JP2006049962A - Image reading apparatus and image forming apparatus provided with the image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reading apparatus with a simple configuration for reducing a disturbing wave radiation level and hardly affected by external noises and to provide an image forming apparatus provided with the image reading apparatus. <P>SOLUTION: The image reading apparatus for optically reading an original and acquiring the read result as image data is configured with: a conductive machine frame 2 made of a metal or the like; mobile frame bodies 4, 5 on which at least part of optical components relating to acquisition of the image data is mounted and provided movably with respect to the machine frame 2; and a connection member 21 for electrically interconnecting the machine frame and the mobile frames so as to bring the machine frame and the mobile frames to be nearly at equi-potential. The connection member 21 is provided to interconnect the machine frame and the mobile frames at least at an image reading start position. Through the configuration above, since the machine frame and the mobile frames can reach the equi-potential, the disturbance radiation level can be reduced and occurrence of malfunctions due to the external noises or the like can be suppressed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus and an image forming apparatus, and in particular, an image reading apparatus in which at least a part of optical components involved in acquiring image data is movably provided with respect to a machine frame, and the image reading apparatus. The present invention relates to an image forming apparatus provided.

  A flat bed type image reading apparatus mounted on an image forming apparatus such as a copying machine has one or two optical components such as a light source, a condensing lens, a mirror, a light receiving element, and a circuit board for controlling the optical component. The document is mounted on a moving frame, and the moving frame moves along the lower surface of the document table, whereby the document placed on the document table is acquired as image data.

  In the above configuration, the ground of the circuit board mounted on the movable frame body is electrically connected to the ground of the circuit board provided on the machine frame side (hereinafter referred to as the main body side) by wiring. In addition, when the image reading apparatus has a configuration in which the moving frame body and the metal machine frame are connected by a drive wire that drives the moving frame body, the ground of the circuit board on the moving frame body side becomes the moving frame body. The connection is grounded.

  However, a flexible flat cable or the like having a sufficient length that does not hinder the movement of the moving frame is used for the wiring. For this reason, the inductance, resistance, etc. of the wiring are interposed between the circuit board mounted on the movable frame and the ground of the main circuit board, and sufficient grounding cannot be obtained. In the grounding using the drive wire, since the drive wire is usually about 1 mm in diameter, the moving frame body is connected to the machine frame via the inductance and resistance of the drive wire. I could not get a good ground. As described above, since the circuit board on the mobile device frame side is insufficiently grounded, the circuit board has an increased level of interference wave radiation such as EMI (Electro Magnetic Interference), and conversely external noise such as static electricity. There was a problem that could cause malfunction.

As a countermeasure against the above-described problem, Patent Document 1 listed below includes a circuit board on the moving frame and a circuit board on the main body side in order to suppress radiation of interference waves and reception of external noise via the wiring. There has been proposed a configuration that eliminates wiring between the two. That is, a memory for storing information to be transmitted from the circuit board on the main body side to the circuit board on the moving frame body side and information to be transmitted from the circuit board on the moving frame body side to the circuit board on the main body side is mounted on the moving frame body. A connector that connects both boards only when the moving frame is in a specific position is provided, and when the connector is in a connected state, information is exchanged collectively, or the moving frame is wirelessly communicated. A configuration for exchanging information between a circuit board on the body side and a circuit board on the body side is disclosed.
Japanese Patent Laid-Open No. 2003-110821

  However, according to the configuration of Patent Document 1, a transmission / reception device that provides a large-capacity memory on the moving frame body or transmits and receives information between the circuit board on the main body side and the circuit board on the moving frame body side is provided. Therefore, there is a problem that the manufacturing cost increases and the control for acquiring the image data becomes complicated.

  The present invention has been proposed based on the above-described conventional circumstances, and reduces an interference wave radiation level with a simple configuration and is hardly affected by external noise, and an image including the image reading device. An object is to provide a forming apparatus.

