JPH02100567A - Original reader - Google Patents

Abstract

PURPOSE:To surely support a wiring cable in a stable state at the time to move a reading part, and to prevent the disturbance of a picture due to a noise at the time of movement, etc., by providing a planar supporting member constituted of elastic material for supporting a flat cable. CONSTITUTION:A main scanning pedestal 1 supports an image forming lens L and a CCD 20 as a light receiving part, etc., and reciprocates on a pair of rails 2a, 2b of a subscanning part U installed in a main scanning direction (arrow mark A or B direction). When the main scanning rack 1 is moved in the direction of the arrow mark A, and reading by the CCD 20 is performed, a main scanning pedestal 1 is driven by a spring 7, and since the vibration of a wire 6 due to the vibration caused by a stepping motor M or the vibration by resonance with the vibration is absorbed by the spring 7, the vibration of the wire 6 is not transmitted to the main scanning rack 1. The flat cables C1, C2, C3 wired from the prescribed parts of a device main body are fixed to a bottom plate by fixtures 26, and fixed so as to be adhered tightly to a back plate 27 as the supporting member constituted of a metal plate (phosphorus bronze or stainless steel) with elasticity.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is applied to a reading optical system of a copying machine, or a copying machine,
The present invention relates to a document reading device connected to a printer or the like, and particularly to a document reading device equipped with a reading section that moves to guide an optical image of the document to a light receiving section.

(Prior Art) In recent years, copying machines have replaced the so-called analog copying machines, which form images by guiding the light image of the original onto a photoreceptor, by reading the original image using a reading means such as a COD image sensor The number of so-called digital copying machines that are composed of a document reading device that outputs a signal and a printer that forms a document image on recording paper in accordance with the electrical signal is increasing.

Conventionally, in such document reading devices, from the viewpoint of availability and cost reduction, as shown in FIG. 12, a very short C.
A CD is used as the reading means 100. When reading an image of a document, the reading device 100 is moved in the arrow Y direction (main scanning direction) while illuminating the document to read a predetermined area, and then the reading device 100 is moved in the arrow X direction (sub scanning direction). The entire surface of the document is read by repeating the operation of moving the scanner in the scanning direction and reading the next area. By adopting such a configuration, it is possible to provide a lightweight, compact, and inexpensive device.

(Problem to be Solved by the Invention) By the way, in such a conventional example, the reading means 10
0 is built into the reading section along with the illumination lamp, lens, etc., and since this reading section moves vertically and horizontally as mentioned above, it is necessary to use safe, compact and durable wiring (power supply, signal supply) for the reading section. It is necessary to carry out (receipt, delivery, etc.).

However, in the past, in order to prevent excess force from being applied to the wiring cables, the cables were routed by hanging them down at the bottom of the equipment over a fairly long distance. Since each device was designed, extra space was required for each, resulting in an increase in the size of the device.

In addition, especially when reading large-sized manuscripts such as A1,
This also had the disadvantage that the cable had a wider area to crawl over, making the stiffness and stiffness of the cable inconsistent, making the reading unit run unstable and affecting the image.

Furthermore, in the conventional example described above, the cable may rub against other members, which causes wear on the cable sheath and core wire, causing short circuits and malfunctions.

In addition, in the conventional example, there was a problem in that the read image was disturbed by noise caused by the movement of the reading unit or noise from the outside.

Therefore, the present invention has been made to solve the problems of the prior art described above, and its purpose is to reliably support the distribution cable in a stable state when moving the reading section. It is an object of the present invention to provide a small-sized document reading device that can prevent image distortion caused by noise during movement.

(Means for solving problems) In order to achieve this objective, the present invention has the following objectives.

In a document reading device that moves at a predetermined speed a reading section that has a reading optical system and is wired to electrical components of the reading optical system using a flat cable in order to guide a light image of the document to a light receiving section. A plate-shaped support member made of a conductive elastic material is arranged in a bent state in the moving direction of the reading unit to support the flat cable extending from the reading unit,
Furthermore, the reading section is grounded by connecting the supporting member to the reading section.

