JP2000289885A - Sheet carrier device, picture image formation device and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent wasteful consumption of electric power that a needless electric power source is supplied even when it does not work on a sheet carrier device to which an electric power source for signal processing and an electric power source of two systems for load driving are supplied for supply of the electric sources from a picture image formation device. SOLUTION: This carrier device checks whether there are any sheets on an accumulation tray or not by a sheet detection sensor after copying motion is finished, and an electric power source control circuit 301 stops supply of an electric power source to a motor driver 304 of a power system electric power source by instruction of a CPU 100 when there is no sheet on the accumulation tray. Thereafter, when the sheet is set on the accumulation tray, electric power source supply to the motor driver 304 of the power system electric power source is started.

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 used for an image forming apparatus such as a copying machine or a laser beam printer for conveying a sheet material to the image forming apparatus, an image forming apparatus, and a control method therefor. .

[0002]

2. Description of the Related Art Conventionally, a document feeder such as an ADF separates documents (sheets) set on a document tray one by one and transports the separated documents to a predetermined position of an image reading section of an image forming apparatus. Then, after image formation, the document discharged from the transport unit is discharged to a discharge tray. It is known that power is supplied from the image forming apparatus main body for this operation.

Further, power is supplied from the main body of the image forming apparatus in two systems, one for driving a load for driving a motor or the like in the document feeder and the other for signal processing for performing internal signal processing. Some are known.

[0004]

However, in the document feeder in which the power is supplied from the main body of the image forming apparatus as in the above-mentioned conventional example, there are the following problems.

In a document processing apparatus in which power is supplied from the image forming apparatus main body, even when the image forming apparatus is not operating, or when the image forming apparatus is operated without using the document processing apparatus, the original processing is performed. Power is supplied to the device.

For this reason, even if the motor or the like is not driven, if the power is supplied to the apparatus, the driving circuit may consume power for the purpose of maintaining the state, etc. Not necessary, wasteful. If power is supplied to two systems, power supply for signal processing is required in this case, but power supply for driving the load is not required.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-described problems. In a sheet conveying apparatus in which power is supplied from an image forming apparatus to two systems, one for signal processing and the other for driving a load, It is an object of the present invention to provide a sheet conveying apparatus which prevents wasteful power consumption such as supply of unnecessary power even when not operating, an image forming apparatus having the same, and a control method therefor.

[0008]

A sheet conveying apparatus, an image forming apparatus and a control method thereof according to the present invention are configured as follows.

(1) In a sheet conveying apparatus used in an image forming apparatus and supplied with two power supplies for signal processing and load driving from the image forming apparatus, sheet stacking means for stacking sheets, A sheet detecting unit that detects the presence or absence of a sheet on the sheet stacking unit; and a supply of a load driving power supplied from the image forming apparatus to the load driving circuit in accordance with a detection result by the sheet detecting unit. Power supply control means is provided.

(2) In the sheet conveying apparatus of the above (1), the power supply control means supplies power to the load drive circuit when the sheet detection means detects that a sheet is not placed on the sheet stacking means. When the supply is stopped and the sheet detection unit detects that a sheet is placed on the sheet stacking unit while the supply of power to the load driving circuit is stopped, the power supply to the load driving circuit is stopped. The supply was started.

(3) In the sheet conveying apparatus according to the above (1) or (2), there is provided a counting means for counting the time from the end of the image forming operation, and the power control means is provided with a predetermined time by the counting means. Is counted, and then the supply of power to the load drive circuit is stopped when the sheet detecting means detects that no sheet is placed on the sheet stacking means.

(4) In an image forming apparatus for supplying two power sources for signal processing and load driving from a main body of the image forming apparatus to the sheet conveying apparatus, a sheet stacking means for stacking sheets on the sheet conveying apparatus; A sheet detecting unit for detecting the presence or absence of a sheet on the sheet stacking unit; and supplying a load driving power supplied from the image forming apparatus main body to the load driving circuit according to a detection result by the sheet detecting unit. A power control means for controlling is provided.

