JP3205616B2 - Sheet transport device and overhead projector using the sheet transport device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying apparatus which can be mounted on an overhead projector (OHP) which places a sheet document having information such as images and graphs and projects it on a screen. The present invention relates to a sheet conveying apparatus capable of storing originals in a long conveying member and efficiently conveying the originals to a projection position.

[0002]

2. Description of the Related Art Conventionally, a schematic configuration of a sheet transporting device used for an overhead projector (OHP) device (not known) proposed by the present applicant will be described. When the document abuts against the pair of rollers on the supply side, the document detection sensor detects this and drives the motor that is the driving source of the pair of rollers.

[0003] The rotation of the motor rotates the common roll on the winding side, and winds up the transport film and the holding film, which are long transparent films wider than the sheet document. As a result, the sheet document is conveyed by the conveying film, the upper surface is pressed by the pressing film, and the sheet document is wound on a common roll while being sandwiched by both films.

After the first sheet document has been conveyed in this manner, the second and subsequent sheet documents are similarly conveyed, and a plurality of sheet documents are wound around a common roll. Of the plurality of sheet documents wound on the common roll, an arbitrary sheet document is conveyed onto the reading area of the exposure unit and irradiated with light, and the transmitted light is projected on a screen via a reflection mirror and a lens. Is done.

[0005]

However, in the conventional sheet conveying apparatus, as shown in FIG. 5, the conveying film 52 and the pressing film 53 have the same width and a sheet original.
Since the width is wider than 51, there are the following problems. (1) The exposure area of a currently commercially available OHP apparatus is “28
5 mm x 285 mm ", for example, A4
When a sheet original 51 of a size is conveyed with the longitudinal side (297 mm) of the sheet original 51 arranged perpendicularly to the conveying direction (hereinafter referred to as “transverse feeding”), an image may be missing. In such a case, the sheet document 51 sandwiched between the transport film 52 and the pressing film 53 is once taken out, and the center of the sheet document 51 is shifted from the center of the exposure unit R so that a necessary image is not missing, so that the position of the sheet document 51 is shifted. It had to be corrected and transported again, and the correction work was troublesome. (2) Even when the sheet document 51 is skewed on the exposure section R, the sheet document 51 has to be taken out and corrected once as in (1).

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a sheet conveying apparatus capable of easily correcting the position of a sheet document conveyed while being held between a conveying member and a pressing member on an exposure unit. It is in.

[0007]

A typical configuration according to the present invention for achieving the above object is a long transport member for transporting a sheet document, and a long transport member for pressing the sheet document. Holding member, a first winding unit for winding the conveying member to one side outside the reading area of the exposure unit,
A second winding unit for winding the transport member to the other side outside the reading area of the exposure unit; and a driving unit for driving the first winding unit and the second winding unit. The width of the conveying member is wider than the width of the sheet document, and the width of the pressing member is narrower than the width of the sheet document.

[0008]

In the above construction, the width of the conveying member is made wider than the width of the sheet document, and the width of the pressing member is made narrower than that of the sheet document, so that the sheet conveyed while being held between the conveying member and the pressing member. The original can be easily moved on the exposure unit to correct the position.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a sheet transporting apparatus for an overhead projector (OHP) using the present invention will be described with reference to FIGS. FIG. 1 is an external view of an OHP apparatus using the sheet conveying apparatus according to the first embodiment, FIG. 2 is a cross-sectional view of the sheet conveying apparatus, and FIG. 3 is an explanatory view of a driving system of the sheet conveying apparatus. 4 is a top view of the exposure unit.

