JPH0738704A - Original conveyer and overhead projector - Google Patents

Abstract

PURPOSE:To make an original image projected on a screen look more attracting by cutting off the exposure of an original out of the image area. CONSTITUTION:Exposure shielding members 37a, 37b, 43a and 43b are arranged outside an exposure area R, and racks 35 and 36 and racks 41 and 42 are respectively formed at the exposure shielding members 37a and 37b and the exposure shielding members 43a and 43b and respectively engaged with a pulley gear 34. Since driving is transmitted through the pulley gear 34 to the racks 35 and 36 by the driving force of a motor, the exposure shielding members 37a and 37b move to right and left and enter/leave the exposure area R. Similarly since the driving is transmitted to the racks 41 and 42 by the motor, the exposure shielding members 43a and 43b move upward and downward and enter/ leave the exposure area R. The rotating speed of the motor is controlled corresponding to the number of clocks from a home position corresponding to the size of the original and at the time of reset, the respective exposure shielding members 37a, 37b, 43a and 43b are returned to the home position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an original conveying apparatus which can be mounted on an overhead projector (OHP), and more particularly, an original having information such as an image and a graph is placed on a long conveying member to efficiently project a projection position. The present invention relates to a document conveying device that can convey a document.

[0002]

2. Description of the Related Art Conventionally, an original conveying device mounted on an overhead projector (OHP) device will be described with reference to FIGS. In FIG. 5, document feeder A
Is mounted on the OHP device B shown by the chain double-dashed line in the figure.
The original document 51 is automatically conveyed.

That is, as shown in FIG. 6, a plurality of originals 51 are sequentially sandwiched and held between a conveying member 52 made of a long transparent film and a pressing member 53 made of a long transparent film. To do. Both ends of the films 52 and 53 are fixed to the first winding means 54 and the second winding means 55, respectively, and the exposure section is held with the original 51 being sandwiched by the stretching means 56.
It is constructed so as to be in close contact with 101. Fig. 5 in this state
By driving the right motor 57, which is the first driving means, or the left motor 58, which is the second driving means, shown in FIG. 1, to wind both films 52, 53 around the first winding means 54 or the second winding means 55. A desired original 51 is conveyed onto the platen glass 102 of the exposure unit 101 of the OHP device B. Then, the original 1 is irradiated with light from the exposure section 101, and the transmitted light is projected on a screen (not shown) via the reflection mirror 104 and the lens 105 held by the arm 103.

[0004]

However, in the above-described conventional document feeder, since a fixed area is always exposed regardless of the size of the document 51, at least one of the vertical and horizontal directions of the document 51 is smaller than the exposure area. In this case, since the light is projected on the screen without being blocked, the projection image may be difficult to see because it is dazzling. In particular,
The size of the exposure area of most commercially available OHP devices B is a square shape with a size of 285 mm × 285 mm, but the size of the A4 size document 51 is 210 mm × 297 mm, which is the length in the lateral direction. 210 mm is 75 mm from one side of the exposure area of 285 mm
Light is leaked and projected onto the screen in a short exposure area of 75 mm x 285 mm.

In order to solve the above-mentioned problems, a document feeder A
In OHP device B that does not use, the original 51 was attached to the frame with a window in the center,
511 It takes a lot of time and effort to paste each one. Further, the original 51 attached to the frame having appropriate rigidity and thickness was not suitable for being automatically fed by the original conveying device A.

The present invention solves the above-mentioned problems of the prior art. The object of the present invention is to improve the appearance of the original image projected on the screen by blocking the exposure outside the image area of the original. A document feeder is provided.

[0007]

A typical configuration according to the present invention for achieving the above object is mounted on an overhead projector for irradiating an original image on an original table with light from an exposure section and projecting it onto a screen. In a document feeder for automatically feeding a document, an exposure blocking means for blocking light outside the image area of the document placed above the document transport surface on the document table is provided.