(5) In the image forming apparatus of (4), the power supply control means supplies power to the load drive circuit when the sheet detection means detects that no sheet is placed on the sheet stacking means. When the supply is stopped and the sheet detection unit detects that a sheet is placed on the sheet stacking unit while the supply of power to the load driving circuit is stopped, the power supply to the load driving circuit is stopped. The supply was started.

(6) The image forming apparatus according to the above (4) or (5), further comprising a counting means for counting the time from the end of the image forming operation, wherein the power control means is provided with a predetermined time by the counting means. Is counted, and then the supply of power to the load drive circuit is stopped when the sheet detecting means detects that no sheet is placed on the sheet stacking means.

(7) In any one of the image forming apparatuses (4) to (6), an image forming means for forming an image on a recording sheet conveyed on the basis of an image of the sheet conveyed by the sheet conveying device is provided. To have.

(8) In a control method of an image forming apparatus for supplying two power supplies for signal processing and a load drive from a main body of the image forming apparatus to the sheet conveying apparatus, the sheet provided in the sheet conveying apparatus is controlled by The presence or absence of a sheet on the sheet stacking unit to be stacked is detected by the sheet detecting unit, and supply of the power for driving the load supplied from the image forming apparatus main body to the load driving circuit is performed according to the detection result by the sheet detecting unit. Controlled.

(9) In the control method of the image forming apparatus described in (8), when the sheet detecting means detects that the sheet is not placed on the sheet stacking means, the power is supplied to the load driving circuit. And when the sheet detection unit detects that a sheet has been placed on the sheet stacking unit while power supply to the load driving circuit is stopped, power is supplied to the load driving circuit. To start.

(10) In the control method of the image forming apparatus according to the above (8) or (9), the time from the end of the image forming operation is counted by the counting means, and the predetermined time is counted by the counting means. Thereafter, when the sheet detecting means detects that no sheet is placed on the sheet stacking means, the supply of power to the load drive circuit is stopped.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a basic configuration of an image forming apparatus (copier) to which a sheet conveying apparatus according to the present invention can be applied will be described with reference to FIG.

FIG. 1 is a sectional view showing the basic structure of an image forming apparatus according to the present embodiment. In FIG. 1, reference numeral 1 denotes an image forming apparatus main body (copier main body), and an image forming apparatus main body (copier main body). 1) platen glass 3 as a document table, a light source 907, a lens system 908, a paper feeding unit 909,
An image forming unit 902, a sheet conveying apparatus main body (hereinafter, also referred to as an ADF) for feeding the sheet document P to the platen glass 3;
2. A sheet processing device 940 that sorts sheets on which images have been formed and discharged from the image forming apparatus main body 1 is provided.

The paper feed unit 909 has cassettes 910 and 911 that house recording sheets S and are detachable from the apparatus main body 1 and a deck 913 that is disposed on a pedestal 912. An image forming unit (image forming unit) 902 includes a cylindrical photosensitive drum 914 and a developing device 915 around the photosensitive drum 914, a transfer charger 916, a separation charger 917, a cleaner 918,
A primary charger 919 and the like are provided. On the downstream side of the image forming unit 902, a conveying device 920, a fixing device 9
04, a discharge roller pair 905, and the like.

The operation of the image forming apparatus main body 1 will be described.

When a sheet feed signal is output from a control device (control means) 930 provided on the apparatus main body 1 side, sheets S are fed from the cassettes 910 and 911 or the deck 913. On the other hand, light reflected from the light source 907 on the original P placed on the platen glass 3 is irradiated on the photosensitive drum 914 via the lens system 908.
The photosensitive drum 914 is charged in advance by a primary charger 919, and an electrostatic latent image is formed by irradiation with light, and then the electrostatic latent image is developed by a developing unit 915 to form a toner image. .

The sheet S fed from the sheet feeding unit 909 is
The skew is corrected by the registration rollers 901, and the skew is sent to the image forming unit 902 at the same timing. In the image forming unit 902, the toner image on the photosensitive drum 914 is transferred to the transferred sheet S by the transfer charger 916, and the sheet S on which the toner image has been transferred is transferred to the transfer charger 916 by the separation charger 917. It is charged to the opposite polarity and separated from the photosensitive drum 914.