First, the overall structure of a sheet conveying apparatus A and an OHP apparatus using the present invention will be described. The sheet conveying apparatus A is loaded into an OHP apparatus B shown by a two-dot chain line in FIG.
The OHP sheet original 1 to be used in the apparatus B is automatically sent out. That is, a plurality of sheet documents 1 are sequentially sandwiched between a transport member 2 made of a long transparent film and a pressing member 3 also made of a long transparent film. It is wound around the winding means 4 and the second winding means 5. Then, the two films 2 and 3 are brought into close contact with each other on the exposure unit 101 with the sheet document 1 sandwiched by the stretching means 6. In this state, the right motor 7 as the first driving unit or the left motor 8 as the second driving unit is driven to wind both films 2 and 3 around the first winding unit 4 or the second winding unit 5. Then, the desired sheet document 1 is conveyed onto the platen glass 102 of the exposure unit 101 of the OHP apparatus B. The sheet original 1 is irradiated with light from the exposure unit 101, and the transmitted light is transmitted to the arm 1
By projecting onto a screen (not shown) via a reflecting mirror 104 and a lens 105 as projection means supported upward by 03, an image described in the document is enlarged and projected.

Next, the configuration of each part of the sheet conveying apparatus A will be described individually. (Conveying Film and Pressing Film) The conveying film 2 and the pressing film 3 hold the sheet document 1 so as to sandwich it. The transport film 2 carries the sheet document 1 and transports the sheet document 1 as the transport film 2 is wound. The pressing film 3 presses the upper surface of the sheet document 1 on the transport film 2 to prevent the sheet document 1 from curling and to prevent the sheet document 1 from being damaged.

The transport film 2 and the holding film 3
For example, as shown in FIG. 4, the width of the transport film 2 is the width of the sheet document 1 (A4 size width 297 mm).
A wider film (width 297 + β mm) is used, and the width of the pressing film 3 is wider than the width (285 mm) of the reading area R of the exposure unit 101 and the width of the sheet document 1 (A4 size width 297). mm) film (width 285)
+ Α (<297) mm). A transparent film is used for the transporting film 2 and the pressing film 3, and the film is preferably thin as long as the strength is maintained, and a film having a thickness of about 25 μm to 60 μm is suitably used. As the material, a material having good light transmittance and stable heat resistance is preferable. For example, a polyethylene terephthalate film or the like is preferably used.

As shown in FIG. 4, frame marks 2a are provided at predetermined intervals at the widthwise end of the transport film 2. By detecting the frame mark 2a by the frame detection sensor, a desired document is conveyed and set on the exposure unit.

(First Winding Means) The first winding means 4 winds one end of the long transport film 2 and one end of the pressing film 3, and as shown in FIG.
Are arranged outside the reading area of the exposure unit 101. In this embodiment, as shown in FIGS. 2 and 3, a transport roll 4 a that is disposed on the right outside the reading area of the exposure unit 101 and winds the transport film 2 between the front and rear frames 9 a and 9 b, and a presser that winds the presser film 3. The roll 4b is attached rotatably.

That is, as shown in FIG.
Is fixed between the front and rear frames 9a and 9b by screws or the like, and the front and rear pulleys 4a2 and 4a3 rotatably mounted on the roll shaft 4a1 are press-fitted onto both ends of the transport roll 4a and mounted. The transport film 2 is wound around the sheet. Similarly, for the holding roll 4b, a roll shaft 4b1 is fixed between the front and rear frames 9a and 9b with screws or the like, and the front and rear pulleys 4b2 and 4b3 rotatably attached to the roll shaft 4b1 are pressed into both ends of the holding roll 4b. The holding film 3 is wound around the holding roll 4b.

The transfer roll 4a and the holding roll 4
As shown in FIG. 2, the positional relationship with the transport roll 4a
Are arranged on the lower side, and the holding roll 4b is on the upper side.

(Second Winding Means) The second winding means 5 winds the other ends of the long transport film 2 and the pressing film 3, and as shown in FIG.
Are arranged outside the reading area of the exposure unit 101.
In the present embodiment, as shown in FIGS.
Of the front and rear frames 9a, 9b
A common roll 5a around which the transport film 2 and the holding film 3 are wound is rotatably mounted therebetween.

