JPH0676153B2 - Sheet handling equipment - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet handling device that detects the size of a conveyed sheet.

2. Description of the Related Art Generally, in an image forming apparatus such as a copying machine, a document handling device for feeding a document to a predetermined position such as an exposure position may be additionally used.

In such a document handling device, there is a document handling device that detects a document to be fed by an optical sensor or the like and determines the document size based on the output. This document size determination is normally performed by detecting the leading edge of the document at the document inlet and operating a timer or the like to measure the time until the trailing edge of the document is detected, and the document size is determined according to the counted time. Has been determined.

Some originals have punch holes for files, and the positions and sizes of these holes are various. When a document has punched holes, the sensor detects this hole at the document entrance and determines that the trailing edge of the document has been detected, and the size cannot be accurately determined. .

The present invention has been made in view of the above points, and it is an object of the present invention to provide a sheet handling apparatus capable of preventing the sheet size from being erroneously detected due to a change in the sheet presence / absence detection signal due to punch holes or the like and accurately detecting the sheet size. It is intended.

Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of a document handling apparatus to which the present invention can be applied. In the figure, reference numeral 1 denotes an entrance tray on which sheet originals are stacked, and the sheet originals 2 on the entrance tray 1 are stacked on the front side (image surface) on the lower side in the drawing. The first document detection sensor 3 is a reflective sensor that detects the presence or absence of a sheet document. The feed rollers 4 and 5 are in pressure contact with each other to sandwich and convey the sheet document. The second document detection sensor 6 is a reflective sensor that detects the leading edge and the trailing edge of the sheet document.
When the document detection sensor 6 detects the leading edge of the document, control for stopping the document at the exposure position is performed. The output of the document detection sensor 6 determines the document size as described later. The full-face belt 7 is an endless belt having a width large enough to cover the entire surface of the original sheet, and the surface thereof has a sufficient friction coefficient so that the original can be conveyed by sliding on the original glass 10 by frictional force. Drive roller 8
It is also wound around the turn roller 9 so that the entire surface belt 7 and the drive roller 8 do not slip. Further, the discharge rollers 11 and 12 are in pressure contact with each other, and the document whose copy is completed is sandwiched between the document glass 10 and discharged, and the discharge detection sensor 13 detects the discharged document by the reflection type sensor. The output of the discharge detection sensor 13 detects a jam when the document is discharged. The originals sent by the discharge rollers 11 and 12 are sent to the discharge guide plate 14 and are sequentially stacked on the discharge tray 17 by the discharge rollers 15 and 16 that are in pressure contact with each other. The drive from the drive motor 21 (FIG. 2) is transmitted to the feed roller 4 by the clutch 18, and the front surface belt drive roller and the paper discharge rollers 11 and 15 are transmitted from the drive motor 21 by the clutch 19. Has been done.

In the document handling device, the size of the fed document is determined by the output of the document sensor 6. That is, the time taken for the document to pass through the document sensor 6 is measured by detecting the leading and trailing edges of the document, and the size of the document is full size (A3, B4) or half size (A4R) according to the passing time. , B5R, A4, B5). Next, FIG. 2 is a block diagram showing the control section of the document handling apparatus (hereinafter referred to as DF). In the figure, 30 is a well-known microcomputer (hereinafter referred to as μCOM), INT is an interrupt port, and a pulse signal from the clock generator 20 when the drive motor 21 rotates is input. DF operation control is performed based on this pulse signal. The input port P ₀ inputted signal S ₀ from the first document sensor 3, the input port P ₁ to the signal S ₁ is input from the second original detection sensor 6, the input port P ₂ is The signal S ₂ from the discharge detection sensor 13 is input.
Further, based on the input signal from the output ports F _{0 to} F ₃ to the μCOM 30, the drive signal of the drive motor 17, the drive signal of the clutch 18, the drive signal of the clutch 19 and the drive signal of the JAMLAMP 22 are output via the drivers D _{1 to} D ₄ , respectively. A lighting signal is output.

Further, a DF start signal from the copying machine body is input to the input port P ₃ , and a copy start signal to the copying machine body is output from the output port F ₄ . Further, the detected document size data is output from the output port F ₅ to the main body of the copying machine. The main body of the copying machine selects and displays a cassette according to the document size data.

