JP3355134B2 - Document feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DSPF (Duplex Single P
ath Feeder) type document feeder.

[0002]

2. Description of the Related Art In a recent image forming apparatus, a roller which repeats contact and detachment is used in a conveyance system such as a document conveyance device used for automatic document reading. An image forming apparatus using such a roller is disclosed in JP-A-59-18568.
There is a printer disclosed in Japanese Patent Laid-Open Publication No. 1 (1994) -123.

As shown in FIG. 9, the ink jet printer disclosed in the above publication has a platen 101 on which paper is wound and loaded, and a paper
And a pressing roller 102 for pressing the pressing roller 102. The pressing roller 102 is urged by a tension spring 103 so as to elastically contact the platen 101.

When the paper is loaded on the platen 101, the pressing roller 102 is temporarily locked while being separated from the platen 101. After the paper is loaded, the locked state is released and the platen 101 is re-opened. Contact 101. When the pressing roller 102 is separated, the pressing roller 1
02 is locked against the spring force of the tension spring 103, and when the locked state is released, the pressing roller 102 is restored by the restoring force of the tension spring 103.
Collision with 01.

In order to eliminate the collision sound when the pressing roller 102 is released from the locked state and comes into contact with the platen 101, the printer disclosed in the above publication is provided with an impact relaxation mechanism 104 as shown in FIG. When the locking of the roller 102 is released, the pressing roller 102 is gently pressed against the platen 101 by the impact relaxation mechanism 104.

In the above-described example, an additional material such as a damper is provided as the impact mitigation mechanism 104 to thereby absorb the collision sound. A method of absorbing sound is also widely used.

[0007]

However, the above-described conventional configuration has the following problems.

In other words, a large space is required to add a damper or the like as the shock absorbing mechanism 104, and there is no effect in providing a cushioning material if the cushioning member is attached to a portion other than the collision portion.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has as its object to provide a mechanism capable of stably silencing a limited space at a low cost. Is to provide.

[0010]

According to a first aspect of the present invention, there is provided a document feeder, comprising: a first roller; and a second roller detachable from the first roller. , A shaft member supporting the second roller, and a frame member supporting the shaft member, wherein the shaft member is movable in an elongated hole formed in the frame member. And the frame member has a sound-absorbing member made of an elastic body (for example,
Rubber, sponge, etc.) is disposed between the frame member and the shaft member so as to contact the shaft member.

According to the above construction, when the shaft member moves within the long hole of the frame member, the uncomfortable sound of collision when the shaft member collides with the frame of the long hole is effectively absorbed by the sound deadening member. And the noise reduction member can be arranged in a limited space.

According to a second aspect of the present invention, in addition to the first aspect, the shaft member presses the second roller toward the first roller by a plurality of pressing springs. The muffling member is disposed between the adjacent pressure springs, and is always in contact with the shaft member.

According to the above arrangement, by disposing the silencing member between the adjacent pressure springs, the unevenness of the pressing force applied to the shaft member by the silencing member can be minimized. Thus, when a plurality of second rollers are supported by the shaft member, the pressing force of each roller can be kept uniform.

Further, by constantly contacting the noise reduction member with the shaft member, the noise reduction of the noise reduction member can be prevented, and the effect can be stabilized for a long period of time.
Roller unevenness due to the presence or absence of a document or a driving load can be reduced, and stable document transportability can be obtained.

According to a third aspect of the present invention, in addition to the configuration of the first aspect, the hardness of the muffling member is JIS K63.
01-95 The spring type hardness test is characterized by being in the range of 20 degrees to 70 degrees specified by the A type.

If the silencing member is too hard, for example, during mass production, a slight variation in dimensions causes a variation in the braking effect. On the other hand, if the silencing member is too soft, a sufficient braking effect cannot be obtained, and effective silencing cannot be achieved.

According to the above configuration, by setting the hardness of the silencing member to an appropriate value, a sufficient silencing effect can be obtained.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In the following embodiments, a case where the document feeder according to the present invention is applied to an image forming apparatus capable of performing double-sided printing will be exemplified.

