JP2972007B2 - 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 document feeder suitable for use in a facsimile machine and the like, and more particularly, to a document feeder capable of adjusting a stop position of a document.

[0002]

BACKGROUND OF THE INVENTION In a facsimile apparatus, even if the size of an image, for example, a character, described in a document to be transmitted is different, a plurality of types of resolutions are provided to clearly transmit these images. In general, it is possible to select a suitable resolution.

This resolution is represented by the number of scanning lines included within a predetermined distance (1 mm) in the sub-scanning direction, that is, the vertical direction of the document, and is usually 3.85 lines / mm, 7.7.
About three types of line / mm and 15.4 line / mm are provided.

[0004] The higher the resolution of an image to be transmitted, the higher the resolution, that is, by selecting a resolution with a large numerical value, the receiving side can recognize the details of the received image.

If the speed of reading one line is constant,
The resolution is determined by the document conveying speed. That is, the transport speed when the resolution is 3.85 lines / mm is set to “1”.
Then, the transport speed when the resolution is 7.7 / mm is "1/2", and the transport speed when the resolution is 15.4 lines / mm is "1/4".

As described above, in the facsimile apparatus, it is necessary to make the document conveyance speed variable, and therefore, a pulse motor or a servo motor whose speed is easily controlled is used for document conveyance.

In some facsimile machines, a "done" stamp indicating that the transmission has been completed is impressed on the rear end of the back side of the transmitted document.

This "done" stamp is usually pressed once after stopping the original, so that the pulse motor stops when the sensor detects the trailing end of the original that has been transmitted. .

There is a facsimile apparatus using a document detection sensor 1 as shown in FIG. 4A for detecting the trailing edge of a document. This document detection sensor 1 is an actuator 2
First, the document D fed into the facsimile apparatus pushes down the lower side from the fulcrum 21 of the actuator 2, whereby the upper side of the actuator 2 is pushed up as shown in FIG. And enters the inside of the photo interrupter 3.

Thus, as shown in FIG. 5, the light projected from the light emitting section 31 of the photointerrupter 3 to the light receiving section 32 is blocked, whereby the leading end of the document D is detected. Subsequently, the document D is conveyed, and reading is performed a predetermined time after the leading edge is detected.

When the document D is conveyed by a predetermined distance, the rear end of the document D is separated from the actuator 2, whereby the upper side of the actuator 2 descends and returns to the original state. As a result, the light in the photo-interrupter 3 conducts and the original D
Is detected.

At this time, the pulse motor is stopped by the detection signal sent from the photo interrupter 3, and the conveyance of the document D is stopped. Then, after the “Done” stamp is pressed on the back side of the document D, the document D is conveyed again and discharged out of the facsimile machine.

[0013]

In the above-described document detection sensor 1, after the rear end of the document D is separated from the actuator 2, the upper portion of the actuator 2 naturally falls and remains constant until the light in the photo-interrupter 3 becomes conductive. It takes time T. During this time T, the document D is transported at a transport speed defined by the resolution.

For example, if the distance at which the upper part of the actuator 2 falls until the light of the photo-interrupter 3 becomes conductive after the rear end of the document D separates from the actuator 2 is 4 mm, the time T required for this is about 0.03. Seconds.

Here, the original reading speed is set to 0.0025.
Assuming that the resolution is 3.85 lines / mm, the transport distance is about 3.1 mm during the time T (0.03 seconds). When the resolution is 7.7 lines / mm, half of this is carried by about 1.6 mm, and when the resolution is 15.4 lines / mm, about 0.78 mm is carried.

As described above, the distance that the document D travels during the time T differs depending on the resolution. For example, the position where the “Done” stamp is pressed changes each time the resolution is changed, and in some cases, the stamp is protruded from the document D. Something like that. In this case, it may happen that the transmission is not completed and the transmission is performed again.

If the position at which the document stops differs depending on the resolution, the reading start and reading end positions change each time, and in some cases, there is a problem that extra communication time is required.

Accordingly, the present invention has been made to solve the above-described problem, and has as its object to propose a facsimile apparatus capable of accurately stopping a document D at a predetermined position even when resolutions are different. It is assumed that.

[0019]

In order to solve the above-mentioned problems, according to the present invention, there are provided a conveying means for conveying a document, a speed control means for controlling a speed of the conveying means, and a leading or trailing end of the document. In the document feeder which has a document end detecting means for detecting the position of the document and stops the conveying means by a detection signal of the document end detecting means, the time between when the leading end or the rear end of the document is detected and when the document stops. A transport distance control means for adjusting a transported distance in accordance with the speed of the speed control means is provided.

[0020]

In FIG. 1, a document D fed into a facsimile apparatus is transported by transport rollers 41. Transport roller 4
1 is controlled by the speed control means 8 to a speed determined by the resolution. Fig. 4
The document information is read by the reading means 5 after a predetermined time has passed.

When the document D is conveyed by a predetermined distance, the rear end of the document D is separated from the actuator 2 of the document detection sensor 1.

