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain excellent assembling performance with a compact configuration, to move the reader in the subscanning direction stably and to improve the maintenability for lower components or the like of an optical system unit, by arranging a connection section between a torque transmission member and an optical unit to a lower part of an image read means. SOLUTION: In the image reader provided with a close contact image sensor 1 as an image read means conducting main scanning for image information on an original, an optical unit U1 with the image sensor 1 mounted thereon and moved in the subscanning direction, a drive means to move the optical unit U1, and a timing belt 10 as a torque transmission member to tract the optical unit U1 with the drive means, a connection part between the timing belt 10 and the optical unit U1 is arranged under the image sensor 1. Thus, the connection part is arranged without being projected in the subscanning direction of the optical unit U1 and does not interfere the movement of the optical unit U1 in the subscanning direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is applicable to an image reading apparatus and an image forming apparatus, and is characterized by the configuration of an optical unit equipped with image reading means. Examples of specific applied products include image scanners, facsimile machines, and copying machines.

[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. FIG.
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
A stop reading method of reading one by one, a fast reading of a plurality of sheet-like originals, and a scanning reading method of 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 when an image of a document such as a book that cannot be scanned by the operator is placed on the platen 104, in the image reading area of the platen 104 from P102 to P103, 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, a wire is generally used as a mechanism for moving the optical system unit, and there are many parts and adjustment points, and the platen of the optical system unit is used. The holding mechanism for maintaining a constant focal length with respect to is also of a complicated structure and has a low assemblability, so that there is a drawback that the optical system unit becomes large and cannot be constructed at low cost.

Further, in the moving mechanism of the optical system unit using the timing belt, it is necessary to manually move the optical system unit for maintenance work or the like, and there is a possibility that the fixing portion of the belt or the driving gear may be damaged. . It is possible to remove the timing belt so that it will not be damaged, but it is necessary to install the connection part between the optical system unit and the timing belt at a position accessible by the operator, which may cause the device size to increase by protruding from the optical system unit. I was getting tired.

The present invention has been made to solve the above-mentioned problems of the prior art. The object of the present invention is to make it possible to perform stable movement in the sub-scanning direction with a compact structure, and to provide an optical system. Another object is to improve the maintainability of components below the unit and to provide an optical system unit that is easy to assemble.

[0013]

In order to achieve the above object, according to the present invention, an image reading means for performing main scanning of image information of an original, and an image reading means for mounting the image reading means in the sub-scanning direction. An image reading apparatus comprising: a moving optical unit; a driving unit for moving the optical unit; and a driving force transmitting member that pulls the optical unit by the driving unit, the driving force transmitting member and the optical unit. The connecting part of is arranged below the image reading means.

According to this, the connecting portion can be arranged without protruding from the sub-scanning direction of the optical unit, and the movement of the optical unit in the sub-scanning direction is not hindered. In other words, the width of the optical unit in the sub-scanning direction can be reduced, and the image forming apparatus can be made compact.

The optical unit has a linear sliding means located in the vicinity of the position of the center of gravity in the main scanning direction with the sub-scanning direction as the axial direction, and is located at the end of the optical unit relative to the center of gravity of the linear unit. Equipped with a base supported by a track
The distance in the main scanning direction between the connecting portion of the driving force transmitting means and the linear sliding means is shorter than the maximum width of the optical unit in the sub scanning direction.

According to this, since the vicinity of the center of gravity of the optical unit is pulled, generation of a moment acting in the direction of rotating the optical unit when pulling is small, and smooth movement in the sub-scanning direction without galling or chattering is performed. be able to.

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. And a urging means for urging the image reading means in the platen direction for supporting the original document. .

According to this, since the image reading means is rotated about the rotation shaft and is biased following the platen, good image reading is performed, and when the platen is largely detached and largely opened, The connection part under the image reading means is exposed.

It is also preferable that the driving force transmission member is a toothed timing belt.

The connecting portion between the driving force transmitting member and the optical unit is located at a position opposed to an abutting portion which is provided on the base and which receives the back surface of the belt, through the toothed timing belt. And a fixing member that has a fitting portion that fits with the tooth flank of the belt and that is detachably attached to the base.

According to this, the timing belt can be easily connected / disconnected by the fixing member.

The fixing member is characterized by using an elastic material that causes a tooth jump at the fitting portion when an excessive load is applied to the optical unit.