Then, the separated sheet S is conveyed to the fixing device 904 by the conveying device 920, and
04, the transfer image is permanently fixed on the sheet S. The sheet S on which the image is fixed is discharged from the apparatus main body 1 by the discharge roller pair 905.

In this way, an image is formed on the sheet S fed from the sheet feeding unit 909, and the sheet S is discharged from the apparatus main body 1.

FIG. 2 is a diagram showing the configuration of the operation unit of the image forming apparatus main body 1. In FIG. 2, reference numeral 201 denotes the apparatus main body 1
This is a power switch for controlling power supply to the power supply. A reset key 202 operates as a key for returning to the standard mode during standby. 203 is a copy start key. A clear key 204 is used to clear a numerical value.

Reference numeral 205 denotes an ID key.
Thus, the copying operation can be performed for a specific operator, and the copying operation can be prohibited for other operators unless an ID is input with an ID key. A stop key 206 is used to interrupt or stop copying. Reference numeral 207 denotes a guide key, which is used when the user wants to know each function.

An upper cursor key 208 is used to move the pointer upward on each function setting screen. A down cursor key 209 is a key for moving a pointer downward on each function setting screen. 210
Is a right cursor key for moving the pointer to the right on each function setting screen. A left cursor key 211 is a key for moving the pointer to the left on each function setting screen.

Reference numeral 212 denotes an OK key, which is depressed on each function setting screen when this is sufficient. An execution key 213 is pressed to execute a function output to the lower right of a display screen described later in each function setting screen.

A fixed size reduction key 214 is used to reduce a fixed size to another fixed size. Reference numeral 215 is used to select the same-size copy. Reference numeral 216 denotes a standard enlargement key, which is used to enlarge the standard size to another standard size. Reference numeral 217 denotes a cassette selection key for selecting a cassette stage to be copied. A copy density adjustment key 218 reduces the density. An AE key 219 automatically adjusts the copy density with respect to the density of the original.
Reference numeral 220 denotes a copy density adjustment key for increasing the density.

Reference numeral 221 denotes a key for designating sorter operations such as sorting, stapling positions, the number of stapling points, and punching (piercing). Reference numeral 222 denotes a preheating key, which is used to turn on / off a preheating mode. Reference numeral 223 denotes an interrupt key which is used when an interrupt is required during copying to perform copying. A numeric keypad 224 is used to enter a numerical value.

A marker processing key 225 sets trimming and masking (contour processing, halftone processing, shadowing processing, negative / positive processing). Reference numeral 226 denotes a patterning processing key, which is used for expressing a color in a pattern or expressing a color by a density difference. A color processing key 227 is used when a specific color is to be deleted. An image quality key 228 is used to set the image quality.

Reference numeral 229 denotes a negative / positive key which is used when performing a negative / positive process. An image create key 230 is used when performing contour processing, shadowing processing, halftone processing, italic, mirror processing, and repeat processing. 231
Is a trimming key used to designate an area and perform trimming.

A masking key 232 is used to designate an area and perform masking. A partial processing key 233 specifies an area, and then specifies partial processing (contour processing, halftone processing, shadowing processing, negative / positive processing). Reference numeral 234 denotes a frame erase key, which is used when performing frame popping according to the mode. In the modes, the sheet frame eraser (creates a frame for the sheet size), the document frame eraser (creates a frame according to the document size, the document size is specified), the book frame eraser (matches the spread size of the book) To create a blank in the center of the frame, and specify the spread size of the book).

A binding margin key 235 is used to create a binding margin at one end of a sheet. Reference numeral 236 denotes a move key, which is used when the user wants to move. The movement includes parallel movement (up, down, left and right), center movement, corner movement, and designated movement (point designation).

Reference numeral 237 denotes a zoom key for setting a copy magnification to 2
5% to 400% can be set in 1% steps. In addition, main scanning and sub-scanning can be set independently. Reference numeral 238 denotes an automatic scaling key, which automatically enlarges or reduces the size according to the size of the copying machine. In addition, the main scanning and the sub-scanning can be independently auto-zoomed. Reference numeral 239 denotes an enlargement continuous shooting key which is used when one original is enlarged a plurality of times and copied. Reference numeral 240 denotes a reduced layout key, which is used when copying a plurality of originals by enlarging or reducing them to one sheet.

