JP3415673B2 - Image reading device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus used in a digital copying machine, an analog copying machine, an image scanner, a facsimile, etc., and more particularly, an air resistance which the optical carriage receives the return control of the optical carriage. The present invention relates to an image reading apparatus which is executed by a drive motor for driving an optical carriage and reduces air resistance during exposure scanning to smooth image reading.

[0002]

2. Description of the Related Art Conventionally, an image reading apparatus reciprocally moves an optical carriage integrally formed with an illumination lamp, a mirror, and the like to expose and scan an image of a document set on a document table to read it. At this time, the optical carriage reads the original image while moving in a predetermined direction, returns the optical carriage to the start position and stops it after finishing the reading process, and prepares for the next reading process. Further, in such an apparatus, in order to improve the reading processing speed, it is required to minimize the time required for returning the optical carriage. Therefore, the return speed when returning the optical carriage is generally set to several times the reading speed.

Further, as the reading process becomes faster, for example, there is an apparatus in which the speed of the optical carriage at the time of returning is set to reach several meters per second. Further, it is required to reduce the size and weight of the apparatus itself. Therefore, the stop position of the optical carriage needs to be as close to the reading start position as possible. In this case, when the optical carriage is returned, it is necessary to rotate the drive motor in the reverse direction so that the drive motor travels at a high speed to a position close to the standby position and then suddenly stops.

Further, the optical carriage is housed in a substantially hermetically sealed box-shaped housing and is capable of reciprocating movement. When reading an image, the optical carriage is restarted from the position where it is returned and stands by. The reading operation is performed at a predetermined speed.

Further, as a reference technical document relating to the flow of air generated as the optical carriage travels, for example, "Image forming apparatus" and Japanese Patent Laid-Open No. 4-334260 disclosed in Japanese Patent Laid-Open No. 244069/1990. The "document reading device" disclosed in Japanese Patent Publication is known. The "image forming apparatus" of Japanese Patent Application Laid-Open No. 2-244069 uses an air flow generated by the traveling of an optical carriage to cool a document table and the like. In addition, JP-A-4-3342
The "original reading device" of Japanese Patent Laid-Open No. 60 is a device that devises the shape of the optical carriage to reduce air resistance during traveling.

[0006]

However, in the conventional image reading apparatus as described above, the optical carriage is abruptly applied with the braking force by the reverse rotation of the drive motor in the vicinity of the reading start position. Since the drive system that stops the carriage is used, the load torque during braking of the drive motor is larger than the load torque during reading operation, and a large one that matches the output torque of the motor with the braking force during return is required. I was trying. Further, as the drive motor becomes larger, the drive power supply for supplying a large braking current also becomes larger. Therefore, not only the installation space for the drive motor and the drive power source becomes large, but also a member supporting them and a casing and peripheral parts thereof that can withstand an impact received when the optical carriage is stopped are required. As described above, there are problems that the reduction in size and weight of the device is hindered and the economical efficiency is deteriorated.

Further, a force in the opposite direction acts on the optical carriage due to the volume change of the gas inside the machine as the optical carriage is activated. Therefore, there is a problem in that the energy required for starting increases and the time and distance required for starting increase. Further, there is a problem that negative pressure fluctuation occurs when the inside of the machine is depressurized due to the traveling of the optical carriage to a non-depressurized area, which causes uneven speed of the optical carriage.

The present invention has been made in view of the above, and reduces the braking force by the drive motor at the time of returning of the optical carriage, and eliminates the negative pressure fluctuation at the time of starting the optical carriage to eliminate the speed unevenness. The purpose is to improve the reading quality.

[0009]

In order to achieve the above object, in an image reading apparatus according to a first aspect of the present invention, a document to be read is housed inside a casing having a hermetic structure. An image reading device that reads an image of the original by reciprocating an exposure scanning unit that exposes and scans the original along a surface of the original from a reading start position to a reading end position of the original. A first space of the space formed by the outer surface of the exposure scanning means and the inner surface of the housing, which is compressed when the exposure scanning means moves from the reading end position to the reading start position and is returned. Contact
The inside of the first space is provided on the wall surface of the housing
An opening through which air is opened so as to flow into, the at the time of forward movement to move from the exposure scanning unit the reading start position to the reading end position, due to the opening of the opening
From the outside of the housing to the inside of the first space.
When air flows in through the mouth and returns, the opening
By closing the part, the first
No air flows into the space of No. 1 through the opening.
And an opening / closing means for carrying out the above.

