JP2004013048A - Picture reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent influence, including vibration in accelerating a reader, vibration developed at a contact section against a guide member in travelling a movable frame or the like on read information by holding an optical reader-provided reading unit on the movable frame through elastic members. <P>SOLUTION: The picture of a manuscript set on a platen 3 is read by moving the reader 10 along the bottom of the platen 3 of the picture reader 1 by means of a reading means provided to a reading unit 20. Where, a reading unit 20 is supported through the elastic members 16, 17 or the like on the movable frame 11 to absorb the vibration developed by the travelling of the movable frame 11 by means of the elastic members. In addition, upper sliders 21 sliding on the bottom of the platen 3 are provided on the reading unit 20 to constantly retain spaced intervals with respect to the manuscript. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a reading device supporting means provided in an image reading device, and more particularly, to a device capable of supporting a reading unit so as not to receive vibration or the like due to movement of the reading device and moving the reading unit in a scanning direction.
[0002]
[Prior art]
In an image reading apparatus provided in combination with an image forming apparatus such as a facsimile machine or a copying machine, a reading apparatus that moves along the lower surface of a platen on which a document is set is provided, and the reading apparatus can be moved in the sub-scanning direction. It is assumed. The reading device may be configured as a single unit by combining a lamp as a light source and a plurality of mirrors, and an imaging lens and a photoelectric conversion unit such as a CCD. Then, by moving the reading device along the lower surface of the platen on which the document is placed, information on reading the image of the document is output as a digital signal. The digital signal transmitted from the reading device is used as a transmission signal in a facsimile device, and in a copying machine, is transmitted to a writing unit in an image recording unit and used to write optical information on a photoconductor. ing. To move the reading device of the image reading device, a guide member parallel to the moving direction of the reading device is arranged in the main body frame, the reading device is connected to the belt, and reciprocating along the lower surface of the platen. It is configured to be moved.
[0003]
[Problems to be solved by the invention]
In general, the speed of a reading device is increased stepwise by a stepping motor, and the speed is controlled so that reading is started after reaching a certain speed. When reading is started, the quality of the read image is affected by the quality. Conventionally, reading is started after a lapse of a predetermined time (time until the vibration stops) after the state of moving at a constant speed, so that a certain extra distance in the reading direction is provided. Therefore, there is a problem that the configuration of the apparatus becomes large by securing an extra space in the frame of the scanning apparatus. Further, in the reading device in which the scanning unit is configured as one unit, when the scanning unit is moved along the guide rod or the guide rail, the scanning unit moves between the guide surface of the guide member and the guided member. If the frictional state is not constant, there is a problem that the reading device is difficult to be guided smoothly. However, under the current situation in which the moving speed (scanning speed) of the reading device is increased, the driving device such as a pulse motor is stepped up, so that the influence of the vibration due to the change in the moving speed occurs more greatly. Therefore, the image information read by the reading device is affected by noise such as vibration applied to the reading device during the period from the start-up state to the constant speed movement, which affects the image quality. There is.
[0004]
According to the present invention, the reading unit is elastically held with respect to the moving frame of the reading device, so that the depth at the time of accelerating the reading device can be quickly converged. It is intended to provide a possible device.
[0005]
[Means for Solving the Problems]
The present invention relates to an image reading apparatus in which a reading apparatus is reciprocally movable along a lower part of a platen provided on an upper part of an apparatus main body. The invention according to claim 1 of the present invention is configured such that the reading device is connected to driving means, and a moving frame guided along guide means and a reading unit supported by the moving frame are combined, The reading unit is supported on the moving frame by using elastic support means.
[0006]
The invention according to claim 2 is characterized in that the elastic support means for supporting the reading unit with respect to the moving frame is provided downstream in the moving direction when the reading device is moved in the sub-scanning direction.
[0007]
The invention according to claim 3 is characterized in that an upper guide member for holding a mirror at a predetermined interval is provided on an upper portion of the reading unit with respect to a lower surface of the platen.