The schematic structure of the image forming apparatus will be described with reference to FIG.

In the image forming apparatus, a document feeder 2 according to the present invention is disposed on a copying machine 1 which is a main body of an image forming apparatus capable of printing on both sides. The document 3 is automatically fed onto the document reading section 4 of the copying machine 1 so that image information on both sides of the document 3 can be read.

The copying machine 1 houses the document reading section 4, an image forming section 5 for printing image information of the document 3 read by the document reading section 4 on a recording sheet 7, and contains the recording sheet 7. And a paper feed unit 6 for sequentially feeding the stored recording paper 7 to the image forming unit 5.

As shown in FIG. 3, the document reading section 4
A lamp reflector assembly 8 for exposing the surface of the document 3, and a reflected light image from the document 3 is converted into a photoelectric conversion element (hereinafter, referred to as CC).
Reflection mirrors 9a to 9 for guiding to 11)
c, an optical lens body 10 for forming an image of the reflected light from the document 3, and a CCD 11 for converting the reflected light image formed by the optical lens body 10 into an electric image signal. The document reading unit 4 converts the image information of the document 3 read as described above into an image processing unit (not shown).
The laser beam corresponding to the image signal is converted into a semiconductor laser 1 as shown by a solid line in FIG.
2 to irradiate the surface of the photoconductor 13 of the image forming unit 5;
An electrostatic latent image is formed on the surface of the photoconductor 13.

The image forming section 5 includes a drum-shaped photosensitive member 13.
A developing unit 14 that visualizes the electrostatic latent image of the photoconductor 13 with toner; a transfer unit 15 that transfers a visible image of the photoconductor 13 with toner to the recording paper 7; The cleaning unit 16 includes a cleaning unit 16 for removing residual toner, a charging unit 17 for charging the photoconductor 13 to a predetermined potential, and a fixing unit 18 for fixing the toner image transferred to the recording paper 7 by heat and pressure.

When an image forming operation is performed in the copying machine 1 having the above-described configuration, the recording paper 7 is transported from the paper feed unit 6 to a recording paper transport path 19 that passes between the photoconductor 13 and the transfer unit 15. In the recording paper transport path 19, the recording paper 7
It is once held by the first roller 20. That is, the first roller 20 is used in the image forming section 5 to
In order for the toner image on the surface of the photoconductor 13 to be accurately transferred to the recording paper 7, the recording paper 7 is formed at a predetermined timing so that the leading edge of the image information including the toner image and the leading edge of the recording paper 7 are aligned. It is transported to the section 5.

The recording paper 7 on which an image has been formed by passing through the recording paper transport path 19 is sent to a paper discharge unit 23 by driving a second roller 21 capable of normal and reverse rotation in the normal direction. At this time, if the image forming operation is a one-sided printing process, the recording paper 7 is discharged to the paper discharge unit 23 as it is. However, if the image forming operation is a double-sided printing process, then, in order to print on the back surface of the recording paper 7, the second roller 21 is inverted with the rear end of the recording paper 7 sandwiched therebetween. The recording paper 7 is driven and sent to a recording paper re-conveyance path 24 which forms a loop with the recording paper conveyance path 19. A third roller 22 is provided in the recording paper re-conveying path 24 to normally convey the recording paper 7.
Is provided.

Further, in the copying machine 1, a side cover 25 disposed on a side surface of the recording paper re-conveying path 24 is provided rotatably about a shaft 26. When a paper jam or the like occurs in the recording paper transport path 19, the side cover 25 is opened to perform a jam processing.

As shown in FIG. 3, the document feeder 2 includes a document tray 31, a PS (Paper Stop) roller 32, a paper discharge roller 33, and a paper discharge tray 34. Transport path 35 for transporting the original 3 to the original reading position, and a reverse transport path 36 for feeding the original 3 switched back during double-sided reading to the main transport path 35 again.
have.