Further, in the image reading apparatus according to the second aspect of the present invention, the exposure scanning means which is housed in the housing of the hermetically sealed structure on which the document to be read is placed and which exposes and scans the document, An image reading apparatus for reading an image of the original by reciprocating between a reading start position and a reading end position of the original along the surface of the original, the outer surface of the exposure scanning unit and the housing. The exposure scanning means of the space formed by the inner surface is provided on the wall surface of the exposure scanning means that is in contact with the first space that is compressed during the backward movement of moving from the reading end position to the reading start position ,
Said first opening air to the inside of which is opened to the inflow space, wherein at the time of forward movement to move from the exposure scanning unit the reading start position to the reading end position, the opening
By opening the outer surface of the exposure scanning means and the
The forward movement of the space formed by the inner surface of the housing
From the second space, which is sometimes compressed, to the interior of the first space
Air flows in through the opening, and when returning, the front
From the second space by closing the opening
Air flows into the first space through the opening
And an opening / closing means for preventing it.

According to a third aspect of the present invention, in the image reading apparatus according to the first or second aspect, the opening / closing means is the first scanning means according to the movement of the exposure scanning means.
It is characterized in that it is formed so as to be automatically opened and closed by the fluctuation of the air pressure in the space.

Further, in the image reading apparatus according to the fourth aspect, in the invention according to the first or second aspect, the control means for controlling the opening / closing means to open / close with the movement of the exposure scanning means. Is further provided.

[0013]

[Action] The image reading apparatus according to the present invention (claim 1), first
An opening is provided on the wall surface of the housing that is in contact with the first space, and the opening is opened at the time of forward movement so that the opening is opened from the outside of the housing.
Air flows into the space of No. 1 through the opening, and when returning, the opening is closed from the outside of the housing.
No air will flow into the first space through the opening
I will This eliminates negative pressure fluctuations when the exposure scanning means is started (forward movement), eliminates speed unevenness, improves reading quality, and controls the drive motor when the exposure scanning means returns (reverse movement). Reduce power.

Further, in the image reading apparatus according to the present invention (claim 2) , an opening is formed in the wall surface of the exposure scanning means in contact with the first space.
Section is provided, and by opening the opening when moving forward ,
Through the opening from the second space to the interior of the first space
When air flows in and returns, it is possible to close the opening.
Then, through the opening from the second space to the inside of the first space
So that air does not flow in.

An image reading apparatus according to the present invention ( claims
3 ) automatically opens and closes the opening by the fluctuation of the air pressure in the first space due to the movement of the exposure scanning means.

An image reading apparatus according to the present invention ( claims
4 ) controls to open and close the opening in accordance with the movement of the exposure scanning means.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an explanatory diagram showing a schematic configuration of an image reading apparatus to which the present invention is applied. In FIG. 1, the image reading apparatus includes a contact glass 101 on which a document to be read is placed, an illumination lamp (fluorescent lamp) 102 for exposing and illuminating the document, and an illumination lamp 102.
Plate 1 for reflecting the light of the surface of the contact glass 101
03 and the first mirror 1 for guiding the reflected light of the document to the next mirror
An optical carriage 105 that supports 04 and is integrally configured;
A mirror carriage 108 that integrally configures the second mirror 106 and the third mirror 107, and a photoconductor or a CCD.
A lens 109 for forming a light image on an image pickup device (not shown) such as the above is housed in a box-shaped casing 110 having a closed structure. The hatched portion in FIG. 2 indicates the space where the image forming means is arranged.

Next, the basic operation of the image reading apparatus configured as described above will be described. The original placed on the contact glass 101 is exposed and scanned by the optical carriage 105 and the mirror carriage 108 in parallel with the contact glass 101 while the illumination lamp 102 is lit, and the reflected light of the original is reflected by the first mirror 104 and the second mirror 104. Mirror 1
06, it is guided to the lens 109 via the third mirror 107.
After that, in the case of an image reading apparatus for an analog copying machine, reflected light corresponding to the image of the original is irradiated onto the photoconductor through an image forming means such as a mirror, and the image is reproduced according to a generally known copying process. To form an image.

On the other hand, in the above case, in the case of the image reading apparatus for the digital copying machine, the reflected light of the original is imaged on the image pickup device such as CCD to obtain the electric image data.
Then, based on the image data, for example, after writing on the photoconductor by a laser writing unit (not shown), an image is formed based on the copying process as described above. Further, when the image reading device is used as an input device to a facsimile, a computer or the like, after being read by an image pickup device such as a CCD and converted into electric image data, image processing or the like is executed according to each purpose. To be done.