[0008]

According to the above means, by providing the exposure blocking means for blocking the light outside the image area of the document placed above the document transport surface on the document table, the appearance of the document image projected on the screen can be improved. You can get better.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the document feeder according to the present invention will now be described with reference to FIGS. 1 is a cross-sectional configuration diagram of the document feeder, FIG. 2 is a diagram of the drive system of the document feeder, FIG. 3 is a top view of the exposure blocking means, and FIG. 4 is a diagram of the transport film.

First, the overall structure of the sheet conveying apparatus A and the OHP apparatus according to the present embodiment will be described. This is to load the sheet conveying apparatus A into the OHP apparatus B shown by the chain double-dashed line in FIG.
The original 1 for OHP used in the apparatus B is automatically sent out. That is, a plurality of originals 1 are sequentially sandwiched between a conveying member 2 made of a long transparent film and a pressing member 3 made of a long transparent film, and both films 2 and 3 are wound in a first roll. It is wound around the winding means 4 and the second winding means 5. And the two films 2,
In the state that the document 3 is sandwiched between the document 1 by the stretching means 6, the exposure unit 10
1 Make sure they are in close contact with each other. In this state, the right motor 7 as the first driving means or the left motor 8 as the second driving means is driven to wind both films 2 and 3 around the first winding means 4 or the second winding means 5. The desired original 1 is conveyed onto the platen glass 102 of the exposure unit 101 of the OHP device B.
By irradiating the original 1 with light from the exposure section 101 and projecting the transmitted light onto a screen (not shown) via a reflecting mirror 104 and a lens 105, which are projection means supported above by an arm 103, It is configured to project the image described in the document in an enlarged manner.

Next, the structure of each part of the sheet conveying apparatus A will be individually described.

(Conveying film and pressing film)

The transport film 2 and the pressing film 3 hold the original 1 so as to sandwich it, and are made of a transparent film which is long and wider than the width of the original 1. It is preferable that the film is thin if the strength is maintained, and a film having a thickness of about 25 μm to 60 μm is preferably used. As a material, a material having good light transmittance and stable heat resistance is preferable, and for example, a polyethylene terephthalate film or the like is preferably used.

The original film 1 is placed on the transport film 2, and the original document 1 is transported as the transport film 2 is wound. On the other hand, the pressing film 3 is the transport film 2
The upper surface of the upper original 1 is pressed to prevent the original 1 from curling and to prevent the original 1 from being scratched.

Further, as shown in FIG. 4, frame marks 2a are provided at predetermined intervals at the end portions of the transport film 2 in the width direction. By detecting the frame mark 2a by a frame detection sensor, a desired document is conveyed and set on the exposure section.

(First winding means)

The first winding means 4 is for winding one end of the long transport film 2 and the pressing film 3 and is arranged outside the reading area of the exposure section 101 of the OHP device B as shown in FIG. To be done. In the present embodiment, as shown in FIG. 1, a conveyance roll 4a, which is arranged on the right side outside the reading area of the exposure unit 101 and winds the conveyance film 2 between the front and rear frames 9a and 9b, and a pressure roll 4b which winds the pressure film 3. Is rotatably attached.

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

The carrying roll 4a and the pressing roll 4
The positional relationship with b is as shown in FIG.
Is on the lower side and the pressing roll 4b is on the upper side.

(Second winding means)

The second winding means 5 is for winding the other ends of the long conveying film 2 and the pressing film 3 and is arranged outside the reading area of the exposure section 101 of the OHP device B as shown in FIG. It is what is done. In this embodiment, as shown in FIG. 1, it is arranged on the left side outside the reading area of the exposure unit 101, and a common roll 5a around which the transport film 2 and the pressing film 3 are wound is rotatably attached between the front and rear frames 9a and 9b. There is.