Therefore, the inertial load of the moving optical unit is absorbed, and the damage of the device itself is prevented even if an excessive load is applied.

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.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) The present invention will be described below as an embodiment shown in the drawings. FIG. 1 shows an optical unit U1 to which the present invention is applied.
2 is a perspective view of FIG. 2, and FIG. 2 is a flat-bed type scanner SC as an image reading apparatus equipped with the optical unit U1.
1 is a perspective view and FIG. 3 is a flatbed scanner S of the same.
FIG. 9 is a perspective view of a facsimile device F1 equipped with C1.

In FIGS. 1 and 2, reference numeral 1 denotes a contact type image sensor as an image reading means, which has a long focus SELFOC lens (not shown) inside and is provided on the surface of a platen glass 20 as a platen. It is set to be in focus. Further, a light source (not shown) is provided inside, and a long focus and high-speed scanning up to a main scanning speed of 0.7 msec / 1ine are possible.

Reference numeral 2 is an arm member for holding the contact image sensor 1, and 3 is a carriage as a base on which the arm member 2 can be rotatably supported in a vertical direction by a rotary shaft 4 serving as a fulcrum. .

The arm member 2 is provided substantially at the center of the contact type image sensor 1 in the main scanning direction, and has a left-right balance. The distance from the rotary shaft 4 to the reading line L1 in the reading area for performing the main scanning of the original of the contact image sensor 1 is tilted in the sub-scan direction due to variations in the dimensions of each component. In order to prevent the illumination angle from deviating and the focal length from changing, the distance from the reading line L1 of the contact image sensor 1 is a predetermined distance (about 30 mm) or more.

Reference numerals 5a and 5b denote height adjusting members, which are provided on the housing of the contact image sensor 1 in a pair of left and right. As shown in FIG. 4, the height adjusting members 5a and 5b made of a slidable resin have a gap between the back surface of the original platen glass 20 and the image sensor 1, that is, a height for keeping the focal length constant. There is a restricting portion 5c, and by tightening a screw 5d for fastening the height adjusting members 5a and 5b to the contact image sensor 1, the height restricting portion 1b rotates clockwise and contacts the upper surface 1a of the image sensor 1. The height dimension can be regulated without any gap.

The height adjusting members 5a and 5b are the height regulating portion 5
The leading end of c is provided outside the main scanning range of the reading line L1. This is because even when the tip of the height regulating portion 5c comes into contact with the lower surface of the platen glass 20 and moves, the contact portion is abraded and a contact mark is generated on the lower surface of the platen glass 20, which affects the read image. This is to prevent it from reaching.

The biasing springs 6a and 6b as biasing means are arranged on the carriage 3 and elastically support the contact type image sensor 1 which is supported so as to be rotated by the rotating shaft 4 in the direction of the original glass 20. are doing.

The carriage 3 is slidably supported in the thrust direction (that is, the sub-scanning direction) with respect to the guide shaft 8 as the linear sliding means via the bearings 7a and 7b. The bearing position is provided at a position slightly deviated from the center of gravity in the vicinity of the center of gravity of the optical unit U1 including the contact image sensor 1, the carriage 3, the adjusting members 5a and 5b, and the biasing springs 6a and 6b in the main scanning direction. ing.

A sliding member 9 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 8 are the scanner SC1.
The frame 21 is horizontally fixed and supported. Frame 21
Is provided with a slide rail 22 as a track parallel to the guide shaft, and the height is set so that the contact type image sensor 1 is kept horizontal by the sliding member 9 contacting the slide rail 22. When the carriage 3 moves along the guide shaft 8 in the sub scanning direction, the sliding member 9 comes into contact with the slide rail 22 and moves.

Reference numeral 10 is a timing belt as a driving force transmitting means for moving the carriage 3 in the sub-scanning direction, and 11 is a driving unit equipped with a stepping motor. 12
Is a fixing member for fixing the timing belt 10 to the carriage 3. The surface contacting the timing belt 10 is a belt at an interval which is an integral multiple of the pitch of the timing belt 10 which functions as a fitting portion for fitting with the tooth flank of the belt. At least two convex portions parallel to the peaks are provided, and the fixing member 12 is made of a resin material having high rigidity but elasticity (Young's modulus of 2500 kgf / mm ² or less).