(Function) In the present invention having the above configuration, since the plate-shaped support member that supports the flat cable is provided, the moving area of the flat cable extending from the reading section is restricted, and when the reading section moves, the plate-shaped support member is provided. In addition, the flat cable is prevented from protruding into unexpected areas or coming into contact with other members. in this case.

The support member is bent in the direction of movement of the reading unit, so it does not interfere with the movement of the reading unit, and the flat cable is always kept in the same bent wiring state regardless of its stiffness. can do.

Furthermore, since the reading section is grounded by connecting the conductive support member to the reading section, the reading section is in a grounded state not only when stopped but also when moving.

(Example〕 The present invention will be explained below based on illustrated embodiments.

1 and 2 are a plan view and a perspective view showing essential parts of an embodiment of a document reading device according to the present invention. As shown in the figure, the main scanning table l of this embodiment is provided on the sub-scanning section U, and these constitute a reading section. The main scanning table 1 is mounted so as to be movable within a plane parallel to the document surface by the following configuration. First, the main scanning table 1 holds a lens L for imaging, a C0D20 as a light receiving section, etc., and has a pair of rails 2a, 2b in a sub-scanning section U provided in the main scanning direction (direction of arrow A or B). move back and forth above.

This rail 2a.

2b is held between the sub-scan front side plate 3 and the rear side plate 4. Then, main scanning for one line is performed by moving the main scanning table l back and forth in the directions of arrows A and B on these rails 2a and 2b. In this case, the reciprocating drive is performed by the wire pulley 5 and the pulley 22 press-fitted into the stepping motor M.
This is done by moving the wire 6 that is wound around the main scanning table 1 and connected to the main scanning table 1.

In this embodiment, the wire 6 is connected to the main scanning table 1 from both sides in the main scanning direction, and in this case, the spring 7 and the tension spring 8 having a predetermined spring constant are used.
is interposed.

Then, move the main scanning table 1 in the direction of arrow A to scan the CCD 20.
When performing reading, the main scanning table l is driven by the spring 7, and the vibration of the wire 6 caused by the vibration generated by the stepping motor M or resonance with this vibration is absorbed by the spring 7, so that the vibration of the wire 6 is It is not transmitted to the main scanning platform l.

Therefore, the main scanning table 1 moves smoothly along the rails 2a and 2b, and no vibration occurs in the CCD 20, so that a clear read image without expansion or contraction can be obtained. The tension spring 8 provided in the direction of arrow B is a weak spring that is almost the same as the spring 7, and is used to absorb the shock at the start of driving and the long-term elongation of the wire 6. Also, 19
is a fixing plate for fixing the spring 7 when the spring 7 and the tension spring 8 are stretched.

The sub-scanning front and rear side plates 3.4 are placed on a pair of sub-rails 9 provided in the sub-scanning direction (arrow C or D direction). Each time a main scan is performed, the motor 16 is rotated, and the rotation of the small pulley 15 is transmitted to the large pulley 13 by the timing belt 14 to rotate the sub-scanning wire pulley 12, and the pulley 12 and the sub-scanning front and rear side plates 3 are rotated. , 4 connected to wire 1
0°11 to move these front and rear side plates 3.4 in the direction of arrow C. Conventionally, it has been said that if the drive side is reciprocated via an elastic body such as a spring, uneven reading will occur due to transient vibrations, but if springs 7 and 8 are selected with an appropriate spring constant, , it is possible to smoothly move the main scanning table 1 without causing this unevenness.

In addition, in FIG. 2, Sl is a sensor that detects the stop position of the main scanning table 1. The scanning of the main scanning table 1 starts from this position, and the document is read from the position of the sensor S2 provided near the sensor S1. Start. Furthermore, S3 is a sensor that detects the stop position (home position) of the main scanning table I in the sub-scanning direction, and is designed to detect the end of the sub-scanning section U as shown in FIG.