Reference numeral 243 denotes a continuous shooting key, which is used to divide a copy area on the platen glass surface into two right and left sides and automatically perform continuous copying of two sheets (page continuous shooting, double-side continuous shooting). A double-sided key 244 is used when two-sided output is desired (single-sided double-sided, page continuous copying double-sided, double-sided double-sided). A multiplex key 245 is used when multiplexing is to be performed (multiplexing, page continuous multiplexing). Reference numeral 246 denotes a memory key which is used when a mode using a memory is desired (memory combining, area combining, watermark combining).

Reference numeral 247 denotes a project key, which is used when making settings for a printer. Reference numeral 250 denotes a mixed original key, which is used when originals are mixed when copying using the feeder. A mode memory key 251 is used to register a copy mode set for copying or to call up the registered copy mode.
A display unit 252 displays the state of the apparatus, the number of copies, the copy magnification, and the copy paper size, and displays the mode to be set while the copy mode is being set.

FIG. 3 is a sectional view showing the structure of the ADF 2, and the detailed structure of the ADF 2 will be described. As shown in detail in FIG. 3, the ADF 2 is provided with a loading tray (loading unit) 510 as a first document tray for setting a bundle of documents. In addition, the stacking tray 510 is provided with a feeding unit that constitutes one part of the document feeding unit.

The feeding means includes a half-moon roller 531, a separation conveyance roller 532, a separation motor (SPRMTR)
(Not shown), a registration roller 535, an entire belt 536, a belt motor (BELTMTR) (not shown), a reversing roller 537, and a transport motor (FEEDM).
TR) (not shown), a flapper 541, a document detection sensor (sheet detection means) 553 for detecting the presence or absence of a document,
Pre-cycle end sensor 542 and paper feed sensor (EN
TS), a reversing sensor (TRNS) and the like.

The right side of the ADF is provided with a paper discharging means for discharging and stacking the read originals. This paper discharging means includes a paper discharging roller 550 and a paper discharging motor (EJCTM).
TR) 552, paper discharge tray 551, paper discharge sensor (EJT)
S) (not shown) and the like.

Half moon roller 531 and separation conveyance roller 532
Is rotated by a separation motor (SPRMTR) to separate documents one by one from the bottom of the document bundle on the stacking tray 510. The registration roller 535 and the entire belt 5
Numeral 36 conveys the document rotated and separated by the belt motor (BELTMTR) to the exposure position (sheet path c) on the platen glass (document table glass) 3 via the sheet paths a and b.

After the reading is completed, the original is discharged. There are a first discharge mode in which the original is discharged to the stacking tray 510 and a second discharge mode in which the original is discharged to the discharge tray 551.

In the first paper discharge mode, first, the transport large roller 537 is rotated by the transport motor (FEEDMTR) to transport the original on the platen glass 3 from the sheet path c to the sheet path e. The document conveyed along the sheet path e is returned to the stack of documents on the stacking tray 510 by the discharge rollers 540.

In the second paper discharge mode, after reading is completed, the belt motor (BELTMTR) is rotated again to drive the entire belt 536, and then the paper discharge motor 552 is rotated to drive the paper discharge rollers 552. , Paper output tray 5
The original is discharged to 50 and stacked.

The pre-cycle end sensor 542
Is an optical sensor that detects the last sheet of the document and includes a light emitting unit of an LED and a light receiving unit of a phototransistor, and is disposed on the upper surface of the stacking tray 510. The final document is fed, and the trailing end of the final document passes through the pre-cycle end sensor 542 to detect the final document of the document bundle.

The feeding means 530 guides the original once from the sheet paths a and b to c during double-sided original, then rotates the large conveying roller 537 and switches the flapper 541 to guide the leading end of the original to the sheet path d. Then, the sheet is passed through the sheet path b by the registration roller 535, and thereafter, the document is conveyed onto the platen glass 3 by the entire belt 536 and stopped, thereby turning the document over. That is, the original is reversed on the sheet paths c to d and b.