The original tray 31 holds a plurality of originals to be read. The PS roller 32 is disposed before the document reading position in the main transport path 35 and
After the document 3 sent to the document 5 is temporarily stopped here, the document 3 is fed to the document reading position at a predetermined timing in order to control the reading start position of the document 3. The paper discharge roller 33 is a roller that can be rotated in normal and reverse directions, and is used to discharge a document that has been read to a paper discharge tray 34 or to send the document to a reverse conveyance path 36. The discharge tray 34 is a discharge destination of the document 3 that has been read.

When reading only one side of the document 3 in the document feeder 2, the document 3 fed from the document tray 31 is picked up by the pickup roller 37 and the sheet feeding roller 3.
The document is sent to the main transport path 35 by 8 and the original 3 is read at the original reading position. The paper feed roller 38 is in contact with a paper feed pad 39, and when two or more originals 3 are simultaneously sent out by the pickup roller 37, the lower original 3 is conveyed by the paper feed pad 39. Is regulated, so that the originals 3 can be sequentially sent out one by one from the top.

Here, the original reading position is defined as the copying machine 1
Reflector assembly 8 in the original reading section 4 of FIG.
Is a position where the light is irradiated. That is, the document reading unit 4
A platen glass 27 is provided on the upper surface of the document corresponding to the position of the lamp reflector assembly 8, and when the document 3 moves on the upper surface of the platen glass 27 which is a document reading position, light is irradiated on the document surface. Reading is performed on the lower surface of the document 3. In the original reading position, a position regulating member 40 is disposed above the platen glass 27, and the original 3 is placed on the platen glass 27 and the position regulating member 40.
, The optimal positional relationship with the platen glass 27 can be maintained. Further, the position regulating member is urged downward by a conical coil spring 41 so that the distance between the document 3 and the platen glass 27 can be appropriately maintained regardless of the thickness of the document 3.

The original 3 thus read is discharged onto the discharge tray 34 by the transport roller 42 and the discharge roller 33.

When reading both sides of the original 3,
First, the front side of the document 3 is read by the document reading unit 4 by the same operation as that for the above-described single-side reading. The document 3 whose front side has been read is sent out to the reversing tray 43 side instead of the paper ejection tray 34 side. That is, a switching gate 44 is disposed downstream of the discharge roller 33, and the destination of the document 3 can be switched between the discharge tray 34 and the reversing tray 43 depending on the position of the switching gate 44.

Then, in order to read the back side of the original 3,
When the document 3 is sandwiched between the discharge rollers 33, the discharge roller 33 is driven to rotate in the reverse direction, and the document 3 is sent to the reverse conveyance path 36. That is, on the upstream side of the paper discharge roller 33, the switching gate 45 is provided at the junction of the main transport path 35 and the reverse transport path 36.
And the original 3 sent to the reversing tray 43
When the trailing edge of the document has passed the leading end of the switching gate 45, the position of the switching gate 45 is switched, and the discharge roller 33 is driven to rotate in the reverse direction. The document 3 sent out to the reversing conveyance path 36 is again sent from the main conveyance path 35 to the document reading position, and is discharged onto the paper discharge tray 34 after the reading of the back surface is completed.

In the above description, the operation of reading the original 3 by the automatic transport mechanism of the original transport device 2 has been described. However, when there is only one original 3 and it is not particularly necessary to use the automatic transport mechanism. Alternatively, when the material of the original 3 is hard and it is difficult to use the automatic transport mechanism, the original 3 can be read without using the automatic transport mechanism.

For this reason, as shown in FIG. 4, the document feeder 2 is provided so as to be rotatable with respect to the copying machine 1, and a readable document is provided on the upper surface of the copying machine 1. 3
The table glass 28 corresponding to the maximum size is provided. In this case, the document feeder 2 is opened, the document 3 is placed on the table glass 28 with the reading surface down, and then the document feeder 2 is closed. An elastic material 46a and a white film 46b are provided on the lower surface of the original conveying device 2.
A document pressing member 46 is formed, and the document 3 is pressed against the table glass 28 by closing the document conveying device 2. In this state, the document reading unit 4
By scanning the scanning unit constituted by the lamp reflector assembly 8 and the reflection mirrors 9a to 9c along the document surface, the document 3 can be read.