The carriage 3 has an opening 3a, which serves as an abutting portion for receiving the back surface of the belt so that the fixing member 12 can urge and fix the belt when the fixing member 12 is brought into contact with the timing belt 10 through the carriage opening 3a. There is a fixed portion 3b, which is slightly inclined so that it is free to bite. Further, by configuring the belt fixing member 12 with an elastic body, even if the carriage should move out of the sub-scanning area and reach the end of the frame 21, the belt fixing member 12 is elastically deformed to open the belt 10 ( It also has a function to prevent damage to the belt connection.

Reference numeral 20 denotes a document table glass, the width (depth direction) of which is larger than the entire width of the contact image sensor 1, and the document image glass 1 is removed to allow the contact image sensor 1 to rotate about the rotation axis 4. Since the belt fixing member 12 can be rotated and lifted, the belt fixing member 12 can be easily attached and detached.

After removing the belt fixing member 12, the carriage 3 can be moved on the guide shaft 8 by a light force manually by the operator, so that the belt connecting portion and the drive unit 11 are not damaged. Therefore, since the control board 22 and the like are provided below the carriage 3 and the adjusting parts and the consumable items such as the ROM and the battery necessary for the maintenance of the device can be arranged, the device maintainability can be improved. .

Reference numeral 23 is a flat cable, which is used for the frame 20.
The control board 22 provided on the bottom surface of the contact type image sensor 1 is connected to the contact type image sensor 1 to control the transmission of information from the contact type image sensor 1.

Further, the contact type image sensor 1 is biased from below on the back surface of the platen glass 20, and the contact type image sensor 1 on the optical unit U1 and the upper surface of the platen glass 20 are moved 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 8 and the rail 22 of the frame 21 is adjusted.
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.

A photo interrupter 24 is a home position sensor (hereinafter referred to as HPS 24: Home Posision Sensor) 25 for detecting the reference position of the optical unit U1.
Similarly, a photo interrupter is a right end position detection sensor (hereinafter, RES25: Right End Sensor) that detects a limit position where the optical unit U1 finishes the sub-scanning and reaches the rightmost end.
Then, the infrared light shielding portion 26 provided on the carriage 3 is detected.

A schematic configuration of the facsimile apparatus F1 having the scanner SC1 will be described with reference to FIG. The facsimile apparatus F1 is equipped with an ADF 31 (auto document feeder) similar to that described in the section of the related art, and FIG. 3A shows a state in which the ADF 31 is closed, and FIG.
(B) is a state in which the ADF 31 is opened. With respect to the configuration and operation of the ADF 31, there is no characteristic part that has been changed from the conventional technique, and therefore its explanation is omitted.

Reference numeral 32 denotes a pressure plate, which has a slight flexibility and biases a sheet document or book placed on the platen glass 20 from above so that the read image surface of the document is placed on the platen glass 20. It is what makes them adhere.

Next, the operation of this device will be described. First, after the power is turned on, the optical unit U1 is moved to the right (in the direction of RES25) regardless of the position. At this time, HPS
If 24 detects the presence of the optical unit U1, it is determined that "the optical unit U1 is between the HPS 24 and the RES 25", so the optical system is stopped with the detection position of the HPS 24 as the initial position. Further, when the RES 25 detects the presence of the optical system, it is determined that “the optical unit U1 is at the RES 25 (book reading end position)”, so that the drive unit 11 is inverted and the optical unit U1 is moved to the HPS 24.
Then, when the HPS 24 detects the optical unit U1, the operation is stopped. From the above, the optical unit U1
Regardless of the position, the initial position setting operation can be performed by first moving in the direction of RES25.

The RES 25 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 12 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 attached to 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 HPS 24, which is the reference standby position, to the reading leading end position is determined by driving the drive unit from the HPS 24 by a predetermined number of steps stored in advance in the memory.

Further, since the contact type image sensor 1 which has finished moving may be displaced due to an external impact, a vibration of the sheet scanner motor, a recording portion, etc., the stepping employed 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.

Further, this method is necessary when the dedent torque of the stepping motor is small or the gear ratio of the drive system is small, and 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 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 control of the motor 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. 3 (a)), the contact image sensor 1 first displays a white background at the reference standby position. Prescan is performed, and the contact image sensor 1 starts moving in the document reading direction. When the HPS 24 is turned on, the number of motor steps is started to be counted, and after the contact type image sensor 1 reaches the front end of the document on which the document 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 reading, the image sensor 1 is set to HPS.
Return to the detection position of 24.

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.