  The present invention employs the following means in order to achieve the above object. That is, the present invention provides an image reading apparatus that optically reads a document and obtains it as image data, on which a conductive machine frame and at least a part of optical components involved in obtaining image data are mounted. A moving frame provided so as to be movable with respect to the frame, and a connecting member that electrically connects the machine frame and the moving frame and sets both to a substantially equipotential are provided.

  As the connection member, for example, a conductive plate having elasticity provided in the moving frame can be used, and the conductive plate is supported over the entire moving range of the moving frame. A configuration in which the side wall of the frame (side wall located in the main scanning direction) and / or the bottom surface of the machine frame is in contact can be employed.

  According to this configuration, since the moving frame and the machine frame are equipotential regardless of the position of the moving frame in the moving range, the interference wave radiation level can be reduced and malfunction due to external noise can be reduced. Etc. can be suppressed.

  On the other hand, especially in situations such as offices where the power of the image reading apparatus is always on, the standby state occupies most of the power on (for example, the moving frame is the image reading start position, etc.). In the home position), the radiation level and the resistance to external noise are problems.

  In such a case, the image reading start position of the flat bed method or the sheet-through method (image reading method in which the moving frame is fixed at a specific position and the document moves relative to the moving frame) is started. It is also possible to adopt a configuration in which the moving frame body and the machine frame are connected by a connecting member in at least one of the positions, preferably both.

  That is, the connecting member is formed of, for example, an elastic conductive plate provided on the moving frame, and the conductive plate moves when the moving frame is at a document reading start position where the reading of the document starts. It contacts the side wall (side wall located in the sub-scanning direction) of the machine frame located in the backward movement direction of the frame.

At this time, the sheet-through type image reading start position is set in the vicinity of the flat-bed type image reading start position, and the same conductive plate can be elastically deformed at both of the image reading start positions of both types. It is preferable to use a configuration that contacts the frame.
Of course, the image reading apparatus having the above-described configuration may be applied to an image forming apparatus such as a copying machine.

According to the present invention, the interference wave radiation level can be reduced with a simple configuration, and the influence of external noise can be reduced.
In addition, if the connection member connects the machine frame and the moving frame at least at the image reading start position, the interference wave radiation level in the standby state can be reduced and the influence of external noise can be reduced. .

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a schematic perspective view of an image reading apparatus according to the present invention, and FIG. 2 is a cross-sectional view of the image reading apparatus according to the present invention. FIG. 3 is a perspective view of a connection member applied to the image reading apparatus according to the present invention.

  As shown in FIGS. 1 and 2A, an image reading apparatus 1 according to the present invention includes a document table 3 on which an original is placed, and the other surface is made of a conductor such as metal. For example, it has a rectangular parallelepiped machine casing 2.

  In the machine frame 2, the first moving frame body 4 and the second moving frame body 5, for example, reciprocate in the long side direction of the machine frame 2 (hereinafter referred to as the sub-scanning direction) along the document table 3. It is movable and provided over the entire width in the short side direction (hereinafter referred to as the main scanning direction). Here, an arbitrary structure may be adopted as the mechanism for movably disposing both the moving frame bodies 4 and 5, for example, a cross section extending in the sub scanning direction on the side wall in the main scanning direction of the machine frame 2. In addition to providing a U-shaped guide rail, the moving frame bodies 4 and 5 are configured to slide in the guide rail at both ends in the main scanning direction, for example, to provide a sliding member made of a resin having a spherical bottom. Can be adopted.

  The first moving frame 4 is reflected by a linear light source 6 that emits light to the document table 3 and a document that is emitted from the linear light source 6 and then placed on the document table 3. The first mirror 7 that reflects the reflected light in the direction of the second moving frame 5 provided parallel to the document table 3 and on the backward movement side of the first moving frame 4 is the entire width in the main scanning direction. It is provided over.

  The second moving frame 5 includes a second mirror 8 that reflects the light reflected by the first mirror 7 of the first moving frame 4 downward 90 degrees, and a second mirror. A third mirror 9 that further reflects the light reflected by 8 by 90 degrees is provided over the entire width in the main scanning direction. That is, the light reflected by the first mirror 7 is reflected by the second and third mirrors 8 and 9 in the forward movement direction of the movable frame bodies 4 and 5.