The operation of transporting the original when the original 3 having the above-described configuration is used for reading both sides of the original 3 will be described in detail with reference to FIGS.

Each of the paper discharge roller 33 and the PS roller 32 of the document feeder 2 is driven by one motor 70 (see FIG. 3). At this time, the discharge rollers 33
Is directly connected to the motor 70 to enable forward / reverse drive. On the other hand, the PS roller 32 has a clutch 71 (FIG. 3).
), And the clutch 71 opens and closes a driving force transmission path from the motor 70 to the PS roller 32.

In the document feeder 2, when reading the front side of the document 3, the motor 70 rotates forward to transfer the document 3 to the main transfer path 35. At this time, the PS roller 32 is initially stopped, but starts to rotate forward at a predetermined timing after the leading end of the document 3 reaches the PS roller 32. Then, the front surface of the document 3 is read while both the paper discharge roller 33 and the PS roller 32 are driven to rotate forward.

When the reading of the front side of the original 3 is completed, P
The S roller 32 is stopped, and then, at a position where the rear end of the document 3 has passed the switching gate 45, the driving of the discharge roller 33 is temporarily stopped while being held by the discharge roller 33.
Here, as shown in FIG.
Is switched to the position shown in the figure, and the motor 70 is driven to rotate in the reverse direction. As a result, the paper discharge roller 33 rotates in the reverse direction, and starts a reversing operation of sending the document 3 to the reversing conveyance path 36. Also, at this time,
The clutch 71 is released, the driving force of the motor 70 is not transmitted to the PS roller 32, and the PS roller stops rotating.

Next, as shown in FIG. 5B, the original 3 conveyed from the reversing conveyance path 36 to the main conveyance path 35 by the reverse rotation of the discharge roller 33 is fed to the paper input detection switch 4.
The document 3 is conveyed while being in contact with it, and the leading end of the document 3 comes into contact with the nip portion of the PS roller 32 and stops.

At this time, even after the leading end of the document 3 comes into contact with the nip portion of the PS roller 32, the motor 70 is moved so that the discharge roller 33 carries the document 3 for a while.
Is stopped at a timing later than the detection timing of the paper input detection switch 47. The main transport path 35
Are arranged at a certain distance from each other, and an appropriate space is formed in the main transport path 35. Therefore, the leading edge of the original 3 is P
After coming into contact with the nip portion of the S roller 32, the discharge roller 3
The document 3 stops in the space with a slack between the paper discharge roller 33 and the PS roller 32 due to the transport amount given to the document 3 by the document 3. Also, the original 3
Is reliably brought into contact with the PS roller 32 by the restoring force of the slack portion.

Subsequently, the clutch 71 is operated so that the driving force of the motor 70 is transmitted to the PS roller 32. At this time, the position of the switching gate 45 may be simultaneously switched. In this state, when the motor 70 is driven to rotate forward as shown in FIG.
Both the rollers 32 rotate forward and the leading end of the document 3 is the PS roller 3
2 and is transported to the document reading position.

At this time, the paper discharge rollers 33 simultaneously rotate forward, so that the originals 3 are subjected to conveying forces in opposite directions. However, since the originals 3 are slacked at first, these conveying forces are reduced. The slack is absorbed and does not affect the transport of the PS roller 32. However, even after the slack of the original 3 is eliminated, if the conveyance force by the discharge roller 33 is continuously applied,
Normal conveyance by the PS roller 32 cannot be performed. Further, it is conceivable that both the paper discharge roller 33 and the PS roller 32 pull the document 3 to each other, and the paper discharge roller 33 may cause the document 3 to become dirty. Therefore, as shown in FIG. 6B, before the slack of the document 3 is eliminated, the discharge driven roller 33
b from the paper discharge drive roller 33a, and
Release the pressure of 3.