That is, as shown in FIG. 2, the common roll 5a
Is mounted by pressing the roll shaft 5b between the front and rear frames 9a and 9b with screws or the like, and pressing the front and rear pulleys 5c and 5d rotatably attached to the roll shaft 5b to both ends of the common roll 5a. The transport film 2 and the pressing film 3 are wound around 5a.

(Stretching means)

The stretching means 6 stretches the conveying film 2 and the pressing film 3 with the original 1 sandwiched therebetween so as to be in close contact with each other on the platen glass 102 of the OHP device B. In this embodiment, As shown in FIG. 1, a pair of right rollers 6a and 6b is provided on the right side outside the reading area of the exposure unit 101, 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 FIG. 2, the roller shafts 6a1 and 6c1 are fixed between the front and rear frames 9a and 9b by screws or the like,
Front and rear pulleys 6a2, 6a3 rotatably attached to 1, 6c1
On both ends of the lower right roller 6a, and the front and rear pulleys 6c2, 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 above the lower right roller 6a,
Also, by passing under the left roller 6c, the exposure unit 101
It is designed to be stretched tightly on top.

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

(Drive system)

Next, the transport film 2 and the pressing film 3
A drive transmission system for winding up will be described.

The carrier film 2 and the pressing film 3
Is configured to wind the transport roll 4a around which they are wound, the pressing roll 4b, and the common roll 5a into respective rolls by drivingly rotating them. In the present embodiment, the transport rolls 4a and The pressing roll 4b is driven and rotated by the right motor 7 which is a stepping motor, and the common roll 5 constituting the second carrying-up and winding stage.
a is configured to be driven and rotated by the left motor 8 which is also a stepping motor. The specific configuration will be described below.

As shown in FIG. 2, a right motor 7 is attached to the right side of the rear frame 9b. In addition, the transport roll 4
The rear pulley 4a3 press-fitted into one end of a is composed of 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 to drive 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 the roll shaft 4b1 of the pressing roll 4b, and a roll gear 12 is attached via the torque limiter 11. The roll gear 12 meshes with a transmission gear 13a. ing.
The transmission gear 13a is a one-way gear attached to a transmission shaft 13b rotatably attached to the rear frame 9b, and the transmission shaft 13b transmits the rotational force in one direction (the pressing roll 4b winds the pressing film 3). Rotation direction), the transmission shaft 13b is locked and the rotational force is transmitted to the roll gear 12. When the transmission shaft 13b rotates in the opposite direction, the transmission shaft 13b is free from the transmission shaft 13b. Therefore, 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 and the pulley portion of the motor pulley gear 10 are connected by a belt 14. As a result, the driving force of the right motor 7 is transmitted to the transmission shaft 13b, transmitted from the transmission gear 13a to the roll gear 12, and further to the pressing roll 4b via the torque limiter 11.

As described above, the driving force of the right motor 7 transmits the rotational force to the conveying roll 4a and the pressing roll 4b. At this time, the rotating peripheral speed of the pressing roll 4b becomes faster than the rotating peripheral speed of the conveying roll 4a. The gear ratio is set like this. Incidentally, since the high speed is absorbed by the torque limiter 11 as will be described later, the transport film 2 and the pressing film 3 are always at the same speed with the rolls 4a, 4 respectively.
It is wound around b.

Further, as shown in FIG. 2, a brake plate 15 made of a friction member is pressed against a rear pulley 4b3 press-fitted into the pressing roll 4b by a pressing spring 16,
A brake is applied to the rotation of the press roll 4b.

On the other hand, a left motor 8 is attached to the left side of the rear frame 9b, and a motor gear connected to the motor 8 is attached.
17 is pressed into one end of the common roll 5a, and then the pulley 5d
It meshes with the gear part formed on. As a result, the common roll 5a is rotated by the drive of the left motor 8 and the transport film 2 and the pressing film 3 are wound up.

As shown in FIG. 1, the operation panel 18 of the sheet conveying apparatus A is provided with a remote control receiver so that the remote controller 19 can remotely control the drive instructions of the left and right motors 7, 8. I am configuring.