[0008]
With the configuration described above, even if vibration is applied to the moving frame during the reading operation, the vibration is not transmitted to the reading unit by the elastic member, so that the quality of the read image can be maintained satisfactorily. In addition, the elastic member supporting the reading unit can be satisfactorily utilized by arranging the elastic member at a position where the vibration or the like strongly transmitted to the reading unit is canceled. Then, the vibration at the time of accelerating the reading device can be quickly converged, and the influence of the vibration does not appear on the image quality, so that the device can be made compact. Further, the upper guide member provided in the reading unit is set so that the distance between the original and the optical system member does not change. In combination with the action of the elastic member, the reading unit is moved in a stable state, and the reading operation is performed. It can be performed.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
The configuration of the device of the present invention will be described with reference to the illustrated example. The example shown in FIG. 1 is a side view showing a configuration of an image reading apparatus. The image reading apparatus 1 is provided as a reading apparatus in a copying machine or a facsimile apparatus, or is configured to be used as a scanner of a personal computer. You. A platen 3 on which a document is placed is provided on an upper portion of the main body frame 2 of the image reading device 1, and a reading device 10 is provided so as to be able to reciprocate along the lower surface of the platen 3. In order to move the reading device 10 to read an image of a document, the reading device 10 is connected to a driving belt 5 such as a toothed belt stretched over a driving pulley 4 and a driven pulley 4a, and a guide rod 7 and other Guided by a guide member. The pulleys 4 and 4a at both ends for driving the driving belt 5 are provided on the main body frame using a conventionally known supporting means. The driving pulley 4 is driven by a driving source such as a stepping motor. , Provided in combination with any tension applying means.
[0010]
As shown in FIGS. 2 and 3, the reading device 10 combines a moving frame 11 and a reading unit 20 and supports the reading unit 20 with respect to the moving frame 11 via an elastic member. The moving frame 11 includes a rear guide member 12 and a front guide member 13 that are respectively guided by guide rods 7 and guide rails 8 provided on the main body frame 2, and a protruding member 15 that is connected to the drive belt 5. Are protruded from each other. The front-side guide member 13 corresponding to the guide rail 8 is provided with a slider 14 made of a material having a small coefficient of friction. An arbitrary sliding portion such as forming a sliding surface is guided on a guide rail 8 provided with a low friction member on the surface. Further, the rear guide member 12 provided corresponding to the guide rod 7 is treated so as to reduce the coefficient of friction between the two members so that the rear guide member 12 slides lightly with respect to the guide rod 7. It is configured as something.
[0011]
The reading unit 20 supported by the moving frame 11 is held by an elastic member with respect to the moving frame 11, and as shown in FIGS. Are supported using the elastic members 16,. As the elastic member, any elastic body such as a sponge can be used, but in addition, a coil spring or a block-shaped member made of soft rubber can be used. is there. Further, as shown in FIG. 3, the elastic member 18 can be arranged inside the moving frame 11 also in a direction orthogonal to the moving direction of the moving frame 11.
[0012]
The elastic member disposed between the moving frame 11 and the reading unit 20 basically includes a lower elastic member 17 for maintaining a constant distance between the platen 3 and the reading unit 20, and an acceleration member for scanning. It is preferable to provide an elastic member 16 whose operation is affected. In addition to this, another elastic member 18 and the like may be provided in order to stabilize the holding operation of the reading unit 20 in the moving frame 11. In addition, conditions such as the number of elastic members to be arranged in each section and the arrangement position may be such that a predetermined number of elastic members are arranged at predetermined positions so that no defect occurs in image information obtained by the reading device. .
[0013]
The reading unit 20 supported by the moving frame 11 is disposed on the reading unit by disposing an upper slider 21 as an upper guide member above the sliding unit and sliding the upper slider 21 on the lower surface of the platen 3. Among the members of the optical system, the distance from the first mirror 23 can be kept constant. The optical system device provided in the reading unit 20 is provided with a lamp 22 for irradiating the screen of the document, and a plurality of mirrors 23, 23a... To form an image on the CCD 25. The plurality of mirrors arranged in the reading unit 20 set the length of the optical path so that the light reflected from the image surface of the document can be focused on the CCD 25. However, in the illustrated example, the optical path is described as being simplified.
[0014]
In the reading unit 20, since the elastic member 17 is used to press the upper slider 21 against the platen 3, the upper slider 21 pressed against the platen 3 causes the image surface of the document and the first mirror 23 to move. The distance between them can be kept constant. Therefore, when the moving frame 11 holding the reading unit 20 is moved along the guide rod 7 and the guide rail 8, even if it is assumed that the guide surface of the The distance between the original and the first mirror 23 does not change due to the influence of the unevenness of the member, and the optical path length of the scanning light is kept constant.