FIG. 3 is a flow chart for explaining the operation of the document handling apparatus according to the present invention. The flow chart will be described below. A document is placed on the entrance tray 1 and detected by the first document detection sensor 3 (Step 1), so that the drive motor 21, the clutch 18 (paper feed), and the clutch 19
(Transport / Eject) is turned on, and documents are fed and transported (St
ep2). Whether or not the leading edge of the document reaches the second document detection sensor 6 is continuously monitored, and upon detection, the size detection timer Ti, the document stop timer Ts, and the second document detection sensor cancel timer Tc are started to count (Step 3). . The count of each timer is counted up by the pulse signal from the clock generator 20. The second original detection sensor cancel timer Tc prohibits the detection operation for a predetermined time after the second original detection sensor 16 detects the leading edge of the original, and the timer time is set to the discharge rollers 11, 12 and the discharge rollers 15, 15. It is set to be equal to or slightly larger than the time required for the document to be transported between 16 times, that is, the time required for the minimum usable document to be transported. When the second original detection sensor cancel timer Tc is timed up (Step 4), it is checked whether the second original detection sensor detects the trailing edge of the original, that is, whether there is no original. The data of the timer Ti is saved in a predetermined area of the data memory, and the document trailing edge check timer Tw is started (Step 5). This timer time is set to a time corresponding to the diameter of the punch hole. Then, the second document detection sensor 16 is continuously monitored until the document trailing edge check timer Tw times up. If the second document detection sensor 16 detects a document during this time, the document rear end check timer Tw is started by waiting until the document is not present again, and the data of the size detection timer Ti at this time is saved. When the document trailing edge check timer Tw times up, the size detection timer
The counting operation of Ti is stopped and saved, and the data of the size detection timer Ti that has been saved is set in the size detection timer Ti (Step 6).

Then, it waits until the count of the document stop timer Ts is finished, and when it finishes, the drive motor 21, the clutches 18, 19 are turned off, and the document is stopped at a predetermined position (exposure position) on the document glass 10 (Step 7). Next, the data of the size detection timer Ti is output to the copying machine main body as the document size data. In response to this, the main body of the copying machine displays and selects a cassette.
Then, the copy start signal is output from the DF to the main body,
Copying operation for the set number of sheets starts on the main body side (Step
8).

When the copying operation for the set number of sheets is completed and the DFSTART signal is input from the main body side, it is checked whether or not the first original detection sensor 3 detects the original to be copied (Step 9). If detected, the drive motor 21 and the clutch 19 are turned on to drive the entire surface belt 7 to start discharging the document at the exposure position. When the discharge sensor 13 detects the leading edge of the document (Step 10), the process returns to Step 2 to start feeding the next document.

When the first original detection sensor 3 has not detected the original to be fed next, the drive motor and clutch 19 are turned on to discharge the original at the exposure position, and the paper discharge timer To is operated. When the paper discharge timer To is up, the drive motor,
Turn off clutch 19 (Step 11) and return to the beginning.

In this way, after the leading edge of the document is detected, the detection operation of the second document detection sensor 6 is prohibited for a time required for the document of the minimum size to pass, or a slightly longer time than this, and the trailing edge of the document is repeatedly detected. This prevents malfunction of size detection due to punched holes in the document.

The timers Ts, Tc, Ti, Tw, and To are all provided in the data memory in the μCOM 30 and are software-made timers.

Effect As described above, according to the present invention, the data related to the time from the detection of the leading edge of the sheet is measured, the measurement data when the state with the sheet is changed to the state without the sheet is stored, and By continuing the measurement and detecting the sheet existence state within a predetermined time from the change, the stored data is invalidated, so it is possible to prevent the pseudo rear end due to the hole from being judged as the sheet rear end, and the true sheet The trailing edge detection can continue.

Further, if the sheet absence state is detected for a predetermined time from the above change, the detected sheet trailing edge can be determined to be the true sheet trailing edge, so that the sheet size can be accurately detected based on the stored data.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a document handling apparatus to which the present invention can be applied, FIG. 2 is a block diagram showing a control section of the document handling apparatus according to the present invention, and FIG. 3 is a diagram illustrating the operation of the document handling apparatus according to the present invention. It is a flow chart for. 1 is an entrance tray, 3 and 6 are original detection sensors, 4 and 5 are feed rollers, 7 is a full belt, 8 is a drive roller, 9 is a turn roller, 11 and 12 are discharge rollers, 13 is a discharge detection sensor, and 15, Reference numeral 16 is a paper discharge roller, 17 is a paper discharge tray, 18 and 19 are clutches, 21 is a drive motor, and 30 is a micro computer.

Claims (1)

[Claims] 1. A conveying means for conveying a sheet, a sheet detecting means for detecting the presence / absence of a sheet conveyed by the conveying means in a sheet conveying path, and a sheet presence state detected by the sheet detecting means. Measuring means for measuring data relating to time, storage means for storing the data measured by the measuring means, and control means for determining the sheet size based on the data stored in the storing means. However, the control means stores the data of the measuring means when the state with the sheet changes to the state without the sheet in the storage means, and continues the operation of the measuring means to change the state with the sheet to the state without the sheet. After the change to, if the sheet detection means detects the sheet presence state before the elapse of a predetermined time, the data stored in the storage means is invalidated,
On the other hand, when the sheet detecting means continues to detect the sheet-free state for the predetermined time after the change from the sheet-containing state to the sheet-free state, the data stored in the storing means is validated and stored in the storing means. A sheet handling device characterized by detecting a sheet size based on data.