(Document supply configuration)

In the vicinity of the first winding means 4, as shown in FIG. 1, a supply tray 20a for supplying the original 1 is provided with a roll shaft 4a1.
Is mounted so as to be swingable about a center and is configured to swing by the drive of the cam 20b. This supply tray 20
The tip of a is located below the upper right roller 6b, and the tray 20
When a is rocked and the tip is moved upward, the tray 20a
The original 1 placed on the pressing film 3 is pressed against the pressing film 3.

A document detection sensor 20c is provided on the supply tray 20a. This sensor 20c is the tray 20
When the original 1 does not exist on the upper side, the sensor arm stands up. When the original 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 detect the presence or absence of the original 1. Is.

(Frame mark detection configuration)

Further, as shown in FIG. 2, the right roller pair 6a,
A frame detection sensor 21 is provided so as to sandwich the transport film 2 between 6b and the transport roll 4a. The sensor 21 is composed of a transmissive sensor, and detects the frame mark 2a (see FIG. 4) provided at the widthwise end of the transport film 2.

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

(Structure of Exposure Blocking Means)

In FIG. 3, 37a, 37b and 43a, 43b
Is an exposure blocking member, and is a pressing film 3 shown in FIG.
Of the exposure area R shown in FIG. In FIG. 3, the exposure blocking member 37a,
Racks 35 and 36 and exposure blocking members 43a and 43 are provided on the inner and outer surfaces of 37b.
Racks 41 and 42 are formed on the inner and outer surfaces of b, respectively. The racks 35 and 36 mesh with the gear portion of the pulley gear 34, and the racks 41 and 42 mesh with the gear portion of the pulley gear 40, respectively. As shown in FIG. 2, the driving force of the motor 30 is the motor pulley 32 and the belt 33.
Is transmitted to the pulley gear 34 connected through the racks and the drive is transmitted to the racks 35 and 36 meshing with the gear portion of the pulley gear 34, whereby the exposure blocking members 37a and 37b move in the left-right direction in FIG. Then, it moves back and forth from the exposure region R. Similarly, the driving force of the motor 31 is transmitted to a pulley gear 40 connected to the motor pulley 38 via a belt 39,
The drive is transmitted to the racks 41 and 42 meshing with the gear portion of the 40, so that the exposure blocking members 43a and 43b are moved to the position shown in FIG.
Of the exposure area R, and moves back and forth from the exposure area R.

The rotation amount of the motors 30 and 31 is the same as the original document 1.
Are controlled by the number of clocks from the home position according to the size of the
It is managed by 44, 45 and photo interrupters 46, 47. At the time of resetting the document size, first, the exposure blocking members 37a, 37b and 43a, 43b respectively detect the home position of the home position sensor (not shown).
The motors 30 and 31 rotate from this position by the number of clocks corresponding to the document size. Also holding film 3
The distance from the upper surface of the exposure blocking members 37a, 37b and 43a, 43b to the exposure blocking members 37a, 37b and 43a, 43b is maintained at a predetermined interval.
A guide member (not shown) is provided on the exterior cover or the front and rear frames 9a and 9b in order to prevent the inclination of a, 37b and 43a, 43b. Further, the exposure blocking members 37a, 37b and the exposure blocking members 43a, 43b are mounted in different steps so as not to interfere with each other.

(Document transport operation)

Next, the operation of conveying the original 1 by the original conveying apparatus A having the above-mentioned structure will be described.

In FIG. 1, first, the original 1 is supplied to the supply tray 20a.
When the front end is abutted against the right roller pair 6a, 6b, the document detection sensor 20c detects this and the left motor 8 is driven. The rotation causes the common roll 5a to rotate in the clockwise direction in FIG. 1, and winds up the transport film 2 and the pressing film 3. As a result, the original 1 is conveyed by the conveying film 2, the upper surface thereof is pressed by the pressing film 3, and is wound around the common roll 5a while being sandwiched between the films 2 and 3. In this way, after the first original 1 is conveyed, the second and subsequent originals 1 are similarly conveyed to wind a plurality of originals 1 around the common roll 5a. At this time, the right roller pair 6a, 6b and the left roller 6c are rotated by the conveyance of the films 2, 3.