When a plurality of sheet originals are continuously read, the ADF 31 is used to read the image information by the flow reading method and the data is continuously transmitted.

(Second Embodiment) FIG. 7 is a diagram for explaining a second embodiment of the present invention. A roller 43 is provided at the end of the arm member 42 that supports the contact image sensor 1, and both ends of the shaft of the roller 43 are supported by biasing springs 44a and 44b. The diameter of the roller 43 is set to be substantially the same as the height of the tip of the height restricting portions 5a and 5b when the image sensor 1 is supported horizontally.

The three vertices of the roller 43 at the center of the sensor supported by the urging springs 44a and 44b and the height regulating portions 5c of the adjusting members 5a and 5b at both ends of the sensor are abutted against the back surface of the original glass 20. The image sensor 1 can perform the sub-scan while keeping the horizontal. In contrast to the configuration described in the first embodiment, the configuration of the second embodiment can configure an optical system unit without tilting the image sensor 1 even if the length of the arm member 42 is short. Thereby, the size of the optical system unit can be further reduced.

[0058]

According to the present invention described above, the width of the optical unit in the sub-scanning direction can be narrowed, and the image forming apparatus can be made compact.

When the optical unit is moved in the sub-scanning direction, smooth movement in the sub-scanning direction without galling or chattering can be performed, and good image reading can be performed.

Since the image reading means rotates about the rotation axis and is urged following the platen, good image reading is performed, and when the platen is detached and largely opened, the image reading means The connection portion on the side can be exposed, and the maintainability of the components below the optical system unit is improved.

The timing belt can be easily connected / disconnected by the fixing member.

By using the elastic member as the fixing member, the inertial load of the moving optical unit is absorbed, and the device itself is prevented from being damaged even if an excessive load is applied.

[Brief description of drawings]

FIG. 1 is a perspective explanatory view of an optical unit 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 an explanatory diagram of a facsimile apparatus to which the present invention is applied.

FIG. 4 is a view of a height regulation unit.

FIG. 5 is a perspective explanatory view of the optical unit according to the second embodiment.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Contact image sensor (image reading means) 2 Arm member 3 Carriage 4 Rotating shafts 5a, 5b Adjusting member 5c Height regulating part 6 Energizing springs (energizing means) 7a, 7b Bearing 8 Guide shaft 9 Sliding member 10 Timing belt (driving force transmitting member) 11 Driving unit (driving means) 12 Fixing member U1 Optical unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H04N 1/028 H04N 1/028 B

Claims (7)

[Claims] 1. An image reading unit for performing main scanning of image information of a document, an optical unit for mounting the image reading unit and moving in the sub-scanning direction, a driving unit for moving the optical unit, and this driving unit. An image reading apparatus comprising: a driving force transmitting member that pulls the optical unit by means of an image reading device, wherein a connecting portion between the driving force transmitting member and the optical unit is arranged below the image reading unit. apparatus. 2. The optical unit comprises a linear sliding means located in the vicinity of the center of gravity in the main scanning direction with the sub-scanning direction as the axial direction, and an end portion on the center of gravity side of the optical unit with respect to the linear sliding means. A base supported by an orbit positioned at, and the distance in the main scanning direction between the connecting portion of the driving force transmitting means and the linear sliding means is shorter than the maximum width in the sub scanning direction of the optical unit. The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus. 3. The image reading unit has a linear image reading area parallel to the main scanning direction, and a rotary shaft extending from the image reading area in the sub scanning direction and parallel to the main scanning direction at the tip. An arm member is provided, and the base is provided with a bearing portion that supports a rotating shaft of the arm member, and a biasing means that biases the image reading means toward a platen that supports a document. Claim 2
The image reading device according to claim 1. 4. The image reading device according to claim 1, wherein the driving force transmitting member is a toothed timing belt. 5. The connecting portion between the drive force transmitting member and the optical unit faces a contact portion that is provided on the base and receives a back surface of the belt, and the contact portion faces the contact portion through the toothed timing belt. The image reading apparatus according to claim 4, further comprising: a fixing member that has a fitting portion that fits with a tooth surface of the belt at a position, and is detachably attached to the base. 6. The elastic member is used for the fixing member, which causes a tooth jump at a fitting portion when an excessive load is applied to the optical unit.
The image reading device according to claim 1. 7. An image reading apparatus according to any one of claims 1 to 6, and an image forming means for forming image information read by the image reading apparatus on a recording medium. A characteristic image forming apparatus.