By the way, in an apparatus having such a configuration, the lamp 33 and the C0D 20 provided on the moving main scanning table 1 are
It is necessary to wire the electrical components such as those to supply power and exchange signals.

One way to supply power to moving objects is to use flat cables, which are made of multiple ribbon-shaped cords coated with vinyl or rubber, or flexible films, which have copper wires printed on the film (hereinafter collectively referred to as flat cables). However, digital and color reading requires a large number of signal lines, and also requires multiple cables with different pitches and thicknesses to match the elements and connectors used. The space for wiring made the device configuration difficult.

3 is a perspective view clearly showing the vicinity of the part to which the flat cable is connected, FIG. 4 is a view taken in the Q direction in FIG. 3, and FIG. 5 is a view taken in the R direction in FIG. 3.

As shown in the figure, the flat cables CI, C2, and C3 wired from a predetermined part of the device main body are fixed to the bottom plate O by a fixture 26, and are made from an elastic metal plate (phosphor bronze, stainless steel, etc.). Back plate 2 as a supporting member
The back plate 27 is fixed to the upper surface of the fixture 26 with screws Nl. The back plate 27 and the flat cables C1 to C3 are fixed to the bottom part 25a of the cable guide 25, which is made of metal and has a substantially U-shaped cross section, by a fixing member 28 while drawing an arc in the sub-scanning direction. In this case, the flat cable Cl-C5 is folded back in the direction of arrow A at the left end of the cable guide 25 at an angle of approximately 90 degrees. As shown in FIG. 1, the cable guide 25 extends in the main scanning direction and is fixed to the sub-scanning front and rear side plates 3.4, and is adapted to move in the direction of arrow C or D together with the sub-scanning section U. There is. In this case, the cable guide 25 is provided in the ψ range where it does not interfere with the movement of the main scanning table 1 in the main scanning direction. Therefore, the main scanning table 1 and the cable guide 25 do not come into contact with each other, and this will not cause a malfunction.

The flat cable C3 has a wiring cord C3a connected to the motor 21 for adjusting the length of the spring 7 near the left end of the cable guide 25, and a wiring cord C3b connected to the stepping motor M.
It is divided into two parts. Note that 29 is a stopper for fixing the wiring cord C3 at the right end of the cable kite 25.

The flat cable C2 wired to the main scanning table l is fixed near the approximate center of the cable guide 25 with a fixture 30 together with a back plate 31 as a support member similar to the back plate 27 described above. Regarding this fixed part, as in the case of the above-mentioned fixing device 26, flat cables CI and C2 are attached to the bottom surface of the fixing device 30.
is fixed, and on the other hand, the back plate 31 is fixed to the upper surface of the fixture 30 using screws N2 (see FIG. 5). This matter will be discussed later. And flat cable CI.

C2 and the back plate 31 are folded back in the main scanning direction (direction of arrow B) as shown in FIG. Fan 34 for flat cable C2
The wiring code is divided into the wiring code to the lamp 33 and the wiring code to the lamp 33. The flat cable C1 is connected to the wiring guide 3 as shown in the diagram.
5 and is connected to the lower printed circuit board PCB via connectors 36 and 37.

The width of the U-shaped cable guide 25 should be slightly wider than the width of the flat cables 01 to C3. With this configuration, the flat cables 01 to C3 are supported by the bottom surface 25a of the cable guide 25.
Even while the main scanning table 1 is moving in the main scanning direction, power is supplied without rubbing against the bottom plate O or the like. Note that the flat cable 01 that extends upward from the cable guide 25 is
~ Even when the bending state of C3 is disturbed and slightly shifted as shown by the two-dot chain line in Fig. 4, it is smoothly guided and the guide 25
This is to ensure that it fits within the In this case, depending on the wiring method, the flat cable may
Since it rubs against the cable guides 25 on both sides, the sheath may wear out, and the core wire may come into contact with the metal cable guides 25, resulting in a short circuit or an inability to exchange signals. Therefore, in this embodiment, in order to prevent such a failure from occurring, the wiring cords C1a and C1 at both ends of the widest flat cable C1 are arranged as shown in FIG.
1b on the bottom plate O side and main scanning table 1 side with screw N3,
They are each fixed with N4 so that they have the same potential as the bottom plate O. Therefore, even if the coating of the wiring cords C1a and C1b at both ends were torn and came into contact with a metal part, the same problem would not occur because that part is at so-called earth potential.In addition, this configuration is U-shaped. This method is effective even when a type of cable guide is not used.