Next, when an arbitrary document 1 is conveyed onto the exposure area R of the exposure section 101, the first winding means 4 is operated by driving the right motor 7, and the conveyance film 2 is conveyed.
The original 1 is conveyed to the exposure area R by winding the pressing film 3 on the conveying roll 4a and the pressing film 4b, respectively. The exposure blocking members 37a, 37b and
The operation of 43a and 43b can be performed at any time by a document size changeover switch (not shown) provided on the remote controller 19. Before the presentation of the image projected on the screen, operate the remote control 19 to expose the exposure blocking member 37.
By moving a, 37b and 43a, 43b back and forth outside the image area in the exposure area R, the exposure of the original 1 outside the image area can be blocked.

According to the above construction, the exposure blocking members 37a, 37
Since b, 43a, and 43b can block the exposure outside the image area without hindering the smooth conveyance of the document 1, it is possible to project a good-looking image on the screen.

It should be noted that the present invention is not limited to the above-described structure, and for example, the size of the original document 1 placed on the supply tray is recognized and the exposure blocking member 37a, 37a, It is also possible to configure 37b and 43a, 43b to move back and forth. Further, the remote control 19 may be provided with fine movement switches for the exposure blocking members 37a, 37b and 43a, 43b so that only a part of the document 1 is projected on the screen or only a part of the document 1 is deleted and projected.

[0052]

As described above, according to the present invention, the exposure blocking means for blocking the light outside the image area of the document placed above the document transport surface on the document table is provided, and the exposure blocking means is used for the vertical and horizontal size of the document. By moving back and forth to the exposure area according to the above, it is possible to block the exposure outside the image area without hindering the smooth conveyance of the document, so that a good-looking image can be projected on the screen.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration explanatory diagram of a document feeder.

FIG. 2 is an explanatory diagram of a drive system of a document feeder.

FIG. 3 is a top view of the exposure blocking unit.

FIG. 4 is an explanatory diagram of a transport film.

FIG. 5 is an external perspective view of a conventional OHP device.

FIG. 6 is a cross-sectional configuration diagram of a conventional document feeder.

[Explanation of symbols]

 A ... Sheet transporting device B ... OHP device 1 ... Original document 2 ... Transporting film 2a ... Frame mark 3 ... Pressing film 4 ... First winding means 4a ... Conveying roll 4b ... Pressing roll 5 ... Second winding means 5a ... Common roll 6 ... Stretching 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 30,31 ... Motor 32,38 ... Motor pulley 33,39 ... Belt 34,40 ... Pulley gear 35, 36, 41, 42 ... Rack 44, 45 ... Clock disk 46, 47 ... Photo interrupter

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kimiaki Hayakawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (3)

[Claims] 1. A document feeder for automatically feeding a document mounted on an overhead projector, which illuminates a document image on a document table from an exposure unit and projects the light onto a screen. An original conveying apparatus, which is provided with an exposure blocker for blocking light outside the image area of the original arranged in the above. 2. The exposure blocking means includes a plurality of exposure blocking members that can move back and forth in an exposure area, a document size recognition means that can recognize a vertical and horizontal size of a document, and a driving means that moves the exposure blocking member back and forth. 2. The document transport according to claim 1, wherein the exposure section blocking member is moved forward and backward by a driving unit based on the document size information recognized by the document size recognition unit to move out of the image area of the document. apparatus. 3. An exposure unit that also serves as a document table, a document conveyance device according to claim 1, and a projection unit for projecting an image by irradiating the document conveyed by the document conveyance device with light from the exposure unit. And an overhead projector having.