By the way, in the above, the optical carriage 105 and the mirror carriage 108 generally repeat the reciprocating movement to scan the original, but the original is actually exposed and scanned only during the forward movement. Is. At the time of returning (return), it only moves to the reading start position (home position, hereinafter referred to as HP) in preparation for the next scanning. The HP is on the left end side of the contact glass 101 in FIG.

2 to 4 are explanatory views showing the structure of the image reading apparatus according to this embodiment, FIG. 2 is a plan view thereof, and FIG.
Is a sectional view thereof, and FIG. 4 is a side view showing the section.
An air compression unit 201 is provided so that air is compressed between the optical carriage 105 and the mirror carriage 108 and the inner wall of the housing 110 by the movement of the optical carriage 105 and the mirror carriage 108. Also, as shown, the optical carriage 105 and the mirror carriage 10
In order to form an air resistance region by minimizing the gap between the housing 110 and the optical carriage 105 and the mirror carriage 108 at a position where the 8 performs a return motion and starts deceleration to stop at HP. Case 110
The side surface on the side is provided with a protruding portion 202 protruding inward.

In the above structure, the optical carriage 10
The air resistance is used to stop the return movement of the mirror 5 and the mirror carriage 108 during the return operation. By providing this air compression unit 201, the optical carriage 105
Also, the kinetic energy of the mirror carriage 108 is converted into a volume change of air, and the braking force (braking force) required for the optical carriage 105 and the mirror carriage 108 to stop is positively reduced. To explain this in detail, the optical carriage 105 and the mirror carriage 108 are
After the reading scan is completed, a return motion is performed to HP. When the optical carriage 105 and the mirror carriage 108 return, the optical carriage 105 and the mirror carriage 10
An air flow is generated at both ends of 8. Also, the protrusion 202
Since the cross-sectional area of the air flow path is significantly reduced at the location where is provided, it becomes difficult to move the air, and the air is compressed near the HP. Therefore, since the air compression gives air resistance to the optical carriage 105 and the mirror carriage 108, the optical carriage 1 at the time of return is returned.
05 and the mirror carriage 108 can be easily braked.

Therefore, according to the above, the optical carriage 1
05 and the mirror carriage 108 can be saved in energy, and the optical carriage 105 and the mirror carriage 1 can be saved by the cushion effect of air.
It is possible to mitigate the impact that acts on each part of the device when stopping 08. Further, even when the optical carriage 105 and the mirror carriage 108 are returning at high speed, even when the power supply for supplying power to the apparatus is cut off and the control of the drive motor is lost, the optical carriage 105 and the mirror carriage 108 are lost. Since a braking force is applied to 108, the impact due to overrun is significantly mitigated and damage to the device can be prevented.

By the way, when the optical carriage 105 and the mirror carriage 108 return, the air is compressed near the HP and the air resistance effectively acts on the optical carriage 105 and the mirror carriage 108. As the carriage 105 and the mirror carriage 108 move, the volume of the area where the air is compressed increases, and this space is decompressed. Therefore, the optical carriage 105 and the mirror carriage 10
At the time of forward movement of 8, the force in the direction opposite to the traveling direction acts. Therefore, in the present invention, as will be described below, the braking force generated in the air compressing unit 201 is effectively used at the time of stop, and the optical carriage 105 and the mirror carriage 108 are decompressed by the pressure reduction of air at the time of start at the time of forward movement. By reducing the force opposite to the scanning direction, the above problem is solved. The details will be described below.

[First Embodiment] FIG. 5 is an explanatory diagram showing a configuration of an image reading apparatus according to a first embodiment. Further, FIG. 6 is a cross-sectional view taken along the line A of FIG. In both of these drawings, an opening 501 is provided on the side wall of the housing 110 on the HP side (side wall of the housing 110 in the air compression portion 201 portion), and the opening 501 is covered in an openable and closable manner inside the opening 501. On-off valve 502 has hinge 5
It is attached by 03.