Next, the effect of the fixing plate 32 will be described.

In general, machines that are built low in height also take up less space, have more freedom in installation, and are easier to operate. However, as shown in FIG. If the height is lowered, the flat cables CI, C2 and the back plate 31 will bend as shown by the dashed line a in the figure as they move during reading, and will rub against the glass G on which the original is placed, causing the flat cables CI.

This may obstruct the movement of C2 and main scanning platform 1 or cause dust to adhere to the bottom surface of glass G. On the other hand, if the position of glass G is raised to prevent this, the main body of the device will become larger. In the embodiment, the fixing plate 32 is bent downward as shown in the figure to press down the flat cables CI, C2 and the back plate 31, and the flat cables CI,
This structure prevents contact between C2 and glass G. Furthermore,
At the position where the bending force is strongest, that is, near the end of the scan where the free length of the spring becomes short as shown by the two-dot chain line in FIG. This prevents the main scanning platform 1 from being pushed up by the reaction force pushing the flat cables C1, C2, etc.

Here, we will discuss the effects of the back plates 27 and 31. (1) When the flat cable becomes stiff, specifically when the scanning length is long or the temperature is high (2) When the flat cable is left unused for a long time (3) If you have to use a cable that is already thin and weak, use a spring material (made of stainless steel or phosphor bronze with a thickness of 0.5 mm).
1-0.3 mm) by inserting a back plate.

Flat cable CI as shown by the dotted line in Figure 5.

It is possible to prevent the occurrence of C2 sagging. When the cable is bent and the upper and lower cables come into contact with each other, the cable sheathing is made of a material with a high coefficient of friction such as vinyl or rubber, so the cable may remain in contact and remain stuck, or the cable may not bend properly, so the main scanning table The above configuration is very effective as a countermeasure against this problem.

Similar to the grounding of the wiring at both ends of the flat cable C1 as described above, it is also very effective to use the back plates 27 and 31 as a grounding line, so this will be described below.

FIG. 6 is a diagram of the device shown in FIG. 3 viewed from the direction of arrow S,
The main scanning table l is configured to be movable on rails 2a and Zb. That is, the rail 2a is moved by bearings 43a and 43b attached to shafts 39 and 40 fixed to the main scanning table 1, and bearings 43 attached to a shaft 42 fixed to a leaf spring 41 fixed to the main scanning table l. bearing 43cl, which is also attached to shaft 38.
is placed on the axis 2b, and as a result, the main scanning table 1 is placed on the first axis 2b.
It is constructed so that it can be moved extremely easily in the direction of arrow A or B in the figure. In this case, as shown in FIG. 6, the main scanning table 1 is connected to the rail 2a via bearings 43a to 43d
, 2b, it is not grounded, which is undesirable in terms of noise.Similarly, FIG. 8 is a diagram of the device in FIG. 3 viewed from the direction of arrow T. The slide member 44 fixed to the front and rear sub-scanning side plates 3 and 4 is on the rail 9 and is not grounded. In this embodiment, the main scanning table L, which moves in the main scanning direction, also moves in the sub-scanning direction, and since the sub-scanning unit U is also configured to be movable, it tends to be in an electrically floating state.
As described above, in addition to using the wiring cords C1a and C1b at the ends of the flat cable CI as grounding wiring, the back plates 27 and 31 are further grounded to lower the impedance. That is, as shown in FIG. 3, the back plates 27 and 31 are screwed together with screws N1.