It is to be noted that the number of originals in the bundle of originals can be counted by transporting the originals of the original bundle one by one through the sheet paths a to b to c to d to e until the originals are rotated once.

A document regulating plate (not shown) is provided on the stacking tray 510. The document regulating plate (not shown) is in contact with the document to prevent the document from being skewed at the time of document conveyance, and a volume (see FIG. (Not shown), and detects the voltage value corresponding to the position of the document regulating plate to detect the document width size.

Also, while the original is passing through the registration sensor 543 during the transportation of the original, the encoder 544b rotates according to the rotation of the shaft of the transport motor 544a, and the pulse amount of the transport motor clock sensor 544c is measured. Thus, the length in the document conveying direction is detected.

From the two detection results, the size of the conveyed document is determined and sent to the main body control unit as document size data.

FIG. 4 is a block diagram showing a configuration of a control circuit of the sheet conveying apparatus (original processing apparatus) according to the present embodiment.
The control circuit mainly includes a one-chip microcomputer (CPU) 100 having a built-in RAM, and includes an EEPROM 103 and a ROM 102 for backing up adjustment values and set values of the sheet conveying device. The input ports of the CPU 100 receive signals from various sensors.

The analog / digital conversion terminal of the CPU 100 receives an output voltage from the slide volume 120 for detecting the width of the original, so that the value of the slide volume can be continuously detected in 255 steps. It is configured.

Further, a separation sensor 109, a paper feed cover sensor 110, a reversing entrance sensor 112, a DF open / close sensor 1
13, a registration sensor 116, a document detection sensor 117,
Pre-cycle end sensor 118, reversing exit sensor 11
The input from 9 is also input to another analog / digital conversion terminal, and monitors the state of the sensor.

Further, each load is connected to an output port of the CPU 100 via a driver.

Note that the transport clock sensor 114 and the paper discharge clock sensor 115 are
It is used for detecting the rotation amount of the paper discharge motor 107 and for detecting abnormality of each motor.

Reference numeral 105 denotes a transport motor, 106 denotes a belt motor, and 108 denotes an electromagnetic brake.

The ADF exchanges control data with the image forming apparatus main body 1 via the communication IC 101. The received data includes a document feed trigger, a document exchange trigger, a document exchange trigger from the image forming apparatus main body 1. There are a paper discharge trigger and the like, and the transmission data further includes a document feed / replacement / paper discharge operation completion signal, detected document size data, a final document signal indicating the break of the document bundle, and the like.

A control procedure (control program) for controlling the ADF is stored in the ROM 102 in advance, and each input / output is controlled according to the control procedure.

FIG. 5 is a block diagram showing a power supply system in this embodiment. As shown in FIG. 5, power is supplied from the image forming apparatus main body 1 to the control unit 300 of the ADF in two systems, a logic system power supply for signal processing and a power system power supply for load driving. The logic power supply is directly connected to the logic circuit 3.
03 and switching regulator 30
The signal is supplied by a system supplied to the logic circuit 303 through the logic circuit 2 and is used for the logic circuit 303, the sensor 305, and the like. The power system power is supplied to a motor driver 304 or the like which is a load driving circuit, and is used for driving the motor 306 or the like.

The power system power supply control circuit (power supply control means) 301 can control on / off of the power system power supply according to an instruction from the CPU 100. Communication I
C communicates with the image forming apparatus main body via the communication line.

FIG. 6 is a view showing the structure of the pre-cycle end sensor in this embodiment, and FIG.
FIG. 6B is a circuit diagram.

As shown in FIG. 6A, the pre-cycle end sensor 542 uses a reflection type optical sensor composed of a light emitting section 542b and a light receiving section 542a, and a document is placed on the stacking tray 510. Then, the infrared light of the light emitting unit 542b is reflected on the document and received by the light receiving unit 542a, and it is detected that there is paper.

The light emitting section 542b is an LED, and the light quantity decreases as the integrated time of light emission increases. Therefore, in order to keep the light amount constant, adjustment is performed periodically. CPU1
The reference numeral 00 denotes the operational amplifiers 422 and 425 and the transistor 42 using the D / A converter to calculate the amount of light emitted from the light emitting unit 542b.
6 can be varied. In the adjustment method, an adjustment mode is entered in a standby state, a black document having a low reflectance is placed on the stacking tray 510, and an adjustment switch (not shown) is turned on to start adjustment.