Next, the operation of the image reading apparatus constructed as above will be described. FIG. 7 is an explanatory diagram showing the operation of the opening / closing valve 502 of the image reading apparatus according to the first embodiment,
FIG. 8 is a sectional view taken along line A of FIG. The optical carriage 105 and the mirror carriage 108 are stopped at the HP position on the left end side at the start of reading. The optical carriage 105 and the mirror carriage 108 are, as described above, after the image reading operation is completed,
Optical carriage 105 and mirror carriage 1 at high speed
When 08 returns, the braking force is applied by the action of the air compression unit 201 and stops. At this time, FIG.
As shown in FIG. 6, the opening / closing valve 502 comes into close contact with the opening portion 501 by the pressure of the optical carriage 105 and the mirror carriage 108 urging the opening / closing valve 502 toward the housing 110. This allows
Optical carriage 105 and mirror carriage 108
Is given an air resistance by the air compression unit 201 and receives a braking force.

When the optical carriage 105 and the mirror carriage 108 perform a reading operation while moving to the right at a constant speed, the air pressure inside the housing 110 moves to the right due to the movement of the optical carriage 105 and the mirror carriage 108. The open / close valve 502 opens due to the weakening of the air, and the outside air flows in through the opening 501. As a result, the air resistance (negative pressure) in the reading start operation (at the time of starting) of the optical carriage 105 and the mirror carriage 108 can be reduced, and the reading start operation can be smoothly performed.

Second Embodiment FIGS. 9 to 11 are explanatory views showing the configuration of the image reading apparatus according to the second embodiment. 10 is a cross-sectional view showing the portion of the mirror carriage 108 and its surroundings in the direction A of FIG. 9, and FIG. 11 is a cross-sectional view showing the portion of the optical carriage 105 and its surroundings in the direction A of FIG. is there. The structure of the second embodiment is the same as the opening / closing valve 50 of the first embodiment.
2 is provided on the optical carriage 105 and the mirror carriage 108 without being provided on the housing 110. That is, the support of the optical carriage 105 is provided with the opening 501a, and the opening / closing valve 502a is attached to the opening 501a. Further, an opening 501b is provided in the support of the mirror carriage 108, and an opening / closing valve 502b is attached to the opening 501b.

Next, the operation of the image reading apparatus configured as above will be described. 12 is an explanatory view showing the operation of the opening / closing valves 502a and 502a of the image reading apparatus according to the second embodiment, FIG. 13 is a cross-sectional view showing the operation state of the mirror carriage 108 in the A direction of FIG. 12, and FIG. , Fig. 12
FIG. 6 is a cross-sectional view showing an operating state of the optical carriage 105 in the A view direction of FIG. The optical carriage 105 and the mirror carriage 108 are stopped at the HP position on the left end side at the start of reading (position in FIG. 9). This optical carriage 1
05 and the mirror carriage 108, as described above, when the optical carriage 105 and the mirror carriage 108 return at high speed after the image reading operation is completed, the braking force is applied by the action of the air compressing unit 201 to stop. To do. At this time, as shown in FIGS. 9 to 11, the openings 501a and 501b are closed by the opening / closing valves 502a and 502a.
02b is biased toward the housing 110 side by the pressure of the optical carriage 105 and the mirror carriage 108, and is brought into close contact with each other. As a result, the optical carriage 105 and the mirror carriage 108 receive the braking force by the air compression unit 201.

When the optical carriage 105 and the mirror carriage 108 perform a reading operation while moving to the right at a constant speed, the air pressure inside the housing 110 moves to the right due to the movement of the optical carriage 105 and the mirror carriage 108. Open / close valves 502a and 502b to weaken
Opens, and air flows in through the openings 501a and 501b. As a result, the air resistance (negative pressure) in the reading start operation (at the time of starting) of the optical carriage 105 and the mirror carriage 108 can be reduced, and the reading start operation can be smoothly performed.

[Third Embodiment] FIG. 15 is an explanatory diagram showing a configuration of an image reading apparatus according to a third embodiment. 16 is a cross-sectional view showing the portion of the mirror carriage 108 and its surroundings in the direction A of FIG. In FIGS. 15 and 16, a side surface of the housing 110 connects the front and rear of the optical carriage 105 and the mirror carriage 108 during scanning, and a bypass 1501 through which air flows is provided on one side or both sides of the optical carriage 105 and the mirror carriage 108. Furthermore, HP of the optical carriage 105 and the mirror carriage 108
An opening 1502 that relays the bypass 1501 and the housing 110 is provided on the return side and the return side, and an opening / closing valve 1503 that can be opened and closed is provided in the bypass 1501.