By tightening with N2 or pressing with the fixture 28 or the fixing plate 32, the member that moves during main scanning or sub-scanning (main scanning table l or sub-scanning unit U) is brought to the same potential as the bottom plate 0, that is, to the ground. It can be completely removed. in general,
Floating (not grounded and not used for signals)
Metal can easily become a source of noise, but since the planar metal is grounded using the above measures, it also has a shielding effect, making it strong against external noise, and also allowing noise generated by itself to escape. It becomes difficult.

In addition, these back plates 27 and 31 are connected to the stacked flat cables Cl.
- It also has the function of regulating the arbitrary movement of C5.

Next, back plates 27, 31. and flat cable Cl-C5
I will explain how to stack the .

As mentioned above, it is possible to wire the reader in a narrow area by stacking multiple flat cables, but in this case, as shown in Figure 9, the back plate 27, which is the strongest, is placed inside. , and further flat cable 01
-C3 are stacked one on top of the other in order of stiffness on the outside.

Further, for the flat cables 01 to C3, stable bending is performed by arranging the cables in the order of their widths on the outside. That is, if the narrow flat cable c3 is placed on the inside as shown in FIG. 10, the back plate 27 may fall down in the width direction, or in extreme cases it may come off the back plate 27, which may cause a malfunction. Therefore, backboard 27. Layer flat cables 01 to C3,
Furthermore, it is necessary to stack the flat cables 01 to C3 in descending order of width in order to maintain a stable bent state.

Further, as shown in FIG. 11, by giving the back plate 27a a curvature in a direction perpendicular to the bending direction, and by making the bend direction the side that wraps the flat cables C1 to C5 inside, the flat cables C1 to C3 can be It can also be made difficult to come off from the plate 27a. This bending amount j is approximately 0.1 to 0.2 times the width i of the back plate 27a, which is effective. In this case, by giving the back plate a curvature, the curvature when the back plate 27a bends becomes almost constant, so at the point where the curvature is the largest (the position of the - dotted chain line a) in FIG. Since the height of the flat cables C1 and C2 can be kept low, there is also the additional effect that the wiring space can be narrowed. Note that the width of the back plate 27a should be wider than the width of the widest flat cable C1.

Next, the arrangement of the flat cable will be described using FIG. 6.

As shown in the figure, in this embodiment, a lens L and a CCD 20 for reading are arranged approximately in the center of the rails 2a and 2b that guide the main scanning table 1, and the two rails 2a
, 2b are arranged with flat cables 01 to C3. As a result, the back plate 27 and the flat cable 0
Even if 1 to C3 are too stiff, the main scanning table 1 will be lifted off the rails 2a and 2b because a force acts in the direction of the arrow (counterclockwise) centering on the rail 2a, which is supported at three points. For example, flat cables C1 to C3 become hard and difficult to bend when used at low temperatures, so flat cables c1. - When C3 is placed between the rails 2a and 2bc7), if the back plate 27 and flat cable Cl-C5 are too stiff, the main scanning platform 1 may float up, resulting in what is called an out-of-focus condition.
Movement may be hindered. However, with this configuration, such a thing does not occur.

Next, a method of arranging the flat cable Cl-C5 mainly in the sub-scanning direction (direction of arrow C or D) will be described.

In the apparatus according to the present invention, the feed amount in the sub-scanning direction needs to be extremely accurate. In addition, it is preferable in various respects that the size of the device body be small in terms of installation space and weight.

On the other hand, the flat cables 01 to C3
The structure must be such that it can be bent freely with sufficient margin. In this embodiment, in consideration of these points, the flat cable Cl-C5 is configured to protrude from the sub-scanning section U in the direction indicated by the arrow, as shown by part E in FIGS. 1 and 6. (In order to have a structure that does not protrude, it is necessary to arrange it in an area where it does not interfere with the movements of the sub-scanning section U and the main scanning table 1, so the width or height of the main body of the device increases as shown in FIG. 1.) .