Analog / digital conversion input of CPU 100 (hereinafter referred to as A / D input) = sensor signal output level 4
The CPU 100 performs correction by changing the amount of light emitted from the light emitting unit 542b by a D / A converter so that the value of 20 becomes a constant value. The output value of the D / A converter will be referred to as a correction voltage 421. When a series of adjustment operations is completed, the CPU 100 fixes the output value of the D / A converter to a correction value.

The putter system power control operation according to the above configuration will be described below.

(First Embodiment) FIG. 7 is a flowchart showing the power-off control operation of the power system of the ADF according to the first embodiment.

After the copy operation (step S101) is completed,
The state of the document detection sensor 553 in FIG. 3 is checked (step S102). If the document detection sensor 553 (document detection sensor 117 in FIG. 4) is off (there is no paper on the stacking tray), the power supply control circuit 301 in FIG. The power supply is turned off (step S103). Thus, A
The DF enters a standby state, and suppresses unnecessary power consumption.

Next, FIG. 8 shows a flowchart from the standby state until the power supply is turned on.

In the standby mode, the power system power is kept off (step S201). When the document detection sensor 553 is turned on (the document is placed on the stacking tray) (step S202), the power supply control circuit 301 turns on the power system power. Thereafter, when the user presses the copy button, a copy operation is started (step S204).

(Second Embodiment) FIG. 9 is a flowchart showing the power-system power-off control operation of the ADF according to the second embodiment.

After the copy operation (step S301) is completed,
Timer (counting means) t for measuring a specific set time
m1 is set (step S302). tml is decremented (step S303), and tm1 = 0
When (set time has elapsed), the state of the document detection sensor 553 in FIG. 3 (document detection sensor 117 in FIG. 4) is checked (step S305).

If the original detection sensor is off (there is no paper on the stacking tray), the power supply control circuit 301 shown in FIG.
Turns off the power system power, that is, turns off the power supply to the motor driver 304 (step S306). As a result, the ADF enters a standby state, and suppresses unnecessary power consumption.

The control from the standby state until the power system power is turned on is the same as in the first embodiment.

The control operations shown in FIGS.
The instruction is executed based on the program stored in the ROM 102 according to the instruction of 0.

As described above, in this embodiment, when the image forming apparatus is not operating or when the image forming apparatus is operated without using the sheet conveying apparatus, the presence or absence of a sheet on the sheet stacking means is detected. By stopping the supply of the power for driving the load supplied to the sheet conveying apparatus, it is possible to prevent unnecessary power consumption.

[0078]

As described above, according to the present invention,
In a sheet conveying apparatus to which two systems of power are supplied from the image forming apparatus, the presence or absence of a sheet on a sheet stacking unit is detected, and the power for driving the load supplied to the sheet conveying apparatus is supplied to a load driving circuit. , It is possible to prevent unnecessary power consumption.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a basic configuration of an image forming apparatus according to an embodiment.

FIG. 2 is a diagram illustrating a configuration of an operation unit according to the embodiment.

FIG. 3 is a cross-sectional view illustrating a configuration of a sheet conveying apparatus according to the present exemplary embodiment.

FIG. 4 is a block diagram illustrating a configuration of a control circuit of the sheet conveying apparatus according to the present exemplary embodiment.

FIG. 5 is a block diagram illustrating a power supply system according to the present embodiment.

FIG. 6 is a diagram illustrating a configuration of a pre-cycle end sensor according to the present embodiment.

FIG. 7 is a flowchart illustrating a power-system power supply control operation according to the first embodiment;

FIG. 8 is a flowchart showing a power system power supply control operation of the first embodiment.