The light reflected by the third mirror 9 of the second moving frame 5 is a CCD image arranged linearly in the main scanning direction in the machine frame 2 by the lens 10 provided in the traveling direction of the light. An image is formed on the image sensor 11 such as a sensor. Then, the light received by the image sensor 11 is converted into an electrical signal, and image data is acquired.
On the other hand, as shown in FIG. 1 and FIG. 2B, the first and second moving frame bodies 4 and 5 are provided with drive wires 12 for driving both moving frame bodies 4 and 5 in the main scanning direction. It is arrange | positioned at the both ends, respectively.

  One end of the drive wire 12 is fixed to a first fixing portion 13 disposed at an appropriate position on the bottom of the machine frame 2, and the other end is disposed on a return side wall of the machine frame 2. It is fixed to the fixing portion 14 via a tension applying spring 15. In addition, the drive wire 12 is arranged in order from the first fixed portion 13 side in turn in the main pulley in the main scanning direction of the second movable frame 5, the inner pulley of the double pulley 16, and the machine frame 2. Fixed pulley 17 rotatably provided on the forward side wall of the motor, a driving pulley 18 to which driving force from a motor as a driving means is transmitted, and a fixed pulley provided rotatably on the backward side wall of the machine frame 2. 19, wound around an outer pulley of a double pulley 16 provided on the second moving frame 5, and connected to a spring 15 of the second fixing portion 14.

  The first moving frame 4 is fixed to a drive wire 12 between the inner pulley of the double pulley 16 and the fixed pulley 17, and both moving frames 4 and 5 are moved from the image sensor 11 to the document. The optical path length to the original on the table 3 is configured to be moved while being kept constant.

  According to the present invention, in the image reading apparatus 1 configured as described above, when the first moving frame body 4 and the second moving frame body 5 are at a flatbed type document reading start position (hereinafter referred to as a home position). In addition, a conductive plate 21 (21a, 21b) made of stainless steel or the like, which is a connecting member for electrically connecting the return side wall of the machine frame 2 and the two moving frame bodies 4, 5 at the same potential, is first. The moving frame body 4 and the second moving frame body 5 are provided respectively.

  As shown in FIG. 3, the conductive plate 21 has a structure in which, for example, a plurality of cuts 22 are provided from one side of a rectangular plate material to the opposite side, and are divided by the cuts 22. The free end portion 24 of each branch portion 23 is bent in a U shape within a predetermined width from the tip thereof, and has a structure having elasticity in the reciprocating direction. Then, the base end portion 25 of the conductive plate 21 is fixed to the first and second moving frame bodies 4 and 5 with screws 26 in a state where the free end portion 24 is directed to the backward movement side.

  At this time, the length of the conductive plate 21a is slightly longer than the distance between the first moving frame 4 located at the home position and the backward movement side wall of the machine frame 2. The conductive plate 21a is attached, and when the first moving frame body 4 is located at the home position, the tip thereof is in contact with the side wall on the backward movement side. Similarly, the length of the conductive plate 21b is slightly longer than the distance between the second moving frame 5 located at the home position and the backward side wall of the machine frame 2 in the moving frame 5. When the conductive plate 21b is attached and the second moving frame body 5 is located at the home position, the tip thereof is in contact with the side wall on the backward movement side.

  With this configuration, when both the moving frame bodies 4 and 5 are located at the home position, the both moving frame bodies 4 and 5 are surely electrically connected to the machine casing 2 and can be equipotential. it can.

  In the example of FIG. 1, a state is shown in which the conductive plates 21 having the same width are arranged on the movable frame bodies 4 and 5 without overlapping each other. However, the entire width of the conductive plates 21 is preferably as wide as possible. In this way, when the conductive plate 21 connects the movable frame bodies 4 and 5 and the machine frame 2, it is possible to ensure that the machine frame 2 and the movable frame bodies 4 and 5 are equipotential. .