That is, as shown in FIG. 3, the common roll 5a
Is mounted by pressing a roll shaft 5b between the front and rear frames 9a and 9b with screws or the like, and press-fitting the front and rear pulleys 5c and 5d rotatably mounted on the roll shaft 5b into both ends of the common roll 5a. The transport film 2 and the holding film 3 are wound around 5a. A gear 5e is engaged with the rear pulley 5d, and the gear 5e meshes with the motor gear 17 to transmit rotation from the left motor 8. The gear 5e has a built-in torque limiter, and is configured so that the transmission of the driving force from the motor gear 17 is not transmitted to the rear pulley 5d at a certain torque or more.

(Stretching Means) Stretching means 6 comprises a transport film 2 and a pressing film 3 sandwiching a sheet original 1 therebetween.
It is stretched so as to be in close contact with each other on the platen glass 102 of the apparatus B. In this embodiment, as shown in FIGS. 6a and 6b are provided, and a left roller 6c is provided on the left side outside the reading area.

The lower right roller 6a and the left roller 6c are
As shown in FIGS. 2 and 3, roller shafts 6a1 and 6c1 are fixed between the front and rear frames 9a and 9b with screws or the like, and the front and rear pulleys 6a rotatably mounted on the roller shafts 6a1 and 6c1.
2, 6a3 at both ends of the lower right roller 6a, and front and rear pulleys 6c.
2, 6c3 are attached by press-fitting to both ends of the left roller 6c. Then, as shown in FIG. 2, the transport film 2 and the pressing film 3 pass over the lower right roller 6a and pass under the left roller 6c, and are tightly stretched over the exposure unit 101. It has become.

The upper right roller 6b is also rotatably attached to the front and rear frames 9a, 9b, and is urged to the lower right roller 6a by a spring or the like (not shown). The films 2 and 3 are brought into close contact with each other by passing the transport film 2 and the pressing film 3 between the right roller pair 6a and 6b.

(Drive System) Next, a drive transmission system for winding the transport film 2 and the pressing film 3 will be described.

The transport film 2 and the holding film 3
Drives and rotates the transport roll 4a, the holding roll 4b, and the common roll 5a around which these are wound, and in the present embodiment, the transport rolls 4a and The holding roll 4b is driven and rotated by the right motor 7 as a stepping motor, and the common roll 5 constituting the second winding means is rotated.
a is driven and rotated by a left motor 8 which is also a stepping motor. The specific configuration will be described below.

As shown in FIG. 3, a right motor 7 is mounted on the right side of the rear frame 9b. The transport roll 4
After being press-fitted into one end of the right pulley 4a3, the pulley 4a3 is constituted by a pulley gear, and the gear portion of the motor pulley gear 10 connected to the right motor 7 meshes with the gear portion of the rear pulley 4a3, and the driving force of the right motor 7 Is transmitted to the transport roll 4a.

On the other hand, a torque limiter 11 is attached to one end of a roll shaft 4b1 of the pressing roll 4b, and a roll gear 12 is attached via the torque limiter 11, and the roll gear 12 meshes with a transmission gear 13a. ing.
The transmission gear 13a is a one-way gear mounted on a transmission shaft 13b rotatably mounted on the rear frame 9b, and the transmission shaft 13b transmits a rotational force in one direction (the pressing force is transmitted so that the pressing roll 4b winds the pressing film 3). When the transmission shaft 13b rotates in the opposite direction, the transmission shaft 13b is locked with respect to the transmission shaft 13b to transmit torque to the roll gear 12, and when the transmission shaft 13b rotates in the opposite direction, the transmission shaft 13b is free. As a result, the rotational force is not transmitted to the roll gear 12.

A pulley 13c is connected to the transmission shaft 13b, and the pulley 13c is connected to a pulley of the motor pulley gear 10 by a belt 14. As a result, the driving force of the right motor 7 is transmitted to the transmission shaft 13b, and is transmitted from the transmission gear 13a to the holding roll 4b via the roll gear 12 and the torque limiter 11.