[0015]
In the image reading apparatus 1 using the reading apparatus 10 configured as described above, an operator manually inputs document size information or uses a document size detecting unit or the like to detect a document set on the platen 3. The size information is set in the control device. Then, when the apparatus is operated by pressing an image reading button, the drive pulley 4 (shown in FIG. 1) is rotated, and the reading apparatus 10 is moved while gradually accelerating in the sub-scanning direction. From the position corresponding to the end position, reading is performed while moving the reading device 10 at a constant speed. When the reading device 10 reaches the end of the document and the reading operation is completed, a brake means (not shown) is actuated on the driving pulley, and then the driving pulley 4 is driven to rotate in the reverse direction. 10 is returned to the original standby position, and waits for the next reading operation.
[0016]
However, when the reading device 10 is driven, even if the acceleration signal is output from the control device and the motor is driven so that the speed becomes constant at the reading start position, even if the motor is driven until the reading start position is reached. Then, due to the action of gradually accelerating the speed of the reading device 10, vibration or the like due to the acceleration action may remain in the moving frame 11 and the reading unit 20 in some cases. Therefore, as shown in the present embodiment, the reading unit 20 is held by the elastic body with respect to the moving frame 11 so that the moving frame 11 can be supported by the moving frame 11 even when vibrations or the like are generated. The reading unit 20 is not affected by vibration or the like applied when the scanning device is accelerated.
[0017]
In the above embodiment, the shapes and structures of the moving frame 11 and the reading unit 20 constituting the reading device 10 and the arrangement positions of the elastic members are not limited to those disclosed in the embodiment. Can be changed according to the structure or the like. Also, the structure and shape of the guide member for guiding the moving frame 11 in the scanning direction, and the arrangement relationship of the members of the optical system arranged in the reading unit are appropriately changed as long as the same scanning characteristics as in the embodiment can be exerted. Is possible. Further, as a driving unit for driving the moving frame, any conventionally known mechanism can be used.
[0018]
【The invention's effect】
Since the apparatus of the present invention is configured as described above, even if vibration or the like is applied to the moving frame during the reading operation, the vibration is not transmitted to the reading unit by the elastic member. Good quality can be maintained. In addition, the elastic member supporting the reading unit can be satisfactorily utilized by arranging the elastic member at a position where the vibration or the like strongly transmitted to the reading unit is canceled. Then, the vibration at the time of accelerating the reading device can be quickly converged, and the influence of the vibration does not appear on the image quality, so that the device can be made compact. Furthermore, the upper guide member provided in the reading unit is set so that the distance between the original and the optical system member does not change. In combination with the action of the elastic member, the reading unit is moved in a stable state to perform the reading operation. It can be performed.
[Brief description of the drawings]
FIG. 1 is a side view illustrating a configuration of an image reading apparatus.
FIG. 2 is an explanatory diagram illustrating a configuration of a reading device.
FIG. 3 is a front view of the reading device.
[Explanation of symbols]
1 image reading device, 2 body frame, 3 platen,
4 pulley, 5 drive belt, 7 guide rod,
8 guide rail, 10 reading device, 11 moving frame,
12.13 guide member, 15 projecting member, 16-18 elastic member, 20 reading unit, 21 upper slider, 22 lamp,
23 mirrors, 24 lenses, 25 CCDs.

Claims (3)

An image reading apparatus in which a reading apparatus is reciprocally movable along a lower part of a platen provided on an upper part of an apparatus main body,
The reading device is connected to driving means, a moving frame guided along guide means, and a reading unit supported by the moving frame, is configured in combination,
An image reading apparatus, wherein the reading unit is supported on a moving frame by using elastic support means. 2. The image reading apparatus according to claim 1, wherein the elastic support means for supporting the reading unit with respect to the moving frame is provided downstream of the moving direction when the reading apparatus is moved in the sub-scanning direction. 2. The image reading apparatus according to claim 1, wherein an upper guide member for holding a mirror at a predetermined interval with respect to a lower surface of the platen is provided at an upper portion of the reading unit.

Images