  As described above, according to the present invention, the moving frame bodies 4 and 5 in the home position are equipotential with the machine casing 2, so that the circuit board (light emission in the above example) is arranged on the moving frame body 4. By connecting the control board) to the movable frame 4 to obtain a good ground without passing through the inductance and resistance components, the interference wave radiation level is lowered and malfunctions due to external noise are caused. Can be reduced.

  Further, as shown in the cross-sectional view of FIG. 4, when the image reading apparatus 1 includes a sheet-through type automatic document feeder 30 in addition to the above configuration, the document reading start position A (here) of the automatic document feeder 30 Then, it is preferable that the specific position at which the moving frame body 4 is fixed at the time of document reading is set to a position where the moving frame bodies 4 and 5 are moved slightly forward from the home position. . In this way, at the sheet-through type document reading start position, the conductive plate 21 can connect the machine frame 2 and the movable frame bodies 4 and 5, and the conductive plate 21 is within the range where the conductive plate 21 can be elastically deformed. The machine frame 2 and the two moving frame bodies 4 and 5 at the position can be connected (shown by broken lines in FIG. 3). That is, even when the sheet-through type automatic document feeder 30 is in use, it is possible to ensure good grounding, reduce the interference wave radiation level, and improve the resistance to external noise.

  Further, as shown in FIG. 5, both the moving frame bodies 4 and 5 are electrically conductive in contact with the side wall in the main scanning direction of the machine frame 2 and / or the bottom surface of the machine frame 2 at a position that does not interfere with the optical path. With the configuration including the plate 31, good grounding can be ensured even during an operation of reading a document placed on the document table 3 by the flat bed method, and the interference wave radiation level can be reduced. At the same time, resistance to external noise can be improved. In this case, you may make it provide the said electrically conductive plate 21 which connects both the moving frame bodies 4 and 5 and the back side wall of the machine frame 2 as needed.

  In addition, the structure and arrangement | positioning of an electroconductive board demonstrated above show a specific example, and do not limit the technical scope of this invention. It is possible to design arbitrarily within the range where the effects of the present invention are exhibited.

In the above description, the two movements of the moving frame 4 on which the linear light source 6 and the first mirror 7 are mounted and the moving frame 5 on which the second and third mirrors 8 and 9 are mounted are provided. The image reading apparatus provided with the frame has been described. However, the image reading apparatus is not limited to the above configuration, and a configuration in which all the optical components are arranged on one moving frame or a linear shape on one moving frame. Even if the light source and the mirror are arranged and the image sensor acquires the light reflected by the mirror as image data, the same effect can be obtained.
Furthermore, the present invention can be applied not only to an image reading apparatus but also to an image forming apparatus such as a copying machine having an image reading function.

  The image reading apparatus according to the present invention has an effect that the interference wave radiation level can be reduced and the influence of external noise can be suppressed with a simple configuration, and the image reading apparatus and various devices including the image reading apparatus. Useful as.

1 is a schematic perspective view of an image reading apparatus according to the present invention. 1 is a cross-sectional view of an image forming apparatus according to the present invention. The perspective view which shows the connection member concerning this invention. Sectional drawing of the modification of the image forming apparatus concerning this invention. Sectional drawing of the modification of the image forming apparatus concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image reader 2 Machine frame 3 Document stand 4, 5 Moving frame body 6 Linear light source 7, 8, 9 Mirror 10 Lens array 11 Imaging element 12 Drive wire 21, 31 Conductive plate (connection member)

Claims (3)

In an image reading apparatus that optically reads a document and acquires it as image data,
A conductive machine frame,
At least a part of the optical components involved in the acquisition of the image data is mounted, and a moving frame provided to be movable with respect to the machine frame,
A connection member that electrically connects the machine frame and the moving frame body, and makes both substantially equipotential;
An image reading apparatus comprising:   The image reading apparatus according to claim 1, wherein the connection member electrically connects the moving frame and the machine frame at least when the moving frame is at a document reading start position where the reading of the document starts.   An image forming apparatus comprising the image reading apparatus according to claim 1.

Images