As a result, the upper side of the actuator 2 falls naturally and comes out of the photointerrupter 3. As a result, as shown in FIG. 5, the light of the photointerrupter 3 conducts and the detection signal is transmitted. In response to this, the transport distance control means 9 sets the correction distance X corresponding to the resolution as shown in FIG.
The pulse motor is rotated so as to convey the document D by 1 or X2. As a result, the document D always stops at the same stop position even if the resolution, that is, the transport speed changes.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a document feeder according to the present invention is applied to a facsimile machine will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram for explaining the function of the document feeder according to the present invention. In FIG. 1, for example, a document D fed into a facsimile machine is transported inside by a transport roller 41 of a transport unit 4. The transport roller 41 is driven by, for example, a pulse motor (not shown). Then, the leading end of the conveyed document D is detected by the document detection sensor 1, and after a predetermined time from this, the document information is read by the reading means 5.

When the reading is completed and the document D is conveyed by a predetermined distance, the rear end of the document D is detected by the document detecting sensor 1, whereby the pulse motor stops and the conveying roller 41 stops.

Next, the "finished" stamp is pressed on the back side of the document D by the finished stamp 6, and then the document D is discharged to the outside of the facsimile machine by the discharge roller 7.

The rotation speed of the transport roller 41 is controlled by the speed control means 8. This speed is regulated by the resolution set by the facsimile apparatus as described above, and here, a driving device such as a step motor or a servo motor that can be easily controlled in speed is used.

The number of revolutions of the pulse motor for driving the transport roller 41 is controlled by the transport distance control means 9.
The transport distance control means 9 receives the document D from the document detection sensor 1.
When a detection signal indicating the trailing end of the document D is received, the distance at which the document D is conveyed thereafter is controlled to always stop at the same position.

That is, the transport distance control means 9 controls the transport distance of the document D according to the resolution, that is, the speed set by the speed control means 8 as described later.

FIG. 2 shows the configuration of the facsimile apparatus described above. In the figure, reference numeral 11 denotes a CPU that manages transmission / reception control;
A ROM 12 stores various control programs such as a transmission / reception program, and a RAM 13 stores image information to be transmitted.

The image information read by the image reading section 14 is stored in the RAM 13 via the interface 15 or directly sent to a communication line via a modem and a network control circuit (NCU) 16 functioning as a transmitting / receiving means. Is done. The image information input from the communication line is stored in the RAM 13.
Or is supplied directly to the recording unit 18 functioning as a printer via the interface 17 to record the contents.

The telephone number of the transmission destination is supplied to the display unit 20 via the interface 19, so that it is displayed. The operation unit 21 provided in the facsimile apparatus is provided with a plurality of keys (not shown). When these keys are operated, the contents are taken into the CPU 11 via the interface 22.

In this facsimile apparatus, the original D can always be stopped at the same position. For example, when the resolution is 3.85 lines / mm as shown in FIG.
Is a reference stop position. When the resolution is 7.7 lines / mm and 15.4 lines / mm, the shift amount X between the position where the document D stops and the reference stop position.
1 and X2 are measured. The deviation amounts X1 and X2 may be stored in the RAM 13 as a correction table, and the step motor of the transporting unit 4 may be controlled based on the stored amounts.

That is, when the resolution is 7.7 lines / mm or 15.4 lines / mm, the transport speed is lower than the transport speed when the resolution is 3.85 runs / mm.
In the above-described conventional method, the document D stops before the reference position. However, in the present invention, the document D is moved to the reference position by rotating the step motor by an amount corresponding to the correction distance X1 or X2. It will stop. When the transport speed is higher than the reference speed, the document D can be stopped at the reference position by stopping the step motor earlier by the correction amount.

In the above embodiment, the correction distances X1, X2
Has been described in the case where only one type is set, but this may be set in a plurality of stages and selected as appropriate.

[0036]

As described above, in the present invention, the document always stops at the same position even when the resolution, that is, the document conveying speed changes.

Therefore, according to the present invention, the "done" stamp is pressed to the same position, so that the appearance is improved, and the "done" stamp does not come off the document. Can be prevented from being transmitted. In addition, since the reading start position and the reading end position of the document are fixed, it is possible to prevent an extra transmission time from being taken.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating functions of a document feeder according to the present invention.

FIG. 2 is a configuration diagram of a facsimile apparatus to which the present invention is applied.

FIG. 3 is an explanatory diagram illustrating an example of a transport distance control method.

FIG. 4 is an explanatory diagram illustrating an example of a document detection sensor.

FIG. 5 is a detailed view of a photo interrupter.

[Description of Signs] 1 Document detection sensor 2 Actuator 3 Photo interrupter 4 Conveying means 5 Reading means 6 Finished stamp 7 Discharge roller 8 Speed controlling means 9 Conveying distance controlling means 11 CPU 12 ROM 13 RAM 14 Image reading unit 16 Modem and NCU 18 Recording unit 20 Display unit 21 Operation unit 22 Actuator fulcrum 31 Light emitting unit of photo interrupter 32 Light receiving unit of photo interrupter D Document

Claims (1)

(57) [Claims] A document feeder for feeding a document; a speed controller for controlling a speed of the document feeder; a document edge detector for detecting a leading edge or a trailing edge of the document; A document transport device configured to stop the transport unit after transporting the document by a predetermined amount according to a detection signal of a unit, wherein a distance traveled from when a leading edge or a trailing edge of the document is detected to when the document stops. And a transport distance control means for adjusting the distance according to the speed of the speed control means.