Thereafter, the document 3 is further conveyed, and the leading end of the document 3 is conveyed to the paper discharge roller 33 as shown in FIG. At this time, when the trailing end of the document 3 being conveyed passes, the discharge driven roller 33b of the discharge roller 33 is brought into contact with the discharge drive roller 33a. As a result, the discharged original 3 can be discharged. Also, the paper discharge roller 33
Even if the length of the document 3 in the transport direction is longer than the distance that the paper 3 reaches the paper discharge roller 33 again via the reverse transport path 36 and the main transport path 35 from above, Such a feed of the document 3 is possible without the rollers 33 simultaneously pinching the front and rear end portions of the document 3.

At this time, whether or not the rear end of the document 3 has passed the paper discharge roller 33 is determined as follows. That is, at the time of reading the front side of the document 3, the length of the document 3 is detected based on the time when the paper input detection switch 47 is turned on. At the time of reading the back side of the original 3, the passage timing of the original 3 can be calculated based on the length of the original 3 by the above detection and the rotation speed of the motor 70. It is determined whether or not the rear end exists.

As described above, the document feeder 2
Has a separation / contact mechanism for separating / contacting the paper discharge driven roller 33b with respect to the paper discharge drive roller 33a. The structure of the separating mechanism will be described in detail below with reference to FIGS.

As shown in FIG. 1, a paper discharge driven roller (second
The roller 33b is rotatably attached to a shaft (shaft member) 50. Further, the shaft 50 is mounted on a pressure release frame (frame member) 51 and can move within a range of long holes (long holes) 52a and 52b extending in the vertical direction. The shaft 50 is always pushed upward by kick springs (pressing springs) 53a and 53b, and when the paper discharge driven roller 33b comes into contact with the paper discharge drive roller (first roller) 33a (see FIG. 8). The spring force of the kick springs 53a and 53b becomes a pressing force on the paper ejection drive roller 33a. Further, a sponge 54 is attached to the pressure release frame 51 as an elastic silencing member, and is in contact with the shaft 50. The pressure release frame 51 is attached to a shaft 55,
It moves up and down due to the swing of the shaft.

FIGS. 8 (a) and 8 (b) show the movement of each part during pressurization and non-pressurization.

The paper discharge driven roller 33b is separated from and connected to the paper discharge drive roller 33a by the driving of the solenoid 56. That is, as shown in FIG. 8A, when the solenoid 56 is in the non-energized state,
b is in contact with the paper discharge drive roller 33a, and at this time, the paper discharge roller 33 contributes to the conveyance of the document 3. On the other hand, FIG.
As shown in (b), when the solenoid 56 is energized, the discharge driven roller 33b is driven by the discharge drive roller 33a.
Separated from

When the discharge driven roller 33b is shifted from the state in which it is in contact with the discharge drive roller 33a to the separated state, when the solenoid 56 is energized, the pressure release frame 51 is attracted to the solenoid 56 and suddenly. Descends. Following this, the shaft 50 supporting the paper discharge driven roller 33b is pushed up by the kick springs 53a and 53b, and the elongated holes 52a and 5
Touch the top of 2b. At this time, the shaft 50 is
If the speed at the time of contact with 2a / 52b is high, an unpleasant collision sound is generated.

It can be easily imagined that the most effective way to effectively absorb the collision sound is to provide a sound deadening member in the upper portions of the elongated holes 52a and 52b where the shaft 50 collides. However, there is no space in the above portion where a muffling member can be provided, and it is extremely difficult to mount the muffling member in this portion. Further, if the silencing member is attached to the elongated holes 52a and 52b, the stroke of the shaft 50 cannot be sufficiently obtained, and the discharge driven rollers 33
A situation may occur in which the gap between b and the discharge drive roller 33a is not sufficiently secured. In such a case, when a thick paper document (for example, an envelope or the like) is transported, a transport failure occurs,
This can cause jams.