Next, the operation of the image reading apparatus configured as described above will be described. FIG. 18 is an explanatory diagram illustrating the flow of air when the optical carriage 105 of the image reading apparatus according to the third embodiment scans and scans. As shown in FIG. 18, when the optical carriage 105 and the mirror carriage 108 start reading scanning, the bypass 1501
The on-off valve 1503 provided in the above is operated in the direction of the arrow to open the air in the direction of the arrow to the bypass 1501. As a result, an air flow as shown in the figure is generated due to the pressure difference generated in the housing 110 with the optical carriage 105 and the mirror carriage 108 interposed therebetween.

FIG. 17 is an explanatory diagram showing the flow of air when the optical carriage 105 of the image reading apparatus according to the third embodiment returns to HP. As shown in FIG. 17, the optical carriage 105 and the mirror carriage 10
When 8 finishes the reading scan and returns to HP, the opening / closing valve 1503 provided in the bypass 1501 is operated in the direction of the arrow to open the air in the direction of the arrow so as to flow to the bypass 1501. As a result, due to the pressure difference generated in the housing 110 with the optical carriage 105 and the mirror carriage 108 sandwiched, an airflow as shown in the figure is generated. Therefore, the optical carriage 105 and the mirror carriage 10
It is possible to eliminate the influence of the negative pressure on the movement of No. 8.

[Fourth Embodiment] Here, a method of driving the optical carriage 105 will be described. Motor power is applied to the optical carriage 105 from the output shaft of the motor, which is a drive source, using a transmission component such as a wire or a timing belt. Depending on the motor, the gear may be used to decelerate. Since the motor needs speed control such as stable constant speed and rapid acceleration / deceleration when driving the optical carriage 105, a DC servo motor, a stepping motor,
A motor having excellent controllability, such as a brushless servomotor, is mainly used. In this embodiment, an example will be described in which a stepping motor is used and control is performed by making full use of a microcomputer system.

FIG. 19 is a block diagram showing the arrangement of the drive control system of the optical carriage 105 according to the fourth embodiment. In the figure, 1901 is a stepping motor (STM) as a drive source, 1902 is a microcomputer (hereinafter referred to as MCU) for executing control of the entire drive control system, 1
Reference numeral 903 denotes an excitation signal generation circuit for generating an excitation signal, 190
4 is based on the excitation signal of the excitation signal generation circuit 1903,
A constant current driver that excites and drives each phase of the stepping motor 1901 with a current value determined by a current setting signal of the MCU 1902, 1905 is an HP sensor that detects the HP of the optical carriage 105, and 1906 is an MCU 1902.
It is a solenoid valve that opens and closes according to the control signal. In addition,
The MCU 1902 may be mounted alone or may be incorporated as a part of the system. Further, the MCU 1902 is of a general type and has a built-in program memory, data memory, interface functions, etc. in addition to the CPU.

Next, the operation of the drive control system configured as described above will be described. The MCU 1902 turns on / off the power supply to the stepping motor 1901 independently of the rotation of the stepping motor 1901, CLOCK that determines the number of rotations of the stepping motor 1901 to the excitation signal generating circuit 1903, the direction signal that determines the rotation direction. An enable signal for control and a current value setting signal for determining the drive current value of the stepping motor 1901 are generated for the constant current driver 1904, and the HP sensor 1905 indicating the reference point of the stop position of the optical carriage 105 is monitored.

Further, the excitation signal generating circuit 1903 is
In synchronization with CLOCK from U1902, the excitation signal determined based on the direction signal is sequentially output. This excitation signal is determined by the excitation method of the stepping motor 1901, and the constant current driver 1904 excites each phase of the stepping motor 1901 based on this excitation signal. In addition, depending on the excitation method, the current setting signal may also be CLO.
Output in synchronization with CK. The excitation signal generation circuit 19
03 may be configured by being incorporated in the MCU 1902, or may be realized by generating the same signal as above by software. Further, the constant current driver 1904 excites and drives each phase of the stepping motor 1901 with a current value determined by the current setting signal output from the MCU 1902 based on the excitation signal output from the excitation signal generation circuit 1903.

Next, the operation of the optical carriage 105 will be described. The optical carriage 10 when scanning a document
5 starts the scanning operation based on the position of the HP sensor 1905. By the time the position of the HP sensor 1905 reaches the leading edge of the document, the optical carriage 105 is accelerated to a predetermined reading speed, and the document is scanned at a constant speed (scan operation). At this time, not only must the optical carriage 105 reach a predetermined speed by the time it reaches the leading edge of the document, but also the abnormal movement such as vibration must be suppressed.