As described above, the rotational force is transmitted to the transport roll 4a and the press roll 4b by the drive of the right motor 7, and at this time, the rotational peripheral speed of the press roll 4b becomes faster than the rotational peripheral speed of the transport roll 4a. The gear ratio is set as follows. Note that the higher speed is absorbed by the torque limiter 11 as described later, so that the transport film 2 and the pressing film 3 are always kept at the same speed by the respective rolls 4a and 4
b.

Further, as shown in FIG. 3, after being pressed into the press roll 4b, a brake plate 15 made of a friction member is pressed against the pulley 4b3 by a press spring 16.
A brake is applied to the rotation of the holding roll 4b.

On the other hand, a left motor 8 is mounted on the left side of the rear frame 9b, and a motor gear connected to the left motor 8 is provided.
After the 17 is pressed into one end of the common roll 5a, the pulley 5d
And the gear 5e formed at the same time. As a result, the common roll 5a is rotated by driving the left motor 8, and the transport film 2 and the pressing film 3 are wound up.

The operation panel 18 of the sheet conveying device A
Is provided with a remote control receiving unit, and is configured to be able to remotely control driving instructions of the left and right motors 7, 8 and the like by a remote control 19.

(Sheet Document Supply Structure) In the vicinity of the first winding means 4, as shown in FIG. 2, a supply tray 20a for supplying the sheet document 1 is mounted so as to be swingable about a roll shaft 4a1. It is configured to swing by driving the cam 20b. The leading end of the supply tray 20a is located below the upper right roller 6b. When the tray 20a swings and the leading end moves upward, the sheet document 1 placed on the tray 20a is pressed against the pressing film 3. It is configured as follows.

An original detection sensor 20c is provided on the supply tray 20a. This sensor 20c is
When there is no sheet document 1 above, the sensor arm stands up. When the sheet document 1 is placed, the sensor arm falls down, and the state of the arm is detected by a reflection sensor or the like (not shown) to determine the presence or absence of the sheet document 1. It is to detect.

(Frame Mark Detection Structure) As shown in FIG. 2, a frame detection sensor 21 is provided between the right roller pair 6a, 6b and the transport roll 4a so as to sandwich the transport film 2. This sensor 21 is constituted by a transmission type sensor,
It detects the frame mark 2a provided at the width direction end of the transport film 2.

Incidentally, the frame mark 2a is the transport film 2
Are provided continuously in the vicinity of both ends in the longitudinal direction, and the other portions are provided at substantially the same intervals as the length of the sheet document 1. Therefore, when the transport film 2 is wound on the transport roll 4a or the common roll 5a, the frame detection sensor 21 detects the frame mark 2a to detect the position of the sheet document 1, and detects the continuous frame mark 2a. Thus, the winding end of the transport film 2 can be detected.

(Sheet Document Conveying Operation) Next, the operation of conveying the sheet document 1 by the sheet conveying apparatus A having the above-described configuration will be described.

First, the sheet original 1 is placed on the supply tray 20a, and the leading end of the original is abutted against the pair of right rollers 6a, 6b.
The document detection sensor 20c detects this, and the left motor 8 is driven. Due to the rotation, the left roller pair 6c and 6d and the common roll 5a rotate clockwise in FIG. 2 to wind up the transport film 2 and the holding film 3. As a result, the sheet document 1 is transported by the transport film 2 and the upper surface is pressed by the pressing film 3,
The film is wound around the common roll 5a while being sandwiched between the films 2 and 3. At this time, the right roller pair 6a, 6b is driven to rotate by the conveyance of the films 2, 3.

When the films 2 and 3 are wound on the common roller 5a, the transport roll 4a and the press roll 4b are driven to rotate to feed the transport film 2 and the press film 3, respectively, but the right motor 7 is stopped. Then, a rotational load is applied to the transport roll 4a by the stop torque, and the transport film 2 is fed out with a tension applied.