Incidentally, if an unexpected force is applied to the flat cables C1-C5, for example, if a force of 4 is applied to the position indicated by the arrow F in FIG. 6, the position of the sub-scanning section U will shift and the read images will not be connected. In the case of conventionally used devices that read images by scanning, even if the flat cable hits the frame at the home position, there is a run-up distance of several tens of ml, so it is not a problem as long as it does not hit at the position where reading starts. However, in the apparatus of this embodiment, the main scanning table l is moved in the direction of arrow A from the home position, that is, the position where the sub-scanning unit U is detected by the sensor S3 in FIG. It is necessary to prevent other members from touching the flat cable when the unit U is at the home position, thereby preventing it from being disconnected from the next row. Therefore, in this embodiment, escape holes 45a for the flat cables 01 to C3 are provided in the frame 45 so that the flat cables 01 to
It is configured so that the frame 45 or the like does not come into contact with C3 and apply external force. To achieve this purpose, the portion may be recessed, as in frame 45A in FIG.
In particular, when the frame is made of resin or the like, a frame 45A shown in FIG. 7 is preferable from the viewpoint of ease of manufacture and strength.

In the above embodiment, CCD20 is used as the J light receiving section.
Although the present invention has been described using an example of a device that guides a light image of a document, the present invention is not limited to this, and can also be applied to a device that guides a light image of a document to a photoreceptor.

(Effects of the Invention) As described above, in the present invention, the flat cable extending from the reading section is supported in a bent state in the direction of movement of the reading section using a plate-shaped support member made of an elastic material. Therefore, wiring to the reading section can be done reliably and in a narrow area.

Therefore, in particular, power supply to the reading section moving in different directions, signal exchange, etc. can always be performed in a stable state.

Furthermore, as a result, the wiring cable does not come into contact with other members, improving its durability and making it possible to downsize the device configuration.

Furthermore, since the reading section is grounded using a conductive support member, no noise is generated when the reading section is moved, and high-quality reading can always be performed.

[Brief explanation of drawings]

1 to 11 show an embodiment of a document reading device according to the present invention, FIG. 1 is a plan view showing the main parts of the embodiment, and FIG. 2 shows the device of FIG. 1. A perspective view, FIG. 3 is an enlarged perspective view showing the wiring state of the flat cable to the main scanning table and the sub-scanning section, and FIG. 4 is an enlarged perspective view showing the wiring state of the flat cable to the sub-scanning section. Fig. 5 is a view taken in the R direction of Fig. 3 showing the condition of the flat cable as the main scanning table moves, and Fig. 6 is a side view showing the state of the main scanning table being assembled to the sub-scanning section. 7 is a side sectional view showing another example of the frame, FIG. 8 is a front sectional view showing how the sub-scanning section is assembled to the main body rail, and FIG. Fig. 10 is an explanatory drawing showing the state of the plate assembly; Fig. 10 is an explanatory drawing showing the state of the back plate when the arrangement of the flat cables is changed; Fig. 11 is an explanatory drawing showing another example of the back plate; Fig. 12 The figure is an explanatory diagram for showing a reading operation. Explanation of symbols l...Main scanning table 2a, 2b...Rail 6.
...Wire 9...Sub-rail 20...CC
D (Light receiving part) 25... Cable guide 25a... Bottom part 26... Fixture 27.31
...Back plate (supporting member) 32...Fixing plate 33...Lamps A, B...
・Main scanning direction arrows C, D...Sub-scanning direction arrows CI, CI, C3...Flat cable U...
Sub-scanning section Fig. 9 Fig. 10 Fig. 11 Fig. 12

Claims (2)

[Claims] (1) Document reading in which a reading unit, which has a reading optical system and is wired to the electrical components of the reading optical system using a flat cable, is moved at a predetermined speed in order to guide the optical image of the original to the light receiving unit. In the apparatus, a plate-shaped support member made of a conductive elastic material is bent in a moving direction of the reading unit to support the flat cable extending from the reading unit, and further, the support member is arranged to support the flat cable extending from the reading unit. 1. A document reading device characterized in that the reading section is grounded by being connected to the reading section. (2) The document reading device according to claim 1, wherein the flat cable is fixed to the reading section by a fixing member, and further, a supporting member is fixed to the fixing member.