When the document scanning is completed, the optical carriage 105 is braked to decelerate, and the driving direction is reversely rotated to accelerate to a predetermined speed. After driving to the predetermined speed, deceleration is started to stop at the HP sensor 1905 position.
If the P sensor 1905 is detected, it stops at that position (return operation).

As described above, the position of the optical carriage 105 is determined by the CLOCK, the direction signal and the enable signal output to the excitation signal generation circuit 1903 of the stepping motor 1901. Therefore, M
The PU 1902 receives the electromagnetic valve 1906 based on the above signals.
The timing for opening and closing is determined and a signal for controlling the solenoid valve 1906 is output to the solenoid valve 1906.
At this time, the same effect can be achieved by making the operation timing of the solenoid valve 1906 the same as the operation of the other embodiment in which the electromagnetic valve operates.

By the way, although it has been described that the optical carriage 105 is set to the highest speed during the backward movement,
It is during this return that the device itself may be most susceptible to damage and impact. That is, when the optical carriage 105 is traveling at a high speed during the backward movement, the function of the solenoid valve 1906 is lost due to an accident such as a power cutoff, and the optical carriage 105 cannot be braked due to air pressure. It is possible to hit the body 110. Therefore, the solenoid valve 1906 shuts off (closes) the air flow when there is no control input, and functions on the safe side even when an accident such as the above power shutoff occurs.

[0042]

As described above, according to the image reading apparatus (Claim 1) of the present invention , the casing contacting the first space is used.
An opening is provided on the wall surface of the body, and the opening is opened when moving forward .
Open from the outside of the housing to the inside of the first space.
Air flows in through the mouth and closes the opening when returning.
The outside of the housing to the inside of the first space by
Prevent air from entering through the openings. This eliminates negative pressure fluctuations when the exposure scanning means is started (forward movement), eliminates speed unevenness, improves reading quality, and controls the drive motor when the exposure scanning means returns (reverse movement). Power can be reduced. Also,
It is possible to suppress the temperature rise inside the machine due to the inflow of outside air.

According to the image reading apparatus of the present invention (claim 2), the wall surface of the exposure scanning means in contact with the first space.
The opening is provided in the
Therefore, the opening is passed from the second space to the inside of the first space.
Air flows in, and the opening is closed when returning.
To open an opening from the second space to the interior of the first space.
Prevent air from flowing through. This eliminates the negative pressure fluctuation at the time of starting the exposure scanning means (during forward movement) to eliminate speed unevenness and improve the reading quality.
It is possible to reduce the braking force of the drive motor when the exposure scanning unit returns (returns). Further, there is no inflow of air from the outside, and it is possible to extremely reduce the contamination of the optical component due to dust or the like.

An image reading apparatus according to the present invention ( claims
According to 3 ), the opening is automatically opened and closed by the fluctuation of the air pressure in the first space accompanying the movement of the exposure scanning means. This eliminates negative pressure fluctuations when the exposure scanning means is started (forward movement), eliminates speed unevenness, improves reading quality, and controls the drive motor when the exposure scanning means returns (reverse movement). Power can be reduced. Further, it has a simple structure and does not require a special control mechanism.

An image reading apparatus according to the present invention ( claims
According to 4 ), as the exposure scanning means moves, the opening
Control to open and close. This eliminates negative pressure fluctuations when the exposure scanning means is started (forward movement), eliminates speed unevenness, improves reading quality, and controls the drive motor when the exposure scanning means returns (reverse movement). Power can be reduced. Further, because of the special control mechanism, it is possible to surely improve the reading quality and surely reduce the braking force by the drive motor. Further, when the control input to the opening / closing means is OFF, the opening or the air path leading to the opening is set to be closed, so that the air resistance can be maintained even when an overrun of the exposure scanning means occurs due to the interruption of the power source of the apparatus. As a result, the braking force is secured, and the collision of the exposure scanning means can be prevented.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of an image reading apparatus to which the present invention is applied.

FIG. 2 is a plan view showing the configuration of the image reading apparatus according to the present embodiment.

FIG. 3 is a side view showing the configuration of the image reading apparatus according to the present embodiment.

FIG. 4 is a cross-sectional view showing the configuration of the image reading apparatus according to the present embodiment.