Further, the muffling member may wear in the above arrangement due to the history of the collision, and may have a reduced thickness. In such a case, even if the muffling effect is obtained in the initial state, there is a possibility that a sufficient muffling effect may not be obtained after the muffling member is worn through the history.

For this reason, in the document feeder 2 according to the present embodiment, as shown in FIG.
At the time of movement of 0, by friction with the sponge 54,
The moving speed of the shaft 50 is reduced, and the collision sound of the shaft 50 is effectively suppressed.

The sponge 54 includes a kick spring 5
It is arranged substantially at the center of 3a / 53b so that the frictional force of the sponge 54 does not adversely affect the balance of the pressing force applied to the left and right of the paper discharge driven roller 33b. By arranging the sponge 54 as described above, even when a slight difference is generated between the left and right kick springs 53a and 53b when the discharge driven roller 33b is pressed against the discharge drive roller 33a, the sponge 54 can be used. By absorbing the pressure difference, the paper discharge drive roller 33a can be pressed, contacted, and rotated with a uniform pressure on the left and right.

When the pressure of the paper discharge roller 33 is released, not all of the spring force accumulated in the kick springs 53a and 53b is transmitted to the shaft 50, but a part of the spring force is transmitted to the shaft 50. It is consumed by friction with 54. That is, the long hole 52 of the pressure release frame 51
The moving acceleration force of the shaft 50 that collides with the a 52 b is reduced by the friction, so that the sound of collision with the pressure release frame 51 can be effectively absorbed and silenced.

As described above, the document feeder 2 attempts to suppress the collision sound when the discharge roller 33 is separated by bringing the sponge 54 into contact with the shaft 50 of the discharge driven roller 33b. However, at this time, the hardness of the sponge 54 is important to obtain a desired noise reduction effect. The following Table 1 shows the relationship between the hardness of the sponge 54, the collision noise when the paper discharge roller 33 is separated, and the transportability of the document 3. The hardness of the sponge 54 in Table 1 was measured by J
The "spring hardness test (A type)" defined in IS K6301-95 was used.

[0057]

[Table 1]

As is clear from Table 1 above, sponge 5
If 4 is too hard (e.g., 90 degrees), to obtain the desired friction with shaft 50, shaft 5
A high-precision positional relationship is required between the sponge 0 and the sponge 54. In particular, in mass production, a slight variation in dimensions causes a variation in the braking effect.

That is, if the distance between the shaft 50 and the sponge 54 is too large, the frictional force is too small to absorb the rotation unevenness of the shaft 50 or to release the pressure of the discharge roller 33 when the shaft 50 is released. The speed of movement cannot be reduced. Conversely, if the distance between the shaft 50 and the sponge 54 is too small, the frictional force is too large and the shaft 50 is
Inability to move sufficiently within 52b, pressure failure occurs between the paper discharge driven roller 33b and the paper discharge drive roller 33a during document transportation, and irregularity in document reading due to transportation failure of the document 3 and transport jam. May occur.

If the sponge 54 is too soft (for example, 10 degrees), the deformation of the sponge 54 due to the contact pressure of the shaft 50 becomes too large,
0 rotation unevenness cannot be absorbed. Further, when the pressure of the paper discharge roller 33 is released, the moving speed of the shaft 50 cannot be sufficiently reduced, and further, the sponge 54 may be worn by the contact pressure due to the movement of the shaft 50. Worn sponge 54 can cause dirt in the device, dirt on documents, and poor reading.

Therefore, the hardness of the sponge 54 used in the document feeder 2 of this embodiment ranges from 20 degrees to 70 degrees.
It must be selected in the range of degrees, with a range of 30 to 50 degrees being most preferred.

[0062]

According to the first aspect of the present invention, there is provided a document feeder comprising: a first roller; and a second roller capable of being separated from and connected to the first roller. A shaft member that supports the second roller, and a frame member that supports the shaft member, wherein the shaft member is movably supported within an elongated hole formed in the frame member, The frame member includes a silencing member made of an elastic body (eg, rubber, sponge, etc.)
This is a configuration that is arranged between the frame member and the shaft member so as to contact the shaft member.