Then, the frame detection sensor 21 detects the transport film 2
When the frame mark 2a is detected, the driving of the left motor 8 is immediately stopped. Also at this time, since the rotation brake is applied to the transport roll 4a by the stop torque of the right motor 7, the transport film 2 is not fed out due to inertia, and the film 2 does not sag.

On the other hand, when the pressing roll 4b rotates in the direction in which the pressing film 3 is fed out, the transmission gear (one-way gear) 13a is in a free state, so that the right motor 7
Does not act on the holding roll 4b. However, since the brake plate 15 is in pressure contact with the pressing roll 4b, a load is applied to the rotation of the pressing roll 4b by the braking action, and tension is applied to the pressing film 3 that is fed out, and at the same time, the pressing by inertia is stopped when the rotation is stopped. The unwinding of the film 3 is prevented to prevent the film 3 from sagging.

After the first sheet original 1 is conveyed as described above, the second and subsequent sheet originals 1 are conveyed in the same manner, and a plurality of sheet originals are wound around the common roll 5a. When the frame detection sensor 21 detects a continuous frame mark 2a during the document conveyance, the document detection sensor 20c detects the sheet document 1 any more since the conveyance film 2 fed from the conveyance roll 4a is at the end. However, the left motor 8 is not driven.

After the plurality of sheet documents 1 are wound on the common roll 5a as described above, an arbitrary sheet document 1 can be conveyed onto the reading area R of the exposure unit 101 by using a remote control.
When the right frame feed button 19 is pressed, the right motor 7 is driven to rotate the transport roll 4a in the counterclockwise rotation direction in FIG.

When the right motor 7 is driven, the transmission gear 13a
Since the lock state is established, the rotational force of the right motor 7 is also transmitted to the press roll 4b via the torque limiter 11. At this time, due to the setting of the gear ratio, a rotational force that rotates at a higher peripheral speed than the transport roll 4a is transmitted to the press roll 4b, but the brake of the common roll 5a that feeds the press film 3 more than the torque of the torque limiter 11 is transmitted. If the force is large, the torque limiter 11 slips. Accordingly, the pressing roll 4b always follows the rotation peripheral speed of the transport roll 4a, and the pressing film 3 that has been fed from the common roll 5a by the rotation of the transport roll 4a is wound up.

The common roll 5a rotates following the feeding of the transport film 2 and the holding film 3,
Since the left motor 8 is in the stopped state, a rotational load is applied to the common roll 5a by the stopping torque, and the films 2 and 3 are unwound with tension applied.

Then, the frame detection sensor 21 detects the transport film 2
When the frame mark 2a is detected, the driving of the right motor 7 is immediately stopped. Also at this time, since the rotary brake is applied to the common roll 5a by the stop torque of the left motor 8, the transport film 2 and the pressing film 3 are not fed out by inertia, and the films 2 and 3 There is no sagging.

As described above, when the frame detection sensor 21 detects the frame mark 2a and stops the transport of the transport film 2, as shown in FIG. The interval between the frame marks 2a is set so as to be located at the center of the reading area R. This is to prevent the OHP apparatus from enlarging the exposure image through the lens so that the periphery of the screen is dark and the image is not clearly projected.

When the right frame feed button of the remote controller 19 is further pressed, the next sheet document 1 is similarly conveyed so as to be located in the reading area of the exposure unit 101. The sheet original 1 that has passed through the exposure unit 101 is sequentially wound up on a transport roll 4a together with the transport film 2.

Therefore, the desired sheet document 1 is
It is possible to easily stop the frame feed in the state of reaching the first reading area and project the original 1.

The remote controller 19 is provided with a right fine movement feed button and a right continuous feed button. By these operations, the right motor 7 is finely rotated to finely feed the sheet document 1, or the right motor 7 is continuously rotated. Then, the sheet original 1 can be continuously conveyed. In the case of continuous feeding, when the frame detection sensor 21 detects the continuous frame mark 2a, the driving of the motor is automatically stopped because the conveyed film 2 has been fed to the vicinity of the end.