FIG. 5 is an explanatory diagram showing the configuration of the image reading apparatus according to the first embodiment.

6 is a sectional view taken along line A of FIG.

FIG. 7 is an explanatory diagram showing the operation of the opening / closing valve of the image reading apparatus according to the first embodiment.

8 is a sectional view taken along line A of FIG.

FIG. 9 is an explanatory diagram illustrating a configuration of an image reading apparatus according to a second embodiment.

10 is a cross-sectional view showing a mirror carriage portion and its surroundings in the direction A of FIG.

11 is a cross-sectional view showing an optical carriage portion and its surroundings in the direction A of FIG.

FIG. 12 is an explanatory diagram showing an operation of an opening / closing valve of the image reading apparatus according to the second embodiment.

13 is a cross-sectional view showing an operating state of the mirror carriage in the A direction of FIG.

FIG. 14 is a cross-sectional view showing an operating state of the optical carriage in the direction A of FIG.

FIG. 15 is an explanatory diagram illustrating a configuration of an image reading apparatus according to a third embodiment.

16 is a cross-sectional view showing the mirror carriage portion and its surroundings in the direction A of FIG.

FIG. 17 is an explanatory diagram showing a flow of air when the optical carriage of the image reading apparatus according to the third embodiment returns to the HP.

FIG. 18 is an explanatory diagram showing the flow of air when the optical carriage of the image reading apparatus according to the third embodiment reads and scans.

FIG. 19 is a block diagram showing the configuration of a drive control system of the optical carriage according to the fourth embodiment.

[Explanation of symbols]

105 optical carriage 108 Mirror carriage 110 housing 201 Air compressor 502 Open / close valve 1501 bypass 1503 Open / close valve 1906 Solenoid valve 1902 MCU

Front page continued (72) Inventor Ishii Kimiku 1-3-6 Nakamagome, Ota-ku, Tokyo Stock company Ricoh (72) Inventor Yuko Oshima 1-3-3 Nakamagome, Ota-ku, Tokyo Share expression Ricoh Company (72) Inventor Keisuke Uchida 1-3-6 Nakamagome, Ota-ku, Tokyo Co., Ltd. Ricoh Company (56) Bibliography SHO 61-126244 (JP, U) (58) Fields investigated (58) Int.Cl. ⁷ , DB name) H04N 1/04-1/207

Claims (4)

(57) [Claims] 1. A closed structure on which a document to be read is placed.
The exposure scanning means, which is housed inside the housing for scanning the original, performs reciprocating movement between the reading start position and the reading end position of the original along the surface of the original. An image reading apparatus for reading an image, wherein the exposure scanning means in a space formed by an outer surface of the exposure scanning means and an inner surface of the housing moves backward from the reading end position to the reading start position. Is provided on a wall surface of the housing in contact with the first space, which is sometimes compressed ,
An opening which is opened to air to the inside of the first space flows, the forward movement of the exposure scanning unit is moved to the reading end position from the reading start position, to open the opening
From the outside of the housing to the inside of the first space
Air flows in through the opening, and when returning, the front
From the outside of the housing by closing the opening
Air flows into the first space through the opening
Image reading device comprising a switching means for so as not to, further comprising: a. 2. A closed structure on which a document to be read is placed.
The exposure scanning means, which is housed inside the housing for scanning the original, performs reciprocating movement between the reading start position and the reading end position of the original along the surface of the original. An image reading apparatus for reading an image, wherein the exposure scanning means in a space formed by an outer surface of the exposure scanning means and an inner surface of the housing moves backward from the reading end position to the reading start position. Is provided on the wall surface of the exposure scanning means in contact with the first space which is sometimes compressed .
Is the a first opening formed to allow air into the interior flows of space, the at the time of forward movement to move from the exposure scanning unit the reading start position to the reading end position to open the opening thing
By the outer surface of the exposure scanning means and the inner surface of the housing.
Compressed during the forward movement of the space formed by
The opening from the second space to the inside of the first space.
Air flows in through it and closes the opening when returning.
The first space from the second space by speaking.
So that air does not flow into the space through the opening
An image reading device, comprising: Wherein said opening and closing means, by variations in air pressure in the first space with the movement of the exposure scanning unit, automatically to claim 1 or 2, characterized in that it is formed so as to open and close The image reading device described . 4. The image reading apparatus according to claim 1 , further comprising a control unit that controls the opening / closing unit to open / close with the movement of the exposure scanning unit.