Therefore, when the shaft member moves in the elongated hole of the frame member, an unpleasant collision sound when the shaft member collides with the frame of the elongated hole can be effectively absorbed by the silencing member. In addition, there is an effect that the muffling member can be arranged in a limited space.

According to a second aspect of the present invention, as described above, in addition to the configuration of the first aspect, the shaft member includes a plurality of pressure springs for connecting the second roller to the first roller. Pressure is applied in a biasing direction, and the muffling member is arranged between the adjacent pressure springs and is always in contact with the shaft member.

Therefore, in addition to the effect of the first aspect, by disposing the silencing member between the adjacent pressure springs, the unevenness of the pressing force applied to the shaft member by the silencing member is minimized. be able to. Accordingly, when a plurality of second rollers are supported by the shaft member, an effect is obtained that the pressing force of each roller can be kept uniform.

Further, by constantly contacting the noise reduction member with the shaft member, the noise reduction of the noise reduction member can be prevented, and the effect can be stabilized for a long period of time.
It is possible to reduce the unevenness of the rotation of the roller due to the presence or absence of the document or the driving load, and to achieve an effect that a stable document transport property can be obtained.

According to the third aspect of the present invention, as described above, in addition to the configuration of the first aspect, the hardness of the muffling member is defined by JIS K6301-95 Spring type hardness test A type. The range is 20 degrees to 70 degrees.

Therefore, in addition to the effect of the first aspect, by setting the hardness of the silencing member to an appropriate value, there is an effect that a sufficient silencing effect can be obtained.

[Brief description of the drawings]

FIG. 1 illustrates one embodiment of the present invention, and is a perspective view illustrating a separation / contact mechanism of a discharge roller.

FIG. 2 is an explanatory diagram showing a schematic configuration in a case where a document conveying device including the above-described paper discharge roller and a copying machine are combined.

FIG. 3 is a cross-sectional view illustrating a schematic configuration of the document feeder.

FIG. 4 is an explanatory diagram showing a case where the document feeder is opened to a copying machine.

FIGS. 5A and 5B are explanatory views showing a part of the document transport operation when reading the double-sided document by the document transport device. FIGS.

FIGS. 6A and 6B are explanatory diagrams showing a part of the document transport operation when reading a double-sided document by the document transport device. FIGS.

FIG. 7 is an explanatory diagram showing a part of a document transport operation when reading a double-sided document by the document transport device.

8 (a) and 8 (b) are explanatory diagrams showing a separating / contacting operation of the discharge roller of FIG. 1. FIG.

FIG. 9 is a side view showing a shock absorbing mechanism of a separation roller in a conventional image forming apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 copier 2 document feeder 33 paper discharge roller 33a paper discharge drive roller (first roller) 33b paper discharge driven roller (second roller) 50 shaft (shaft member) 51 pressure release frame (frame member) 52a / 52b Long hole (long hole) 53a / 53b Kick spring (pressure spring) 54 Sponge (silence member)

Claims (3)

(57) [Claims] A first roller, a transport roller pair including a second roller detachable from the first roller, a shaft member supporting the second roller, and a shaft member. And a frame member for supporting the shaft member, wherein the shaft member is movably supported within an elongated hole formed in the frame member, and the frame member includes a silencing member made of an elastic body, A document conveying device disposed between the shaft member and the shaft member so as to contact the shaft member. 2. The shaft member is pressed by a plurality of pressure springs in a direction for urging the second roller against the first roller, and the muffling member is disposed between adjacent pressure springs. 2. The document feeder according to claim 1, wherein the shaft is always in contact with the shaft member. 3. The hardness of the muffling member is JIS K63.
2. The document feeder according to claim 1, wherein the angle is in a range of 20 degrees to 70 degrees defined by a spring type hardness test A type.