FIG. 9 is a flowchart illustrating a power-system power supply control operation according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 2 Sheet conveying apparatus main body 100 CPU 102 ROM 117 Document detection sensor (sheet detection means) 300 Control part 301 Power supply control circuit (power supply control means) 302 Switching regulator 303 Logic circuit 304 Motor driver (Load drive circuit) 305 Sensor 306 Motor 510 Loading tray (sheet loading means) 553 Document detection sensor (sheet detection means)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Choho 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Yoshiyuki Nakashima 3-30-2 Shimomaruko, Ota-ku, Tokyo Non-corp. F term (reference) 2H027 DA40 DC18 EA15 EF16 EJ17 EJ18 2H072 AA05 AA12 AA22 AB21 BA03 BB04 CA01 3F048 AA02 AA05 AB01 BA02 BB02 CA05 CB03 EA02 EA08

Claims (10)

[Claims] A sheet stacking unit for stacking sheets, wherein the sheet stacking unit is used in an image forming apparatus, and is supplied with two types of power for signal processing and load driving from the image forming apparatus; Sheet detecting means for detecting the presence or absence of a sheet on the sheet stacking means, and a power supply for controlling supply of a load driving power supplied from the image forming apparatus to a load driving circuit in accordance with a detection result by the sheet detecting means A sheet conveying device comprising a control unit. 2. The power supply control means stops supply of power to a load drive circuit when the sheet detection means detects that a sheet is not placed on the sheet stacking means, and supplies power to the load drive circuit. And supplying power to the load drive circuit when the sheet detection unit detects that a sheet is placed on the sheet stacking unit in a state where the supply of power is stopped. 1
The sheet conveying device according to claim 1. 3. A counting means for counting the time from the end of the image forming operation, wherein the power supply control means counts a predetermined time by the counting means, and thereafter, the sheet detecting means puts it on the sheet stacking means. 3. The sheet conveying device according to claim 1, wherein the supply of power to the load driving circuit is stopped when it is detected that the sheet is not placed. 4. An image forming apparatus for supplying two power sources for signal processing and a load drive from a main body of the image forming apparatus to a sheet conveying apparatus, wherein sheet stacking means for stacking sheets on the sheet conveying apparatus; Sheet detecting means for detecting the presence or absence of a sheet on the sheet stacking means; and controlling supply of a load driving power supplied from the image forming apparatus main body to a load driving circuit in accordance with a detection result by the sheet detecting means. An image forming apparatus comprising: 5. A power supply control means for stopping supply of power to a load drive circuit when the sheet detection means detects that a sheet is not placed on the sheet stacking means, and for supplying power to the load drive circuit. And supplying power to the load drive circuit when the sheet detection unit detects that a sheet is placed on the sheet stacking unit in a state where the supply of power is stopped. 4
The image forming apparatus as described in the above. 6. A counting means for counting the time from the end of the image forming operation, wherein the power supply controlling means counts a predetermined time by the counting means, and then the sheet detecting means puts it on the sheet stacking means. 6. The image forming apparatus according to claim 4, wherein supply of power to the load drive circuit is stopped when it is detected that a sheet is not placed. 7. An image forming apparatus according to claim 4, further comprising image forming means for forming an image on a recording sheet conveyed based on an image of the sheet conveyed by the sheet conveying device. Image forming apparatus. 8. A method for controlling an image forming apparatus, wherein two power sources for signal processing and a load drive are supplied from a main body of the image forming apparatus to the sheet conveying apparatus, wherein the sheets provided in the sheet conveying apparatus are stacked. The presence or absence of a sheet on the sheet stacking means is detected by the sheet detecting means, and the supply of the power for driving the load supplied from the image forming apparatus main body to the load driving circuit is controlled in accordance with the detection result by the sheet detecting means. A method of controlling an image forming apparatus. 9. When the sheet detecting means detects that a sheet is not placed on the sheet stacking means, the power supply to the load driving circuit is stopped and the power supply to the load driving circuit is stopped. 9. The image according to claim 8, wherein when the sheet detection unit detects that a sheet is placed on the sheet stacking unit in a state where the operation is stopped, power supply to the load driving circuit is started. A method for controlling a forming apparatus. 10. A counting unit counts the time from the end of the image forming operation, and after a predetermined time is counted by the counting unit, the sheet is placed on the sheet stacking unit by the sheet detecting unit. 10. The control method for an image forming apparatus according to claim 8, wherein the supply of power to the load driving circuit is stopped when it is detected that there is no power supply.