After the sheet document 1 is wound on the transport roll 4a as described above, the sheet document 1 wound on the roll 4a is transported again to the reading area R of the exposure unit 101. When the left frame feed button is pressed, the left motor 8 is driven and the sheet document 1 is conveyed so as to be wound up from the conveying roll 4a to the common roll 5a. As a result, the desired sheet document 1 can be conveyed to the reading area of the exposure unit 101. When the sheet document 1 is taken up from the transport roll 4a to the common roll 5a, the left fine feed and the left continuous feed can be performed by operating the remote controller 19 in addition to the left frame feed.

According to the above configuration, by defining the widths of the transport film 2 and the pressing film 3 as described above, a portion of the sheet original 1 that is exposed outside the pressing film 3 on the transport film 2 is provided. With this operation, the sheet document 1 can be easily moved on the reading area of the exposure unit 101, and the lines on both sides of the pressing film 3 are projected on the screen, which adversely affects the appearance of the projected image. Can also be prevented.

Although the present embodiment has been described with respect to only the A4 size sheet document 1, the present invention is not limited to this, and can be applied to all sizes of sheet document.

[0053]

As described above, according to the present invention, the width of the conveying member is made wider than the width of the sheet document, and the width of the pressing member is made narrower than that of the sheet document. It is possible to easily move the written sheet document on the exposure unit to correct the position, and to project a missing image on the screen. Also,
The correction of the skew of the sheet document can be performed instantaneously without taking out the sheet document.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view of a sheet conveying device according to a first embodiment of the present invention, which is loaded in an OHP device.

FIG. 2 is an explanatory cross-sectional configuration diagram of a sheet conveying device.

FIG. 3 is an explanatory diagram of a driving system of the sheet conveying device.

FIG. 4 is a top view of an exposure unit.

FIG. 5 is a top view of an exposure unit of a conventional OHP apparatus.

[Explanation of symbols]

 A: Sheet conveying device B: OHP device 1: Sheet document 2: Conveying film 2a: Frame mark 3: Holding film 4: First winding unit 4a: Conveying roll 4b: Holding roll 5: Second winding unit 5a: Common Roll 6 ... Tension means 6a, 6b ... Right roller 6c ... Left roller 7 ... Right motor 8 ... Left motor 9a, 9b ... Frame 11 ... Torque limiter 12 ... Roll gear 13a ... Transmission gear 13b ... Transmission shaft 13c ... Pulley 14 ... Belt 15 ... Brake plate 16 ... Pressing spring 18 ... Operation panel 19 ... Remote control 20a ... Supply tray 20c ... Document detection sensor 21 ... Frame detection sensor 101 ... Exposure unit 102 ... Platen glass 103 ... Arm 104 ... Reflection mirror 105 ... Lens

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuhiro Matsuo 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-4-288534 (JP, A) JP-A-60 -1634734 (JP, A) JP-A-2-136843 (JP, A) JP-A-60-46536 (JP, A) JP-A-4-40232 (JP, U) JP-A-61-176541 (JP, U) ) 62-146132 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03B 21/132

Claims (3)

(57) [Claims] An elongate conveying member for conveying a sheet document; an elongate pressing member for pressing the sheet document; and winding the conveying member around one side outside a reading area of an exposure unit. A first winding unit for taking up, a second winding unit for winding the transport member to the other side outside the reading area of the exposure unit, and the first winding unit and the second winding unit. And a driving unit for driving the sheet conveying device, wherein the width of the conveying member is wider than the width of the sheet document, and the width of the pressing member is narrower than the sheet document. 2. When the sheet document width is wider than the exposure area width, the width of the transport member is wider than the sheet document width.
2. The sheet conveying apparatus according to claim 1, wherein the width of the pressing member is larger than the width of the exposure area and smaller than the width of the sheet document. 3. An overhead projector comprising: the sheet conveying device according to claim 1; and a projection unit configured to project light emitted from the exposure unit onto a sheet document.